"to*, Sufcfc OAA TR NMFS CIRC-389 NOAA Technical Report NMFS CIRC-389 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service tfHM Marine Flora and Fauna of the Northeastern United States Crustacea : Decapoda AUSTIN B.WILLIAMS SEATTLE, WA April 1974 NOAA TECHNICAL REPORTS National Marine Fisheries Service, Circulars The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic distribution of fishery resoun. understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the rasourt M NMFS is also charged with the development and implementation of policies for managing national fishing grounds, development and enforcement of domestic fisheries regulations, surveillance of foreign nited States coastal waters, and the development and enforcement of international fishery agreements and policies. NMFS also assists the fishing industry through marketing service and economic- analysis programs, and mortgage insurance and vessel construction subsidies. It collects, analyses, and publishes statist us on various phases of the industry The NOAA Technical Report NMFS CIRC series continues a series that has been in existence since 1941. The Circulars are technical publications of general interest in tended to aid conservation and management. Publications that review in considerable detail and at a high technical level certain broad areas of research appear in this series. Technical papers originating in economics studies and from management investigations appear in the Circular series NOAA Technical Reports NMFS CIRC are available free in limited numbers to governmental agencies, both Federal and State. They are also available in exchange for other scientific and technical publications in the marine sciences. Individual copies may be obtained (unless otherwise noted) from D83. Technical Information Division, Environ- mental Science Information Center, NOAA. Washington, DC. 20235. Recent Circulars are: nopsis of biological data on the chum salmon. Oncorhynchus keta (Walbaum) 1792. By Richard G. Bakkala. March 1970, iii + 89 pp., 15 figs.. 51 tables. 347 Synopsis of biological data on Pacific ocean perch, Sebastodes atutus By Richard L. Major and Herbert H. Shippen. December 1970. iii + 38 pp.. 31 figs.. 11 tables. 319. Bureau of Commercial Fisheries Great Lakes Fishery Laboratory. Ann Arbor, Michigan. By Bureau of Commercial Fisheries. March 1970, 8 pp., 7 figs. 349. Use of abstracts and summaries as communication devices in technical articles. By F. Bruce Sanford February 1971, iii + 11 pp., 1 fig. 330. EASTROPAC Atlas: Vols. 1-7. Catalog No. I 49.4:330/(vol.) 11 vols. Available from the Superintendent of Documents. U.S. Government Printing Office, Washington, D.C. 20402. 350. Research in fiscal year 1969 at the Bureau of Commercial Fisheries !'■ Laboratory. Beaufort. N.C. By the Laboratory staff. November 1970. ii + 49 pp 17 tables 331. Guidelines for the processing of hot-smoked chub. By H. L. Seagran, J. T. ski, and .1. A. Emerson. .January 1970, iv + 23 pp., 8 figs., 2 tables. 332. Pacific hake. (12 articles by 20 authors.) March 1970. iii + 152 pp.. 72 figs.. 47 tables. 333. Recommended practices for vessel sanitation and fish handling. By Edgar W Bow man and Alfred Larsen. March 1970. iv + 27 pp., 6 figs. 335. Progress report of the Bureau of Commercial Fisheries Center for Estuarine and Menhaden Research, Pesticide Field Station, Gulf Breeze. Fla., fiscal year 1969 By the Laboratory staff. August 1970. iii + 33 pp., 29 figs.. 12 tables. 336. The northern fur seal. By Ralph C. Baker. Ford Wilke, and C. Howard Baltzo. April 1970. iii + 19 pp.. 13 figs. 337 Program of Division of Economic Research, Bureau of Commercial Fisheries, fiscal year 1969. By Division of Economic Research. April 1970. iii + 29 pp.. 12 figs., 7 tables. 338. Bureau of Commercial Fisheries Biological Laboratory. Auke Bay, Alaska. By Bureau of Commercial Fisheries. June 1970, 8 pp.. 6 figs. 339. Salmon research at Ice Harbor Dam. By Wesley J. Ebel. April 1970. 6 pp., 4 figs, 340. Bureau of Commercial Fisheries Technological Laboratory, Gloucester. Measachu setts. By Bureau of Commercial Fisheries. June 1970, 8 pp., 8 figs. 341. Report of the Bureau of Commercial Fisheries Biological Laboratory, Beaufort, r the fiscal year ending June 30, 1968. By the Laboratory staff. August 1970. iii + 24 pp., 11 figs.. 16 tables. 342. Report of the Bureau of Commercial Fisheries Biological Laborabory, St. Petersburg Beach, Florida, fiscal year 1969 By the Laboratory staff August 1970. iii + 22 pp.. 20 figs.. 6 343. Report of the Bureau of Commercial Fisheries Biological I-aboratory, Galveston. Texas, fiscal year 1969. By the Laboratory staff. August 1970, iii + J9 pp.. 28 figs.. 9 tables. 344. Bureau of Commercial Fisheries Tropical Atlantic Biological Laboratory pi 1965-69, Miami. Florida. Bv Ann Weeks. October 1970. iv + 65 pp., 53 figs. 361. Bureau of Commercial Fisheries Exploratory Fishing and Gear Research Base, Pascagoula, Mississippi. July 1, 1967 to June 30. 1969. By Harvey R Bullis. Jr., and John R Thompson. November 1970. iv + 29 pp., 29 figs., 1 table. 352. Upstream passage of anadromous fish through navigation locks and use of the stream for spawning and nursery habitat. Cape Fear River. N.C. 1962-66. By Paul R. Nichols and Darrell E. Louder. October 1970. iv + 12 pp.. 9 figs., 4 tables. 356. Floating laboratory for study of aquatic organisms and their environment. By George R. Snyder, Theodore H. Blahm, and Robert J. McConnell. May 1971, iii + 16 pp., 11 figs 361. Regional and other related aspects of shellfish consumption — some preliminary findings from the 1969 Consumer Panel Surve\ H\ MortonM Miller and Darrel A Nash June 1971. iv + 18 pp.. 19 figs.. 3 tables. 10 apps. 362. Research vessels of the National Marine Fisheries Service. By Robert S Wolf August 1971, iii + 46 pp.. 25 figs 3 tallies For sale by the Superintendent of Documents, U S Government Printing Office, Washington, D.C. 20402. 364. History and development of surf clam harvesting gear. By Phillip S Parker. Oc- tober 1971. iv + 15 pp.. 16 figs. For sale by the Superintendent of Document- I S Government Printing Office, Washington, D.C 20402. 365 Processing EASTROPAC STD data and the construction ol vertical temperature and salinitv sections by computer By Forrest R Miller and Kenneth A. Blisv February 3 appendix figs, For sale by the Superintendent of Documents, I S Government Printing Office, Washington. D.C 20402. 366. Key to field identification of anadromous juvenile salmonids in the Pacific Northwest, By Robert -I McConnell and George R. Snyder January 1972, tv + 6 pp.. 4 figs For sale by the Superintendent of Documents, U.S. Government Printinj Washington. D.C 20402. 367 Engineering economic model for fish protein concentration processes. By K. K. Almenas. I. C Durilla. R.C. Ernst, J. W Gentry. M. B Hale, and J. M. Marchello. Oc- tober 1972. iii + 175 pp.. 6 figs.. 6 tables For sale b\ the Superintendent ol Documents. U.S. Government Printing Office, Washington. D.C. 20402. 368. Cooperate sico estuarine inventory and study, Florida: Phase I. area description. By J Kneeland McNulty, William N Lindall. Jr.. and James l November 1972. vii + 126 pp 46 figs . 