Contributions from the Mote Marine Laboratory Volume 1, Number 1

On The Relationship of Teleost Scales to Pigment Patterns C. M. Breder, Jr.

Sarasota, Florida 1972 ANNOUNCEMENT

Volume 1, Number 1 of CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY represents the first of a series based on work entirely or chiefly undertaken at this Laboratory. Future numbers and volumes will be issued as circumstances warrant. It is appropriate that the first num­ ber of this series is by Dr. Charles M. Breder, Jr. who has been associated with the Laboratory since its beginning. The Mote Marine Laboratory is an outgrowth of the Cape Haze Marine Laboratory founded in 1955 by William H. and Alfred G. Vanderbilt and originally located at Placida, Florida. In 1961 the Cape Haze Marine Lab­ oratory was moved to Sarasota, Florida, and in 1967 its name was changed to honor its president, William R. Mote. The Mote Marine Laboratory is a private, nonprofit institution, staffed by resident scientists and visiting in­ vestigators. Major areas of interest include continuing programs in Neuro­ biology and Behavior, Biomedical Studies, Estuarine Ecology, Microbiology and the Biology of Elasmobranch Fishes. The publication of the first number in this series is made possible by a generous financial contribution from Mr. Eligio Del Guercio of Marathon, Florida.

PERRY W . GILBERT Director Sarasota, Florida January, 1972 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY

Volume 1, Number 1

On The Relatiol1ship of Teleost Scales to Pigment Patterns

c. M. Breder, Jr.

Sarasota, Florida 1972 Additional copies may be obtained from

MOTE MARINE LABORATORY 9501 Blind Pass Road Sarasota, Florida 33581 $3.50 postpaid

PRINTED IN U.S.A. BY ALLEN PRESS, INC., LAWRENCE, KANSAS 66044 ABSTRACT

Two types of patterns on the sides of fishes are recognized, primary and secondary. The primary patterns are aligned with scale rows: longitudinal, transverse and two diagonals, which four account for most of the patterns found on the more primitive teleosts. The secondary patterns are not aligned with scale rows, but are basically polar, centered about variously placed foci, and exist with or replace the primary patterns in the more advanced teleosts. The primary patterns evidently appeared first in phylogeny and in all but the most advanced teleosts, they appear first in ontogeny, while the secondary patterns begin to appear later in the ontogeny of the intermediate teleosts, usually as secondary sex characters. In the most advanced teleosts they may appear early and sometimes males and females develop very different per­ manent patterns. The primary patterns appearing long before sexual develop­ ment are basically dull in color, bright or vivid colors appearing on sexual maturity, if at all, with the males making the greatest changes, but with little or no change in pattern. The secondary patterns that appear early in only very advanced groups may pass through distinct transformations before the permanent adult pattern is reached and this sometimes reverts to a compara­ tively simple pattern seeming to approach the primary patterning. In nearly all cases these patterns tend to be much more colorful and vivid than the pnmary ones. The preceding statements are supported by examination of integumentary conditions covering arrangement of scales and their refractive characteristics, scale pocket formation and the possibility of moire effects. The influence of sex on pattern and color is discussed. Changeable and mimetic patterns and colors, as well as less specialized integumentary conditions indicate that the primary patterns are basically of value in reducing visibility against a general background and the secondary patterns are basically of value in social or other signaling. A general discussion of the phylogenetic distribution of various types of pattern is given, with a systematic list of representative forms. CONTENTS

INTRODUCfION . 1

THE ENVIRONMENT OF PIGMENT PATTERNS. 3

The internal environment . 3 The basic plan of squamation 3 The effects of dermal scale pockets . 15 The underlying myomeres . 16 The light refracting characteristics of scales . 17 The structure of patterns 20 The external environment . 21

CLASSIFICATION OF PATTERNS. 23

The simplest cases: primary patterns . 23 Longitudinal patterns 23 Transverse patterns . 24 Diagonal patterns 25 Combinations 25 Combinations not found 28 Spots . 29 Vermicula tions 31 Relations to the lateral line . 32 The more complex cases: secondary patterns . 34 Polar patterns 34 Intermediates 37 Changeable patterns 40 Relations to sex . 41 Scale size, arrangement and pigmentation . 44 Pattern on head and fins . 47 Moire effects . 48

vii CON TEN T S (Continued)

FUNCfIONS OF PATTERNS . 51

Negative functions. . 51 Positive functions . . 51 Relations of negative and positive functions. 51 Phylogeny of patterns. . 52

PA'ITERNS AND SYSTEMATICS 55

SYSTEMATIC LIST OF SPECIES. 63

LITERATURE CITED . . . . 75

viii On The Relationship of Teleost Scales to Pigment Patterns

C. M. BREDER, JR. Mote Marine Laboratory

INTRODUCTION

The vast variety of pigmentary patterns to be seen on the sides of teleost fishes is usually noted as the result of selective processes, without further comment. While these processes certainly are involved, there are a number of constraints which evidently limit the variety of patterns attainable and restrict their possible detail. The purpose here is to indicate those parameters, the apparent limits attainable, and to show how the restrictions have some­ times been circumvented. The patterns do not lend themselves to easy analy­ sis, nor to facile explanation of how they reached their observed states. How­ ever, a number of suggestive considerations arose during a study of this matter, which are here developed as a step toward an understanding of the physical basis of at least some of these patterns. Although the word 'pattern' has the sanction of usage in present connections and superficially seems adequate to indicate the deployment of pigment on the side of a fish, it does require some explanation and an indication of its limits as here used. The word itself has many usages and definitions, as is indicated in any unabridged dictionary. The second edition (1957) of the Merriam­ Webster Dictionary gives definitions concerned with "An artistic or mechanical design."l before the following: "6. Hence, in natural or chance formations, markings, groupings, or in a series of events, an arrangement of parts, ele­ ments, or details that suggest a design or orderly distribution; as frost patterns." This definition covers the present usage. Although this may seem to be some­ what vague, the difficulty here is with the concept rather than with the words. Whether a surface is covered with a pattern, or not, is much a matter of the visual capabilities of the observer and his perceptive ability to recognize the existence of a state of regularity in the arrangement of elements. This fact in no way vitiates the objectivity of the patterns. To substitute some other word as a synonym, such as design, model or motif could only lead to greater subjective difficulties. The ability to rec­ ognize pattern, aside from the limitations of personal comprehension, is still further restricted by various geometrical considerations. The pattern may simply be too complex to be freely recognizable at once, by even the most

1. The 1955 edition of The Oxford Universal Dictionary gives no definition of usage in reference to 'natural' patterns, confining the word to the handicrafts of man. The American Heritage Dictionary, 1969, gives the following relevant definition, "4a. A design of natural or accidental origin", essentially in agreement with The Webster volume. 2 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1 comprehending individual, an effect not apt to arise in present connections. However, developmental circumstances may be such as to suppress part of what once was a pronounced pattern, so as to reduce it to a mere hint. One cause of this could be over- or underdevelopment of pigment cells. Also a simply spotted fish may show what appears to be random spotting, whereas the spots may be very precisely placed. Such a condition may become evident only after the examination of a considerable series of individuals. Here such questions arise as to whether such spotting constitutes a pattern, in any sense of the word. Cases of this kind will be discussed as they occur for none has any important bearing on the main theme. Although there is a large literature on pigment cells and a considerable one on animal patterns, evidently no author has made a systematic attempt to classify the patterns of pigment together with those of scales. Gregory (1951) however, arrived at a list of pattern types, without reference to other features. These names and definitions are discussed where pertinent. Among the many sources of assistance rendered by individuals and institu­ tions in connection with preparation of this study the following require formal acknowledgement: the Mote Marine Laboratory and many of its staff, especially Dr. Perry W. Gilbert, Executive Director, Miss Patricia Morrissey, Secretary, Mrs. Lynn Erdoesy, Secretary, Mr. Hugh H. Scott, Boat Captain, Mrs. Roberta Scott, Laboratory Technician, Mrs. Susanna Dudley, Research Assistant and Mrs. Alice Brown, Special Assistant, for access to the library and preserved collection, as well as necessary services of many kinds and Mrs. Alice Byron, typist. Dr. Donn E. Rosen, Chairman of the Department of Ichthyology of the American Museum of Natural History kindly loaned cer­ tain specimens for study. Dr. Ross F. Nigrelli, Director of the Osborn Lab­ oratory and the New York Aquarium of the N. Y. Zoological Society and Dr. Robert W. Harrington, Jr. of the Entomological Research Center of the Florida State Board of Health, provided special information. The following persons kindly read and criticized the manuscript: Dr. Perry Gilbert and Mrs. Claire Gilbert (general organization), Dr. H. David Baldridge, Captain, U. S. Navy, and Research Associate of the Mote Marine Laboratory (special reference to its physical and mathematical aspects), and Dr. James W. Atz, Curator of the Department of Ichthyology of the American Museum of Natural History (items involving endocrinology). 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 3

THE ENVIRONMENT OF PIGMENT PATTERNS

THE INTERNAL ENVIRONMENT

The physical and physiological influences on integumentary chromato­ phores, such as innervation, blood supply, location, associated tissues, hor­ mones, et cetera, have been sufficiently discussed for present purposes by Parker (1948), Rawles (1948), Odiorne (1957), Fingerman (1963) and Waring (1963). Therefore only the influences of scales and closely related matters are considered here. A brief description of the basic plan of squama­ tion usual to the sides of teleosts, certain features of imbrication, scale struc­ ture and associated tissues is essential for a clear understanding of the situation. In ontogeny the appearance of chromatophores precedes the development of scales. Usually these are melanophores but in some species other pigment cells appear commonly along with them in the egg or in the pre-larva, that often are otherwise almost entirely of a glass-like transparency. Obviously these cells cannot be influenced by scales, for they have not yet developed. Also there is no evidence to support the idea that the location of scales has been influenced in any way by these early pigment cells. The later pigment cells, that appear along with or shortly following the scales, are evidently either influenced by the scales, or the scales and pigment cells are both responding to some as yet undefined influences. The pre-scale pigment cells have their own, species dependent, pattern which usually in no way resembles the final scale patterning and disappears as the fish transform to larvae or post-larvae. With this transformation comes the complete or nearly complete investment of the body of the fish with chromatophores. This usually com­ plete covering of the fish with pigment insures the opacity of the adult and coincides, in most cases, with the development of scales. The ontogenetic influences involved in the establishment of scale pattern and pigmentary investment must, in any case, be considerable for together they form a rather complex interdevelopment as a fish passes from its larval stages to the adult. In many forms the patterns follow the scale rows and frequently this scale-pattern relationship is retained throughout life. In other species the patterns pass gradually into their final pattern and in some through a series of pattern transformations.

THE BASIC PLAN OF SQUAMA TION. The shape of teleost scales is referable to the hexagonal arrangement found in or on many animate and inanimate sur­ faces. Only where scales do not overlap one another, like shingles, is it pos­ sible for the hexagonal effect to become obvious, and then only if the growth is great enough to cause the scales to meet. This condition is found in the Ostraciontidae where the highly specialized scales abut one another and ap­ proach quite regular hexagonal plates, except where eruptive structures or radical changes in body form cause the hexagons to become distorted. In 4 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1 most teleosts the anterior scales overlap those immediately posterior to them, which at once provides the fish with a degree of flexibility and masks the hexagonal tendency by the simple fact that the scales grow at a slight angle to the surface and thereby avoid mutual interference. Thompson (1948) and those before him have described the occurrence of hexagons in both animate and inanimate structures, including hexagonal cells in gasses and liquids. Shearing forces in these produce patterns similar to imbricated surfaces, such as seen in teleost scales and pine cones. These patterns normally run with the force producing them, that is, in the direction of water flowing past a swimming fish. The slippage of the imbricated scales, that permits flexibility of the body, may be basically accounted for as a relief device to mechanical stress, both in the plane of the scales and perpendicular to them. In the Ostraciontidae, with abutting hexagonal plates there are no body flexures and consequently no such strains involved. The larvae of these fishes are too rotund at hatching to wriggle and they lie passively for most part, interrupting this by short darts, propelled by twitches of the tail only. By the second day pectoral fin propul­ sion appears, accompanied by tail tip vibrations. In less than five days the body becomes rigid, except for the protruding tail portion. See Breder and Clark (1947) . Mechanical engineers have studied the effects of stress in metal plates perforated by circular holes deployed on the apices of equilateral triangles composing regular hexagons in an allover pattern as shown in Fig. 1. These have been given extensive mathematical study and it may be that eventually equations, such as those given by Horvay (1951) for metal plates, with suitable modification, could find application to further study of scale arrangements. The work of Aleev (1963) on the bending of fish bodies is also suggestive in this connection. Regular hexagons are produced on a plane surface if a number of equipo­ tential centers of activity are deployed and develop all at the same time. These may be scattered at random but must have some degree of mobility and sufficient power, in respect to distances apart, to interfere with each other's fields of influence. With such a situation the mutually antagonistic pressures will adjust the positions so they also become the center of regular hexagons, each being surrounded by six others,2 as shown in all but the lower right of Fig. 1. If the centers of force are unequal the hexagons will be irregular in proportion to the differences. This effect can be produced by growth on a surface such as discussed here or by bees producing honey combs, where each bee is so nearly similar that very nearly regular hexagonal cells are produced.

2. The word "quincunx" is sometimes unfortunately used to describe the basic arrangement of teleost scales. It properly refers to an arrangement of five objects or points, four on the corners of a rectangle and one at its center. Although such an arrangement of points can be discerned on a scale covered surface, so can a vast variety of other geometrical configurations. Therefore the word "quincunx" has been avoided herein as more likely to confuse than to clarify present considerations. 972] BREDER: TELEOST SCALES AND PIGMENT PAITERNS 5

Fig. 1. Regular hexagons covering a surface. Diagonals passing through the midpoints of opposite sides of a hexagon, Series A I 'C', 'L', 'R', are shown in solid lines. Diagonals bise-eting the angles of a hexagon, Series B, 'E', 'F', 'T', are shown by dashed lines. The six tria.ngles composing each hexagon are indicated in the ]ower right.

See Thompson (1942) and Hilbert and Cohn-Vossen (1952) respectively for other biological details and mathematical considerations. Before scales, feathers, hairs or other similar surface structures grow from their particular sites, some earlier dermal influence must have ordained the precise spots. Stuart and Moscona (1967) demonstrated that in birds "a lattice-like system of collagenous tracts" developed in the embryonic dermis can be recognized by its birefringence. These were seen to be exceedingly regular and to be located on the apices of equilateral triangles. Since a hexagon contains six such triangles, a feather-germ was located, one each, on the comers of a hexagon and another at its center. This sort of arrangement is evidently based on fine structure such as that revealed in electron microscopy, as is indicated for echinoderm skeletal elements by Donnay and Pawson 6 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol.l,No.1

( 1969). These elements show evidence of a hexagonal pattern in which the relationships between inorganic crystal structure and organic amorphous mat­ ter display a periodic minimal surface. Evidently fish dermis has a similar basis for its scale development, in which case scales developing equally at each point would become hexagonal plates,3 except for the fact that they override one another in systematic fashion. The three sets of opposite sides of the regular hexagons shown in Fig. 1, marked by the lines 'L', 'C' and 'R' respectively are each 60° apart. These three lines, 'L', 'C' and 'R', mutually intersect at the center of each hexagon and each line bisects the two opposite and mutually parallel sides at right angles. The projections of these lines pass through a series of hexagons in an identical manner. This construction can be made for every hexagon. These three lines all have the same relations to the pattern of hexagons and will be called Series A. A similar series, indicated by dotted lines, also shown in Fig. 1, 'T, 'E' and 'F' also pass through the center of the hexagon but bisect the angles formed by the intersecting sides and will be called Series B. Projections of these lines pass through the centers of and bisect the corresponding angles of other lines of hexagons. These lines run concurrently with the mutual sides of the adjacent two hexagons in Series A. This construction of Series B, if carried out for all hexagons, divides each into the six equilateral triangles that compose them. The angular distances between these lines are the same as those of Series A but they are displaced from them by 30°. The reasons for and the significance of this slight excursion into the geometrical char­ acteristics of an allover pattern of regular hexagons will become evident when the pigmentary alignment is considered. Although this study is confined to teleosts, it is essential at this point, to indicate some recognition of the problems in the surface deployment of exo­ skeletal units of their presumed ancestors in order to avoid possible misunder­ standing of the present interpretations. This is especially necessary in refer­ ence to the pattern of squamation of the Semionotiformes and other heavy scaled fossil groups related to it. Many of these fishes have heavy rhomboid scales that are commonly interlocked to some extent and are not imbricated in the sense common to most teleosts. The vast differences between the typical teleost scale and those of the various groups of pre-teleosts has been most recently indicated briefly by Van Oosten (1957) as has the considerable variety of the highly specialized scales of advanced members of teleosts. Both the primitive pre-teleost scales and the special derivatives or replacements of the cycloid or ctenoid scales show their primary relationships fairly clearly and present no particular difficulty, at least in connection with present pur-

3. Bony plates and other structures, evidently developed independently, such as found in the Loricariidae, Syngnathoidei, Ostraciontidae and other smaller groups are all considered to­ gether here. Pigmentary patterns of these fishes evidently have similar relationships to their scales. What differences they may have could only have small bearing on the present central interests. BREDER: TELEOST SCALES AND PIGMENT PATTERNS 7

Fig. 2. Lattice arrangement of scales. The scales of Archosargus probatocephaIus, drawn from the mid-side of a fish, are shown to the left and its lattice to the right. Scale rows, Series A, 'C', 'L', 'R', are shown in solid lines, Series B, 'E', 'F', 'T', are shown by dashed lines. The two series are shown on a separate center on the scales, but on a common center on the lattice. The double line in the latter identifies the basic hexagon. The arrows on the scales indicate the lay of the scales in rows 'C' and 'R'. poses. One matter deriving from this, that might lead to confusion, is that allover surface patterns of basically hexagonally arranged structures can yield a pattern which presents a graph-like network in which the units appear as quadrilaterals rather than hexagons. This is more of a geometrical circum­ stance than a biological one. The nexus of the matter is that hexagons are the normal polygons formed under conditions defined on a surface. These are basically physical and are not especially related to organic activity. In­ deed, a pattern of hexagons may be demonstrated to develop spontaneously by a froth of soap bubbles compressed between two parallel sheets of glass, brought very close together. This matter has been discussed at length by Thompson (1942). There is clearly an intimate relationship between a lattice of two sets of parallel lines, intersecting at an angle, and other surface features relevant to present concerns. The case of both sets of parallel lines being equally spaced and at right angles and thus forming squares, may be taken as a starting point with others considered as derivative. Diagonals of the squares similarly form squares whose sides will be just half the diagonals of the first squares, i.e. the sides of the two sets of squares will be in ratio of 1 to 0.7071. Obviously if any other angle existed between the generating sets of parallels it would yield similar relationships, differing only in geometrical proportions. 8 CONTRmUTIONS FROM THE MOTE MARINE LABORATORY [Vol. 1. No.1

