J. LAURENS BARNt Keys to the Hawaiian Marine Gammaridea, 0-30 Meters SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY NUMBER 58 SERIAL PUBLICATIONS OF THE SMITHSONIAN INSTITUTION The emphasis upon publications as a means of diffusing knowledge was expressed by the first Secretary of the Smithsonian Institution. In his formal plan for the Insti- tution, Joseph Henry articulated a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge not strictly professional." This keynote of basic research has been adhered to over the years in the issuance of thousands of titles in serial publications under the Smithsonian imprint, commencing with Smithsonian Contributions to Knowledge in 1848 and continuing with the following active series: Smithsonian Annals of Flight Smithsonian Contributions to Anthropology Smithsonian Contributions to Astrophysics Smithsonian Contributions to Botany Smithsonian Contributions to the Earth Sciences Smithsonian Contributions to Paleobiology Smithsonian Contributions to Z0°l°iy Smithsonian Studies in History and Technology In these series, the Institution publishes original articles and monographs dealing with the research and collections of its several museums and offices and of professional colleagues at other institutions of learning. These papers report newly acquired facts, synoptic interpretations of data, or original theory in specialized fields. Each publica- tion is distributed by mailing lists to libraries, laboratories, institutes, and interested specialists throughout the world. Individual copies may be obtained from the Smith- sonian Institution Press as long as stocks are available. S. DILLON RIPLEY Secretary Smithsonian Institution SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY NUMBER 58 j. Laurens Barnard Keys to the Hawaiian Marine Gammaridea, 0-30 Meters SMITHSONIAN INSTITUTION PRESS CITY OF WASHINGTON I971 ABSTRACT J. Laurens Barnard. Keys to the Hawaiian Marine Gammaridea, 0-30 Meters. Smithsonian Contributions to Zoology, 58, 135 pages, 1971.—Methods of collecting Hawaiian Gammaridea, their preservation, sorting by color schemes and head shapes, dissection, terminology and identification are presented. Keys to taxa illustrated with drawings are given for 120 species found in depths from 0 to 30 m. Synonymies, dis- tribution, and notes on crucial characters of each species are given. This paper supple- ments the formal descriptions of the Hawaiian species contained in Smithsonian Contributions to Zoology, number 34. Official publication date is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1071 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1.75 Contents Page Introduction 1 Methods of Presentation 2 Collection of Amphipods 3 Dissection 3 Appendages—Positions and Terms 5 Appendages—Setae and Spines 5 Glossary 6 Diagnosis of the Basic Gammaridean 8 Identifications—Objective 10 Identifications—Non-Objective 12 Body Shape 14 Color in Preservative 14 Head and Eyes 16 Kinds of Uropod 3 18 Taxonomic Arrangement 19 Order Amphipoda 19 Key to Hawaiian Families of Gammaridea 20 Ampeliscidae 22 Amphilochidae . '. 25 Ampithoidae 29 Anamixidae 40 Aoridae 40 Biancolinidae 52 Cheluridae 54 Colomastigidae 54 Corophiidae 55 Dexaminidae (=Atylidae) 61 Eusiridae (—Calliopiidae) 61 Gammaridae 66 Isaeidae (=Photidae) 88 Ischyroceridae 97 Leucothoidae (cf. Anamixidae) 102 Liljeborgiidae 103 Lysianassidae 105 Ochlesidae 105 Oedicerotidae 105 Phliantidae 109 Phoxocephalidae 109 Pleustidae 109 Podoceridae 113 Sebidae 117 Stenothoidae 120 Superfamily Talitroidea: Families Hyalidae, Hyalellidae 122 Literature Cited 131 Index 133 j. Lamens Barnard Keys to the Hawaiian Marine Gammaridea, 0-30 Meters Introduction phipoda is a very minor consideration but worth inves- tigating. Mechanisms in tube building, swimming, Gammaridea are the commonest suborder of Amphi- maintenance of nestling positions, saltatory escape, and poda on the nearshore benthos of Hawaii and one of copulation are of considerable interest and almost the most common groups of medium-size and small unstudied anywhere. Predation and parasitism upon organisms (1-7 mm body length). Caprellidea, a sub- amphipods by other organisms, life histories, and repro- order of skeleton shrimps are also prevalent but less ductive rates are all known only rudimentarily, even in common and not treated here; Hyperiidea, the third those few species thus far studied. major suborder, occur primarily in the oceanic This paper presents a system, based on the known bathypelagic realm. species, of identifying Hawaiian Gammaridea dwelling Hawaiian Gammaridea are very small organisms in the range 