62 tables For sale l»y the Superintendent of Documents, 1 S Government Printing Office. Washington, D.C. 20402. 346 Sp de to handling, smoking, and preserving Great Lakes coho salmon, iron Dudley, J. T Graikoski.H I. Seagran. and Paul M. Earl. September 1970. iii 369 Field guide to thi I Pomacanthidae) in the western Atlantic By Henry A. Feddern. November 1972. iii + 10 pp., 17 figs. For sale by the Superintendent of Documents IS Government Printing Office. Washington. D.C. 20402. Continued on inside back cover. ^SHfS^ U.S. DEPARTMENT OF COMMERCE Frederick B. Dent, Secretary NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION Robert M. White, Administrator NATIONAL MARINE FISHERIES SERVICE NOAA Technical Report NMFS CIRC-389 Marine Flora and Fauna of the Northeastern United States. Crustacea : Decapoda ^= 5p| ru /IBL/WHOI m cr o □ □ ^^■^■y ^^^^^ ^= □ AUSTIN B.WILLIAMS 7 ^6-l9l fe Seattle, WA April 1974 For sale by Ihe Superintendent of Documents, U.S. Government Printing Office Washington. DC. 20402 FOREWORD This issue of the "Circulars" is part of a subseries entitled "Marine Flora and Fauna of the Northeastern United States." This subseries will consist of original, illustrated, modern manuals on the identification, classification, and general biology of the estuarine and coastal marine plants and animals of the Northeastern United States. Manuals will be published at irregular intervals on as many taxa of the region as there are specialists willing to collaborate in their preparation. The manuals are an outgrowth of the widely used "Keys to Marine Invertebrates of the Woods Hole Region," edited by R. I. Smith, published in 1964, and produced under the auspices of the Systematics-Ecology Program, Marine Biological Laboratory, Woods Hole, Mass. Instead of revising the "Woods Hole Keys," the staff of the Systematics- Ecology Program decided to expand the geographic coverage and bathymetric range and produce the keys in an entirely new set of expanded publications. The "Marine Flora and Fauna of the Northeastern United States" is being prepared in collaboration with systematic specialists in the United States and abroad. Each man- ual will be based primarily on recent and ongoing revisionary systematic research and a fresh examination of the plants and animals. Each major taxon, treated in a separate manual, will include an introduction, illustrated glossary, uniform originally illustrated keys, annotated check list with information when available on distribution, habitat, life history, and related biology, references to the major literature of the group, and a system- atic index. These manuals are intended for use by biology students, biologists, biological ocean- ographers, informed laymen, and others wishing to identify coastal organisms for this region. In many instances the manuals will serve as a guide to additional information about the species or the group. Geographic coverage of the "Marine Flora and Fauna of the Northeastern United States" is planned to include organisms from the headwaters of estuaries seaward to approximately the 200-m depth on the continental shelf from Maine to Virginia, but may vary somewhat with each major taxon and the interests of collaborators. When- ever possible representative specimens dealt with in the manuals will be deposited in reference collections of the Gray Museum, Marine Biological Laboratory, and other universities and research laboratories in the region. After a sufficient number of manuals of related taxonomic groups have been pub- lished, the manuals will be revised, grouped, and issued as special volumes. These vol- umes will thus consist of compilations of individual manuals within phyla such as the Coelenterata, Arthropoda, and Mollusca, or of groups of phyla. 11 CONTENTS Page Introduction 1 Glossary 2 Key to the marine decapod crustaceans of the Northeastern United States, inshore and shelf waters 4 Annotated systematic list 39 Selected bibliography 44 Index to scientific names 48 Acknowledgments 50 Coordinator's comments 50 The National Marine Fisheries Service (NMFS) does not approve, rec- ommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this publication furnished by NMFS, in any advertising or sales pro- motion which would indicate or imply that NMFS approves, recommends or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication. MARINE FLORA AND FAUNA OF THE NORTHEASTERN UNITED STATES. Crustacea: Decapoda AUSTIN B. WILLIAMS 1 ABSTRACT The manual includes an introduction to general classification, an illustrated key, an annotated system- atic list, a selected bibliography and a systematic index to the marine decapod crustaceans of the in- shore and continental shelf waters of the northeastern United States. INTRODUCTION The Order Decapoda contains the largest and probably most familiar crustaceans occurring along seacoasts of the United States. Generally speaking there are two main body types exhibited by this group. The first group is long tailed with a conspicu- ously extended abdomen and the whole body usually compressed (narrow and deep). These are the shrimps (Suborder Natantia) with abdominal swim- merets (pleopods) well developed and adapted for swimming (Fig. 1). The second group (Suborder Rep- tantia) is diverse in shape, lobsterlike or crablike, with the body more or less depressed (dorsoven- trally flattened). Three subsets within this assem- blage are fairly distinct: 1 ) lobsters and mud shrimps (Section Macrura) with abdomen extended and al- ways equipped with a tail fan, adapted for feeble swimming, crawling, or burrowing; 2) an anom- alous group (Section Anomura) that either have the body asymmetrical and adapted for housing in hol- low objects (hermit crabs), or symmetrical with the abdomen fairly well developed but more or less flexed under the thorax (porcellanid crabs and rela- tives); and 3) short tailed true crabs (Section Brach- yura) with greatly reduced abdomen more or less permanently flexed beneath the thorax, adapted primarily for locomotion on a substrate (Fig. 2). These body types have been variously treated in 1 Systematics Laboratory, National Marine Fisheries Service, NOAA, National Museum of Natural History. Washington, DC. 20560. forming classifications of the higher categories of decapod crustaceans for nearly 200 yr and the one that is adopted here has become the conservative (and practical) arrangement used for the last few decades. It is a classification that considers the long tailed forms to be most primitive, the anomalous group to be composed of radiating side branches of the main stem, and the short tailed forms to be the most specialized in the order. Such a broad state- ment does not do justice to fine points of supposed relationships based on many lines of evidence but will serve as a working outline. The decapod crustaceans treated here are re- stricted to species living within the 200-m limits of the neritic province, on beaches, or nearby marshes along the northeastern United States. Species living primarily outside these limits off the northeastern United States have distributions which extend