The only case of specific interest here is based on an angle between parallels equal to two thirds of a right angle. Here the quadrilaterals are composed of two equilateral triangles and the diagonals are no longer equal. The sides of the second set of parallelograms are in the ratio of 1 to 2. If these hexagons are allowed to be rounded off and to grow so that they overlap each other from one side, that is to imbricate, the pattern shown in Fig. 2 appears because the outer edges of the overlapping scales produce the crisscross network of quadrilaterals seen on the sides of teleosts. Whether they overlap deeply, as do teleost scales, or only marginally as in many Holosteans, is not important as in both cases the quadrilaterals are formed. In the Ostraciontidae however, where the scales are represented by thin bony plates that abut one another, the hexagons formed still form the crisscross network, as it is indicated in Fig. 1, but it is not nearly so conspicuous. Another way to look at the relations between the basic hexagons is to ap­ proach it as a matter of moire systems. If a pattern of dots be deployed as shown in Fig. 3a, it is obvious that each dot is a vertex of six equihiteral triangles. Fig. 3a could also represent a condition in which a second layer of dots exists immediately in back of the first, and in perfect register with it. If one of these two sets of dots is moved to the right, or to the left by one-half the distance between the dots, the condition shown in Fig. 3b results. The dotted lines are equivalent to 'L'. If the movement is upward at an angle of 60° from the horizontal to the left, the condition shown in Fig. 3c results, which is equivalent to 'C'. Similarly, if the movement is 60° to the right the equivalence is to 'R', as shown in Fig. 3d. These cover Series A. If move­ ments are made along the lines 'T', 'E' or 'F' another pattern is formed. This pattern which is referable to Series B consists of small hexagons, as is indicated in Fig. 3e. The hexagons are identical for each of the three lines of orienta­ tion, and cannot be distinguished by observation. In this respect they differ from those in Series A which show their origins by the angles of the dotted lines, as is indicated in Fig. 3b, c, and d. Because of the inherent differences in the two series of transformation pat­ terns, Series A and Series B, a slightly different amount of movement is necessary. Series A requires that the movement be parallel to one of the sides of the basic equilateral triangles and equal to half the length of a side. Series B requires that the movement be parallel to one of the altitudes of the triangles and that the movement be equal to a distance of 0.5661, measured from the triangle's vertex, where the sides are equal to unity. That is, the movement must place a dot at the center of the respective triangle, at the intersection of the three altitudes of it. Angular displacement between the two sets of dots produces hexagons of various sizes, as seen in Fig. 3f and g, the sizes of the hexagons varying ac­ cording to the angle between the two sets. The smallest angles, from perfect register of the dots, produces the largest hexagons at each of the three points 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 9 ...... · ...... ••....••.••.••...•...... • ·· ...... •.....•...•...... •..•.•....• ~ ...... •...... •.•.....•.....•.•...... •. · ...... •...... •...... •.....•...... ·· ...... •...•.....•...•...... •. · ...... •.•..•...... · ...... •..•...... •.•...... ·· ...... •...... •..••••...... •...... · ...... A ...... · ...... B ...... • • • • • '. a, " " " " ~ ~ ~ ~ ~~ ·· ...... ·· ...... , ...... · ...... " " ...... · · ...... ~~~~~. ~~~~~~~~~~. ·· ...... ~~~~~~ .~~~~~~~~~ · ·...... ~~~~~~~\~~~~~~~~...... ··· ...... ~~~~~~~~~~~~~~~~~ ·· ...... ~~~~~~~\\\~~~~~~. '...... ·· ...... ·· ...... '. '...... ·· ...... · '. '. '. '. '...... " " " " " " ·· ...... '. '. '. '. " " " ~ " ~ ~ ...... ·...... c o .•.••...... : ...... :, ...... - .•.••..••.•.•.•.....••..••...•...... :...... ' ...•...... •...... •...... :, ..... ~ ...... , ..•.•...... : .. :" •••••••••• I ... . ~ ...... : ...... •.•...... •...... •...... •. .. : '. '. '. ' '. '.' ' .. '...... '. ... '. .' ...... •••••. •• •• •• : I .. ••••••••• • .... : ...... •.•...... · ...... - ...... •...... •.•..•..•..... • • :...... • ••• I. •• .•.•...... •..•.•.•.•...... ' ...... : ..... , ...... •...•..••.•....•.. · : ...... :' ...... : ....-...... : E F

...... ,-...... # . . \\\~-':f!:~~·-,~~ ...... tilt .. - ...... , ~~: ...... ::::, .. ,\ .. . • • • •••••• • • • I • • • • • • ~~~~~~~~~~-----~...... •....•...... ~~~~~~~~~~~MN ___ ~ • • • •• .....,..... I · ...... ~ ...... : : : : . •• : : ~ ~ ~ , • , I : : ...... ······1·'..... '·.········ .... ·· ...... , ...... ··...... It· ••• ' • • • • ••••••••••••••••••• • • • , ••• I ••• ••••••• ·...... • •• , • fill , • • • •• • •••. .•.•..•••...•••••.•••.•.•...... , ...... -. . .. _. ~. .- -...... - . ·...... G H Fig. 3. Effects produced by a pattern of dots, all of which are at the apices of equi­ lateral triangles, when overlain by an identical pattern, in various manners. A. A single pattern of dots or two in precise register. B. Two patterns with one displaced to the right or left a distance equal to one half the side of the triangles. Similar to 'L'. C. Displacement as in B but based on movement at 60 0 to the horizontal, upward to the left. Similar to 'C'. D. Displacement as in C but to the upper right. Similar to 'R'. E. Displacement in a vertical direction. Similar to 'T'. The movement is equal to 0.5661 of that used in the preceding cases. F. Angular displacement of 300 produces minimum hexagons. G. Angular displacement of circa 15 0 produces intermediate hexagons which increase greatly in size as 0 0 is approached. If· Angular displacement at small angles circa 2 0 produces maximum hexagons which tend to break up at their comers into small hexagons, similar to those shown in E. 10 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I,No. 1 of register, each of which is 60° from its fellows, as is shown in Fig. 3h. Half­ way between these points of register the smallest hexagons are produced. Justification for this approach to these surface structures is to be found in the section covering moire pigmentary effects, but is introduced here as a device to develop the relations of the scale rows to their associated surface structures. Fig. 3 shows clearly that the angles of the lineal series of dots approximates the scale rows, 'L', 'C' and 'R', about as closely as would be expected on a surface of double curvature, such as shown by the body of a typical fish. The vast majority of associated patterns behave in a similar manner, suggesting again, that these patterns are primarily, but not completely, influenced by the disposition of the scales. Passing from plane figures to those on the sides of a fish the four directions of lineal scale rows that are of interest here are designated as Longitudinal, 'L'; Transverse, 'T'; Clockwise, 'C'; and Retrograde, 'R', following the usage indicated in Figs. 1, 2 and 3. The scales run in continuous series, except as they may be interrupted by eruptive structures, such as fins. These intersecting lines, designated as above, all four of which run through each scale, are geodesic lines, which feature has been indicated by Breder (1947a). The lines 'L' lie approximately parallel to the body axis; lines 'T' may lie roughly at right angles to this axis, but are generally slightly divergent from it. Lines 'C' and 'R' wrap around the body in opposite directions as shown in Fig. 4. Lines 'L' are usually as nearly parallel to the body axis as their confine­ ment to an undevelopable surface permits. Lines 'T' encircle the body as closed figures, which form the perimeter of the body section at that locus. In the head-on view of Fig. 4 the lines 'C' and 'R' are seen as clockwise and counterclockwise, "retrograde" being used herein to prevent confusion. In the side view of the fish, Fig. 4, with the head end toward the viewer's left, any two crossing scale rows form an "X" on the side of a fish in such a manner that the 'C' series appears as the arm of the 'X' that runs from the upper left to the lower right and the 'R' series, forming the other arm, runs from the upper right to the lower left. Thus these series may be characterized as "down and back" for 'C' and "down and forward" for 'R'. The lines produced by the two series 'L' and 'T' form a grid not unlike the coordinates of a graph, and the two series 'C' and 'R' form a similar grid. These grids change proportionally with ontogenetic or phylogenetic modifica­ tions of the shape of the fish, as they adjust to the corresponding warping and area changing. The 'C' and 'R' set, since it encloses each scale in a quadri­ lateral, therefore agrees with the change in shape of scales that normally takes place under such transformations. Scant notice has been given this naturally occurring set of coordinates, which are subject to the same type of distortions found in the sets of arbitrary superimposed coordinates conceived by Thompson (1942). The scales forming the two diagonal rows show complementary imbrication. 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 11

Fig. 4. Diagram of a schematic fish showing how the scale rows 'C' and 'R' spiral around the body. A single course of each is indicated, the portions on the side away from the viewer being represented by dashed lines. Other courses are indicated by short diagonals from the dorsal outHne. The direction of the spiral files of scales is indicated in the frontal view of the fish by two arrows.

The rows running down and back, 'C', overlap from the top down, while the rows running down and forward, 'R', overlap from the bottom up as shown in Fig. 2. It might be thought that these two directions of overlapping could be reversed and that possibly in some fishes this condition obtained. This is not possible because of the rather complex manner in which the scales are imbricated. Such a reversal of scale positions could only result in a longitudi­ nal reversal of the entire scale pattern, so that the scales would be backwards from their normal shingling from head to tai1. 4 A piece of skin stripped off with the scales intact, when viewed from the underside shows this reverse arrangement, indicating clearly that the imbrication changing results in a mirror image inversion. At the dorsal and ventral midline, in teleosts, where there is no fin base or other eruptive structure, the diagonal scale rows cross over to the other side, so that the up-facing rows become the down-facing and vice versa. The geometry of this is shown in Figs. 5 and 6. In Fig. 5 outlines of scales have been drawn which are supplanted caudad by dotted lines which delimit the quadrilaterals enclosing each scale. This figure of MugU cephaJus is based solely on the pattern of squamation found on one typical individual and in­ cludes what small individual variations it happens to possess. In Fig. 6 the longitudinal diagonals of these, 'M M' and the transverse diagonals, 'T T', respectively define the 'L' and 'T' series of scales. The line, 'M M', could represent either the midline of the back or that of the venter. In the two diagonal rows, to the left, it is clear that the scales in row 'R' are facing up below 'M M' and that on passing over the back and down the other side are facing down. The scales in 'C' are performing oppositely, as both rows wind their way to the peduncle. If it be thought that instead of geodesic spirals, the rows should be treated as chevrons that meet at 'M M', as shown by 'W W' and 'V V' it at once be­ comes evident that the scales in the longitudinal row 'M M' become indepen-

4: This condition has actually been found as a rare anomaly. which subject has been re­ Viewed by Gunter (1948) and added to by Dawson (1962 and 1967). 12 CONTRffiUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1

I R 'c Fig. 5. Dorsal view of Mugil cephaJus, showing crossing over of scale rows in front of dorsal insertion. Drawn from an individual 77 mm. in standard length, showing minor individual variations. Lettering as in Fig. 4. See text for full explanation. dent and are not a part of a system. If the chevron points are arranged to include the 'M M' row, as apical scales, alternating from right to left, the arrangement becomes even less satisfactory. Such an approach in any case would necessarily disregard the fact that the scales follow geodesics, and would present a very unsatisfactory and conceptually difficult situation. An item that should be recognized is that there is a slight, but very real reduction of the size of the scales from head to tail. Fig. 5 shows this condition in MugU cephalus. Also the angles between the diagonal scale rows change along with this size reduction. The angle is very close to 58 0 over the pectoral bases and increases to very close to 63 0 just before the dorsal insertion. In fishes, such as Archosargus probatocephalus, those diagonal scale rows that run toward the dorsal fin, do not stop there but continue their courses onto the fin where, greatly reduced in size, they disappear. This is also true of a variety of other fishes, especially in forms in which the dorsal profile is faired into the base of the dorsal fin. Several details should be kept in mind in reading any discourse of the present kind. Because of the fact of animal variation, especially in any struc­ ture which is present in great redundancy, as are fish scales, the geometric regularities here mentioned are not always realized in the precise details of the diagrams shown. Therefore one must consider these as a close approximation, about which the fine details of structure cluster but do not always exactly attain. Other aspects of similar variation have been given by Breder (1947 a) . The following additional data are given in order to more fully indicate the inherent nature of a mesh applied to a convex surface, such as the body of a fish. This may be most easily accomplished by considering the case of a convex body of simple geometrical properties, specifically a right cone. Circles and straight lines may be drawn on such a surface only if the circles are parallel to the base of the cone and only if the straight lines pass through the apex. These must necessarily intersect the circles at fixed angles. Ob­ viously these would make a mesh if repeated regularly, not unlike that made \9721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 13

Fig. 6. Plane surface diagram of the crossing scale rows shown in Fig. 5, M-M, dorsal midline; T-T, transverse scale row; C-C, clockwise scale row; R-R; retrograde scale row; see text for explanations of WOW and V-V. by 'L' and 'T' on a fish. Squamation seldom follows the lines discussed above, except in the Syngnatbidae where their elongate, very slightly tapering, bodies are surrounded by bony rings, similar to the circles on the cone. The bony rings are provided with ridges at intervals that very closely approximate straight lines and intersect the rings at right angles. Other lines on a cone would spiral about in the manner of 'C' and 'R' on the bodies of many fishes, if both lines are repeated regularly in the way that scales are deployed. Such a line spiraling from the base of a cone to its apex has its successive turns closer together as the apex is approached, because of the continually reducing radius of the conic surface. This condition is also to be observed on the tapering body of a fish, in fusiform species reducing the size of the scales from the largest mid-section toward both head and tail. Mugil as earlier indicated tapers from the head to the tail, because in this fish and a variety of others the greatest breadth is normally just after the head. The word 'pitch', used mostly in reference to the angle of the threads on a screw to its axis, can be appropriately employed in reference to the windings of both 'C' and 'R'. These actually represent, what are in mechanics, right- and left-handed threads. In these terms the circles and straight lines of syngnatbids indicate merely that the pitch is respectively zero or infinite. In other forms where the pitch has neither of these values, the pitch of 'C' and 'R' controls the shape of the scales and their tilt with respect to the body axis. Screw threads as used on machines may be either single or multiple. The latter may be of any suitable number. The mUltiple threads are only rarely 14 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I. No.1 made, compared to the ubiquitous single threads of most common bolts and screws. Apparently the redundant rows of fish scales are all mUltiple in this sense, sometimes to a very high degree. Since the utility of the spiral fish scale rows is entirely different from that of screws, they are not so limited.5 If fishes should have scales proportioned about as most machine screws, employing single threads, it would be immediately apparent. The actual number of rows of scales winding about a fish, equivalent to multiple threads in a machine screw, may be determined by counting the number of rows passed until that same row is encountered again, as shown in Fig. 3. If the files of scales that wind around the body of a fish, in opposite direc­ tions, be viewed in phantom profile, they may be compared to modified sine curves, for present purposes at least, instead of screw threads. Thus they may be said to display both wavelength and modulation. There is a remarkably large number of fishes that show just about three full wavelengths, as in­ dicated in Fig. 4. They include fishes of such diverse forms as Amia, Carassius auratus, domestic, Xiphophorus, Lepomis, Lachnolamus, and Dormatator. Such forms as Lepisosteus, Synodus foetens, and Cyprinus carpio (American stock) , show four, while Membras shows a full five wavelengths and Calo­ michthys has eight. At the other end of the sequence Balistes capriscus shows two and Holocanthus isabelita shows only one. This data is illustrated in Breder (1947a). The amplitude and its modulation may be considered as forming an "envelope" which is the outline of the fish body, as is indicated in Fig. 4. That is, the outline marks the maximum departure from the axis, or zero value, as modulated, both positive and negative. The same modulation also induces the changes in wavelength, as is also indicated in Fig. 4. It follows that only a perfectly cylindrical fish, or other object, would show no change in amplitude or wavelength throughout its length, if generated in the same manner. In some fishes, such as Scomber, this "envelope" is very close to being symmetrical, above and below the axis, or 'base line', of the fish, while in others it is dis­ tinctly asymmetrical about that line, so that the axis may be low and the backs high, as in Anisotremus and Calamus, or just the opposite, as in Toxotes and Notopterus. It may seem strange to refer to an organic structure in the preceding terms and it is, of course, done purely to establish the rather complex character of a superficially simple arrangement of redundant elements, as well as to refer to the data in terms of well known frames of reference, the mechanics of screw threads and the graphics of radiant energy.

5. Machine screws seldom have more than two or three threads in multiple, while fish may have as many as a dozen as in Cyprinus carpio and very many higher in smaller scaled forms. The torque necessary to drive a screw of high number of multiple threads because of the decreased angle between the axis and the thread (the pitch) rapidly becomes prohibitive. The need for movement between successive fish scales along the longitudinal axis of a fish is best served by having the angles of the scale rows at relatively greater angles to the axis, which is about what is generally found, modified to some degree by other biological demands. 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 15

In a variety of fishes, such as many of those of the genus Notropis, the lateral line runs down the longitudinal row of scales over or very close to over the lateral septum that divides the lateral musculature into the epaxial and hypaxial portions. There is little or no disruption of the pattern of scales in these cases. In others the lateral line is bowed downwards, also usually with little modification of the scale pattern as in Notemigonus and generally in the Exocetoidei where the lateral line follows closely parallel to the ventral profile. In the Perciformes the lateral line may be variously arched and mayor may not influence the scale arrangement, notably modifying it in most of the Sparidae, Sciaenidae, and Pomadasidae, as for instance in Archosargus. Pogonius and Orthopristis. In still other fishes the lateral line may be multiple, in which cases it seems to modify the scale pattern very little, if at all, in such as the Hexagrammidae and Cynoglossidae, or interrupted as in the Scaridae, or absent, as perforations through the scales, as in the Cyprinodonti­ dae and Gobiidae. That those fishes with no lateral lines show only a smooth flow of the network of scales, supports the idea that the lateral line is often the causative factor in such scale pattern modifications, especially where a high anterior arching is present.

THE EFFECTS OF DERMAL SCALE POCKETS. Since the scales develop in pockets of the dermis and are overlain by the epidermis it is necessary to under­ stand their relationships because these two integumentary tissues bear the pigment cells that form the surface patterns and colors. The locus of these pigment cells may be in the dermis, just under the dermis (i.e. between the dermis and the subcutis) over or under the scales or in both places and some­ times in the epidermis. See Van Oosten (1957) for further details. Typically, pigment cells lie over each scale and are, mostly if not entirely, over the exposed outer portion of its caudad quadrant. That is, the overlying pigment cells are posterior to the growth center of the scale and are frequently there only as a narrow band of melanophores along the edge of the scale, or other limited area. The folding of the dermis and the blocking obstruction of the solid scales presents a somewhat rugged terrain for migrating melanophores, growing capillaries and general physiological activity. Just what or how much bearing these circumstances may have on the location of the pigment cells is not clear. One of the functions of the scales, generally accepted by physiologists, is to help restrict possibly excessive osmotic activity through the integument. Those pigment cells that are outside of the scales, are also outside of this physiological semi-barrier, and all cellular activity in this site must necessarily reckon with this exposed environment. Rawles (1948) indicated that an abrupt change in tissues can prevent melonoblasts from moving about freely in both am­ phibians and birds. Also there are evidences of strong interactions between melanophores and their tissue environments. 16 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1

A c R

L --t---:t--H L

A B c Fig. 7. Diagram of the relationships of scale rows to myomeres. Alternate myomeres are shaded for clarity. Modified after Breder (1947a), based in part on Ryder (1892) and Hase (1907). A-A, myomere; B-B, myomere overlaid by scales; 'C', 'L' and 'R' as in Figs. 1 and 2.

It has been abundantly shown that, at least melanophores appear in integu­ mentary sites where traumata have been inflicted. Other injurious incidents have also resulted in melanophore concentrations, e.g. radiation such as Roentgen rays (Smith, 1932a and b, 1934, and Ellenger, 1940) and the encystment of parasites (Chapman and Hunter, 1954).

