Anatomical Considerations of Pectoral Swimming in the Opah, Lampris guttatus Author(s): Richard H. Rosenblatt and G. David Johnson Source: Copeia, Vol. 1976, No. 2 (May 17, 1976), pp. 367-370 Published by: American Society of Ichthyologists and Herpetologists Stable URL: http://www.jstor.org/stable/1443963 Accessed: 02/06/2010 14:24

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http://www.jstor.org ICHTHYOLOGICAL NOTES 367

(1936). On the other hand, the name L. regius FOWLER,H. W. 1936. The marine fishes of West Africa. Bull. Amer. Mus. has more recently been used by Fowler (1936), Nat. Hist. 70:489-490. Smith Tortonese and Bini GOODE,G. B., AND T. H. BEAN. 1896. Oceanic (1965), (1970) (1970). Smithson. Contr. Knowl. 30. As the date ichthyology. of publication is specified only as HUREAU,J. C., AND T. H. MONOD. (Eds.) 1973. 1788 in the works of Bonnaterre and of Checklist of the fishes of the northeastern At- Briinnich, and as there is no definite evidence lantic and of the Mediterranean (CLOFNAM). to the the exact date for both Unesco, Paris. 1. contrary, publica- JORDAN,D. S., B. W. EVERMANNAND H. W. CLARK. tions has to be taken as 31 December 1788, in 1930. Checklist of the fishes and fishlike verte- accordance with Art. 21(b) of the International brates of North and Middle America north of the northern of Code of Zoological Nomenclature. Lampris gut- boundary Venezuela and Columbia. App. X, Rep. U. S. Comm. Fish., 1928, Pt. II:1- tatus and L. regius, therefore, are to be con- 670. sidered as synonyms simultaneously published, MULLER,O. F. 1806. Zoologia danica, seu ani- and the relative priority is determined, in ac- malium Daniae et Norvegiae rariorum ac minus cordance with Art. of the Code, the notorum descriptiones et Historia, Havniae, Vol. 24(a) by 4. action of the first reviser. As first reviser, in this MURRAY, J., AND J. HJORT. 1912. The depths of the sense, only Muller (1806) is acceptable. He ocean. London. used L. guttatus as the name for the taxon under ORKIN,P. A. 1950. A history of the Opah Lampris consideration and a detailed list of guttatus (Brunnich). Scott. Nat. 62:129-141. gave syn- A. 1799. for the Both Bonnaterre and RETZIUS, J. Lampris, en ny fiskslaegt. onyms opah. Kongl. Vet. Acad. Handl. 20:91-100. Briinnich were cited in this list, in addition to SMITH,J. L. B. 1965. New records and descriptions other important works, but Muller chose to use of fishes from southwest Africa. Occ. Pap. the name L. guttatus in preference to any of Ichthyol. Rhodes Univ., Grahamstown, No. 3:13- the others. so he determined the 23. By doing, TORTONESE,E. 1970. relative in accordance with Art. 24 Osteichthyes (Pesci ossei). priority and, Parte Prima. Fauna d'Ital., Bologna 10:470-472. (a)(i) of the Code, the name Lampris guttatus G. PALMER, the British Museum should be used as the correct specific name formerly of for the opah. (Nat. Hist.), London, England, and H. A. We are indebted to J0rgen Nielsen and OELSCHLXGER,Forschungs-Institut Senckenberg, West Torben Wolff of the Universitetets Zoologiske Frankfurt, Germany. Accepted 17 Feb. 1975. Museum, Copenhagen, 0ystein Fr0iland of the Zoologisk Museum, Bergen University, and M. Desoutter of the Museum National d'Histoire naturelle, Paris for information on the dates of publication of the works of Bonnaterre and Briinnich in which the names for the opah were ANATOMICAL CONSIDERATIONS OF PEC- used for the first to Peter time; Whitehead of TORAL SWIMMING IN THE OPAH, LAM- the British Museum London and (Nat. Hist.)., PRIS GUTTATUS.-The opah, Lampris gut- Michael Tiirkay, Forschungs-Institut Sencken- tatus (Briinnich), is a large, predatory fish of berg, Frankfurt for helpful criticism of the the open ocean occurring from near the surface to 500 text. m (Gudger, 1930). A number of papers have dealt with the anatomy and morphology of LITERATURECITED Lampris. The structure of the pectoral girdle has been dealt with by Gill BINI, G. 1970. Atlante dei delle Coste italiane. Boulenger (1902), pesci and Starks Le Vol. 3. Mondo Sommerso, Milano. (1903), Jordan (1926) (1930). Danois and BONNATERRE,J. P. 1788. Ichthyologie. Tableau (1935) described, partially figured, the encyclopedique et methodique des trois regnes pectoral musculature, and Oelschlager (1974), de la nature. Paris. in connection with his discussion on ontogenetic M. T. 1788. Om en den BRUNNICH, ny fiskeart, changes, briefly treated the ved i pectoral anatomy, draabeplettede pladefisk, fanget