far beyond the region, hence are seldom part of the local fauna. A few species bridge the neritic and oceanic provinces and these have been selectively included. Within the continental shelf area, only species with recorded occurrence between southern New Jersey and the northern border of Maine are considered. The shrimps and crabs of this area belong essen- tially to two temperature regimes, a boreal compo- nent in the north which includes some arctic species and a temperate component in the south which em- braces a few invaders from both the boreal as well as the warmer Carolinian Province south of Cape Hat- teras. Cape Cod forms a landward boundary be- tween these regimes of temperature, though offshore there is a good deal of latitudinal displacement and the whole seasonally oscillates to some degree in a north-south fashion. The essential composition of this crustacean fauna has been well documented since the turn of the cen- tury, but there have been refinements in species definitions, limits of ranges, and some new dis- coveries. This key borrows heavily from the past, but a new set of illustrations and restructuring should make it more usable than the older keys or their abridgments. The key is designed for biologists, biology stu- dents, and informed amateurs. The format consists of a series of contrasting statements almost always offering two clear alternatives, although sometimes supplementary information is added. The user selects that statement in a couplet that fits best. This will lead to a number which heads a new set of alternatives. Eventually the choices lead to a. specific name. Names of higher categories are in- cluded. Numbers in parentheses allow a user to work the key in reverse, any parenthetic number being that of the preceding couplet in the sequence. Labelled diagrams and a glossary of technical terms are provided. Almost all characters employed in the dichotomies are illustrated by line drawings, but these may not adequately differentiate the species outside the area of the northeastern United States. Wherever practicable, drawings were made of specimens from the northeastern United States. Scales on all figures are in millimeters. An annotated list of 92 species is given separately. Among this number are exceedingly scarce species as well as abundant ones. Only 17 of the latter are large enough to be valuable in commerce, but these contribute to some of our richest fisheries. The shrimps, Penaeus setiferus and P. aztecus aztecus, whose centers of distribution are in the Carolinian Province, are commercially exploited by trawling only south of Cape Hatteras. Their northern coun- terparts, Pandalus borealis and to a lesser extent P. propinquus and P. montagui, occur in a smaller trawl fishery from Cape Cod Bay to the Maritime Provinces of Canada. The American lobster, Homarus americanus, long a favorite seafood, is caught mainly by trapping in cold temperate waters of the continental shelf northward from Cape Hat- teras. The American blue crab, Callinectes sapidus, which thrives in estuaries, is caught by a variety of means from Long Island to Texas and marketed in both hard- and soft-shelled states. The systematic and distributional section is fol- lowed by a selected bibliography of systematic and general biological works at the end. GLOSSARY abdomen jointed hind part of body ; tail ; consisting ideally of 6 segments; muscular, extended or bent in shrimps, lobsters, etc.; asymmetrical in hermit crabs; reduced and more or less permanently held beneath thorax in crabs. adrostral groove groove beside base of rostrum extending posteriorly along dorsal side of carapace (on shrimps). antenna one of second pair of appendages; mov- able segmented organ of sensation behind, below, or lateral to antennule; the large feeler. antennal scale elongate, flattened, bladelike or fin- like exopod of antenna; usually with distolateral spine. antennular peduncle proximal 3 articles of an- tennule. antennule one of first pair of appendages; mov- able segmented organ of sensation preceding an- tenna; the small feeler. anterolateral teeth teeth on margin of carapace be- tween orbit and lateralmost point (on crabs). article general term for segment of appendage. carapace dorsal and lateral shieldlike covering on cephalothorax. carina keellike ridge or prominence. carpus third article from distal end of a leg. cephalothorax coalesced head and thorax. chela arrangement of distal 2 articles of a crusta- cean limb in which terminal element is opposed to element preceding it in such a manner that append- age is adapted for grasping. In a true chela, elements are shaped as fingers closing against each other. In a subchela. terminal article (dactyl) usually closes against distal surface of penultimate article (propodus). cheliped leg bearing a chela. dactyl terminal or distal article of a leg or maxil- liped; movable finger of a chela. epistome a sternal plate of varying shape lying an- terior to mouth between bases of antennae. In Anomura the broad epistome comes in contact with the carapace on each side; in Brachyura it becomes firmly united with the carapace. exopod lateral ramus of a biramous appendage. frame of mouth plates surrounding area in which mouthparts repose (in crabs); composed of fused epistome (anterior) and ventrolateral extensions of carapace (each side) more or less thrown into ridges forming a "frame" for nested mouthparts. front margin of carapace between eyes (in crabs). hepatic region subtriangular, anterolateral region behind orbit. interocular teeth teeth on frontal margin between eyes. ischium fifth article from distal end of leg or maxil- liped; usually largest article of maxilliped. mandibles third pair of appendages; mouth parts adapted for crushing or grinding. merits fourth article from distal end of leg or maxil- liped. orbit cavity or emargination in carapace accom- modating eye; variously formed. Commencing orbit: a stage of specialization between lack of orbit and fully formed orbit in certain spider crabs. palm proximal portion of propodus of chela. palp tiny accessory appendage on mandible. pleopod swimmeret; one of biramous abdominal appendages on any except sixth segment. pleura lateral overhanging plate on abdominal segment. postorbital tooth - spine tooth or spine behind eye . propodus penultimate article of leg or maxilliped. rostrum median pointed process at anterior end of cephalothorax. sclerotized thickened and hardened. sternite exoskeletal plate on ventral side of body. supraocular eave overhanging dorsal border of orbit (in certain spider crabs). supraorbital spine spine near margin of orbit above base of eyestalk (in certain shrimps). suture line of junction between exoskeletal plates. telson terminal piece attached to end of sixth ab- dominal segment; forms, together with uropods, a tail fan. tergum dorsal plate on abdominal segment. third maxilliped appendage preceding first leg. thorax central portion of body to which legs and maxillipeds attach. uropods broad paired appendages on sixth abdom- inal segment; often forming, together with telson, a tail fan. adrostral groove "*<>~»~^_ 1 V J 1 1 W 1 , , j . L- X i ~""""^d/l^ — *^^ antennuleT * . y\f e y e J ^ ^supraorbital spine V carapace a ntenKap^^=7«-rJ — -Z_x_ scale aH^^*"^ a n t e n n a-^ «=— _ _j— exopod— _, -i third maxilliped-' s u b c h e 1 a^^-— <^^ Pi subdivided yy carpus ropodus Hegs- -dactyl pleopods_ Figure 1. — Diagram of shrimp in lateral view showing structures and terms used in key. -telson -uropod a n antennu.le epistome postorbital tooth .anterolateral teeth VENTRAL DORSAL Figure 2. — Diagram of crab in dorsoventral views showing structures and terms used in key. KEY TO MARINE DECAPOD CRUSTACEANS OF THE NORTHEASTERN UNITED STATES, INSHORE AND SHELF WATERS General form shrimplike, usually compressed (if depressed, with pleura of second abdom- inal segment overlapping those of first segment); abdomen well developed; pleopods always present and in full number (5 pairs), used for swimming shrimps Suborder Natantia General form lobsterlike or crablike, usually depressed; abdomen either well developed (asymmetrical in a few species adapted for living in mollusk shells) or greatly reduced in size; pleopods often reduced or absent, not used for swimming lobsters; mud shrimps; hermit, porcellanid, and mole crabs; true crabs Suborder Reptantia 18 2 (/) Pleura of second abdominal segment not overlapping those of first segment Section Penaeidea 3 2 (/) Pleura of second abdominal segment overlapping those of first segment Section Caridea 5 Figure 3. — Penaeidean abdomen, lateral view. Figure 4. — Caridean abdomen, lateral view. 3 (2) First 3 pairs of legs chelate, all 5 pairs of legs well developed Family Penaeidae 4 3 (2) First 3 pairs of legs chelate, last 2 pairs of legs absent; slender planktonic species with head greatly elongate Family Sergestidae Lucifer faxoni Figure 5. — Lucifer faxoni; carapace and head appendages, lateral view. 4 (J) Rostrum with ventral teeth Penaeus A (4) Adrostral grooves not extending be- yond base of rostrum P. setiferus, white shrimp Figure 6. — Penaeus setiferus; \ 10 carapace, lateral view. A (4) Adrostral grooves reaching almost to posterior margin of carapace P. aztecus aztecus, brown shrimp Figure 7. — Penaeus aztecus aztecus; \ carapace, lateral view. 4 (J) Rostrum without ventral teeth; carapace with both longitudinal and transverse su- tures Parapenaeus longirostris Figure 8. — Parapenaeus longirostris; carapace, lateral view. 5 5 (2) First pair of legs chelate (minute in some species) 6 2 5 (2) First pair of legs subchelate (always easily visible) Family Crangonidae 15 Figure 9. — Chelate leg with carpus entire. Figure 10. — Subchelate leg with carpus entire. 6 (5) Carpus of second pair of legs entire; first pair of legs always with well-developed chelae Family Palaemonidae 7 6 (5) Carpus of second pair of legs subdivided into 2 or more articles 8 » 7 (6) Rostrum with 6 or more (seldom 5) ventral teeth; mandible with palp Leander tenuicornis Figure 11. — Leander tenuicornis; A. carapace of male, lateral view: B, carapace of female, lateral view: C. mandible. 2 Pasiphaea mullidentata (Pasiphaeidae) with fingers of chelae on first and second legs slender, all edges comblike, is a pelagic form which occurs often enough off New England that its presence should be mentioned. Ovigerous females have a carapace length of 33 to 37 mm. 7 (6) Rostrum with no more than 5 ventral teeth, usually fewer; mandible without palp Palaemonetes A (7) Rostrum with first 2 teeth of dorsal margin behind orbit, dorsal rostral teeth reaching to apex, ventral margin with 3 to 5 teeth; dactyl of second leg with 2 teeth, immovable finger with 1 on cutting edge; carpus of second leg in adult fe- male shorter than palm, in males slightly longer or shorter (1.1 times) than palm P. vulgaris B Figure 12. — Palaemonetes vulgaris; A, carapace, lateral view; B, chela of second leg. A (7) Rostrum with only 1 dorsal tooth behind orbit; dactyl of second leg with single tooth or without teeth, immovable finger without teeth on cutting edge; carpus of second leg in adult female much longer than palm (1.3 to 1.5 times), in male almost as long as whole chela B B (A) Rostrum with unarmed stretch before dagger-shaped tip, ventral margin with 2 to 4, generally 3, teeth; fingers of second leg without teeth on cutting edges P. pugio Figure 13. — Palaemonetes pugio; A, carapace, lateral view; B. chela of second leg. B (A) Rostrum with dorsal teeth reaching up to often bifurcated apex, ventral margin with 4 or 5 (seldom 3) teeth; dactyl of second leg with 1 distinct tooth on cutting edge P. intermedins Figure 14. — Palaemonetes intermedins; A, carapace, lateral view; B, chela of second leg. 7 8 (6) Chelae of first pair of legs distinct Family Hippolytidae 9 8 (6) Chelae of first pair of legs microscopic or absent Family Pandalidae 14 9 (8) Carpus of second leg divided into 3 articles 10 9 (8) Carpus of second leg divided into 7 articles (proximal to distal, 2 short, 1 long, 4 short) 12 Figure 15. — Second leg with subdivided carpus, 3 articles. Figure 16. — Second leg with subdivided carpus, 7 articles. 10 (9) Without series of small spines on anterior margin of carapace below eye 11 10 (9) A series of small spines (5 to 9) along anterior margin of carapace below eye Lotreutes fucorum Figure 17. — Latreutes fucorum; carapace and head appendages, lateral view. 1 1 (10) Rostrum considerably less than twice length of carapace proper and with both dorsal and ventral teeth Hippolyte A A (11) Tip of rostrum not exceeding antennular peduncle H . pleuracanthus Figure 18. — Hippolyte pleuracanthus; carapace and head appendages, lateral view. A (11) Tip of rostrum obviously exceeding antennular peduncle H. zostericola Figure 19. — Hippclyte zostericola; carapace and antennule, lateral view. 11 (10) Rostrum nearly twice length of carapace proper, smooth above, toothed on ventral margin Tozeuma carolinense Figure 20. — Tozeuma carolinense; carapace, lateral view. 12 (9) Supraorbital spines present 13 12 (9) Supraorbital spines absent Eualus A A (12) Tip of rostrum usually not reaching distal edge of eye (rarely exceeding eye) E. pusiolus Figure 21. — Eualus pusiolus; carapace and eye. lateral view. A (12) Tip of rostrum greatly exceeding distal edge of eye B B (A) Rostrum slender, toothed dorsally throughout length E. gaimardii Figure 22. — Eualus gaimardii; carapace, lateral view. B (A ) Rostrum lacking dorsal teeth on dis- tal part beyond eye E. fabricii Figure 23. — Eualus fabricii; carapace, lateral view. 13 (12) Carapace with 2 or more supraorbital spines on each side; third maxilliped with exopod Spirontocaris A A (13) Dorsal teeth extending to, or beyond, posterior third of carapace B A (13) Dorsal teeth falling short of posterior third of carapace 5. phippsii ~7* Figure 24. — Spirontocaris phippsii; carapace, lateral view. B (A ) Ventral margin of rostrum with 4 to 6 teeth; tip ascending to a well-defined single point S. liljeborgii Figure 25. — Spirontocaris lilljeborgii; carapace, lateral view. B (A ) Ventral margin of rostrum with about 2 (occasionally 3) large teeth and variable number of smaller ones (none to many); tip single or double and often almost equalled or surpassed by distalmost ventral tooth S. spinus Figure 26. — Spirontocaris spinus; carapace, lateral view; A, B, two examples of variation in rostral tooth pattern. 