THE UNDERLYING MYOMERES. The myomeres, on which the integument rests, have been studied by Ryder (1892) and others in relation to the location of scales and cognate matters. The principal point of interest of this, in present connections, is with the manner in which much of the zigzag course of the superficial myomeres coincides with the deployment of the scales and the lattice based on their arrangement, which is shown in Fig. 7. There are many variations on this basic plan, but these need not be discussed here, except to say that there is a tendency, in some groups of fishes, to increase the number of scale rows per myomere. Thus several scale rows may follow a single myomere instead of holding the one-ta-one relationship indicated in the figure. In the development of a young fish the primary metamerism of the myomeres is well established and fully functional long before the scales begin 1972] BREnER: TELEOST SCALES AND PIGMENT PATTERNS 17 to appear, although the manner of the development of the scales varies con­ siderably from one group of fishes to another. In general, however, the scales begin to develop on the caudal peduncle along the lateral line and spread forward, from whence they then spread upwards and downwards along diagonals, 'C' and 'R', running outward and forward. They do not necessarily follow the course of an individual myomere but step from one to the other, as indicated by Fig. 7. See, for instance, Elson (1939), Ward and Leonard (1954) and Van Oosten (1957). A very detailed analysis of the complex constitution of teleost myomeres is given by Alexander (1969) in which he recognizes small subsidiary bundles along the dorsal and ventral profiles. They presumably influence the overlying scale rows, as part of the general disturbance induced primarily by the eruptive fins. All the segmented units, scales, myomeres and vertebrae, discussed above, are elements of the basic metameral structure of vertebrates expressed differently, in accordance with their specific functions.

THE LIGHT REFRACTING CHARACTERISTICS OF SCALES. Most teleost scales are normally transparent and often sculptured in various manners on their outer surface, according to their kind. 6 The inner surface is almost always smooth. The sculpturing varies from radial ridges on the anterior parts to the fine, nearly microscopic, circulae. These surface features refract light in such a fashion as to concentrate it below the inner surface of the scale. This can be demonstrated by mounting a scale so that a light may be placed about an inch behind it and a translucent screen a similar distance in front, with some means of adjusting the distance between the scale and the screen. A simple shadowgraph would be obtained if there were no differential refrac­ tion, but a display of bright areas and dark is produced because of the bending of the light rays. Much of the radial ridge sculpturing approximates the form of a plano­ convex cylindrical lens. None of these ridges nor other sculpturings have been found to resemble a positive lens sufficiently to make good image forma­ tion possible, but they do concentrate light and radiant heat under themselves. Even if the scales could produce an image, it would still not be formed within a fish because of the refractive and colloidal nature of the surrounding tissues. However the presence of the scales, because of their transparency, allows the light to penetrate farther than if it had to pass through that much additional colloid. This may be seen directly in a piece of skin, with scales intact, stripped from a freshly dead fish and viewed against a light with the inner side toward the viewer. The tissues in which the scales are imbedded are translucent. The presence of pigment cells, reduces the amount of light transmitted in direct proportion to the dispersion of the granules. Often,

6. Those which are not transparent are mostly translucent, a condition encountered in very large scales of normal type or highly specialized scales which depart widely from the usual. 18 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. 1, No. 1 especially in small fishes, the tissues approach transparency. 7 In a heavily pigmented piece of skin, this effect is greatly reduced or eliminated. The light areas produced in such a piece of skin by the imbedded scales are nat­ urally not as sharply defined as those from a detached scale for the reasons given above. In the ctenoid scales, in addition to the ridges and other sculpturing of cycloid scales above discussed, the presence of cteni adds another element that influences the light passed. These fine pointed structures are often nearly circular in cross section and thus could further add to the light con­ centration over the area they occupy, even though their axis is at a slight angle to the scale surface. The circulae probably do not contribute signifi­ cantly owing to their extremely small size. The radial ridges may vary from a nearly semicircular section to a quite flattened curvature, a difference which would control the distance below the scale level at which the light intensity is greatest. The refractive index of any scale has evidently not been deter­ mined, but clearly it is sufficient to produce the conditions described. Since pigment cells sometimes lie under the distal portion of the scales it is only here that any overlying structures could have direct effect on these cells. This at once eliminates the radial ridges, which evidently would have the most effective ability to increase the light intensity under themselves. How­ ever the cteni of ctenoid scales are located over the area which covers the pigment patches. A dark investment does not tend to warm up a fish, as has been shown by Bauer (1914) and which has been discussed by Breder (1970). The effect of concentrating radiant energy in or below the integument by means of refractory devices in the fish tissues is not so clear. This could, if sufficient, increase dermal and subdermal temperatures and so increase local physiological proc­ esses. This could conceivably be of importance to fishes in shallow water otherwise too cold for such activity. Fishes that have a nearly complete investment of a dense layer of guanine often have the scale sculpturing reduced and flattened, as in Megalops atlantica, or completely or nearly eliminated as in most of the herrings, notably in Clupea harengus. Since such a heavy layer of guanine is mirrorlike in its reflectivity, there would seem to be no point to the retention or to the development of highly refractive scales. Other functions have been generally ascribed to the scale sculpturing, mentioned above, as sufficient reason for their existence. The radii, which are deep grooves in the scales, have often been supposed to provide the scales with additional but unspecified flexibility. This view, published as an hy­ pothesis, by Taylor (1916) is neither confirmed nor entirely refuted by the

7. Larval fishes often have nearly all their tissues of a glass-like transparency. These are not considered here as they are usually devoid of pigment cells. See Breder (1962) for com­ ments on this transparent condition. 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 19 detailed study of scale anatomy and development of Wallin (1957). Some of these ideas cannot be accepted at face value for the following reasons. The radii of normal scales on the side of a fish either lie in a plane at right angles to the plane of the body movement or very close to it. The departures from it, owing to the fact that they radiate from the focus of the scale, hardly ever reach as much as 45° on either side of a longitudinal line parallel to the locomotor axis of the fish. These radii are found, in most cases, in either the anterior or posterior quadrant of a scale and sometimes in both. Less fre­ quently they are found also in the dorsal and ventral quadrant. Apparently none have ever been found within the dorsal and ventral quadrants alone. If the radii were necessary to normal swimming motions of the fish body, it would be expected that these vertical and near vertical grooves would be the general case. Moreover the imbricated arrangment of scales ordinarily pro­ vides for an adequate freedom of movement for the lateral bending normal to fishes. This may be checked simply by manipulating any generalized free swimming fish that has scales large enough to readily permit observation of the movement. The squamation of such a fish is sufficiently aligned with respect to its swimming axis to insure the required slippage, unless the scales are so minute as to be negligible. Most fishes have very little ability to bend in a vertical plane, despite the manner in which some taxidermists mount game-fishes for alleged artistic effect. Even if fishes could bend in such a direction, longitudinal and sub­ longitudinal grooves would have little, if any value. The utility of fitting the scales to conform to the shape of the fish is a different matter that seems not to have been analyzed. The dermal pockets in which the scales have been formed already conform to the body shape, as they must since the dermis invests the muscle and visceral mass comprising the fish body. The generally more or less convex surface of the fish body changes with both physiological conditions (amount of food ingested, extent of gravidity, retention of cellular fluid, et cetera) and the normal growth changes. The curvature changes caused by growth are very slow and the size of the scale increases in reasonably close proportion to that of the body, details of which are reviewed by Van Oosten (1957). Changes other than growth, some of which may be relatively rapid and a few of which are noted above, change both the body curvature and those of the scale pockets, with no concomitant change in the scales. In such cases there is little doubt that scales may change to accommodate the new curvatures. A definite measure of the extent of this ability of scales to fit the body is given with fishes suffering a serious condition of edema. The swelling outline reaches a point where the scales no longer hug the body tightly, but stand out in an almost fur-like condition with the posterior edges of the scales protruding beyond the surface of the fish. 20 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. t, No.1

THE STRUCTURE OF PATTERNS. As chromatophores on the sides of fishes are usually small in reference to the patterns they form, they may, in many ways, be compared to the dots that fonn halftone color prints.s The two systems differ in structure and operation in a manner to be expected between an organic structure and a mechanical printing technique. The optical effects on a viewer however may be essentially similar. Both systems, chromatophores and halftone dots, theoretically should be able to form any conceivable pat­ tern. This is absolute in halftone plates, but is not automatically attained by chromatophores of a fish side. In the former all the elements provided are equally available over the area covered because of the deliberate design of the equipment. On fish sides this condition is not realized for several reasons that are complexly interconnected. All the chromatophores are not uniformly distributed, but exist in greater concentration in the areas which call for their particular color or activity to maintain the usual pattern found in a given species. This situation is often modified under specific environmental condi­ tions. That is, in the lightest phase possible, there is great reduction in the number, for instance, of melanophores, while in the darkest phase their number is vastly greater than the 'normal' or 'average' amount. Changes in these conditions are not rapid, but are brought about slowly, governed by the speed at which additional melanophores may be developed or eliminated, to the limit of possibility in either direction. These are the 'morphological' changes of authors. Rapid changes, but not as extensive as seen in the pre­ ceding type, are brought about, sometimes extremely rapidly, by neuro­ endocrine control, in which the pigments are dispersed or concentrated to a tiny dot, resulting in as much lightening (nervous control) or darkening (hormonal control) as is possible. These changes may take place in fractions of a second or as long as a day, the nervously controlled naturally being the more rapid. These are the 'physiological' changes of authors.9 The other pigment cells proper, those that also function on a basis of molecular resonance, the xanthophores, erythrophores and allophores operate

8. There are some exceptions to this, where individual chromatophores are large enough to be easily seen by the naked eye. One alone may form a conspicuous part of the pattern, as in Apogon stellatus, where the "stars" on each side comprise a single dermal pigment cell as has been indicated by Rasquin (1958). These may reach at least a diameter of 1 nun. Otherwise pattern elements on most fishes are made up of a great many individual chromtc­ phores or chromatosomes which latter are, at most, seen as a composite spot. The word 'chromatosome' is used differently in cytology than in histology, physiology and related fields. It is here used in the histological sense, to indicate a cluster of chromatophores, usually of more than one kind, which function in relation to each other. See Parker (1948), Fingerman (1963), Fitzpatrick et al (I 966) and Fujii (1969) for background on this matter. The use of 'compound chromatophores' has been avoided, as possibly leading to further confusion. Chromatophores and chromatosomes commonly run from about 0.5 to 0.005 mm. in their visible diameters. Thus they are comparable to common half-tone screen sizes, that run about the same way. Newsprint mostly approximates 0.38 mm. 9. Neither type of control, however, is able to obliterate the basic and certainly genetic pat­ tern of chromatophore distribution, as witnessed by the return of the specific pattern on the return of environmental conditions which permit it. See Breder (1970) for further evidence of this effect. 19721 BREDER: TELEOST SCALES AND PIGMENT PATIERNS 21 in a basically similar manner, each with some special modification and each usually operating independently or sometimes even oppositely to the rest. 10 The guanophores do not operate on this basis but produce interference colors, except the chalk-white leucophores.ll The guanophores may be combined with overlying pigment-bearing cells to form chromatosomes, which may pro­ duce a wide variety of effects, often involving great brilliance and saturation. It is clear that printing processes do not have the brilliant resources in color available to fishes, but do have an immediate ability to yield any pattern at any place within the area of operation. The array of limitations and possibilities of color and pattern production by fishes is further modified by the presence of scales with which the chromato­ phores are so intimately associated. In effect it is as though a much coarser screen was laid over the finer grained scattering of pigment cells. The resulting interference and its consequences is the concern of the discussion of "Primary patterns" and is the reason for this account of the basic relations of the chromatophore system. The influence of physico-chemical activities within the integument of fishes is not easy to evaluate, especially in regard to the distribution of pigment that forms the patterns. These matters lead to studies which rapidly become entangled in the complexities of colloid chemistry. Even the geodesics of the scale rows themselves may be under at least partial control of these activities. Thompson (1942) reviews the long history of studies on both plants and ani­ mals that attempt to refer repetitive patterns of banding primarily to rhythmic crystallization taking place in a gel. Of interest here, since both scales and pigment cells are under such alternating influences, is the possibility of their being controlled by the same basic mechanism, the effects of which are ex­ pressed differently because of the differences in the elements involved.

THE EXTERNAL ENVIRONMENT

Most of the gross influences of the external environment have been ade­ quately treated by the authors noted in the preceding section. Therefore the following data cover only items that have special significance for present purposes.

10. See Fox (1953 and 1957), Fox and Vevers (1960), Fingerman (1963) and Fujii (1969) for details on the physical and chemical operation of these chromatic effectors. All but the carotenoid pigments, which provide the xanthophores and erythrophores with their yellow and red colors, can be synthesized by animals. The carotenoids can only be synthesized by plants, ~o that these colors are alone directly dependent on diet. The allophores are evidently chemically distinct from the others, known collectively as Iipophores. 11. The guanophores, a class term, include the iridiophores and leucophores, which contain the colorless crystalline guanine. The first are responsible for iridescent and silvery colora­ tion by interference effects, which may be brilliant and of great saturation. Leucophores have their guanine in a finely divided state, which accounts for the whiteness. 22 CONTRmUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I. No. 1

Since pigmentation is intimately associated with light and vision, it is not surprising that both have a profound effect on pattern and coloration. The presence of at least some light is evidently necessary to maintain pigmentation in surface fishes. Blinded fishes that are exposed to light develop a melanosis. In darkness both visually intact and blinded fishes lose the patterns and pig­ ment colors. In water deep enough to be beyond the possible penetration of daylight, effects become apparent before that limit is reached. Vividness of pattern diminishes greatly in as little as five fathoms. Often it is evidenced by a general increase in red pigment, hinting at the condition found in depths of about 160 to 270 fathoms where most of the pigments of fishes are smoothly distributed and are either distinctly red or black. This red pigment is only seen as such in surface light for the red rays do not penetrate beyond about 150 fathoms. In lesser depths a rather mixed lot may be present owing to vertical movements of some individuals altering their depth more rapidly than they can adjust their pigmentary systems, and to some species that have changed their vertical range without changing their pigments. Another effect, purely physical and immediate, which reduces the contrast of any pattern a fish may have, is caused by the filtering effect of the supernatant water. In­ creasing water depth makes the penetrating light approach more and more to the monochromatic as various wavelengths become totally absorbed, thus washing out the vividness that any pattern may have had at the surface, while at the same time reducing the intensity of the total light until finally it becomes fully extinguished. As the depths are reached where no surface light pene­ trates most of the fishes are solidly black. 12 In this area where no pigment patterns could function, they may be replaced by self-luminous photophores. These spots are highly specific in arrangement and not infrequently the sexes shine in different patterns. The effect in caves is distinctly different. Here there is no submerged illumination, or at least none has so far been discovered. Pigment cells be­ come reduced and finally completely eliminated, as do the eyes. The fishes become mostly pinkish owing to the absence of the pigmentary covering. This pinkish color is caused by blood and other interior substances showing through the skin, which, deployed in accordance with the anatomy of the fish, can scarcely be considered a pattern, certainly not an investing pig­ mentary pattern and in any case nothing can be seen in the total darkness of such caverns. All these fishes, that do not display pigmentary patterns, are not further referred to herein. From here on it is to be understood that any fishes dis­ cussed are living in an environment exposed to sufficient light to support chromatophores and a possible pigment pattern.

12. See Breder (1970) for a discussion of the melanic investment of deep sea fishes. \972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 23

CLASSIFICATION OF PATIERNS

The preceding discourse on the environment of pigment patterns requires an accompanying classification of the patterns on fish sides, suitable, at least, for the purposes of this study. Gregory (1951) gives what is apparently the only prior attempt to categorize patterns. Although his list is directly con­ cerned with special evolutionary problems, mainly involving his isomere concepts, there is a surprising amount of overlap of tenns and evidently ideas, between his views and the present ones. Gregory's categories Present categories Relationship Banded Transverse Roughly similar Striped Longitudinal Perhaps identical Concentric Polar Includes radiating and concentric types. Spots Spots Gregory includes ocelli. Aggregations Based on evolutionary ideas and Residuals implications not used in the pres­ Mixed or confused ent studies. Evidently would in­ clude 'Combinations,' 'Polar pat­ terns' and 'Intennediates'. That there is this much agreement in the two sets of ideas is striking since the present categories were arrived at in the course of a study of scale arrangement and the various physiological influences in the corium.

THE SIMPLEST CASES: PRIMARY PATTERNS

The simplest cases are those in which pigment cells are aligned with scale rows, in one of the six possible lines, along which scale rows may be serially counted. These are shown in Fig. 1, of which only four, 'L', 'T, 'C' and 'R', have been found with aligned pigment cells.

LONGITUDINAL PATTERNS. In many fishes the longitudinal scale rows, 'L', are accompanied by specific pigment cells. On each scale there may be a single dot or a large spot, a dark line meeting its fellows on the preceding and following scale, or other arrangement on only a single row of medial scales, as for instance in various species of Notropis, e.g. N. hudsonius and N. whip­ plei and in Mulloidichthys martinicus. Single longitudinal lines are almost always accompanied by other elements. Examples of these cases are given later. Multiple longitudinal rows of pigment spots, from two to a considerably larger number, are present on some species, as in Thymallus arcticus, Ictiobus 24 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. 1. No.1

Fig. 8. Details of the imbrication of MegaJops atlantica. Drawn from a specimen, not diagrammatic. Modified after Breder (l947a). cyprinellus, Melanotaenia sps., MugU cephalus (not very conspicuous), Poecilia (Mollienesia) sps., Holocentrus xanthergthrus, H. ascension is and H. rufus, Roccus saxatilis, Lutjanus griesus, Orthopristis chrysopterus, and Stenotomus chrysops. These cases of multiple rows are usually not accom­ panied by any other conspicuous elements. Sometimes a longitudinal line of pigment covering the entire exposed surfaces of the scales involved will occur. If so, it is necessary that the two immediately adjacent rows be unpigmented -or of another color, in order for the linearity to be apparent as in some species of Pseudotropheus.

TRANSVERSE PATTERNS. Transverse scale rows, accompanied by pigment cells, are nearly as frequent as the longitudinal and not infrequently both occur on one fish and are commonly alternately suppressed by nervous con­ centrations of the pigment granules in the chromatophores of one set or the other. Representative species with transverse bars are Leporinus fasciatus, Puntius hexazona, Archosargus probatocephalus,13 HapJopagrus guntheri, Chaetodipterus faber, Platax sps., Pogonius chromis, Pterophylum scalare, Symphysodon discus, Abudefduf saxatilis, Sebastodes serriceps, and Macro­ podus opercularis. There is a feature of the transverse rows which, as part of Series B, has no counterpart in the other rows. All in Series A are longitudinal, clockwise or retrograde. Fig. 2 shows clearly that the edges of the scales in the same trans­ verse row do not reach their nearest fellows. This is equally true of the edges hidden under the overlapping rows. Each scale rests in its own dermal pocket and must be separated at least by tissues forming these individual invagina­ tions. The details of this arrangement in Megalops is shown in Fig. 8. Ob­ viously, however, from the above lists, this has not prevented pigment pat­ terns from following the transverse rows.