Helsing0r and mentioned the dark Nords0en, 1786. K. danske Vidensk. Selsk. Skr. nature of the pectoral (N.S.) 3:398-406. muscles, first noted by Mortimer (1750). This COLLETT,R. 1874. Norges Fiske, med Bemaerk- study was initiated when a frozen specimen ninger om dere Udbredelse. Forh. Vid. Selsk. (SIO74-93, 780 mm SL) was turned over to Khristiania. us by Al Pentiss. It was dissected, and CUVIER,G., AND A. VALENCIENNES.1835. Histoire ultimately naturelle des Poissons. Vol. 10. Paris. skeletonized. EHRENBAUM,E. 1936. Handbuch der Seefischerei There can be little doubt that normal cruising Nordeuropas. Vol. 2. Leipzig. in L. guttatus is accomplished by pectoral swim- 368 COPEIA, 1976, NO. 2

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Fig. 1. Lampris guttatus, 780 mm SL. Oblique view of right side, pelvics and lower lobe of caudal trun- cated. Pectoral and pelvic musculature exposed. A, cut edge of subcutaneous adipose layer. C, exposed portion of cleithrum. DA, deep abductor. SA, superficial abductor. P, pelvic musculature. ming. The shoulder girdle is massive and gives pectoral musculature of Lampris is rich in attachment to large, red, adductor and abductor mitochondria and the fibers are small in di- muscles (Fig. 1). In our 28.1 kg specimen the ameter (G. Dobbs pers. comm.) indicating that pectoral musculature weighed 4.5 kg, or 16% it probably functions physiologically as red of the total weight. The total lateral body muscle. According to the currently accepted musculature, determined by removing one fillet hypothesis, red muscle is aerobic and used as completely as possible and doubling its in continuous activity, and white muscle anaer- weight, was 7.7 kg. (The total lateral red muscle obic and used in burst swimming (Bone, 1966). is small, 346.8 g, making up only some 3% of Our dissection does not agree with the multi- the total muscle.) The pectoral muscle is thus plicity of muscles described by Le Danois. 37% of the total propulsive musculature. This Rather, we find the normal complement (Allis, is about twice the relative amount of red muscle 1903; Greene and Greene, 1913; Winterbot- in the rainbow trout (Webb, 1971) and about tom, 1974): a superficial abductor; an arrector three times the maximum value for 10 scombrid ventralis; a deep abductor, divisible into an species given by Magnuson (1973). More anterior and posterior part; an adductor, again apropos, the sen6rita (Oxyjulis californica), a with anterior and posterior divisions; and an labrid which relies on the pectorals for normal arrector dorsalis. None of these muscles inserts locomotion and lacks lateral red muscle, has on the pelvic rays, as indicated by Le Danois. about 2% of the body weight, and 5% of the The superficial adductor is much smaller than propulsive musculature as pectoral red muscle the deep one (Fig. 1), and, together with the (RHR, original data). In fact the pectoral mus- arrectores probably serves to control the angle culature of Lampris is probably exceeded in of attack of the pectoral fin. relative bulk only by that of the freshwater An unusual feature is the presence of a thick hatchet fishes (25% of body weight in Gastero- adipose layer of lipid and connective tissue pelecus according to Ridewood, 1913). under the skin. The cut edge of this layer Microscopic examination reveals that the red is visible in Fig. 1, just behind the operculum. ICHTHYOLOGICAL NOTES 369

The adipose layer is present only over the superficial abductor and arrector dorsalis to- pectoral musculature, where it is from 7.5-15 gether causing the posterior edge of the fin to mm thick, thinning posteriorly. (Le Danois re- trail on the upstroke. This would provide the ported a "Couche de grasse" 25 mm thick in angle of attack necessary for the generation of her specimen of unstated size). The lipid ma- lift and thrust (Gray, 1968:194-197). Flapping terial is predominantly triglyceride (C. Phleger, flight of necessity generates vertical as well as pers. comm.). horizontal propulsive forces (Webb, 1973). The It is tempting to speculate that the adipose large pelvic fins (1800 cm2 total area) which layer might act as an insulator, allowing the extend out from the body, with their surfaces maintenance of an elevated temperature in the parallel to the direction of forward motion, pectoral musculature. However, there is no could act to dampen the resultant vertical os- countercurrent heat-exchanger in the blood cillation. If the angle of