10 3 (12) Carapace with 1 supraorbital spine on each side; third maxilliped without exopod Lebbeus A A (13) Four prominent spines along middorsal line of carapace L. groenlandicus Figure 27. — Lebbeus groenlandicus; carapace, lateral view. A (13) No more than 2 spines along dorsal line of carapace B B (A) Rostrum long, tip exceeding proximal article of antennular peduncle in juveniles and entire peduncle in adults L. polaris Figure 28. — Lebbeus polaris; carapace and antennule. lateral view of adult. B (A) Rostrum short, tip not exceeding proximal article of antennular peduncle (body conspicuously banded) L. zebra Figure 29. — Lebbeus zebra; carapace and antennule. lateral view. 11 14 (8) Third maxillipeds with exopod Dichelopandalus leptoceras Figure 30. — Dichelopandalus leptoceras: A, carapace, lateral view; B, third maxilliped showing slender simple exopod at base. 14 (8) Third maxillipeds without exopod Pandalus A A (14) Abdomen with small median spine on posterior edge of third and fourth segments P. borealis Figure 31.— Pandalus borealis: A, carapace, lateral view; B. abdomen, lateral view; C. third maxilliped. A (14) Abdomen with no median spines on segments B B (A) Distolateral spine of antennal scale exceeding extremely narrowed blade; rostrum upturned at about 45° angle P. propinquus Figure 32. — Pandalus propinquus: carapace and antennal scale, lateral view. 12 B (A) Distolateral spine of antennal scale not exceeding somewhat narrowed blade; rostrum upturned at considerably less than 45° angle P. montagui Figure 33. — Pandalus montagui: carapace and antennal scale, lateral view. 15 (5) Second legs slender and chelate 16 15 (5) Second legs reduced and simple, not chelate Sabinea A A (75) Rostrum with rounded tip hardly exceeding eyes; telson with narrow but trun- cate tip bearing 8 or more spines or stout setae S. septemcarinata Figure 34. — Sabinea septemcarinata: A, carapace and eyes, dorsal view; B, tip of telson. A (75) Rostrum with acute tip reaching beyond eyes; telson ending in sharp tip flanked by 1 or 2 spines on each side S. sarsii 0.5 Figure 35. — Sabinea sarsii: A, carapace and eyes, dorsal view; B, tip of telson. 13 16 (15) Second legs almost as long as other legs 17 16 (15) Second legs much shorter than other legs Pontophilus A A (16) Tip of rostrum reaching about to distal edge of eyes P. norvegicus Figure 36. — Pontophilus norvegicus; carapace and eyes, dorsal view. A (16) Tip of rostrum falling far short of distal edge of eyes P. brevirostris Figure 37. — Pontophilus brevirostris; carapace and eyes, dorsal view. 17 (16) Body neither heavily sclerotized nor sculptured Crangon septemspinosa Figure 38. .rangon septemspinosa; carapace and eyes, dorsal view. 14 17 (16) Body heavily sclerotized and sculptured Sclerocrangon boreas Figure 39. — Sclerocrangon boreas; A, carapace and eyes, dorsal view of adult; B, rostrum and eyes of juvenile. 18 (/) Abdomen extended, symmetrical, pleura sometimes, and tail fan always well de- veloped Section Macrura 19 18 (/) Abdomen bent upon itself or flexed beneath thorax; pleura usually small or absent; tail fan variable in development; third legs unlike first, never chelate 24 19 (18) Abdomen well armed, pleura well developed; third legs chelate like first Superfamilv Astacidea, Family Nephropsidae, Homarus americanus, American lobster Figure 40. — Homarus americanus; A, abdomen and tail fan, lateral view; B, tail fan, dorsal view. 19 (18) Abdomen more or less membranous, pleura small or absent; third legs unlike first, never chelate Superfamily Thalassinidea, mud shrimps 20 Figure 41. — Abdomen and tail fan of mud shrimp, lateral view. 15 20 (19) First legs subchelate, dactyls fold- ing to reflexed position when closed . . .Family Laomediidae, Naushonia crangonoides Figure 42. — Naushonia crangonoides; A, carapace, dorsal view; B, subchela of first leg. T 2 1 20 (19) First legs either chelate or approaching subchelate condition, but never with dactyls folding to reflexed position when closed 21 21 (20 ) Rostrum prominent, extending beyond eyes 22 21 (20 ) Rostrum short; flattened, pointed eyes fully exposed Family Calli- anassidae Callianassa atlantica Figure 43. — Callianassa atlantica; A, carapace and eyes, dorsal view; B, major chela of male. 22 (21 ) Rostrum hairy and nearly flat, few teeth along sides, flanked on each side by large spine Family Upogebiidae, Upogebia affinis Figure 44. — Upogebia affinis; A, carapace, dorsal view; B, chela. 16 22 (21) Rostrum hairless, evenly toothed along sides and with median low carina Family Axiidae 23 Figure 45. — Carapace of an axiid, dorsal view. 23 (22) Eyes normal with pigmented, rounded cornea; outer blade of uropods lacking trans- verse suture distally Axius serratus Figure 46. — Axius serratus; A, ocular region, lateral view; B, portion of tail fan, dorsal view. 23 (22) Eyes lacking pigment, flattened obliquely on distal surface; outer blade of uropods with transverse suture distally Calocaris templemani Figure 47. — Calocaris templemani; A, ocular region, lateral view; B, portion of tail fan, dorsal view. 24 (18) Abdomen variously developed and with uropods present; or with uropods absent and only 4 pairs of well-developed legs visible; carapace not apparently fused with epistome Section Anomura, hermit crabs, porcellanids, mole crabs, and lithodids 25 24 (18) Abdomen permanently flexed beneath thorax; uropods absent and 5 pairs of legs vis- ible; carapace fused with epistome Section Brachyura, true crabs 30 17 25 (24) Abdomen well developed, symmetrical or asymmetrical 26 25 (24) Abdomen reduced in size, symmetrical and flexed under thorax Superfamily Hippidea. Family Hippidae, Emerita talpoida, mole crab Figure 48. — Emerita talpoida. lateral view. 26 (25) Abdomen symmetrical (or superficially so), more or less flexed beneath thorax; thorax depressed and crablike Superfamily Galatheidea 27 26 (25) Abdomen asymmetrical, tail fan reduced and adapted for holding body in mollusk shells Superfamily Paguroidea, Family Paguridae, Pagurus, hermit crabs A A (26) Palm of small (left) chela roughly oval in cross section, upper surface flattened, not divided by a ridge B A (26) Palm of small (left) chela triangular in cross section, upper surface divided by longitudinal ridge into 2 obliquely sloping facets E Figure 49. — Cross sections of pagurid palm (propodus); A, oval; B, triangular. B (A) Cornea of eye dilated, length of eyestalks not more than 3.5 times greatest width C B (A) Cornea not dilated, length of eyestalks at least 4 times greatest width (small species) P- annulipes Figure 50. — Pagurus annulipes; A, anterior part of body; B. chelae and carpi, dorsal views. 