13. Departures from the usual numbers of transverse bars in Archosargus are discussed by Caldwell (1958). who indicates the amount of variation that is sometimes present in these patterns. \9721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 25

A rather special feature of the transverse scale following patterns is that some fishes show a pattern in which comparatively wide bands alternate with irregular dotted lines or very narrow continuous lines, instead of the usual condition in which each element of the pattern approximates the others. The dotted line condition is seen in Amphistichus argenteus and the thin line in Pterois volitans. Conditions of this kind have led to speculations on the pos­ sible role that the Liesegang phenomenon might play in the development of patterns. See Thompson (1942). Two only distantly related species mentioned above, Archosargus probato­ cephalus and Sebastodes serriceps resemble each other in having a series of rather broad transverse dark bands. The most noticeable thing about these bands is that they are set at a different angle to the longitudinal axis, about 85° for the first and 74° for the second, as the anterior angle is measured above the axis. Thus the angular difference between the banding of these two fishes is the same as that between their respective scale rows, 'L' and 'T'. The angles between the axis and 'C' are 67.5° and 48°, those of 'R' are 105 0 and 9r respectively. These angles are tipped further forward in Sebastodes, relative to Archosargus, almost as a unit, the angular differences being for 'T' 0 11 0, 'C' 19.5 and 'R' 8 ° .

DIAGONAL PATTERNS. Either of two of the diagonal types of scale rows, 'C' and 'R', may be accompanied by pigment. Type 'C', clockwise (down and back) is represented by Etheostoma flabel­ lare, E. caeruleum, Percina caprodes, and CoUsa fasciata. Type 'R', retrograde (down and forward) is represented by Hypentelium nigricans, Esox americanus, Micropogon undulatus, Aplodinotus grunniens, Chaetodon melanotus and Trichogaster trichopterus.

COMBINATIONS. Pigment-bearing scales of the four lines, 'L', 'T', 'C' and 'R', form the bases of more complex patterns by a variety of combinations. The total number of scale aligned patterns possible with the four elements, taken at one, two, three and four at a time is fifteen.14 This is in cases where none of the combinations produces a pattern cancelling any element. The six combinations of two elements cover the cases, 'LT', 'LC', 'LR', 'TC', 'TR', oCR' fishes, discussed below. The longitudinal and transverse 'LT' patterns are not common except as alternate patterns, one fading as the other appears, although some species occasionally show them together. An example of the latter, Katsuwanus pelamis, is reported and illustrated by Strasburg and Marr (1961). The following four pattern-combinations of two elements have not as yet been found on any fish, in an unequivocal form. It is possible that they are truly absent or merely rare or obscure.

14. The sums of nC, = N!/r!(n-r)! where n = 4 and r = 1,2,3,4. Or, more simply, for the n total combinations only, 1, nC t = 2 - 1. 26 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, NO.1

The longitudinal and clockwise 'LC'. The longitudinal and retrograde 'LR' .15 The transverse and clockwise 'TC'. The transverse and retrograde 'TR'. The clockwise and retrograde 'CR' are very common. If pigment occupies only the marginal free edges of the scales, which when darkened form a grid of coordinates, the pattern becomes very distinct. Sometimes its absence on an otherwise dark fish will show a negative of the same pattern, or in some cases even structural differences in the scale edges of large fish will do the same thing, as in Megalops. Representatives with distinct pigmentation produce scale edgings in various species of Notropis, Lucania parva, female Poecilia (Libestes) reticulata, and Holotrachus lima. In the mature female P. reticulata the dark scale edgings which compose the crisscross pattern are composed of melanophores deployed in a narrow band, about six across. The squamation varies considerably in Cyprinus carpio, a plain drab­ colored fish. The "normal" American stock has about 36 'C' scale rows, with enough visible dark scale edging to show a good but usually faint 'CR' mesh. The most distinct pigmentary differentiation is the somewhat darker marks just after the hinder edge of each scale, between the edges of the two over­ lapping scale rows. The so-called mirror carp has a disorganized scale pattern in which all that remains are some ragged rows of mostly irregularly enlarged scales, one row on each side of the dorsal profile, another along the midline and usually scattered scales on each side of the ventral profile. Where the skin is free of scales the color is completely uniform, except only for the usual counter shading, which lightens the color towards the under parts. The so­ called leather carp, which is devoid of scales, has a uniformly smooth integu­ mentary pigmentation. In the partly scaled form the pigment spots still re­ main with the enlarged scales. Where a scale has no scale anterior to it, there is usually a spot that would normally have followed the absent scale. Fre­ quently these spots are much enlarged beyond the normal size, often as a con­ siderable blotch. These would seem to be the result of the absence of the scale and its pocket, since there is no fold in the dermis. This case could be inter­ preted to mean that the continued spread of melanic patches is inhibited by the presence of scale and scale pockets. Chavin (1956) reported that addition of sodium chloride, as little as 0.7%, to the water in which completely xanthic Carassius auratus swam induced the

15. There is a case which might conceivably be put in the 'LR' category, but it is considered too equivocal. Camegiella marlhae has a single strong 'L' along the middle of its side. On the greatly dilated thoracic region, housing the flight muscles, there are dotted lines running on the 'R' series of scales. These are distant from the axial line that runs approximately parallel and close to the dorsal profile. Between these dark marks there is nothing but the silvery surface common to these fishes. Because of the heterogonic growth necessary to produce the dilation, the scale grid on it is distorted and tipped at an angle to the grid on the lateral sides of the trunk proper. 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 27 development of melanophores. The melanic areas showed no particular pat­ tern, but the scale-edge limitation discussed above was closely observed. This effect also suggests the strength of the scale pocket influence. If more than the scale's free edges are occupied by pigment, a variety of results are obtained, such as uniform spotting one to a scale, if only the central area is pigmented. Finally if the scales are fully covered with a single kind of pigment, the fish is uniform, which is a degenerate case, indistinguishable from the 'LTCR'. The four combinations of three elements cover the cases, 'LTC', 'LTR', 'LCR', 'TCR'. The following three have not as yet been found on any fish, in the same sense as noted for four of the combinations of two elements. The longitudinal, transverse and clockwise 'LTC'. The longitudinal, transverse and retrograde 'LTR'. The transverse, clockwise and retrograde 'TCR'. The longitudinal, clockwise and retrograde 'LCR' is represented well in the Cyprinidae, e.g. Notropis bi/renatus and many of the species listed under "Longitudinal" . In some fishes, as in the male of Geophagus jurupari, the sides are covered with regularly arranged light round spots, one to a scale, that are very small in comparison to the exposed areas of the scales. These light spots are nestled against the edge of the longitudinally anterior scale and between the edges of the overlapping scales of the row above and below, called 'the base of the scale' from here on. The result is that all four lines of scales 'LTCR' are clearly marked as dotted lines, which is evident at a glance, including the transverse row, in which the small spots are seen to be notably farther apart than those in the other three series, 'LCR'. In other species with larger spots, this may still be noted, but the series are not so quickly recognized. The con­ dition becomes increasingly less noticeable as the spots approach the size of the visible area of the scale, in which condition the optical effect becomes one of a network of lines along the scale edges, which effect emphasizes the diagonal rows and is then recognized as the condition 'CR', the elements 'LT having disappeared. Minytrema meZanops has spots at the scale bases of about five 'L' scale rows, which appear as longitudinal dotted lines. These equally well represent the diagonal rows 'C' and 'R', running through five scales each, as well as the 46 'L' row scales. The latter catch the uncritical eye, evidently because of their greater length, although the other two are geometrically just as valid. More commonly the spots are elongate along the scales they occupy, very often along the longitudinal series. Some nearly reach across the entire scale and thus grade into continuous pigmentary lines along scale series. It is im­ possible, at this time, to determine if spots of this sort represent the breaking up of a line of pigment or whether such a line of pigment represents a coales- 28 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. 1. No. 11

cence of what were individual spots. It would seem probable that in the evolu­ tion of teleosts these two types of pattern were pushed one way and then an­ other many times, even in a single ancestral chain. Examples of species show­ ing dotted lines of this sort have already been discussed under "Longitudinal patterns" . These kinds of dotted lines are not apparent in the transverse rows. It is to be recalled that the transverse series of scales are farther apart from each other than those of the other three series. The alternate dotted lines noted under "Transverse patterns" are not common and are not recognizable as the breakup of a solid band. Astracion cubicus, A. cyanurus and Lactophrys bicaudalis have a single spot near the center of each of the highly specialized scales that form the rigid cuirass encasing them. Unlike Geophagus jurupari, these spots do not line up very well, as the hexagonal plates are variously distorted to fit the shape of the surface on which they were formed in meeting each other to make a solid surface. Imbricated scales which do not abut each other do not have this type of distortion. The first two species have light spots and the third, dark. The fifteenth and final case of one combination of all four elements 'LTCR', completes the set. It is not always easy to establish or deny that a given fish has all four elements, especially if there is one large spot on each scale. As it approaches the size of the scale the fish finally becomes a uniform hue, the degenerate case mentioned under the combinations of two elements. See also the diagram of pattern relationships shown in Fig. 9 and the following illustra­ tive cases.

COMBINATIONS NOT FOUND. All three of the scale-aligned types of pattern, 'L', 'C' and 'R', follow scale rows of Series A, while only one, 'T' follows a scale row of Series B. Thus two scale rows in the latter series are not known to have an accompaniment of lineal pigmentation. Since there are six scale rows recognized, it is clear that there are many more scale row combinations that are without row-aligned pigment than the preceding section might suggest. The possible combinations of six scale rows and those that are pigment­ occupied are compared in the following tabulation, calculated in the same manner used on the four scale row aligned pigment lines. Scale rows Total Pigment lines Scale row combina- taken in possible taken in tions without combination combinations combination lineal pigment 1 6 4 2 2 15 2 13 3 20 1 19 4 15 1 14 5 6 0 6 6 1 0 1 Totals 63 8 55 1972) BREDER: TELEOST SCALES AND PIGMENT PATTERNS 29

Since there are 63 possible combinations of six kinds of scale rows and only four types of scale-following pigment lines there are obviously many more combinations of unoccupied scale rows, 55, that is only 13 - % have accom­ panying lineal pigmentation. The conditions of patterning on the sides of fishes have been studied in this connection by examining preserved and living material and photographs of many sorts adequate for these purposes.16 In all some thousand valid species have been so examined, in as wide a selection of families and orders as was practicable. It is not necessarily thought that all the 55 cases noted above will never be found. The data presented, however, are considered good presumptive evidence that there exists a vast difference between the frequency of occurrence of the combinations that were found as against those that were not. The clear abundance of the patterns found compared with none at all in this sampling is too great to be without some significance. Considering only the four cases where scale-aligned patterns are present, the following tabulation serves to consolidate these data. Combinations present Combinations not found All 'L','T','C','R'. 4 None 0 4 'LT', 'CR'. 2 'LC', 'LR', 'TC', 'TR'. 4 6 'LCR'. 1 'LTC', 'LTR', 'TCR'. 3 4 'LTCR'. 1 None 0 1 Totals 8 7 15 This usage is justified in that the Series A lines are all represented, while only one of the Series B lines is present. The peculiarities of Series B make it notable that there is even one represented. The tabulation including all the scale rows is such that graphic treatment would tend to confuse rather than clarify, with a gross dilution with 55 blank spaces. Therefore the simpler conceptual treatment is given in Fig. 9.

SPOTS. The relation of the condition of a spot on every scale, as compared with that of a lineal series, has been mentioned in some detail on the pages immediately preceding and more generally throughout the section 'Longitudi­ nal patterns'. The gradation of pigment linearly aligned with scale rows to individual, nearly circular or unaligned spots is a fine one with representatives of almost every conceivable step. Solitary spots might be considered simply as the remnants of a solid uniform color or an all-over spotting in which all but one spot had disappeared. These spots enlarging to cover the entire scale or an assemblage of a few, could account for a spot exceeding a single scale in size. That this is not mere speculation is evidenced by the many cases

16. Drawings, even when made by competent artists, have not been used in this connection for it was found early that the match of pigment pattern and squamation was often too in­ accurate to be used, as based on drawings compared with specimens in hand. 30 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No. I

Fig. 9. Chart of combinations of scale-following lines, 'L', 'T, 'C' and 'R'. Con­ ventionalized outlines of fishes indicate the presence of the combinations shown. Small circles indicate that the combinations have not yet been found in any fishes. The solid lines connecting the fishes indicate the elements combined. Combinations of three and four elements can be obtained in a variety of ways, although only one way is indicated above. See text for full explanation. where such spots do closely match one or a group of adjacent scales. Close inspection reveals that, what may seem to be a round spot, usually shows that the edges of the spot are not smooth, but follow exactly the limits of the exposed portion of the marginal scales. In instances where the spot is not as large as the scale, since a spot may vary in size, shape and location on the scale, the resulting pattern may differ widely from that of the scale filling spots. The spot may become too small to be seen, thus again reducing the fish to a uniform color. There is evidently a marked tendency, among many groups of fishes, to develop a large dark spot on certain areas of the body. The locations of these spots, and examples of the fishes that illustrate the condition follow.

Nuchal spots. None found except as follows. The natural hybrids between Holocanthus ciliaris, which has a nuchal ocellus and H. isabelita, which has none, usually show a nuchal spot. These hybrids formerly were considered separate species, H. bermudensis and H. townsendi.

Scapular spots. (Single): Brevoortia tyrannus, Melanogrammus aeglifinus. (Multiple): Clupea sirm, Pomolobus sapidissma, Dorosoma cepedianum, Polynemus sextarius. 19721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 31

Sub-dorsal spots. Lutjanus synagris, L. analis, Geophagus brasiliensis.

Peduncular spots. Labeo dussumieri, L. fisheri, Diplodus holbrookii.

Regular spots. Minytrema melanops, Sciaenops ocellata, Geophagus jurupari, Scarus guacamaia, Holocanthus isabelita, Pomacanthus arcuatus.

Scattered spots. Salvelinus namaycush, Gymnothorax nigromarginatus, Synodontis angelicus, Astroscopus y-graecum, Ephinephelus guttatus, E. microspilos, E. e1on­ gatus, Scatophagus argus. The full implications inherent in these spots is considered under the secondary patterns, as they introduce concepts not involved in the primary patterns.

VERMICULATIONS. Markings that are customarily called vermiculations17 by taxonomists are found in a considerable variety of fishes, ranging from the Salmonifonnes to the Tetraodontiformes. Compared with the numbers of fishes not showing such markings, however, those that do, comprise a very small number. This matter is introduced here because it occurs more com­ monly in various fishes that otherwise show only primary patterns. The rela­ tionships to other markings seem to be numerous and complex and their derivation is not entirely clear, as will be developed later. Typically these fishes have very small scales, examples of which include the following: Salve linus fontinalis and S. namaycush, Esox niger and E. vermiculatus. Scomber scombrus and S. colias. The precise form of individual vermiculations tends to vary greatly from one individual to another. Hunt (1923) shows this graphically for Scomber colias. This lack of detailed uniformity from one fish to another, as well as variations from one side of an individual to the other, has little or no effect on the pattern as viewed from about a foot and one half. This condition is rather general wherever a sizeable area is covered with vermiculations. It suggests that the utility of the effect is important to the bearer of the reticula­ tions at some distance, while the fine details which produce it are not. The most startling cases are to be found in Siganus vermiculatus, S. spinus (to a lesser degree), and Centropyge bispinosus (the marks mostly tend toward verticality). These and Balistopus undulatus, Alutera scripta and

17. The term "reticulations" such as seen on Esox niger are here included under vermicula­ tions as the latter word is more general and in many cases one grades insensibly into the other. 32 CONTRI.BUTIONS FROM THE MOTE MARrNE LABORATORY [Yol.I,No. 1

Lactophrys quadricornis are all cases belonging to the fishes with secondary patterns. Vermiculations on Symphysodon discus appear as bluish wavering lines, the main trends of which approach the horizontal. With them, trans­ verse dark bands mayor may not appear as both patterns are changeable. These more pronounced vermiculations closely resemble certain patterns produced in liquids by convection currents under special conditions discussed by Whitehead (1971). The conditions include differential heating and a solid plate against which the patterns appear. The responsible influences are purely physical. A variation of these can change the patterns to a surface of hexagons, in the absence of the plate. These hexagons are similar to the squamate coverings of the Ostraciontidae. Scales generally would seem to be the equivalent of the above plates, while their sculpturing provides the means of altering the temperature relationships. These conditions, with the presence of melanophores, suggests a highly modified but basically similar set of condi­ tions. If so, the effects would probably be started with the appearance of the precursors of both scale and pigment arrangements. Further discussion of this would lead away from present purposes.

RELATIONS TO THE LATERAL LINE. The modification of scale rows often associated with an upward arching of the lateral line involves the pigmentation related to the scale rows concerned. This fact indicates the strength of the bonds that hold these two integumentary features together. The following accounts of two sparids and one pomadasid indicate the extent and type of pattern changes associated with lateral line changes. In Lagodon rhomboides yellow lines, alternating with bluish, follow longitu­ dinal scale rows which run parallel to the body axis below the lateral line, as in most central Perciformes. Above the lateral line, the yellow lines run parallel to the arch of it. Above the pectoral insertion and below the lateral line there is a tendency for the scales to enlarge considerably, evidently related to the greater depth of the fish, the increase of which may be primarily re­ sponsible for all these changes. In this area there is a slight upward arching of the larger scale rows approaching parallelism with the lateral line. Slightly farther back these rows straighten out and abut the descending limb of the lateral line and show no tendency to conform to its curvature. Stenotomus chrysops of the same family, agrees closely with the preceding. In Orthopristes chrysopterus, a pomadasid, the scale size changes very little, if at all, above the lateral line. Instead the crossing 'C' and 'R' rows "tip forward" as a unit, so that the 'L' rows, parallel to the body axis below the lateral line, run up and back from the lateral line to the dorsal profile at an angle of about 42 0 as measured over the pectoral base. This angle decreases to about 13 0 below the soft dorsal and to zero on the caudal peduncle. These lines, just back of the head, are strongly curved but this curvature flattens to a straight line as one progresses backward to under the soft dorsal. The 19721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 33 yellow lines on this species follow the 'L' rows throughout, making those above the lateral line appear to be entirely unrelated to those below. Superficially they appear to follow 'R'. Above the strongly arched lateral line of Archosargus, the squamation is notably modified, but in the Hexagrammoidei, Hexagrammos has scales which show little if any modification in that area. In this case the scales would seem to be more under the influence of the lateral septum than under that of the lateral line. In Umbrina roncador, lines follow scale rows, 'R', run up and back, but after crossing the lateral line they nearly parallel it. Each scale of Lutjanus johni carries a longitudinally elongate spot. The resulting dotted lines below the lateral line closely approximate parallelism with the body axis, while those above the line run parallel to its arched course. With L. lineolatus the scale rows and lines are basically oriented as in L. johni below the lateral line, but those above it run down and forward, 'R' and abut the lateral line. Both Embiotoca latera lis and Hysurus cary; have basically similar patterns. The first shows longitudinal lines, usually blue, located on the central parts of the scales separated by usually orange lines, below the lateral line. Above this, the same type of colored lines run parallel to it. Only minor details differ in the second species. In addition to the evidently profound influence of the position of the lateral line in some fishes there are a few fishes that have the lateral line, itself, pig­ mented. These fishes are almost entirely confined to the Gadiformes. Gadus morhua, Microgadus tomcod and Pollachus virens have light colored lines while Melanogrammus aeglefinus has black ones. Urophycis reg ius has a lateral line interrupted at regular intervals by light spots and U. chuss usually has a faintly pale lateral line. Other species and genera of this family mostly have undistinguished lateral lines. All these genera have very small scales. The family Centropomidae tends to have very conspicuous black lateral lines, that of Centropomus undecimalis being even more distinct than that of the unrelated gadoid, M elanogrammus. Some fishes with a single bright silver stripe running along the midline from head to tail must be noted here because of what seems to be a negative connection with the lateral line. For instance, the lateral stripes of Anchoa hepsetus, Menidia beryllina and Chryodorus atherinoides seem to follow the septa between the epaxial and hypaxial muscles. The Engraulidae and the Atherinidae have no lateral lines, while the Exocoetidae have the lateral line displaced downwards so that it runs parallel with and close to the ventral profile. The silvery stripe of the above three forms is below the scale level and backed by dark material. Otherwise the three silvery stripes are each produced by a different arrangement of elements. In A nchoa there are two argenteous layers, the outer being level with the under surface of the corium and the 34 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, NO.1 inner bowed inward. The edges of the two silvery layers are in contact so that a transverse section of this double stripe appears lense-shaped. Because of the intensity of the guanine investment the two stripes together resemble a section of a flattened silver tube. Within this area there is a sparse scattering of melanophores between the two walls, imbedded in nearly transparent tissue and close to the innerside of the outer wall of the silvery tube. In M enidia there is a single layer of the highly reflective guanine, backed by a layer of melanophores, under which lies a band of very dark musculature, which partakes to some extent in darkening this area. In Chryodorus a very similar situation exists, except that the dark underlying material instead of being dark musculature, consists of a heavily pigmented membrane that invests a small bundle of light colored muscle. These lateral pigment stripes, whatever their structure may be, evidently protect sensitive parts from injurious radiation, as has been suggested by Titschack (1922), Yamamoto (1931) and others and reviewed by Parker (1948) for other pigmented tracts. It is obvious that here it is not lateral lines that are being protected. In all three of these fishes there is a very fine, usually nearly invisible mesh of melanophores lightly edging the scales as lines running with the 'C' and 'R' scale rows over the backs to at least the silvery stripe and which, in the case of Menidia, extends over it and fades out on the lower flanks.