attack could be varied supply, making conservation of heat an ap- slightly, the up and down forces would be con- parently insuperable problem (Carey et al., verted to thrust. Whether this actually is the 1971). Carey et al. reported a body tempera- case can only be determined by observations on ture measurement for Lampris of only 1 C a living individual. above surface ambient (depth of capture was Neither the pectorals nor the pelvics can be not reported), but their measurement was al- rotated normal to the direction of motion. This most certainly taken in the lateral body muscula- means that they cannot act as brakes (as sur- ture. The presence of the possibly insulating mised by Orkin, 1950) as they do in most fishes adipose layer suggests that it would be of in- (Harris, 1953). Turning can be accomplished terest to determine the temperature of the by using only one pectoral or, more likely, by pectoral red muscle in a living fish. inclining the caudal and posterior portions of The bones of Lampris are cancellous and the dorsal and anal to one side. We can en- filled with oil, again predominantly triglyceride. vision no means by which sudden stops can be For example, 73% of the dry weight of the achieved. In the pelagic environment they may lachrymal was oil. The oil alone is apparently never be necessary. not enough to confer neutral buoyancy, as Orkin (1950) felt that normal cruising in there is a functional gas-bladder. Because of the Lampris is achieved by caudal-swimming, and presence of the gas-bladder, and uncertainty that the pectorals are used for acceleration and as to depth of capture, it was not possible to manuevering. However at that time the func- determine the relative buoyancy of our speci- tional significance of red and white muscle was men. not known. Judging from the relatively small Several authors have commented on the hori- size (1400 cm2) and high aspect ratio (6.6) of zontal pectoral insertion of Lampris. Orkin the pectorals, they should be high-speed, low- (1950) cites Boulenger (1902) in stating that torque devices. This leads us to the following the pectoral cannot be raised above the mid- hypothesis of swimming modes in Lampris. Low line, but the pectoral can in fact be completely speed swimming is the function of the caudal appressed. The horizontal insertion of the stiff fin and the lateral red musculature. Accelera- pectoral led Le Danois to hypothesize that tion to cruising speed of a few body lengths Lampris must swim in a head-down attitude, per second is achieved by burst-swimming with in order to accelerate water backward on ab- the lateral white muscle and caudal, with the duction, and thus progress. However, she did pectorals maintaining cruising speed. Increases not consider that the adduction stroke would in fast cruising speeds are probably also achieved cancel any motion thus produced. In fact, the by burst-swimming, with the pectorals main- pectoral of Lampris, although stiff, does not taining the new rate. have an absolutely fixed shape. There is a The fin and muscle functions hypothesized well developed arrector ventralis, with a strong here are of necessity inferential and can only tendon inserting on the bases of the first two be tested by observations of swimming, and rays. The superficial abductor, which in most temperature measurements, of living individ- fishes is relatively large and inserts on all the uals. It is hoped that this paper may stimulate rays, here is reduced and inserts only on the such observations. posterior rays. These two muscles are well LITERATURE CITED suited to control the angle of attack and camber ALLIS,E. P. 1903. The skull and the cranial and of the fin, with the arrector inclining the an- first spinal muscles and nerves in Scomber terior edge of the fin on the downstroke, and the scomber. J. Morph. 18:45-380. 370 COPEIA, 1976, NO. 2