18 C (B) Both chelipeds slender, sub- cylindrical, relatively smooth or lightly granulate (small species) P. longicarpus Figure 51. — Pagurus longicarpus; A, anterior part of body; B, chelae and carpi, dorsal views. C (B) Both chelipeds stout; conspicuously broad and smooth, or sharply spined D D (C) Dactyl of major chela with sharply produced angle on mesial margin; upper surface of both chelae sharply but even- ly granulated P. pollicaris Figure 52. — Pagurus pollicaris; A. anterior part of body; B, chelae and carpi, dorsal views. D (C) Dactyl of major chela with no sharply produced angle on mesial margin, border usually spiny; upper surface of both chelae covered with short, sharp spines, and often with broad longitudinal red-orange stripe persistent in alcohol P. acadianus Figure 53. — Pagurus acadianus; A, anterior part of body; B, chelae and carpi, dorsal views. 19 E (A) Palm of small (left) chela with conspicuous longitudinal ridge crested with single row of elevated sharp principal spines slanted inward; anterior portion of ster- nite between third legs somewhat rectangular (almost twice as wide as long), setae few and short. (Usually occurs offshore.) P. pubescens Figure 54. — Pagurus pubescens; A, anterior part of body; B, chelae and carpi, dorsal views; C, stemite between third legs, ventral view. E (A ) Palm of small (left) chela with broad longitudinal ridge crested with sharp or blunt spines (tending to form double row) not slanted inward F (£) Chelipeds both sharply spined and hairy on upper surfaces; anterior portion of sternite between third legs almost semicircular (nearly as long as broad), setae many and long. (Usually occurs inshore.) P. arcuatus Figure 55.— Pagurus arcuatus; A, anterior part of body; B, chelae and carpi, dorsal views; C, sternite between third legs, ventral view. 20 F (£) Chelipeds bluntly spined (occasionally sharply) but not hairy on upper surfaces. (Occurs in deep water offshore.) P- politus Figure 56. — Pagurus politus; A, anterior part of body; B. chelae and carpi, dorsal views. 27 (26) Tail fan well developed 28 27 (26) Tail fan lacking, uropods absent; fifth legs hidden making only 4 pairs of legs apparent Family Lithodidae, Lithodes maja Figure 57. — Well-developed tail fan of porcellanid crab, dorsal view. Figure 58. — Lithodes maja, terminal portion of abdomen. 21 28 (27) Form somewhat lobsterlike; rostrum long and narrow Family Galatheidae, Munida . . A A (28) Second (apparent first) abdominal segment armed with tiny anterior spines M . iris Figure 59. — Munida iris, dorsal view with abdomen flexed. A (28) Both second (apparent first) and third abdominal segments armed with series of tiny anterior spines (a large species) M. valida Figure 60. — Munida valida. dorsal view with abdomen flexed. 28 (27) Form crablike; rostrum short and broad or absent Family Porcellanidae 29 29 (28) Carapace distinctly broader than long, front smooth in dorsal view Polyonyx gibbesi Figure 61. — Polyonyx gibbesi, carapace and chelae. 22 29 (28) Carapace longer than broad, front strongly tridentate in dorsal view Porcellana sigesbiana Figure 62. — Porcellana sigesbiana; carapace, and chelae (twisted to show tooth pattern). 30 (24) Frame of mouth elongate and triangular, sides converging anteriorly Subsection Oxystomata 3 1 30 (24) Frame of mouth either rectangular (prolonged in certain swimming crabs) with sides parallel, or transversely somewhat ellipsoid or kidney shaped 33 1 ^§g?% 1 Figure 63. — Brachyuran mouth frames; A, triangular; B, rectangular; C, kidney-shaped or transversely ellipsoid. 31 (30) Carapace very short, exposing first 2 or 3 abdominal terga in dorsal view; front with 2 bifid (appear as 4) laminar teeth Family Dorippidae Ethusa microphthalma Figure 64. — Ethusa microphthalma, portion of body in dorsal view. 31 (30) Carapace not so short, exposing little if any of abdomen in dorsal view 23 32 32 (31) Body hemispherical Family Leucosiidae: Persephona aquilonaris Figure 65. — Persephona aquilonaris; carapace and eyes, right cheliped. 32 (31 ) Body longer than broad; each cheliped with greatly extended lateral spine on merus Family Calappidae: Acanthocarpus alexandri Figure 66.— Acanthocarpus alexandri; carapace and eyes, chelipeds. 33 (30 ) Body elongate rectangular in dorsal view; last pair of legs permanently folded over back; first pleopods present in female Subsection Dromiacea, Family Homolidae: Homola barbata Figure 67. — Homola barabata; dorsal view, portion of body and insertion of last pair of legs. 33 (30) Body never elongate rectangular in dorsal view; last pair of legs not permanently folded over back; first pleopods lacking in female Subsection Brachygnatha 24 34 34 (33) Body conspicuously narrowed in front; rostrum usually distinct and often forked; or- bits often incomplete Superfamily Oxyrhyncha, spider crabs .35 34 (33) Body moderate to broad in front; rostrum absent or greatly reduced; orbits usually complete Superfamily Brachyrhyncha 41 35 (34) Chelipeds not much larger than other legs Family Majidae 36 35 (34) Chelipeds very much larger than other legs Family Parthenopidae 40 36 (35) Whole length of rostral horns either coalesced or closely approximated along mid- line; male abdomen terminally broadened, telson elliptical to subquadrate Subfamily Oregoniinae, Hyas A (36) Hepatic region behind post- orbital spine not expanded H . araneus Figure 68. — Hyas araneus; A, carapace and eyes; B, male abdomen. A (36) Hepatic region behind postorbital spine expanded laterally H. coarctatus Figure 69. — Hyas coarctatus, carapace and eyes. 36 (35) Rostral horns divergent near tip; male abdomen not terminally broadened, telson subtriangular Figure 70. — Male abdomen of spider crab with subtriangular telson. 25 37 (36) Eyes without orbits; eyestalks retractile against acute postocular spine, affording no concealment; proximal (fused) antennal article extremely slender (viewed ventrally) Subfamily Inachinae 38 37 (36) Eyes with commencing orbits, each composed of cupped postocular process into which eye retracts, and supraocular eave; proximal (fused) antennal article not ex- tremely slender (viewed ventrally) Subfamily Pisinae 39 0: > ^ Figure 71. — Orbital areas of spider crabs in ventral view; A. Inachinae; B, Pisinae. 38 (57) Fused proximal article of antenna terminating in single blunt spine. [Rathbun (1925) recognized New England form as subspecies marthae.] Euprognatha rastellifera Figure 72. — Euprognatha rastellifera, portion of body in dorsal view. 38 (37) Fused proximal article of antenna with compound lateral spines Collodes robustus Figure 73. — Collodes robustus, portion of body in dorsal view. 26 39 (37) Supraocular eave and postocular process touching or somewhat overlapping Libinia A A (39) Median line of carapace with about 9 spines and/or spiniform tubercles L. emarginata Figure 74. — Libinia emarginata, portion of body in dorsal view. A (39) Median line of carapace with about 6 spines and/or spiniform tubercles L. ditbia Figure 75. — Libinia dubia, carapace and eyes. 39 (37) Supraocular eave and postocular spine or process clearly separated (small, smooth, rounded, pubescent species) Pelia mutica Figure 76. — Pelia mutica, carapace and eyes. 27 40 (35) Carapace not laterally expanded over walking legs; unevenly spinose .... Parthenope pourtalesii Figure 77. — Parthenope pourtalesii, carapace and right cheliped. 40 (35) Carapace more or less laterally expanded forming a vault overlying and concealing walking legs; nearly smooth Heterocrypta granulata Figure 78. — Heterocrypta granulata, carapace and left cheliped. 