THE MORE COMPLEX CASES: SECONDARY PATTERNS

The supposition is here made that in the simplest cases, the primary patterns are the more ancient. They are closely linked to squamation. Those patterns which clearly do not follow the scale rows are designated the more complex cases, the secondary, and are considered the more recent. These scale-inde­ pendent patterns strongly recall the earlier mentioned Liesegang phenomena. They usually develop from a center on a fairly flat surface and may thus be considered polar.

POLAR PATTERNS. Patterns that appear to be concentric about or radiating from a center or axis may represent a first step away from those closely related to the arrangement of the scales. None of these are the common property of many species, but they appear as early as Amia and rarely in some elasmobranchs, but become most numerous in the advanced teleosts. What are here called polar patterns divide easily into two groups. The first group is comprised of ocelli which may be variously placed. Most frequently they are found on the caudal peduncle, on the sides under the dorsal fin, on the dorsal fin and sometimes also on the anal fin. Usually they are single, or at least very few, unless they are very small, in which case they may be numerous. In one sense these ocelli could be classified under J972] BREDER: TELEOST SCALES AND PIGMENT PATIERNS 35 the terminal group of the Primary patterns as "Spots", for they may be con­ sidered spots surrounded by contrasting rings. At most they must be con­ sidered as transitional. As yet there is no obvious morphological or physiologi­ cal reason for their occurrence in the precise places found. In the second group there are no ocelli in the ordinary sense of the word, but concentric ellipses or other curves surround an axis or lines may radiate from it, the presumed center of influence. Many such axes are centered on the fish body and others seem to be off it. Only comparatively thin, flat-sided fishes give this latter appearance. In comparatively broad backed fishes it is at once obvious that the axes of these designs are on the dorsal profile and that part of the designs are on the back while the rest of them follow the surface of the fishes down over each side. 18 These designs sometimes may be incomplete, crude or merely vague suggestions of such patterns. This group includes the designation "Concentric" of Gregory (1951). These concentric and radial patterns are apparently mutually exclusive for no fish has been found that shows both concentric curves and radial lines. The polar patterns have shown a strong tendency to not follow scale rows and to ignore the shape of single scales. The curved marks, bowed forward on the sides of some fishes, seem to be closely related to the 'T' series of transverse marks and some may be transi­ tional, as for instance in Chaetodipterus faber, which has been included in the 'T' series earlier. There is however a very slight forward bow in the bold transverse bands, but they still fol1ow the scale rows which have the same bow, evidently brought about by a general transformation incident to the deepening of the body. The fact that this species is closely related to the Chaetodontidae suggests that the forces releasing pattern from scale domina­ tion may have not yet made a clear separation here. In almost all fishes displaying these independent patterns there remain traces or more of the scale-aligned patterns. In many species, especially of the less advanced types, there may be more scale-aligned pattern coverage than independent pattern. This is at least partly because of the criterion separating the two pattern types. The first (scale-aligned type) excludes any of the second (independent type). The latter requires only that there is some clear evidence of the second type. Considering all fishes, the bulk of species are in the first category even with this arrangement, which appears to be the least arbitrary. Some of the species showing both the primary and secondary patterns have extremely complex mixtures of the two types.

18. As a geometrical matter this can be considered as a polar design on a plane, with its axis perpendicular to the plane. If this plane is bent downwards so that its highest part lies on a straight line representing the dorsal profile of a fish and the bending continued, the plane is finally folded on itself, the design's two halves merge into one. Viewed from one side, the perpendicular axis now appears as projecting in the same plane as the half design. The ap­ parent center of a concentric curve in the design then appears as though its center (or new axis) lies off the fish at some point on the old axis and perpendicular to it, at a distance equal to the radii of the curves. 36 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1

All the extreme examples appear to be confined to the Chaetodontidae, as exemplified by Chelmon rostratus, which shows an incredible mixture of both pattern types, and the Balistidae, as exemplified by Balistoides niger. Al­ though many of the related families of both approach these conditions, none quite equals them in the sense here used. Examples of the various polar patterns follow.

Ocelli. Nuchal: Holocanthus ciliaris. Scapular19: Pomacanthodes annularis. Sub-dorsal: Lutjanus rivulatus, L. monostigma, Hemichromis bimacu­ latus, Chaetodon unimaculatus, Canthigaster margritatus. Peduncular: Rivulus, many sp. females only, Leptolucania ommata, Sciaenops ocellata, sometimes several, Astronotus ocellatus, Cichlasoma festivum, Bostrichthys sinensis. 20 Scattered : Salmo fario, Salvelinus fontinalis, Cephalopholis argus, C. fulva, LopholatiJus chamaeleonticeps.

Axial. 21 Concentric : Therapon jarbua, Plectorhynchus cinctus, Pomacanthus im­ perator, Spheroides annulatus, S. testudineus, often vague in both species. Less perfectly developed, Nematistius pectoralis, Equetus pulcher, Haemulon plumeri, H. sciurus. 22 Radial : Menticirrhus, several sp., best shown in young. This case could be interpreted as concentric with the center above the dorsal insertion, instead of radial from a point near the pectoral base.

19. As an exceptional item Arothron hispidus often has an ocellus in the center of which the pectoral base and the opercular opening are located, a feature also to be seen in a number of its near relatives. 20. Bothus lunatus has many scattered bluish circles over both bodies and fins. Many of them are not complete. Even those that are incomplete have such a large dark center, in comparison to the width of the bluish circle that it is difficult to reconcile them with ocelli, but this is evidently where they belong. Spheroides nephelus is covered with light ocelli on a brownish background. The circles of the larger ones are composed themselves of miniature ocelli. Ancylopseua quadrocellata has four large ocelli that are very conspicuous when the general background matching pattern is small or uniform. The ocelli are not nearly so con­ spicuous when the fish has matched a coarsely pebbled bottom. 21. The forms that have a center of gyration near the caudal peduncle, as seen on Pomacanthus semicirculatlls and P. imperator permit the inclusion of more concentric lines than does any other location. The distance between the successive lines increases as their distance from the axis. In this feature they resemble the logarithmic spacing of some types of Liesegang precipi­ tation lines on a flat surface, reviewed by Thompson (1942), but this spacing may follow non­ logarithmic progressions, dependent on the chemical nature of the substances involved. Al­ though it was not feasible to make an elaborate check on the type or types of progressions present, measurements made on P. semicircuiatllS, P. imperator and Therapon jarbua produced acceptably straight lines when the number of each primary ring, from the center, was plotted against the log. of its distance from the center, so at least these series could not be distinguished 1972) BREDER: TELEOST SCALES AND PIGMENT PATTERNS 37

INTERMEDIATES. The fishes named as examples, illustrative of the various types of patterns, were thus far chosen because they happened to unequivocally indicate the specified patterns. Those fishes however, do not always show the named type of pattern alone. The purpose here is to indicate some complex situations of interest that were not necessary to the preceding explanation of pattern types. A finely graded series of intermediate patterns may be found in most, if not all of the pattern elements designated by name and letters in the preceding listing. This however is no more of a problem than geometricians have in considering the circle and the straight line as limiting forms of the ellipse. Neither does the problem of taxonomists essentially differ when trying to give designations to real but "close" species. The ocelli of the secondary patterns, reducing to Spots of the primary pat­ terns by the shrinkage of the width of the outer ring to zero, or its reverse, may serve as an example. Or, the case of the primary longitudinal pattern of multiple lines reducing to the secondary concentric pattern by the anterior and posterior ends of these lines curving upwards to meet their fellows of the other side at the dorsal midline. Many other cases can be recognized as simple geometric exercises. How many patterns have actually transformed in this fashion and in which direction, is an evolutionary problem not directly pertinent to this study. The conditions found in Sciaenops ocellata, however, may serve as an example of the simpler type of spot to ocellus transformation. This species develops a dark peduncular spot at a small size, which may be located near the end of the peduncle where the scales are comparatively small or in a more anterior position as far forward as under the last portion of the dorsal fin, where the scales are considerably larger. The spot may cover about eight to twelve scales in the posterior site but usually only covers four in the more anterior position. Exceptional cases may show multiple spots distributed in a less limited fashion. Only on the larger individuals does a light ring surround the dark spot. The genesis of this light circle has not been studied. The pigment forming the peduncular spot is located in the dermis over the scales and possibly the epidermis of three of the four scales involved. The fourth, and most anterior of the group, has the pigment in the dermis under it, showing through the otherwise transparent scale. The pigment of the other three scales extends similarly, in all cases, under the scales ahead of

from logarithmic series. They are the reverse in order to the progressions formed by the circuli on fish scales, or the rings of tree trunks, both of which become closer together as they recede from their growth center. The above mentioned species show a tendency to inter­ lard their primary concentric lines with much fainter and narrower secondary lines, which is also a characteristic of the precipitation processes. 22. The eye is seldom part of a polar pattern and of course many patterns are evidently designed to conceal that organ. However Batistes vetula shows a pattern of dark lines mostly radial from the eye. 38 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1 them. The center of this nearly circular spot is located just a little posterior to the free edge of the anterior scale and midway between the limbs of the two scales it overlaps. The spot usually has a radius equal to about half the distance between one exposed scale edge and the next, as measured in longitu­ dinal series. This pigment arrangement is primarily the same as that generally covering the body of the fish. The difference seems to be in the concentration of melanophores and the sharp edged termination of the nearly circular peduncu­ lar spot. The comparatively vague longitudinal lines formed of lighter stipp lings of melanophores on the sides of the fish fade even more on the lower sides and reach under the anterior scale not nearly as far as do those higher on the sides, thus defining the usual countershading. The melanophores on the sides of Eucinostomus guw are essentially ar­ ranged the same as in Sciaenops but the pigment cells are much less numerous and are smaller, as befits a primarily silvery fish. The conditions found in the Family Theraponidae may serve as an example of the fate that may overtake mUltiple longitudinal lines. Here patterns of multiple longitudinal lines could conceivably change to polar concentric patterns, as found in Therapon jarbua. The patterns, but not necessarily the species presently bearing them, could form a presumptive series from Therapon oxyrhynchus or Pelates quadrilineatus through A utisthes puta through Eu­ therapon theraps to Therapon jarbua. In all but Pelates there are about five dark bands on the caudal fin that seem like projections of the body marks. More remote patterns are seen on Therapon caudavittatus and Helotus sexlineatus. The first has only two caudal bands and the body pattern is one of transverse bars running with the 'T' rows of scales. The second also has two caudal bands and longitudinal scale-following lines of pigment, none of which shows any tendency to turning to meet their fellows from the opposite side. Some members of the not very distantly related Family Kuhlidae such as Kuhlia taen;urus have caudal markings strikingly similar to those on T. jarbua while others have caudal markings that appear to be modifications of it or none at all. As this type of caudal pattern is not known from other closely related fishes, this may suggest either a closer relationship than presently recognized or the effects of a common environmental influence on two some­ what similar genera. A less pronounced, but apparently basically similar condition, regarding the nuchal area, is found in the genus Haemulon. H. flavolineatum has two longitudinal lines on each side of the back, the outer two running from snout to caudal peduncle and the two inner lines not reaching farther forward than a point near the hind edge of the orbits. The lines on the sides of the body are diagonal and disjunct from the four longitudinal lines. In both H. plumer; and sciurus the outer pair do not reach the snout, but both turn toward the 19721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 39 dorsal midline and meet at a point just back of the anterior edge of the orbit. The two inner lines stop abruptly about as in H. flavolineatum. All four lines are interrupted at about the dorsal insertion, where the pattern of the sides displaces them for a short distance, after which they are variously in­ terrupted before the caudal area is reached. As noted earlier, some polar patterns seem to have their centers some distance above the fish. It is convenient to think of it in these terms in the case of Microcanthus strigatus. Here the center appears to be at a point above the middle of the fish, a distance about equal to the fish's depth. Cheilodacty­ Ius gibbosus and Equetus pulcher each have at least one line convex down­ wards, the center approximately over the caudal peduncle but at a greater distance from the body. Sebastodes nebulosus has a light arc of very large radius running from near the beginning of the dorsal fin to the caudal peduncle which suggests a center far above the fish. Equetus lanceolatus has its strongly marked arcs with centers high over the back, well after the center of its length. Other patterns, centered elsewhere, are shown by some members of the Chaetodontidae, for instance, Pomacanthus imperator, which has a polar center on the midline near the caudal peduncle with closed curves surround­ ing it. The smaller of these approach circles, while those more distant from the center and reaching to the head, are nearly ellipses. These latter appear only as arcs on the forward half of the fishes and appear to have the major axis about twice that of the minor axis. This species shows considerable variation close to the center of the figures, the young individuals having the lines of the smallest circles doubled on themselves, which feature becomes more regular as the fish grows larger. Although various species in this family have very small scales (auxiliaries) interlarded between their scale rows, it is unnecessary to discuss that fact here because of the great scale-independence of the pigment patterns. Anisotremus virginicus has heavy dark transverse bands anteriorly and 'C' farther back. The transverse bands may be secondary. Scapular ocelli are sometimes apparently displaced forward so as to occur on the operculum. In cases of this sort, the position of the ocellus in reference to the fish as a whole has remained substantially the same, but the head is generally larger, i.e., extended back farther in terms of body length as in Grammistops ocellatus Schultz, of the family Grammistidae. Here the center of the ocellus is just about 30% of the standard length from the tip of the snout. This is close to the position of most scapular spots. The ocelli scattered on the dorsal half of the body of Lopholatilus cha­ maeleonticeps seem to bear a vague relationship to the diagonal scale rows and thus may represent a barely detectable intermediate condition. There are widespread intermediates between patterns that have been 40 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1 designated transverse 'T' and the diagonals, clockwise 'C', and retrograde 'R'. These are probably most common in the perciform fishes. Transverse bars of some width may sometimes be noted to have edges that do not follow the transverse scale rows. On close inspection it will be noted that the midline of the bar follows 'T', but the bar edges follow one or the other of the diagonal series, 'C' or 'R'. Often 'C' is followed along the anterior margin of the bar and 'R' along its posterior margin, in which case the bars taper downward. There are also cases, without 'T' bands or bars, that have only either 'C' or'R'. These form angles wherever a pattern of 'C' following chromatophores interrupts to follow 'R'. An extreme example is Badis badis which seems to have a basically 'R' type on the lower sides and a thoroughly mixed type on the upper, resulting in chain-like markings in part, each 'link' the length of the exposed width of a scale. Others are Etheostoma eaeruleum and Cynole­ bias bel/ottii. These scale following patterns skip from one row to another in an irregular manner, differing pronouncedly from one fish to another. It is tempting to think that these rather erratic shifts may be indicating a tendency to follow myomeres rather than scale rows. Sometimes a bar will follow 'R', beginning at the dorsal midline and then follow 'C' on both sides. In this case there will be an angle in the bar, with its point facing toward the head. These sharp angles are sometimes at the lateral line or at the lateral septum separating the epaxial myomeres from the hypaxial muscles. Examples of this intermediate condition are seen occasion­ ally on an individual Enneaeanthus chaetodon or Perea flavescens. Whether these cases should be considered to be intermediates or accidental imperfections cannot be settled at this time. Presumably both conditions exist, probably varying in relative quantities in different cases. Where a seeming irregularity persists through a large population one can only suppose that the item is now gene-controlled and that its fixation has been brought about by selective processes. Tautoga onitis in its lighter phases shows an irregular network of dark lines, which follows one or another of the diagonal scale rows, switching from one to the other erratically. The pigment is limited strictly to the scales con­ cerned. In the darkest phase these markings are almost or fully obliterated.

CHANGEABLE PATTERNS. All or nearly all fishes are able to change their pigmentation over a period of time that may be very short or very long. It is only those species that change their pattern and color with extreme rapidity, the so-called instantaneous changes, that are considered here. This ability complicates any attempt to classify patterns and demonstrates that there is perhaps always a latent possibility in fishes to switch a pattern, often from stripes to bars and the reverse. Many fishes change their colors in reference to background and a lesser number also change their patterns in this respect. These changes typically 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 41 tend toward matching the background. See for instance, Parker (1948), Fin­ german (1963), Waring (1963) and Breder (1970). Many flounders can change the size of their spots to effectively match the size of the sand grains or pebbles on which they rest and so become very inconspicuous (Mast, 1916). The Lopbiid, Histrio, matches Sargasso weed exquisitely and is capable of changing its pattern in great detail to match its particular back­ ground (Breder and Campbell, 1958). The number of colors to which these fishes respond is directly dependent on the variety of chromatophores in the corium. Thus the related Antennarius is able to match red algae, because of the presence of erythrophores, which Histrio lacks. Fishes that are able to adjust their chromatic elements to resemble definite physical items in their immediate background usually are also able to make their adjustments much more rapidly than are the drabber fishes that are only able to adjust their tones to a background. A still further step has been made by fishes that are able to match some discrete objects sufficiently well to have had the term 'mimicry' applied to their performances. Often these objects are parts of plants, such as stems or leaves. See Breder (1942, 1946, 1949a, 1970). Recorded instances of this sort are eight in the Acanthopterygii, three in the Atheriniformes (Exocoetoidei) and one in the Holostei, although there are doubtless many more. The cases above mentioned are hardly to be considered as pattern bearing, and are noted here, rather as instances where patterns have been reduced to a copy of the random or regular nature of their background. Other changes not so directly imitative of background detail or even in opposition to its features, include those showing only general change. Often, in the case of shore or bottom species that have planktonic larvae, there oc­ curs an abrupt change at the time pelagic life is abandoned for the habitat of the mature. When this sharp change is made, either the transparence or the blue and silver of oceanic-surface forms is replaced by entirely different pigmentary conditions which are more appropriate to living close to solid objects. See for instance: Breder (1949b and 1962) Acanthurus and trans­ parent larvae, Caldwell, D. (1962) Pseudopriacanthus and Caldwell, M. (1962) Mulloidichthys. These changes may take place in a few hours or less. Changes not at all referable to background, but associated with social be­ havior and evidently serving as a means of visual communication are among the most rapid pigmentary adjustments known to fishes. Some of the Labridae, especially Lachnolaimus maximus, approach the speed of cephalopods in chromatophore activity.