BONE, Q. 1966. On the function of the two types TUBERCULATION OF THE PEARL DACE, of myotomal muscle fibre in elasmobranch fish. SEMOTILUS MARGARITA CY- Mar. Biol. Ass. U.K. 46:321-349. (PISCES: J. the three of fish in BOULENGER,G. A. 1902. On the PRINIDAE).-Of species systematicposition the tuberculation of the genus Lampris and on the limits and con- genus Semotilus, has been tents of the suborder Catosteomi. Ann. Mag. Nat. described for S. atromaculatus (Mitchill) (Fowler, Hist. (7) 10:147-152. 1912; Wiley and Collette, 1970) and for S. CAREY,F. G., ETAL. 1971. Warm-bodied fish. Amer. However, Zool. 11:137-145. corporalis (Mitchill) (Reed, 1971). tuberculation of S. has been little GILL,T. N. 1903. On the relations of the fishes of margarita known. the the family Lamprididaeor opahs. Proc. U. S. Nat. Langlois (1929) reported presence of Mus. 26:915-924. breeding tubercles on the pectoral fins of male GRAY, J. 1968. Animal locomotion. Weidenfeld S. margarita. Recently in a life history study and Nicholson, London. of this species in Hamilton Run, Maryland C. AND C. H. GREENE. 1913. The GREENE, W., (Fava and Tsai, 1974), it was found that skeletal musculature of the king salmon. Bull. U. S. Bur. Fish. 33:21-59. breeding tubercles are present not only on pec- toral fins but also of GUDGER,E. W. 1930. The opah, or moonfish, on the many parts the body in eastern coast of North America. Amer. Nat. 64: both sexes. By using these specimens collected 168-178. during the life history study, this paper describes HARRIS, J. E. 1953. Fin patterns and the mode of the tubercles of S. margarita and their life in 17-28. In: in Marine breeding fishes, p. Essays seasonal A male Biology. S. M. Marshall and P. Orr (eds.). Oliver development. breeding (65.6 & Boyd, Edinburgh. mm standard length) and a female (68.2 mm) JORDAN,D. S. 1921. The fish fauna of the California were selected for tubercular measurement. The Tertiary. Stanford Univ. Publ., Univ. Ser., Biol. mean length and diameter of the tubercles on Sci., 1:237-300. each of the and fins were calculated LE Y. part body DANOIS, 1955. Sur la musculature des nage- at least oires et de by measuring five tubercles with an pectorales pelviennes l'opah (Lampris ocular luna, Duhamel). Bull. Soc. Zool. de France. 80: micrometer under the dissection micro- 8-17. scope, 3 X 10 magnification. MAGNUSON,J. J. 1973. Comparative study of adapta- tions for continuous swimming and hydrostatic Tubercles on breeding males.-Tubercles are equilibrium of scombroid and xiphiod fishes. present almost completely over the head and U. S. Nat. Mar. Fish. Serv., Fish. Bull., 71:337- In the head are 356. body. region they closely in the center of the and MORTIMER,C. 1750. The of a fish spaced opercula along description their and extend to the first and second named Opah guinensium-Lampris guttata, shewed edges, to the Royal Society by Mr. Ralph Bigland. Phil. branchiostegal rays. They are cone-shaped with Trans. Roy. Soc. 46:518-520. an average length of 0.07 mm and 0.10 mm H. A. Das OELSCHLAGER, 1974. jugenstadium von diameter. On the parietal, frontal and nasal Lampris guttatus (Brunnich, 1788) (Osteichthyes, areas of the head ein zur Kenntnis seiner they are widely spaced and Allotriognathi), Beitrag have an Entwicklung. Arch. Fisch. Wiss. 25:3-19. average length of 0.04 mm and 0.08 ORKIN,P. A. 1950. A history of the opah Lampris mm diameter. Elsewhere on the head the guttatus (Brunnich). Scottish Nat. 62:129-141. tubercles are more widely spaced and extremely RIDEWOOD,W. 1913. Notes on the South American small, length 0.02 mm and diameter 0.04 mm. freshwater flying-fish, Gasteropelecus, and the On the the common Exocoetus. Ann. Nat. body, tubercles are present along flying-fish, Mag. the of Hist. (8) 12:544-548. posterior edge each scale. The number STARKS,E. C. 1930. The primary shoulder girdle of of the tubercles per scale varies in different the bony fishes. Stanford Univ. Publ., Univ. Ser., regions: 1-3 on the dorsal and abdominal Biol. Sci. 6:149-239. regions; 2-4 on the anterior portion of the WEBB, P. W. 1971. The swimming energetics of chest between the fins and 4-6 trout I. Thrust and at pectoral isthmus; power output cruising on the anterior speeds. J. Exp. Biol. 55:489-520. portion of the lateral side of . 1973. Kinematics of pectoral fin propulsion the body along the lateral line; and 2-10 on in Ibid. 59:697-710. Cynatogaster aggregata. the caudal peduncle. The average length is WINTERBOTTOM,R. 1974. A descriptive synonymy 0.08 mm and diameter 0.11 mm. of the striated musclesof the teleostei. Proc. Acad. On the fins Nat. Sci. Philadelphia. 125:225-317. pectoral large prominent tubercles are present on the dorsal surface from the second to the RICHARD H. ROSENBLATTAND G. DAVID JOHN- eighth ray (Fig. 1). On each ray SON, Scripps Institution of Oceanography, Uni- they are arranged in a single row at the base of versity of California, San Diego, La Jolla, Calif. the ray, and then split into two rows when the 92037. Accepted 3 Feb. 1975. ray splits into two branches. The tubercles are