41 (34) Body round or transversely ellipsoid 42 41 (34) Body quadrate; squared and broadest in front, occasionally somewhat narrowed and rounded 58 42 (41) Free living crabs with parallel sided mouth frame 43 42 (41) Small, usually commensal crabs with reduced eyes; adult females often with carapace somewhat membranous; mouth frame transversely somewhat ellipsoid or kidney shaped Family Pinnotheridae 56 43 (42) Legs (especially last pair) more or less flattened for swimming Family Portunidae 44 43 (42) Legs not flattened for swimming 49 28 44 (43) Carapace with 5 teeth on anterolateral margin 44 (43) Carapace with 9 teeth on anterolateral margin 45 47 Figure 79.— Anterolateral border of portunid carapace; A, 5 teeth; B. 9 teeth. 45 (44) Distal articles of fifth legs not paddlelike 45 (44) Distal articles of fifth legs paddlelike Carcinus maenas 46 Figure 80. — Fifth leg of portunid crab; A, not paddlelike; B, paddlelike. 46 (45) Anterolateral teeth similar; dactyl of swimming paddles broadly oval; male abdomen oblong Ovalipes ocellatus Figure 81. — Ovalipes ocellatus, carapace and eyes. 46 (45) Anterolateral teeth dissimilar, fifth an elongate lateral spine; dactyl of swimming paddle broadly pointed; male abdomen triangular Bathynectes superbus Figure 82. — Bathynectes superbus, carapace and eyes. 29 47 (44) Carpus with mesiodistal spine; abdomen of male triangular 48 47 (44) Carpus without mesiodistal spine; abdomen of male T-shaped Callinectes A B Figure 83.— Carpus of portunid right cheliped; A, Portunus; B, Callinectes. A (47) Front with 2 prominent, broad based, contiguous, triangular teeth between inner orbitals; frontal teeth occasionally with rudimentary submesial teeth on inner slopes C. sapidus Figure 84. — Callinectes sapidus, frontal and orbital regions. A (47) Front with 2 prominent teeth between inner orbitals separated by flattened space bearing pair of rudimentary submesial teeth C. similis 10 i i Figure 85. — Callinectes similis, frontal and orbital regions. 48 (47) Front with 2 bifurcated teeth between inner orbitals; fissures on orbital margin broad- ly open; color light brown, thickly covered over dorsal surface with small white spots, reticulate pattern persisting in alcohol Arenaeus cribrarius ■"■■'■■ ?f°°o^?° 10 Figure 86.— Arenaeus cribrarius, frontal and orbital regions. 30 48 (47) Front with 4 separate teeth between inner orbitals; fissures on orbital margin closed except for shallow notch; color varied but never as above Portunus A A (48) Carapace nearly devoid of ridges and without noticeable short thick covering of hairs P- sayi Figure 87. — Portunus sayi, carapace and eyes. A (48) Carapace with ridges fairly prominent and with noticeable covering of short thick hairs B B (A ) Lateral spine relatively short, not more than about twice length of preceding tooth; a number of meandering ridges on carapace P. spinimanus Figure 88. — Portunus spinimanus, carapace and eyes. B (A) Lateral spine long, obviously more than twice length of preceding tooth; a single ridge (often darkened) leading to lateral spine on each side of carapace P. gibbesii Figure 89. — Portunus gibbesii, carapace and eyes. 31 49 (43) Front with median tooth; antennules folding longitudinally Family Cancridae, Cancer ... A ~&^T~^ Figure 90.— Cancer; A, frontal and orbital regions; B, antennules folded longitudinally. A (49) Anterolateral teeth of carapace with margins granulate; chelipeds granulate, not denticulate C. irroratus Figure 91.— Cancer irroratus; A, right anterolateral border; B. dactyl and upper border of chela. A (49) Anterolateral teeth of carapace with denticulate margins; upper margin of palm denticulate C. borealis Figure 92.— Cancer borealis; A, right anterolateral border; B, dactyl and upper border of chela. 49 (43) Front lacking median tooth; antennules folding transversely or obliquely 50 50 (49) Body transversely oval; fifth anterolateral tooth not enlarged and spinelike; legs not extremely long and slender (occur in shallow water) Family Xanthidae 50 (49 ) Body nearly as long as broad; fifth anterolateral tooth enlarged into lateral spine (blunt in adult); legs extremely long and slender; (usually occurs beyond con- tinental shelf) Family Geryonidae, Geryon quinquedens Figure 93. — Geryon quinquedens; A, carapace and eyes of young; B. orbital and anterolateral border of adult. 51 32 51 (50) Extreme edge of frontal margin with shallow transverse groove (under magnification) Rhithropanopeus harrisii Figure 94. — Rhithropanopeus harrisii, frontal view of body showing transversely grooved front. 51 (50) Extreme edge of frontal margin not transversely grooved, each half presenting single edge (under magnification) 52 52 (51) Major chela with a more or less conspicuous tooth at base of dactyl, tooth often of contrasting color 53 Figure 95. — Xanthid major chela with large basal tooth on dactyl. 52 (51 ) Major chela with no tooth at base of dactyl, or with obsolescent tooth little if any larger than adjacent teeth 55 53 (52) Third and fourth teeth of anterolateral border definitely pointed forward with outer borders curved 54 53 (52) Third and fourth teeth of anterolateral border triangular and pointing outward or slightly forward, outer borders not conspicuously curved Hexapanopeus angustifrons Figure 96. — Hexapanopeus angustifrons, carapace and eyes. 33 54 (53) Tooth at base of major dactyl large and conspicuous; carapace definitely arched above Panopeus herbstii Figure 97. — Panopeus herbstii, carapace and eyes. 54 (53) Tooth at base of major dactyl present but often not large and conspicuous; posterior two-thirds of carapace flattened above Eurypanopeus depress us Figure 98. — Eurypanopeus depressus; A, carapace and eyes; B. fingers of minor chela, inner view. 55 (52) Ischium of third maxillipeds with prominent red spot on appressed surface; fingers of minor chela hollowed or spoon shaped on opposed surfaces distally . . . Eurypanopeus depressus 55 (52) Ischium of third maxillipeds usually lacking red spot on appressed surface, very small in few individuals possessing it; fingers of minor chela hooked but not spoon shaped on opposed surfaces distally N eopanope sayi Figure 99. — N eopanope sayi; A, carapace and eyes; B. fingers of minor chela, inner view. 34 56 (42) Dactyls of walking legs simple, acute 57 56 (42) Dactyls of first, second, and third walking legs bifurcate Dissodactylus mellitae B Figure 100. — Dissodactylus mellitae; A, carapace; B, walking leg with bifurcate dactyl. 57 (56) Third walking legs little if any longer than other legs Pinnotheres A A (57) Small, hard-stage males and females B A (57) Older, larger, posthard (soft) females (and male maculatus) C B (A ) Carapace with a striking pattern of light spots on dark background of pubescence P. maculatus B (A ) No striking color pattern P. ostreum '.■■■-. Figure 101. — Carapace and eyes of male Pinnotheres; A, maculatus; B, ostreum. C (B) Carapace nearly naked C (B) Carapace covered with short deciduous pubescence . . P. ostreum P. maculatus Figure 102. — Carapace of mature female Pinnotheres; A, maculatus; B, ostreum, including portion of greatly expanded abdomen. 