RELA TIONS TO SEX. The role of sex in the development and control of pat­ tern is evidently complex and is not easily analyzed for a variety of reasons. In fishes largely or completely dominated by primary patterns the sex dif­ ferences are apt to be simple and limited to frequently little more than the fins. 42 CONTRIDUTIONS FROM THE MOTE MARiNE LABORATORY [Vol. I, No. 1

Color differences here are much more apt to be striking than those of pattern. Males may show brilliant colors or not, but body patterns are usually not in­ volved. Often also the females show colors that correspond to those of the males, but are not as brilliant. These colors are usually transient, existing only over the reproductive period. In fishes that are marked by bold secondary patterns the sexual differentia­ tion, in this respect, reaches its most vivid and gaudy heights, the males no longer being little more than "decorated females". Here the two sexes may look completely different, in some cases making it difficult to believe them to be male and female of the same species, and there is nothing seasonal about these patterns and colors although they may brighten during the reproductive season. It is to be noted that in cases sufficiently known, these bold male patterns develop late, approximately with the full development of the testes. Unfortunately there is too little known about the details of this matter in fishes with strong secondary patterns to warrant an extended discussion at this time. Some references and notes on seemingly direct hormonal influence on patterns and on non-hormonal influences that can modify patterns and colors are given below as they contain some suggestive data. In Amia calva the males have a peduncular ocellus, which brightens at the onset of the spawning season, but does not do so after gonadectomy. Young fish of both sexes show the ocellus, as do old females with ovarian degenera­ tion, from which Zahl and Davis (1932) concluded that the female hormone was inhibitory. It should be noted in connection with these matters that the males of Rhodeus sericeus have been shown by Brantner (1956) to have little ability to adapt to different backgrounds when displaying the bright reproductive coloration, while the females, which lack this display, retain their normal background responses. The male colorations, in this and many other cases, are evidently of sufficient importance to be permitted to drastically override the background matching tendency. American species of Cyprinidae which, in many cases, have males even more gaudy than Rhodeus sericeus have not been studied in this respect. In these fishes, such as Notropis cornutus and N . umbratilis, the males have red decorations, mostly below their midline. This seems to be the usual place on reproductive males in most of the 'Primary pattern' groups. In the same family the males of Clinostomus funduloides show a lighter red suffusion be­ low the lateral line in the breeding season. This does not begin before May where these observations were made, Breder and Crawford (1922). Preser­ vation in formal-alcohol in winter (January) produced a red suffusion in adults of both sexes similar to that found in breeding males but not as intense. Immature individuals preserved along with them showed no reddening (Breder, 1920). Evidently both sexes when mature have the necessary basis, but only the males develop some complementary element. No other fishes 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 43 have been reported to respond in this manner to these fixatives. Other sub­ stances that have been reported to evoke nuptial colors in cyprinids have been discussed by Astwood and Geschichter (1936) and Pickford (1957) in refer­ ence to Phoxinus and many other species. In other cases, at least in some species of the Cyprinodontidae, the reactions to background differ from the preceding. In the case of Cyprinodon variegatus the mature females are well matched to the backgrounds normal to them, as are the immature and inactive males. Courting males however become in­ vested with bright orange on their lower sides and with bright blue on each side of the nuchal area. If these fish are kept, or preferably reared, against a dark background they will attain their darkest coloration, in which case the colors of the courting males are notably rich. If the aquarium is approached closely and rapidly the brilliant colors will disappear in a few seconds, pre­ sumably being covered by melanophore activity. However, if any of these fishes are quickly transferred to a very light-colored container they will blanch in a very short time, usually in not more than two minutes. The orange and blue of males disappear almost completely in that time, but the melanic pig­ ment is so dense in its areas of greatest concentration that its reduction must wait on the slower onset of morphological pigmentary changes. If these fishes are then returned to a dark background, the effect of the blanching is most striking. Vigorous attempts to hide are made on either transfer, indicating the strong behavioral connection between pigmentation and appropriate loco­ motor behavior. Further discussion of this item is to be found in Breder (1947b, 1970) and Breder and Rasquin (1951). As soon as a pigmentary adjustment has been made to the new background, the fishes return to their usual habits of busy activity. Harrington (1967), working with the hermaphroditic Rivulus marmoratus, found that immature fish had a peduncular ocellus, primary males lost it on development, but fully functional hermaphrodites retained theirs, while sec­ ondary males, transformed from hermaphrodites lost theirs, but developed other elaborate and colorful patterns. No females have been found in this species. In the gonochoristic species of Rivulus most of the females have ocelli, which led Zahl (1934), studying R . uropthalmus, to consider the male hormone as inhibitory. The remarkably labile condition of the dermal chromatophore system of certain advanced teleosts to endocrine substances is illustrated in the condition found in some labrids in which two kinds of males are present, one greatly resembling the females and the other displaying a very different and gaudy pattern and coloration. Reinboth (1962) discusses this situation in detail and refers to an experiment of Stoll (1955) who, by the injection of methyl testosterone, transformed the patterns of both male and female Thalassoma bifasciatum of the less gaudy pattern, a yellowish ground color with dark longitudinal stripes, into the gaudy pattern of certain males, which have a 44 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I,No. 1 vividly blue head with dark transverse bars separating it from the green body. The plain males of this and related species Reinboth considered to be primary males and the gaudy ones to be males transformed by natural processes from females. Such striking differences in pattern between primary and secondary males have been noted in other fishes.

SCALE SIZE, ARRANGEMENT AND PIGMENTATION. Obviously there must be a relation between scale size and scale-aligned patterns. Also the case of scaleless fishes that display patterns requires assessment. A first approach to this complex of many interrelationships, may be made by defining the squamose conditions found in fishes in the broadest possible terms. Thus three partly arbitrary categories of scale differences and three of pigment patterns, purely for purposes of present convenience, are established, as follows. Scales 1. Light, typical teleost scales a. Scales absent or very small. (As in Silurids to typical teleost scales no larger than those of Salmonidae. ) b. Scales medium to large. (Typical teleost scales, larger than those in a to those of Megalops.) 2. Heavy, atypical teleost scales c. Rigid or nearly rigid cuirasses. (Atypical heavy scales as in loricariates, ostraciontids, syngnathids, etc.) Pigment 1. Primary patterns a. Zero pattern, uniform pigmentation or vaguely mottled. (As in many silurids, most apodes, syngnathids and clupeiformids.) b. Clearly mottled, speckled, spotted or vermiculate. (As in some apodes, some salmonids, scombrids, esocids and siganids.) c. Lines, bands and bars. (Scale following) (As in many cyprinids, cyprinodontids, holocentrids, serranids, etc.) 2. Secondary patterns d. Complex pigmentation. (Basically concentric) (As in many chaetodontids, pomacentrids, balistids, and diodontids.) A cross comparison of these two lists, while in this gross form, does not sug­ gest a high degree of correlation, but a more detailed examination of the data develops relationships germane to present concerns. These relationships of 19721 BREDER: TELEOST SCALES AND PIGMENT PATIERNS 45 pattern and scales are considered in some detail in the section on patterns and systematics. It is not possible at this time to reduce the evidences to tenus suitable for statistical treatment, partly because further study and docu­ mentation are required in order to provide an adequate basis for such work, but mainly because this material does not intrinsically lend itself to facile analysis by metrical means. In groups that show only primary patterns, the size of the scales fully deter­ mines the coarseness of the pigmentary patterns, as has already been noted. This is not true of the secondary patterns which are nearly, if not entirely free of scale-row influence. In fishes that show elements of both kinds of patterns, the primary continue to cleave to the scales and the secondary run relatively independently of them as is demonstrated in the large-scaled scarids and in the smaller-scaled chaetodontids. In most of the scarids and in the closely related labrids the patterns are mostly primary, although the colors and patterns are bright and often gaudy, more so on the heads where the secondary patterns are most apt to be, if present at all. In the chaetodontids a similar situation is found but the younger fishes are apt to have pronounced secondary patterns while the adults often change, at least in part, to one that is largely scale limited, as in Pomacanthus aureus and Holocanthus ciliaris. Botia macracanthus and a variety of other species of this genus and related genera have bold transverse bands, which tend to taper downwards. The scales on these fishes are so small that it is not possible to clearly delimit which, if any, scale rows the bands follow. As noted previously, when scales become sufficiently small, the pigment pattern behavior becomes that of the scaleless condition. The scale-aligned pigmentation found in the primary patterns has been clearly demonstrated to be dependent on scale orientation, but the secondary patterns are clearly capable of changing under the influence of forces to which scales are not responsive, as is indicated by the following data. In the earliest known account of abnormal scale arrangement Taki (1938) gave detailed information on the fate of the associated pigmentation. He described patches of unusual scale orientation on two specimens of Zebrias japonicus in which the pigmentary pattern precisely followed the changes in the direction of the scales. The eyed and pigmented side of this sole is crossed by a series of dark bands, which belong to the rows here called 'T'. Taki ap­ parently recognized our 'A' series of scale rows and indicated that the dark bands were not so aligned. He found that the affected scales always occurred in groups of a considerable number, never as few as two. In areas of transition, between those scales normally oriented and those not, he believed that the intermediate orientation displayed the resultant between the nonnal and adverse forces involved. The closely related Zebrias zebrinus may show abnormal bands, usually near the tail, but with the scales normally oriented. This case suggests at 46 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I,No. I once the presence of an influence which does not operate at a sufficiently early age to affect scale arrangement. This could be easily identical with the endocrine influences that have been shown to affect patterns but not scale arrangement. Talei's illustration could even be interpreted as the very be­ ginning of a transition to a polar influence with its axis above the fish, slightly past i.ts mid-point. All the above data support the present views concerning the influence of squamation on pigment patterns and the presence of a strong, probably hormonal, influence capable of overriding the primary influences. The case of fishes completely devoid of scales presents certain peculiarities which at first sight can be puzzling. All the recent scaleless teleosts have evidently descended from other te1eosts which had scales, so the problem is confined strictly to one of scale loss. It has already been indicated that in fishes with very small scales, that also happen to have patterns, it is difficult to follow scale rows as fully as on fishes with somewhat larger scales. This condition may be at the root of the matter, i.e. that if scales are reduced and the scale pockets with them, the patterns may remain long after the scales have vanished. It is conceivable that this might be all there is to it, which is the same as saying that unpatterned scaleless fishes were derived from scaled ancestors that were unpatterned. However this would require that patterned scaleless fishes were derived from patterned ancestors. It is entirely possible that some cases were derived in just this manner, but there are valid indica­ tions that scaleless fishes, in other instances, developed patterns after they had lost their scales. The various groups of patterned eels such as members of the Muraenidae, Echidna nebulosa, E. zebra, E. catenata, Gymnothorax undulatus, G. ocellatus, Channomuraena vittata and of the Ophichthidae, Leiuranus semicinctus and Ophichthus ocellatus and the patterned catfishes, such as members of the Pimelodidae, Microglanis poecilus and Sorubim lima, of the Mochokidae, Synodontis nigriventris and of the Callichthyidae, Corydoras rabauti and C. arcuatus surely did not develop individually from similarly patterned and scaled ancestors. The development of patterns on scaleless fishes might well be based on residual dermal influences responsible for the original location of scales even after the ability to form scales is lost. Most of the patterned scaleless fishes show designs, frequently irregular, that would seem to be derived from primary patterns, but often with a considerable loosening of regularity, to various degrees, suggesting that the dermal influences alone are not as restrictive as they are when accompanied by scale pockets. Two species of Corydoras, of the Callichthyidae, have markings that evi­ dently belong to the secondary patterns. This group of catfish is no longer naked but has large dermal plates which are evidently not derived from ordinary teleost scales. In C. rabauti there is a broad band forming an arc, reaching from the dorsal origin to the caudal peduncle, that is concave up- 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 47 wards. In C. arcuatus a similar band, which continues forward to run through the eye, is convex upwards. Neither shows any indication of being related to the imbrication of the dermal plates. Most of the other armored catfishes of the Loricariidae, have patterns related to their similar coarse armoring. Probably the most satisfactory way to look at this matter is to provisionally consider it only from the standpoint of the survival value of patterns. A pat­ tern of great survival value would be expected to be retained following great reduction of or the loss of scales. A pattern of scant value could either be lost completely or even transformed to a very different pattern, with the constraints of the scales absent. Variations on this theme could easily be supposed to account for any of the patterns mentioned above but much more basic information is needed before the details of operation could be elucidated.

PATTERN ON HEAD AND FINS. Although this paper concerns itself only with body patterns and their relation to squamation, it is necessary to consider the patterns on the head and fins to the extent, at least, of how one may influence the other. In many fishes the patterns on the head and fins appear to be an extension of the body pattern. In some fishes, fins that are ordinarily almost entirely transparent, may become highly colored during the reproductive sea­ son, often red. The male only may be so affected, or both sexes may be, in which case the male is normally the more intensely colored. Nearly always it is the vertical fins that show these responses. The head is less apt to be differentially affected than the fins, but those patterns of the body which con­ tinue on the head become variously distorted, evidently largely determined by the architecture of the skull, chiefly because of the orbits, the opercular mechanism and the jaws. In cases where there are marks on the head that seem discordant with the body pattern, they are usually associated with frontal display, a matter discussed in considerable detail by Barlow (1967). If a black band runs through each eye, it makes the eyes less evident and if in combination with other head marks the whole may act as a general camouflage. In some cases the body pattern runs over the fins with seemingly no regard for their structures. A fine illustration of this type of pigmentation is seen in Brachydania reria, where four longitudinal, straight, blue lines parallel the body axis from the gill cleft to the end of the tail. The highest one is inter­ rupted by the downward curving of the dorsal profile toward the rear, but begins again on the upper caudal lobe, cutting across the tip, still nearly parallel to the second line. The rather long anal fin carries three similar lines, which are not quite parallel to those on the body. The uppermost of the anal fin lines is interrupted by the end of the fin and begins again cutting across the lower caudal lobe in a manner identical to the way the upper body line cuts across the upper lobe. The head in this case is not involved in the striping. 48 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I,No. I

Goodrich and Nichols (1931) removed the anal fin of such a fish, cutting so as to remove each of the three blue lines, but not to damage the base of the fin rays.23 As the fin regenerated three blue lines appeared in the positions that those removed had held. It should be noted here that these lines, in the erected fin, cut across the numerous fin rays at an angle not exactly 90°. Cellular biologists have developed a considerable mass of information on the origin, development, physiology and movements of vertebrate pigment cells. These matters, while clearly related, are not directly helpful to present con­ cerns, although various patterns on fishes have been examined genetically and by the methods of experimental embryology. It has thus been demonstrated that the location and types of chromatophores are, to a considerable extent, deter­ mined by their genetic constitution. The influence of the positions of the pig­ ment cells on the fish, the nature of the adjacent tissues and hormones con­ tribute heavily to the structure of the observed patterns. Alterations of the kind and location of pigment cells can be induced by a great number of both extrinsic and intrinsic influences, the most radical being those hormonally in­ duced. The early fixation of chromatophore types and positions in the integu­ ment, such as shown by Goodrich (1935) supports these ideas. Caldwell and Caldwell (1962) indicate that drastic alterations of the pat­ terns of the prejuveniles of fishes that have a marked metamorphosis, often accompany an abrupt change of environment. This change of habitat is most evident in those marine fishes that have planktonic larvae and is accompanied by what appears to be strong migrations of the melanophores. Evidently these pattern changes are more marked on the fins than on the body.

MOIRE EFFECTS. Moire fringes appear under many guises, where repetitive patterns overlay one another under certain positions of orientation. Evidently only two types could have any relevance to present considerations: the type that occurs where a set of parallel lines overlays another or where sets of small dots lie in an equivalent manner. One type of dot pattern, Fig. 3, has been discussed earlier in connection with the deployment of scales. Patterns of lines forming a mesh, such as on a graph show moire fringes, providing that the angles between the crossing lines are under a certain magnitude, something less than 45°, and that the lines in each set are repetitive according to some regular relationship and are so spaced and have a width that makes them prominent.24 Since intersecting scale rows are often attended by pigments emphasizing the free edges on other parts of the scales, it is necessary to consider the possibility of moire patterns being generated on the sides of fishes.

23 . Damaging the base of these rays prevents normal regeneration or destroys its possibility altogether, depending on the amount and kinds of tissue mutilated. 24. Guild (1956) presents a lucid discourse on the mathematical and physical bases of moire fringes and Oster (1965 and 1968) gives well illustrated introductions to the subject. 19721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 49

A variety of recent fishes have an angle of 45°, or less, between the crossing scale rows on their sides, such as M ega lops, Lachnolamus maxim us, Poecilia (Libestes) reticulata and Lucania parva. These angles are very little below 45°, and none of these or other species seen have the requirements for the occurrence of moire effects. If moire fringes were present they would appear as longitudinal lines, 'L', since the moire fringe, in such a case, shows as a line parallel to the axis of the fish. Furthermore all longitudinal lines of this sort on fishes are seen to be special deposits of pigment with no other pigment lines that could have been combined with them to form fringes. There is the possibility that there is a stricture of selection preventing the development of a moire effect in this manner. There are, however, situations in which the development of the moire effect might seem to be fulfilled. For instance there are fishes which have a bold meshwork of pattern and a bold lateral-streak appearing together or as al­ ternates, as is discussed in the section on primary patterns. Of course any normal moire effect would have parallel lines developed through each set of appropriate intersections. A superficial resemblance to this condition is seen in Poecilia (Mollinesia). However these lines are due to additional pigment tracts. The similarity of chromatophore patterns to those of halftone elements has been noted earlier. It so happens that color halftones present the problem to printers of preventing the appearance of unwanted moire fringes. Where one color is printed over another, the two plates must be oriented so as not to have such a fringe appear. The effect is striking and can ruin an otherwise perfectly printed color picture. In the printing problem both colors are essentially in the same plane, but on the sides of a fish the problem is more complex. In the integument the chromatophores are not necessarily in the same plane and may be separated by as much as the thickness of the dermis. This small, or even a smaller, distance could set up a parallax system. With it the appearance of the surface may be radically altered by exceedingly small changes in the relative positions between the observer's eye and the fish. Changes of this kind could be startling and sometimes spectacular. Such occurrences would nullify whatever reduc­ tion of visibility the chromatophore pattern provided, or if the pattern were one of social or other signal significance such changes could introduce con­ fusion. It is true that very rapid pattern and color changes are found in many fishes but, in all cases known, they are under the direction of the fish's nervous system and not dependent on the incidental positions of the viewer. Moire fringes of the kinds described have not been seen in fishes and the inference is that such conditions are eliminated by selection. The distribution of chromatophores is clearly not sufficiently random to insure a great reduc­ tion of the chances of formation of moire fringes. If the two or more dot systems are in the same plane they may be arranged in reference to each 50 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol.l,No.l other so that the fringes do not form, which is just what printers do. For the printers this is a somewhat critical matter of adjustment, but in fishes it is conceivable that a moire fringe would have such a large selective dis­ advantage that it would be very promptly eliminated. Printers do not have the problem of fringe production by layers of dots in more than one plane, which in fishes would probably be even more rapidly eliminated, because of its greater eye-catching effects. Chromatosomes present another matter, for here there are two chromato­ phores precisely one over the other. The outer one, usually a melanophore, is over an iridiophore, often brilliant blue. These are so close together that the parallax problem does not exist and the blue increases only as the melanin is concentrated. These details do not support the idea that any fish may have brought the ef­ fects of moire fringes into any kind of either camouflage or signaling device. Therefore until some fish turns up with moire fringes on it, there is no reason to believe that any fish is equipped to be able to turn moire patterns into a utilitarian device. On a much smaller scale the plate-like crystals of guanine found in iridio­ phores do certainly produce their vivid brilliance and color by some structural means. If any of these structures operate on a grating principle they have to have rulings as small or smaller than those of a diffraction grating in order to produce the observed effects, a matter not pertinent to this communication. 1972) BREDER: TELEOST SCALES AND PIGMENT PAlTERNS 51

FUNCTIONS OF PATTERNS

The functions that chromatophores perform relative to pattern building are all in the area of visual communication. Those that serve to reduce visibil­ ity of the wearer may be considered negative and those that serve to increase the visibility of the wearer may be considered as positive.