0-30 m. Before attempting a first identi- barely visible to the naked eye and frequently over- fication, however, the observer must have a clear looked by the collector. Most Hawaiian species have understanding of the topics covered in this introduc- bodies less than 5 mm in length, many adults are ap- tion. "Methods of Presentation," for example, contains proximately 1 mm in length, but a few species attain an explanation of the format of the keys and the fig- lengths of 14 mm. They are abundant in algae and ures, as well as a brief discussion of the monographs coral heads and on rubble but are rare on sand bottoms. which the student should have at hand for reference; Mud bottoms, though rare in shallow waters of Hawaii, and this is followed by sections outlining the basic would be expected to have high numbers of amphipods, method of collection and the techniques of dissection. as they do on continental shores; mud bottoms have Problems may arise from oddities in the position of not been explored in Hawaii and this treatment of appendages and difficulties in seeing certain characters Gammaridea concerns primarily those in epifaunal because of the many setae occluding the chitinous sur- biotopes. faces of the appendages; these problems, which the A potential wealth of ecologic, genetic, and physio- observer will note immediately after dissection, are logical problems occurs in the Amphipoda. Some of treated under the sections "Positions and Terms" and these are suggested in Barnard (1969). Food habits, as "Setae and Spines." The "Glossary" found on page 6 one measure of the niche, are of primary interest. contains terms especially applicable to the Amphipoda, Adaptation to food ingestion ranges from epiphytic and a section on "Identification" discusses in general herbivory to ectoparasitic sucking and includes mud terms use of the keys. The "Key to Hawaiian Families," ingesting, sand processing, lignivory, detritus feeding, page 20, is preceded by a headnote warning of prob- slime lapping, filter feeding, carrion ingestion, and lems that may arise during its use. A principal aid to broad spectra of omnivory. Predation by benthic Am- use of the keys is the "Diagnosis of the Basic Gamma- ridean" presented on page 8, which the student is ad- vised to memorize. /. Laurens Barnard, Department of Marine Invertebrates, National Museum of Natural History, Smithsonian Institu- For advanced students wanting assistance and ideas tion, 20560. in rapidly sorting complex samples of amphipods ac- 1 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY cording to a limited number of characters, there is pre* arity with the gross appearance of such families as sented a special section on "Non-Objective" identifica- the Lysianassidae, Ampithoidae, Gammaridae, Steno- tion which may be skipped if the reader is interested thoidae, Amphilochidae, Leucothoidae, Aoridae, Is- primarily in identifying one taxon at a time. aeidae (=Photidae), Ischyroceridae, Corophiidae, The systematic section of this paper is introduced by Dexaminidae, and Liljeborgiidae. But Norwegian a formal diagnosis of the suborder Gammaridea, and talitroids (Hyale and beachhoppers of the genera Or- in this section follow in alphabetical order the keys to chestia and Talitrus) are not typical of tropical mem- families, and under the families, also in alphabetical bers. The work of Chevreux and Fage (1925) dealing order, keys to the genera and species thus far found in with the Mediterranean (including warm-temperate Hawaiian waters. France) is also useful and slightly more oriented towards genera likely to occur in the tropics than is Methods of Presentation Sars' Norwegian work. To minimize text and to avoid long exclusive di- An index to world species sparsely referenced and agnoses, the comments appended to keys and taxa are keyed to the Zoological Record was published by abbreviated to include only major distinctions of the J. L. Barnard (1958), but even in this short time it taxa, and may consequently appear indiscriminate is out of date because of accelerated study in the group. or inconsistent. The reader may assume, however, that In the present work, most of the key characters are when a character is mentioned for one taxon but not illustrated in accompanying figures by outline draw- for another, that it is in a negative state in the other ings. Occasionally the drawings are semidiagrammatic related taxa of that group (family or genus) under and, for clarity of shape, the setae are removed, being discussion. indicated by small circles at the points of attachment. No words or pictures presented in such a format can