35 57 (56) Third walking leg longer and stronger than others, often considerably so Pinnixa A A (57) Chela with immovable finger nearly same length as dactyl, straight or nearly so, not bent downward P. cylindrica \ " ' s . A , i , b Figure 103. — Pinnixa cylindrica: A. carapace and eyes; B. chela. A (56) Chela with immovable finger shorter than dactyl, bent downward, or reduced to stub B B (A ) Propodus of third walking leg less than twice as long as wide P. chaetopterana j 5^ B 1 C _2 , D Figure 104. — Pinnixa chaetopterana: A, carapace and eyes; B, third leg; C. chela of male; D, chela of female. B (A) Propodus of third walking leg slender, twice or more than twice as long as wide P. savana Figure 105. — Pinnixa sayana; A. carapace and eyes; B. third leg. 36 58 (41) Eyestalks shorter than width of front; gap of varying size between third maxillipeds Family Grapsidae 59 58 (41) Eyestalks longer than width of front; third maxillipeds nearly or quite closing over buccal area Family Ocypodidae 60 59 (58) Carapace broader than long and almost rectangular in outline; third maxillipeds with oblique hairy ridge crossing ischium and merus Sesarma reticulatum Figure 106. — Sesarma reticulatum; A. carapace and eyes: B, third maxilliped. 59 (58) Carapace about as long as broad, somewhat narrowed and rounded in adults; third maxillipeds without hairy oblique ridge crossing ischium and merus; legs strongly fringed with hairs. (Occurs on Sargassum and flotsam.) Planes minutus \ - / si *w X < /* Figure 107 — Planes minutus; carapace and eyes. 37 60 (58) Stout eyestalks with conspicuous, enlarged, club-shaped cornea; chelipeds of both sexes well developed and somewhat unequal Ocypode quadrata Figure 108. — Ocypode quadrata; carapace and eyes. 60 (58) Slender eyestalks with cornea not conspicuously enlarged and club-shaped; chelipeds of male very unequal, of female equal and quite small Uca A A (60) Last legs with upper surface of merus straight; large chela of male without oblique tuberculate ridge on inner surface of palm extending upward from lower margin U. pugilator A —^-1 ^ B Figure 109. — Uca pugilator; A, merus of last leg; C, chela of male, inner view. U. pugnax, B. merus of last leg. A (60) Last legs with upper surface of merus curved; large chela of male with oblique tuberculate ridge on inner surface of palm extending upward from lower margin B B (A) A transverse shelf or depression on carapace behind orbit; leg joints red on large cheliped U. minax Figure 1 10. — Uca minax; A, chela of male, inner view; B. carapace and eyes. 38 B (A) Without transverse shelf or depression on carapace behind orbit; leg joints not red on large cheliped V. pugnax Figure 1 11. — Uca pugnax; A, chela of male, inner view; B, carapace and eyes. ANNOTATED SYSTEMATIC LIST This check list is arranged in a systematic hierar- chy accommodating categories from order to species, with genera arranged alphabetically under family and species under genus. Notes on distribution, habitat, and general occurrence are given. Refer- ences to important works are cited. Depths are rounded to 5-m intervals, except those below 5 m. Class CRUSTACEA Order DECAPODA Suborder NATANTIA Section PENAEIDEA Family SERGESTIDAE Lucifer faxoni Borradaile, 1915. Nova Scotia to Rio de Janeiro, Brazil; primarily in coastal waters. Surface to 90 m (Bowman and Mc- Cain, 1967). FAMILY PENAEIDAE Parapenaeus longirostris (Lucas, 1849). Martha's Vineyard, Mass., to Gulf of Mex- ico off Florida, Louisiana, and peninsula de Yucatan; Gulf of Paria off Venezuela; coast of Portugal to Morocco; Mediterranean Sea from Spain to Asia Minor. 25-350 m in west- ern Atlantic; to 460 m in Mediterranean. Rare in north (Williams, 1965). Penaeus (Melicertus) aztecus aztecus Ives, 1891. Brown shrimp. West Falmouth Harbor and Martha's Vineyard, Mass., to off Sanibel Island, Fla.; Appalachicola Bay around Gulf of Mexico to northwestern Estado de Yucatan. Fished commercially. Shallows to 110 m, occasionally 165 m. Summer and fall in north, rare (Perez Farfante, 1969). Penaeus (Litopenaeus) setiferus (Linnaeus, 1767). White shrimp. Fire Island, N.Y., to St. Lucie Inlet, Fla. ; mouth Ochlockonee River [Franklin County], Fla., to northwestern Es- tado de Yucatan. Fished commercially. Shal- lows to 35 m, occasionally to 85 m. Summer in north, rare (Perez Farfante, 1969). Section CARIDEA Family PASIPHAEIDAE Pasiphaea multidentata Esmark, 1866. North- ern Atlantic; western Norway to Mediterra- nean Sea; Iceland; Greenland; Cape Breton Island to Cape Cod. 10 (rarely) to 2,000 m (Sivertsen and Holthuis, 1956). Family PALAEMONIDAE Leander tenuicornis (Say, 1818). Tropical and subtropical waters of world except west coast of Americas; Newfoundland Banks, Bay of Fundy, and New England to Falkland Islands in western Atlantic. Floating Sargassum, pilings, and submerged vegetation (Chace, 1972). Palaemonetes (Palaemonetes) intermedius Holthuis, 1949. Long Island, N.Y., to Port Aransas, Tex. (and literature records from Vineyard Sound, Mass.). Estuaries, espe- cially in submerged vegetation (Holthuis, 1952). Palaemonetes (Palaemonetes) pugio Holthuis. 1949. Newcastle, Me., and Yarmouth, Nova Scotia, to Port Aransas, Tex. (literature re- 39 cords to Corpus Christi, Tex.). Estuaries, especially in submerged vegetation (Holth- uis, 1952). Nova Scotia and other Maine re- cords from R. E. Knowlton and E. C. Bous- field (pers. comm.). Palaemonetes (Palaemonetes) vulgaris (Say, 1818). Southwest coast Gulf of St. Lawrence to Cameron County, Tex. (literature records somewhat farther south). Estuaries, to 15 m, especially in submerged vegetation (Holth- uis, 1952). Canadian distribution from R. E. Knowlton (pers. comm.). Family HIPPOLYTIDAE Eualus fabricii KrOyer, 1841. North Greenland to Cape Cod; Arctic Alaska to Cook Inlet; Siberian seacoast; Japanese Sea. 4-200 m (Holthuis, 1947). Eualus gaimardii (H. Milne Edwards, 1837). Circumarctic southward to Cape Cod, North Sea (Kiel and Yarmouth), White Sea, Sitka (Alaska), Siberia. 10-900 m (Holthuis, 1947). Eualus pusiolus (KrOyer, 1841). Gulf of St. Lawrence to off Cape Henry, Va.; Bering Island, Alaska Peninsula, and Aleutian Is- lands; San Juan Islands, Wash.; Iceland; Murman coast to Channel Islands; northeast- ern Spain. < 1-500 m (Holthuis, 1947). Hippolyte pleuracanthus (Stimpson, 1871). Connecticut to North Carolina. Beds of sub- merged vegetation (Chace, 1972). Hippolyte zostericola (Smith, 1873). Bermuda; Massachusetts; North Carolina to Yucatan; West Indies to Trinidad and Curacao. Beds of submerged vegetation (Chace, 1972). Latreutes fucorum (Fabricius, 1798). Western North Atlantic between lat. 10° and 50°N; Azores and Cape Verde Islands. Pelagic and sublittoral, in floating masses of Sargassum and submerged grasses (Chace, 1972). Lebbeus groenlandicus (Fabricius, 1775). Greenland southward to Rhode Island; arctic Canada and Alaska; Bering Sea to Puget Sound; Sea of Okhotsk. 2-210 m (Holthuis, 1947). Lebbeus polaris (Sabine, 1821). Circumarctic southward to off Chesapeake Bay, Bering Sea, Sea of Okhotsk, Skagerrak, and Heb- rides.