NEGATIVE FUNCTIONS. A pigmentary display in which the color and tone approach that of the general background against which the fishes are usually seen is within the ability of most of the fishes of the taxonomists' Division I and II as well as many of those of Division III and is considered negative. The fishes of the first two divisions have no, or comparatively little, distinct pattern and are mainly drab, in grays, dull greens or browns which are the colors most likely to match aquatic backgrounds. In Division m this condi­ tion carries through the superorders Protacanthopterygii, Ostariophysi, Para­ canthopterygii and Atherinomorpha, the number of drab species decreasing more or less regularly to the Acanthopterygii in which few species merely match the tone of the background. See for instance Parker (1948), Breder (1947b), Breder and Rasquin (1951) and their bibliographies. Along with the drab colors there appears the silvery integument provided by guanine, which in its simple fonn acts as a reflecting surface permitting the fish to automatically take on the appearance of its surroundings. These effects facilitate escape and hiding, but are not efficient for social or other signaling.

POSITIVE FUNCTIONS. Pigment patterns which tend to make a fish more conspicuous than it would be without them appear most frequently in Division m, where they are sometimes carried to extremes. No fishes phylogenetic ally earlier than some of the brilliantly colored and complexly patterned eels can be considered other than basically drab. The few strong marks on a very few holosteans and chondricthians make up all the known earlier "attempts" at strong pattern formation and brighter colors. Patterns and striking colors that make a fish more prominent are evidently mainly of utility as social or sexual signals. At least no other plausible sig­ nificance has been demonstrated for them. There is a considerable literature, mostly at the hands of animal behaviorists, that demonstrates the effectiveness of such marks and colors. Barlow (1963) described in great detail the extent and complications of pattern and color changes shown by Badis badis in­ volving primary patterns.

RELATIONS OF NEGATIVE AND POSITIVE FUNCTIONS. Because of the natural antagonism of the positive nature of some patterns and the negative nature of others there are many complex interrelations between these aspects, some groups largely sacrificing one in favor of the other. It appears that the more primitive forms, in which the emphasis is so largely placed on the reduction 52 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I,No. I of visibility, may be associated with somewhat less complex nervous and endocrine systems. It should be recalled that both prey and predators can play the invisibility gambit to their own advantage. Also to be noted is that the most brilliantly patterned and colored fishes are not noted especially as predators, being more usually grazers and feeders on small items, while the drabber, predator types, such as sharks and Sphyraea, are able to tackle much larger prey, in proportion to their own size. This obviously can have only statistical validity as there are a number of exceptions. Notable exceptions are found in the Antennariidae, where Histrio matches its Sargassum habitat with bold irregular markings of brilliant white and black on a yellow ground color. Antennarius may be solid chrome yellow, bright green or dull red when found in matching association with yellow sponges, green algae or red sponges. In these cases background simultaneously serves the individuals in their status of being both predators and prey. These pigmentary conditions also vary with the developmental stages of many species. In this study the adults have been given chief consideration, partly for simplicity but more especially because so little is known in detail, that could be used in the present connections, about the young stages of most fishes. Unfortunately the more familiar species lack striking pigmentary changes in their larval and post-larval stages. They nearly all show little more than the expected melanophore reactions to background and develop directly by gradual stages to the adult type of pattern.25 Other fishes, usually not well suited to culture in confinement, often have elaborate changes of pattern occurring between the post-larval stages and the terminal adult form, such as in the case of some of the species of Exocoetidae, Serranidae, Pomacentri­ dae and Chaetodontidae. Many of these pass through elaborate patterns which are entirely different from the final one. It should be instructive to have data on which factors in the behavior and environment are associated with these pattern differences, as would also be a detailed study of the manner in which one pattern is transformed into another. The latter is of course more acces­ sible, if a series of many stages of a given species is available, for preliminary study in the present frame of reference.

PHYLOGENY OF PATTERNS. It appears that there has been a general trend, from the primitive fishes to the more specialized acanthopterygians, toward more complex patterns and brighter colors, which evidently follows the in­ creasing complexities of the nervous and endocrine systems. The classification of squamation types and pattern types here presented is to be considered a first attempt to bring some order to this area of study. Patterns and colors, that are both so intimately keyed to the optical properties of the environment, produce an abundance of parallelisms and other modifica-

25. Parker (1948) gives a useful account of the early distribution of melanophores, their origin and migrations and of the onset of background responses. 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 53 tions that amplify difficulties in interpretation. It would not be appropriate to here attempt a thorough examination of a single group, or several, of familial or ordinal rank:. Obviously such an undertaking would involve much time and effort and could not be undertaken lightly. It should include studies covering both scale and pattern structure of the kinds herein discussed, pig­ mentary and other behavior of the species involved and study of the environ­ ment in which the fishes actually are found and in which ones they could be expected to survive, or fail to survive, on a basis of the functioning of their pigmentary equipment. Given the geometrical conditions herein described, it follows that selection must operate within the limits of these primarily physical parameters, which are not necessarily confined to organic structures, but are based on the nature of the constraints on surfaces. Departures from the primarily geometric condi­ tions evidently may be considered a measure of the amount of selection in­ volved in their production. The effect of the pattern on a viewer necessarily varies with the clarity with which it may be seen. For instance, if a fish had a simple mesh of melano­ phores, 'C and R', it could signify one thing to a very good eye, and brain, in clear water and something else in turbid water to the same eye, or to a poor eye, even in clear water. Distance of viewer to fish determines whether a pat­ tern is seen as such or as a mere general tone, a possibly vital point on the "grain" of the pattern, quite similar in principle to the kind of screen used in making a halftone and its consequent dot size. Also color would mean much less in turbid water or to a viewer that had no or little color vision. The evidence indicates that color vision in fishes did not become general much before the advent of the teleosts, possibly at about the time there appeared other pigments besides melanin. This would be consistent with the idea that the simpler primary patterns and scale conditions are not necessarily as adap­ tive to present times as are the secondary complex patterns. Also it would explain why simple patterns are so widespread throughout most groups while the complex ones are more restricted. Although the phyletic lines are not sharply distinct, there appears to be an increasing ability to handle a greater variety of pigments in the more advanced fish species than there is in the primitive forms. See Fox (1957) and his bibliography. It should be noted that the earlier fishes have embryos and young which usually have only melanin, such as Clupea, Coregonus and Menidia, while the later types very often have other chromatophores before the egg is hatched, as in Spheroides. If fish pigmentation began as a uniform distribution of pigment-bearing cells, counter-shading, that is, lightening of the underparts, could begin on a basis of selection with the first fish to swim free of the bottom. If pigmentation began as an irregular spotty process, for instance as a response to irritation, the pattern could appear almost simultaneously. Since the folding and other 54 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No. 1 modifications of the dermal layer could be thought of as a possible basic irrita­ tion, the presence of pigmentation in the sites of the greatest dermal modifica­ tion could be used to support the idea that irritation was one of the sources of integumentary pigmentation in vertebrates. 19721 BREDER: TELEOST SCALES AND PIGMENT PATTERNS 55

PATTERNS AND SYSTEMATICS

Although this study is limited to the relations between the scales and pat­ terns of teleosts, other groups are briefly mentioned here for purposes of com­ parison. Under each heading a brief consideration is given to the common or typical pattern of that group, with notes on exceptional or aberrant patterns. It must be understood that only the main trends in the association of patterns with phylogeny can be discerned at present. Also that the large number of small branches of the teleost phylogenetic tree produces many independent evolving series, many of which show remarkable parallelisms. Counter-shad­ ing is not considered part of the pattern, nor are minor variations at the base of fins, nor patterns on fins, for reasons given earlier. Because of the labile nature of many of the pigments and the demonstrable effects of environment on the patterns and colors of fishes it is to be expected that phylogenetic in­ fluences would be displayed in a complex and sometimes cryptic manner. In using this section it should be remembered that what have been called 'Pri­ mary patterns' hardly ever completely disappear, even when accompanying the most advanced 'Secondary patterns'. This section and the taxonomic list following contain a sampling of the conditions found from the primitive to the more advanced fishes and is not intended to be exhaustive. The classification of Greenwood et aI. (1966), as modified by Rosen and Patterson (1969), has been followed for the teleosts. Taxa that are not mentioned are those which do not have definite pigment patterns and are restricted to areas where daylight does not reach, as in caves or the abyssal portions of the oceans, or are small groups whose mention here would contribute nothing of significance. Most of the fish names present in this section have not been already mentioned. Nearly every popular and many technical books on fishes that make any mention of their patterns or colors cite and usually illustrate some of the more striking cases of what are here called 'primary' and especially of 'second­ ary' patterns. See, for instance, Norman (1947), LaGorce (1952) and Herald (1961). The latter two contain many photographs, some in color which are adequate to illustrate many of the pattern effects here discussed.

AGNATHA All forms are apparently either of uniform dark pigmentation as in the Myxiniformes or are of uniform light, usually tannish pigmentation or are mottled irregularly as in the Petromyzontiformes. All are naked.

CHONDRICHTHYS Both the Squaliformes and the Rajiformes are mostly of uniform or nearly uniform coloration, usually brownish or gray, but the off-shore non-bottom species may be blue. However, the sharks embraced in the Lamnidae, Orectolobidae, Rhinodontidae and Scyliorhinidae, have some members that 56 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No. 1 have pronounced and various patterns. Exceptions in other groups are few, scattered and generally the markings are vague and not very well organized. The rays have patterned members in every order. While all sharks are covered with small dermal denticles, the rays vary from naked to various de­ grees of coverage by usually large dermal dentic1es. One of the most strikingly marked elasmobranchs is Raja texana. It has a single large ocellus on each wing. They have deep blue centers, surrounded by narrow black rings and outer yellow rings. Others with less striking ocelli, similarly located include R. radula, R. miraletus and R . naevus which has dark ocelli-like spots, but with the central areas showing light vermiculations. Narcine brasiliensis is profusely spotted with light brown areas on a tan background, with dark brown dots around the periphery of the brown spots, almost forming ocelli. The Chimaeriformes are naked and are usually silvery, with sometimes dark markings, as in Hydrolagus colliei which is silvery, vaguely mottled with darker cloudings. OSTEICHTHYES Sarcopterygii Both the living Crossopterygii (Latimeria) and the Dipnoi are without distinct patterns of pigment cells. The first is reportedly bluish and the second, comprised of three genera, runs from greenish-brown to slaty-gray. Lepidosiren and Protopterus sometimes show random black patches owing to dense con­ centrations of melanin, but not forming a pattern. These two genera have small imbedded and mostly non-imbricated scales, but Neoceratodus has large scales which resemble those of teleosts.

ACTINOPTERYGII Neither the Acipenseriformes nor the Polypteriformes show definite pig­ mentary patterning. The Acipenseridae are "decorated" with large bucklers, but pigmentary decorations are absent or vague, while the Polyodontidae are of uniform color and are naked except for some vestigial imbedded denticles. In the Polypteriformes all are covered with heavy articulated rhomboid ganoid scales. Here pigmentary spots, little differentiated and scarcely definite enough to be considered as distinct patterns, may be traced following scale rows. HOLOSTEI Semionotiformes Some Lepidosteids are uniformly colored but others carry large dark spots on their sides. Some of these appear to be lined up with scale rows, for short distances, while others seem to lack this association. 1972) BREDER: TELEOST SCALES AND PIGMENT PATTERNS 57

Amiiformes Here pattern on the sides is absent, although the males have an often bold ocellus on the caudal base, the earliest case in fishes where pigment forms a prominent part of secondary sex differentiation. The nearly black center of the ocellus typically covers a patch of 8 to 10 scales. It is surrounded by a light, sometimes yellowish, ring that is only about one scale wide. There is a certain raggedness to the ocellus because both the center and the surrounding ring are confined nearly entirely to the total areas of the various scales oc­ cupied. The scales more nearly resemble those of the teleosts than do the scales of any of the preceding forms.

TELEOSTEI Division I Elaborate pattern is not characteristic of this division. The dominant in­ tegumentary coat is silver. Guanine is there deposited in the form that does not produce vivid interference colors, but is in the nature of a general reflective layer, as is seen most characteristically in the Elopomorpha and the Clupeo­ morpha. In the latter some members of the Clupeidae have one or more scapular spots and in the Engraulidae many species have a broad lateral stripe and most in both families have rather large scales sometimes approaching those of the Elopomorpha. In the Anguilliformes, Anguilla runs from greenish or yellow gray to black in fresh water, but becomes silvery in sea water. The permanently marine forms may be drab or bright in one color without any definite pattern, tan, as in Conger oceanicus, or the normally green Gymnothorax funebris. 26 Others have strong patterns in very contrasting colors, as in Muraena retifera or Echidna catenata. All these brightly colored and strongly patterned eels are resident in brightly illuminated waters. AlI are naked except the Anguillidae which have rudimentary and non-imbricated scales.

Division II The fishes of this division do not differ greatly from Division I in pigmenta­ tion. However Division II lacks entirely any species as colorful or as clearly patterned as some of the Anguilliformes. In the Osteoglossamorpha, the Osteoglossidei show several silvery forms. Osteoglossum bicirrhosum is as silvery as MegaZops, but Arapimia is rather plain brown or greenish brown. Pantodon has a sketchy pattern of irregular dark markings and Notopterus is usually brownish. Hiodon is silvery and herring-like. The Mormyriformes show some species nearly plain silvery, but most are vaguely marked darkish little fishes with no very striking patterns.

26. A notable singularity of this species is that the yellow component is not found in chro­ matophores but the pigment is carried in the surface mucus, removal of which reduces the fish to a bluish-gray, 58 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No. 1

Division III This division, which contains the remaining teleosts, is highly diversified in many respects, including both pattern and coloration. The numbers of taxa, from superorders to species, are many times more numerous than those of Divisions I and II taken together. For these reasons the superorders in Division III are all treated separately. The Protacanthopterygii display various pigmentary conditions. In the Salmonoidei many groups are almost entirely plain silver, e.g. the Coregonidae and Argentinidae. If living in sea water the genera Onchorynchus, Salmo and Salvelinus are normally silvery, but if living in fresh water these may show various patterns of spots and vermiculations, some of which may be very bright, as the red spots on some species of Salvelinus. This makes the group one of the earliest to show such brightening over the usual drabness of the ancient fish integument. The red spots are often the center of an ocellus, surrounded by a narrow blue ring. The red spots generally cover about three scales and the blue ring about nine, i.e. one scale wide. S. namaycush shows many dark, very irregular spots, most of which cover four to ten scales but do not form ocelli. Males of some species of Onchorynchus show some flushing of pinkish on the flanks during the spawning season, and both sexes of O. nerka have brilliant red bodies, which however do not constitute a pattern. The Osmeri­ dae, Osmerus mordax, are usually either nearly uniform silvery or have the scale edge darkening forming a very regular mesh pattern, often associated with a silvery lateral stripe. The Esocoidei are apparently never silvery, but are patterned in various ways, the Esocidae mostly displaying various vermiculations and more or less vague transverse bars. The Umbridae usually display multiple longitudi­ nal lines, brownish and numbering about eleven, but Dallia is vaguely mottled. The Synodontidae tend to have patterns of bands crossing their flattened backs, some with markings resembling those of a rattlesnake. In the Gonorynchiformes, of the Chanoidei, the Chanidae are virtually pat­ ternless, silvery and superficially resemble the pigmentary conditions in the Elopiformes, Clupeomorpha and Argentinidae. The Ostariophysi present some silvery species reminiscent of the Clupeo­ morpha and Elopiformes. Except for these this superorder shows a large variety of pigmentary patterns in a wide spectrum of colors, often of a bril­ liance not seen earlier, except that some of the Salmoniformes approach condi­ tions in this group. The relatively unpatterned forms are largely confined to the Characoidei, which however contain within their limits some of the bright­ est and boldest patterns in this superorder. This condition it shares with the Cyprinoidei, which has males in the Cyprinidae with strikingly brilliant colors in the spawning season, often in the form of bright red stripes, e.g. Chrosomus 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 59 erythrogaster. A few of the Siluriformes have very bold pigmentary patterns, Microglanis poecilus and Sorubim lima, but none are as gaudy as those men­ tioned above. The majority are dull colored fishes with little or no pattern. The fishes of the Paracanthopterygii are a motley assemblage, few of which are marked with strong patterns and still fewer with bright colors. Strong patterns are scattered, but the majority of the members are rather drab, uni­ colored or with only vague patterns. The Percopsiformes are often marked with longitudinal stripes or trans­ verse bars. The Gadiformes are mostly plain, but Lota, Microgadus and Zoarces are marbled, and various genera have special pigment on the lateral line. Various species of Ophidioidei may be somewhat patterned. The Batra­ choidiformes are often marked with strongly contrasting mottlings, which may be very variable, from one individual to another. The Gobiesociformes are mostly plain but some have patterns of no striking contrasts. The Lophiiformes are usually of solid color, but Histrio, in the Antennarioidei, is normally broadly marbled in contrasting colors. The large group, Acanthopterygii, is the only one in which a notable num­ ber of species and higher groups are marked with vivid and sharply contrasting patterns, of the type here designated as secondary. In the Atheriniformes, the members of the Excoetoidei are usually rather plain bodied, except that the genus Hemiramphus and closely related genera may have vertical bars, especially in the young. The same is true of some of the Belonidae. The flying fishes run to plain sides with patterns confined to the wings which in the young may be ornately mottled and colorful. This group is more uniform in the general plan of their patterns than in many of their other features. Meshes of 'c' and 'R' lines are especially prominent in Hemiramphus and related genera. The Cyprinidontoidei also often show transverse bars. In the Cyprinodonti­ dae and Poeciliidae, the occurrence of the 'C' and 'R' meshes is especially prominent. Multiple longitudinal lines are marked in Poecilia ( Mollienesia) latipinna. Complex and various colors decorate many males and in some the males and females are distinctly different, as in lordanella floridae. A peduncular ocellus marks the females of Rivulus in a variety of species. The males of Fundulus majalis have crossbars on their sides while the females have longitudinal lines. In one color phase Fundulus heteroclitus has a light spot on each side just where the scale emerges from under the overlying scales anterior to it. This spot is followed by a broad band of dark pigment, the width of which reaches from the spot to nearly the scale's rear edge, where it is replaced by a very narrow line devoid of pigment cells. F. diaphanus has narrow transverse lines. Leptolucania ommata shows a longitudinal streak, replaced in the male by transverse bars, from the origin of the dorsal fin to the caudal ocellus, a seeming combination of three pattern elements, seen individually in other cyprinodonts. 60 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol.l,No. !

In the Atherinoidei, the Atherinidae, except for the 'C' and 'R' meshes, are usually marked by little more than a single longitudinal stripe, but in the Melanotaeniidae multiple longitudinal stripes appear. The Lampridiformes are mainly deep water silvery fishes with a tendency to bright red decorations, notably in the Lampridae with red spots on a silvery ground color. The Beryciformes and Zeiformes are not among these highly patterned groups. Those that live in the higher illuminations mostly have simple pat­ terns, such as longitudinal stripes, as in the Holocentridae, or vertical bars if anything, as in the Zeidae. Ostichthys japonicus is silvery, vaguely mottled with darker cloudings. Myripristis jacobus has a nearly vertical black bar just back of the operculum, which appears as an elongate scapular spot. The Gasterosteiformes comprise a curious assemblage of fishes mostly of solid colors, chiefly in browns, although some have bright colors and delicate patterns. In the Gasterosteoidei the males of several species of the Gastero­ steidae show vivid red flanks during the breeding season. Some of the Aula­ stomoidei are marked with fine blue lines as in the Fistularidae. In the Aulostomidae there are somewhat similar patterns, of longitudinal lines and transverse bands as well as spots that are less colorful. In both cases the pattern and colors are subject to rapid change in reference to background. The Syngnathoidei may show individuals of a usually brownish species with background related colors; bright red, green or yellow in the Syngnathus and Hippocampus. All may have lines or dots of darker or lighter colors. The Channiformes, including only the Channidae, are normally covered with a rather complex arrangement of light dots and irregular cross bands, all clearly following scale arrangement in an unusual pattern. The Symbranchiformes are mostly uniformly colored, sometimes with speckIings or mottlings, and may have a dark lateral line. The Scorpaeniformes contain a variety of both drab and colorful species which are so various that the details could not properly be characterized in this brief list of principal pattern types. The Dactylopteriformes, covering the single family Dactylopteridae, are very brightly colored, with brilliant blue lines on fins but not on the body, which usually shows dull longitudinal stripes. The Pegasiformes are brownish drab, with only vague patterning, super­ ficially resembling the less colorful examples of the syngnathids. The Perciformes comprise a huge and highly diversified assemblage that defies a general simple statement covering the whole group that would be meaningful in present connections. The Percoidei, the largest suborder of this group, itself is a large assemblage of diverse families, the patterns of which greatly differ. These families range from the Serranidae, through the Carangidae, Chaetodontidae, Embiotocidae, Pomacentridae and its associated families, including a total of seventy-one families, in the classification fol- 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 61 lowed here, which is a considerable reduction of the number of families recognized in earlier lists. The Serranidae alone include fishes of virtually no pattern or one of mul­ tiple longitudinal lines following scale rows, as seen respectively in Roccus americanus and R. saxatilis, to complex patterns subject to rapid changes in both form and color, as seen in Ephinephelus and its close genera. Most of the other families within the Percoidei show patterns which are generally more consistent within familial limits, but with exceptional genera or even species occurring unexpectedly throughout the group. For instance most of the Gerridae are silvery, with little or no pattern, while Diapterus plumeri has multiple scale-row-following lines. In the Theraponidae, T. jarbua shows a pattern of concentric lines centered on the midpoint in the arch of the back which certainly is not aligned with scale rows. It would seem that these were once longitudinal stripes following scales. This would then seem to be a case where the escape from the scale row alignment had been made and possibly represents a transitional stage to a very different pattern. It is within this group that the secondary patterns bloom out to their greatest display, with numerous families, such as the Chaetodontidae, Pomacentridae, Labridae and Scaridae, composed almost entirely of brilliant and gaudy pat­ terns and the many other families partly composed of such fishes, with the remainder usually rather drab or neutral, a condition found in the Balistidae and Tetraodontidae. The above items are mentioned here to indicate that it is in this group (the Percoidei) that the beginning of a substantial separation of pigmentary pat­ tern from scale row influence has begun. For this reason it is no longer pos­ sible to even roughly try to present data in the orderly list that sufficed in the earlier groups. In the Chaetodontidae, for example, not only are the secondary patterns visually prominent, but in various species the young show striking patterns of concentric lines which gradually transform to diagonal, more or less wavy lines which do not follow scales any more than do the juvenile patterns, as for instance in Pomacanthus imperator and Pomacanthodes annularus. In some others the adults lack lined patterns and may be mostly solid colored or spotted as in Pomacanthus striatus, semicirculatus, arcuatus and aureus, Holocanthus clarionensis, isabelita and ciliaris. See Fraser-Brunner (1933, 1951) for details on some of these changes, all of which apparently take place slowly. The sharp line demarking the black portion of Holocentrus tricolor from the yellow anterior part definitely does not show the scale-limited ir­ regular edge, but cuts across scales. Both melanic and xanthic pigment cells are on the under sides of the scales in the pocket dermis. In the Pomacentridae some or all of the lines of sharp demarcation of the broad colored bands in Amphiprion follow 'r or 'R' rows as in A. percu/a 62 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vo!. 1, No.1 and A. sebae. In the larger scaled forms such as Abudefduf saxatilis and Eupomacentrus leucostius transverse bands follow the 'T' series of scales. This is entirely evident in the first, but in the second genus the scale rows involved might superficially be thought to be 'R' because the 'T' row "leans" so far as to make such a confusion possible. The Pleuronectiformes are comprised of fishes with scales that are usually small in respect to pattern size and consequently their patterns, so changeable in respect to their backgrounds, are typical of other groups with a naked or small-scaled skin. The flounders that have slightly larger scales have the diagonal network type of patterns 'CR', as in Citharichthys sordid us and Etropus microstomus. In the Balistidae some of the patterns follow certain scale rows, as in Balistes bursa, but in others most do not, as in B. aculeatus or BaUsteoides niger. In Monacanthus ciliatus, which is a rather drab fish, patches of dark pigment seem to be independent of the tiny specialized scales. Although many species of ostraciontids have a spot centered on each six­ edged scale, others, such as Lactophrys trigonus have spots mostly indepen­ dent, but often along the edges of the hexagons although some may be cen­ tered. L. quadricornis has its spots so run together as to form vermiculations. In Spheroides spengleri the spine-like scales are evidently too small to inter­ fere with the pattern of spots. In Chilomycterus schoepfi there is some inter­ ference between the large spine-like scales and the pigment lines. In many cases the dark lines bifurcate as they seem to avoid a spine by passing on both sides of it, moving caudad. At other places on the same individual a dark line may run from spine to spine, so that the latter appear merely to punctuate the line. 1972] BREDER: TELEOST SCALES AND PIGMENT PATIERNS 63

SYSTEMATIC LIST OF SPECIES This list contains all the generic and specific names used herein and the higher taxa to which they belong. The authorities for the specific names are also given. This treatment is intended to simplify comparison of the pattern conditions in related forms and to serve as a ready reference between the preceding systematic section and its antecedent parts describing the nature of the patterns.

PRE-TELEOSTEI

AGNATHA Myxiniformes

Petromyzontiformes

CHONDRICHTHYES Squaliformes Lamnidae Orectolobidae Rhincodontidae Scyliorhinidae

Rajiformes Rajidae Raja texana Chandler radula Delaroche miraletus Linnaeus naevus MiiUer and Henle Torpedinidae Narcine brasiliensis (Olfers)

Chimaeriformes Cbimaeridae Hydrolagus collie; (Lay and Bennett)

OSTEICHTHYES Sarcopterygii Crossopterygii Latimeria

Dipnoi Lepidosiren Protopterus Neoceratodus 64 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vo!. I, No.1

ACfINOPTERYGfI Polypteriformes Polypteridae Calomichthys

Acipenseriformes Ancipenseridae Polyodontidae

HOLOSTEI Semionotiformes Lepisosteidae Lepisosteus

Amiiformes Amiidae Amia calva Linnaeus

TELEOSTEI

Division I Elopomorpba Elopiformes Elopoidei Elopidae Megalops atlantica Valenciennes AnguilJiformes Anguilloidei Anguillidae Anguilla Muraenidae Gymnothorax /unebris Ranzani nigromarginatus (Girard) undulatus (Lacepede) ocellatus (Agassiz) channomuraena vittata (Richardson) Muraena reti/era Goode and Bean Echidna catenata (Blocb) nebulosa (Abl) zebra Bleeker Congridae Conger oceanicus (Poey) 1972) BREDER: TELEOST SCALES AND PIGMENT PATTERNS 65

Ophichthidae Leiuranus semicinctus (Lay and Bennett) Ophichthus ocellatus (LeSueur) Conger oceanicus (Mitchill)

Clupeomorpha Clupeiiormes Clupeoidei Clupeidae Clupea harengus Linnaeus sirm (Walbaum) Brevoortia tyrannus (Latrobe) Pomolobus sapidissima (Wilson) Dorosoma cepedianum (LeSueur) Engraulidae Anchoa

Division II

Osteoglossomorpha Osteogliformes Osteoglossoidei Osteoglossidae Ostoglossum bicirrhosum Vandelli Arapaima Pantodontidae Pantodon Notopteroidei Notopteridae Notopterus Hiodontidae Hiodon Mormyriformes

Division III

Protacanthopterygii Salmoniformes Salmonoidei Salmonidae Oncorhynchus nerka (Walbaum) Salmo lario (Linnaeus) Salvelinus lontinalis (Mitchill) namaycush (Walbaum) 66 CONTRmUTIONS FROM THE MOTE MARINE LABORATORY [Vo1.I,No.1

Thymallus arcticus (Pallas) Coregonus Osmeridae Osmerus mordax (Mitchill) Argentinoidei Argentinidae Esocoidei Esocidae Esox americanus (Gmelin) niger LeSueur vermiculatus LeSueur Umbridae Dallia Myctopbiformes Myctophoidei Synodontidae Gonorynchiformes Cbanoidei Cbanidae

Ostariopbysi Cypriniformes Characoidei Gasteropelecidae Carnegiella marthae Myers Anostomidae Leporinus fasciatus (Bloch) Cyprinoidei Cyprinidae Cyprinus carpio Linnaeus Carassius auratus (Linnaeus) Phoxinus phoxinus (Linnaeus) Rhodeus sericeus (Pallas) Notemigonus crysoleucas (Mitchill) Brachydanio rerio (Hamilton-Bucbanan) Notropis bifrenatus (Cope) hudsonius (Clinton) cornutus (MitcbiU) umbratiUs (Girard) whipplei (Girard) Clinostomus funduloides Girard Pimephales notatus (Rafinesque) Chrosomus erythrogaster (Rafinesque) 1972) BREDER: TELEOST SCALES AND PIGMENT PATTERNS 67

Puntis hexazona (Weber and de Beaufort) Labeo dussumieri (Valenciennes) fisheri Jordan and Starks Cobitidae Botia macracanthus (Bleeker) Catostomidae Hypentelium nigricans (LeSueur) Ictiobus cyprinellus (Valenciennes) Minytrema melanops (Rafinesque) Siluriformes Ictaluridae Siluridae CJariidae Mochokidae Synodontis angelic us Schilthuis nigriventris David Pimelodidae Microglanis poecilus Eigenmann Sorubim lima (Bloch and Schneider) Cal1ichthyidae Corydoras rabauti La Monte arcuatus Elwin Loricariidae

Sc opel omorpha Myctophiformes Myctophoidei Synodontidae Synodus foetens Linnaeus

Paracanthopterygii Gadiformes Gadoidei Gadidae Gadus morhua Linnaeus Lota Iota (Linnaeus) Melanogrammus aegelfinus (Linnaeus) Microgadus tomcod (Walbaum) Pollachus virens (Linnaeus) Urophycis regius (Walbaum) chuss (Walbaum) Zoarcoidei Zoarcidae Zoarces 68 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1

Batrachoidiformes Batrachoididae Gobiesociformes Gobiesocidae Lophiiformes Antennarioidei Antennariidae Antennarius Histrio histrio (Linnaeus) Acanthopterygii Atheriniformes Exocoetoidei Exocoetidae H emirhamph us Chriodorus atherinoides Goode and Bean Cypselurus Belonidae Cyprinodontoidei Cyprinodontidae Cyprinodon variegatus Lacepede Fundulus heteroclitus (Linnaeus) majalis (Walbaum) diaphanus (LeSueur) lordanella floridae Goode and Bean Lucania parva (Baird and Girard) goodei Jordan Leptolucania ommata (Jordan) Cynolebias bellottii Steindachner Rivulus marmoratus Poey uropthalmus Gunther Poeciliidae Poecilia (Lebistes) reticulata Peters (Mollienesia) latipinna (LeSueur) Xiphophorus variatus Meek Atherinoidei Melanotaeniidae Melanotaenia Atherinidae Membras Menidia beryllina (Cope) Lampridiformes Lampridoidei Lampridae 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 69

Beryciformes Berycoidei Holocentridae Holocentrus rufus (Walbaum) ascensionis (Osbeck) xantherg/hrus Jordan and Evermann Os/ich/hys japonicus (Cuvier) Myripristis jacobus Cuvier Holotrachus lima (Valenciennes) Zeiformes Zeidae Gasterosteifonnes Gasterosteoidei Gasterosteidae Aulostomoidei Aulostomidae Fistularidae Syngnathoidei Syngnathidae Syngnathus Hippocampus Channiformes Channidae Synbranchiformes Scorpaeniformes Scorparnoidei Scorpaenidae Sebastodes nebulosus (Ayres) serriceps (Jordan and Gilbert) Pterois voli/ans (Linnaeus) Hexagrammoidei Hexagrammidae H exagrammos Dactylopteriformes Dactylopteridae Pegasiformes Perciformes Percoidei Percidae Emmelichthyidae Centropomidae Centropomus undecimalis (Bloch) 70 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. 1, No.1

Serranidae Cephalopholis fulva (Linnaeus) argus Bloch and Schneider Ephinephelus guttatus (Linnaeus) macrospilos (Bleeker) elongatus Schultz Roccus americanus (Gmelin) saxatilis (Walbaum) Grammistidae Grammistops ocellatus Schultz Theraponidae Therapon jarbua (Forskal) oxyrhynchus (Temminck and Schlegel) caudavittatus (Richardson) Pelates quadrilineatus (Bloch) Eutherapon theraps (Cuvier) Autisthes pula (Cuvier) Helotus sexlineatus (Quoy and Gaimard) Kuhliidae Kuhlia taeniurus (Cuvier) Centrarchidae Lepomis Enneacanthus chaetodon (Baird) Priacanthidae Pseudopriacanthus Apogonidae Apogon stellatus (Cope) Percidae Etheostoma caeruleum Storer flabellare Rafinesque Perea flavescens Mitchill Percina caprodes (Rafinesque) Branchiosteigidae Lopholntilus chamaeleonticeps Goode and Bean Carangidae Nematistius pectoralis Gill Gerridae Diapterus plumed (Cuvier) Eucinostomus gula (Quoy and Gaimard) Pomadasyidae Anisotremus virginicus (Linnaeus) 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 71

Haemulon flavolineatum (Desmarest) plumeri (Lace pede) sciurus (Shaw) Orthopristis chrysopterus (Linnaeus) Plectorhynchus cinctus (Temminck and Schlegel) Lutjanidae Lutjanus analis (Cuvier) griseus (Linnaeus) synagris (Linnaeus) rivulatus (Cuvier) monostigma (Cuvier) johni (Bloch) lineolatus (Riippell) Haplopagrus guntheri Gill Lobotidae Lobotes surinamensis (Bloch) Sparidae Archosargus probatocephalus (Walbaum) Calamus Lagodon rhomboides (Linnaeus) Stenotomus chrysops (Linnaeus) Diplodus holbrooki (Bean) Sciaenidae Aplodinotus grunniens Rafinesque Equetus pulcher (Steindachner) ianceolatus (Linnaeus) Menticirrhus Micropogon undulatus (Linnaeus) Pogonias chromis (Linnaeus) Sciaenops ocel/ata (Linnaeus) Umbrina roncador Jordan and Gilbert Mullidae Mulloidichthys martinicus (Cuvier) Toxotidae Toxotes Kyphosidae Ephippidae Chaetodipterus faber (Broussonet) Piatax Scatophagidae Scatophagus argus (Linnaeus) Chaetodontidae Centropyge bispinosus (Giinther) 72 CONTRIBUTIONS FROM THE MOTE MARINE LABORATORY [Vol. I, No.1

Chaetodon melanotus (Bloch) unimaculatus Bloch tricolor (Bloch) Holocanthus isabelita Jordan and Rutter ciliaris (Linnaeus) clarionensis Gilbert Pomacanthus arcuatus (Linnaeus) aureus (Bloch) imperator (Bloch) striatus (RiippeJl) semicirculatus Cuvier Pomacanthodes annularis (Bloch) Chelmon rostratus (Linnaeus) Microcanthus strigarus (Cuvier) Cichlidae Astronatus ocellatus (Cuvier) Cichlasoma festivum (Heckel) Geophagus brasiliensis (Quoy and Gaimard) jurupari Heckel Hemichromis bimaculatus Gill Prerophyllum scalare (Lichtenstein) Symphysodon discus Heckel Pseudotropheus Nandidae Badis badis (Hamilton-Buchanan) Embiotocidae Amphistichus argenteus Agassiz Embiotoca lateralis Agassiz Hypsurus caryi (Agassiz) Pomacentridae Abudefduf saxotilis (Linnaeus) Eupomacentrus leucostictus (Milller and Trosehel) Amphiprion percula (Lacepede) sebae Bleeker Cheilodactylidae Cheilodactylus gibbosus Richardson Mugiloidei Mugilidae Mugil cephalus Linnaeus Sphyraenoidei Sphyraena 1972] BREDER: TELEOST SCALES AND PIGMENT PATTERNS 73

Polynemoidei Polynemidae Polynemus sextarius Bloch Labroidei Labridae Lachnolaimus maximus (Walbaum) Tautoga onitis (Linnaeus) Thalassoma bifasciatum (Bloch) Scaridae Scarus guacamaia Cuvier Trachinoidei Uranoscopidae Astroscopus y-graecum (Cuvier) Blennioidei Blenniidae Clinidae Callionymoidei Callionymidae Gobioidei Gobiidae Dormatator Bostrichthys sinensis (Lacepede) Acanthuroidei Acanthuridae Acanthurus Siganidae Siganus vermiculatus (Valenciennes) spinus (Linnaeus) Scombroidei Scombridae Scomber scombrus Linnaeus colias Gmelin Katsuwonus pelamis (Linnaeus) Xiphiidae Istiophoridae Stromateoidei Nomeidae Anabantoidei Anabantidae C olisa fasciata (Bloch and Schneider) Macropodus opercularis (Linnaeus) Trichogaster trichopterus (Pallas) 74 CONTRIBUTIONS FROM THE MOTE MARJNE LABORATORY [Vol. I, No.1

Pleuronectiformes Pleuronectoidei Scophthalmidae Bothidae Citharichthys sordidus (Girard) Etropus microstomus (Gill) Bothus lunatus (Linnaeus) Ancylopsetta guadrocellata Gill Pleuronectidae Soleidae Zebrias japonicus (Bleeker) zebrinus (Bleeker) Cynoglossidae Tetraodontiformes Balistoidei Balistidae Balistes capriscus Gmelin vetula Linnaeus bursa (Lacepede) Balistoides niger Bonnaterre Balistopus undulatus Park aculeatus (Linnaeus) Alutera scripta (Osbeck) Monacanthidae M onacanthus ciliatus (Mitchill) Ostraciontidae Lactophrys quadricornis (Linnaeus) bicaudalis (Linnaeus) trigon us (Linnaeus) Astracion cubicus Linnaeus cyanurus RUppel! Tetraodontoidei Tetraodontidae Canthigaster margritatus (RUppel!) Spheroides annulatus (Jenyns) testudineus (Linnaeus) nephelus (Goode and Bean) spengleri (Bloch) A roth ron hispidus (Linnaeus) Diodontidae Chilomycterus schoepfi (Walbaum) 1972J BREDER: TELEOST SCALES AND PIGMENT PATTERNS 75

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