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Marine Flora and Fauna of the Northeastern 

 United States. Copepoda: Harpacticoida' 



BRUCE C.COULL^ 



ABSTRACT 



This manual contains an introduction to the general biologv', an illustrated key, an annotated 

 systematic list, a selected bibliography, and an index of the 72 genera and 121 species of marine har- 

 pacticoid copepods reported from New Jersey to Maine. The key facilitates identification to genus, 

 whereas the annotated systematic list discusses each known species. 



INTRODUCTION 



Harpacticoid copepods appear to be ubiquitous in the 

 marine environment, occurring from tide pools to the 

 abyssal zone. The suborder Harpacticoida contains ap- 

 proximately 1,500 species of which about 9>W"( are 

 marine. Despite their abundance in the world's oceans, 

 the harpacticoid fauna of the northeastern United States 

 is poorly known. Only one major work (Wilson 1932) 

 deals with the northeastern fauna as a whole. The 

 remainder of the species are reported in theses and short 

 papers. The 72 genera and 121 species here reported are 

 from the northeast and the keys that follow include those 

 genera reported in the literature as occurring between 

 New Jersey and Maine. 



Definition and Diagnostic Characters 



Harpacticoida, one of seven orders of the subclass 

 Copepoda, contains small copepods ranging in size from 

 0.2 to 2.5 mm. Of these seven orders three (Calanoida, 

 Cyclopoida, and Harpacticoida) are primarily free living, 

 although many Cyclopoida are associated to varying 

 degrees with marine invertebrates. The other four orders, 

 all symbionts of one sort or another, include the 

 Notodelphyoida, commensals in tunicates; the 

 Monstrilloida, which are parasitic in polychaetes as lar- 

 vae and lack mouthparts and a functional gut in the 

 planktonir adult stage; and the Caligoida and Ler- 

 naeopoduida, fish ectocommensals or ectoparasites with 

 highly modified bodies. 



Following Gooding's (1957) terminology the copepod 

 body is divided into two major regions as delineated by 

 its narrowest constriction, i.e., the anterior prosome in 

 front of the constriction and the posterior urosome 

 behind the constriction. In most of these, the anterior 

 prosome is further divided into a cephalosome with all 

 the head appendages and the first thoracic appendages 



'Conlribution No. 102 from the Belle VV. Bariich Institute for Marine 

 Biology and Coastal Research. 



■Belle VV. Baruch Institute for Marine Biology and Coastal Research 

 and the Department of Biology, University of South Carolina, Columbia, 

 SC 29208. 



(the maxillipeds), and the "metasome," including 

 somites with legs 1-4 (or 5 in calanoids). Cephalothorax 

 is used to define the cephalosome and any fused swim- 

 ming legs [e.g., in most harpacticoids the first leg (P,) 

 somite is fused to the cephalosome]. Thus the fused 

 cephalosome and P, somite represent the cephalothorax. 

 The "urosome" is then the remaining posterior somites 

 and the animal terminates with the caudal rami. The 

 harpacticoids may be distinguished from the calanoids 

 and cyclopoids by: 1) the position of the prosome- 

 urosome articulation (between the fifth and sixth 

 postcephalosome segments in the harpacticoids and 

 cyclopoids, but between the sixth and seventh 

 postcephalosome somites in the calanoids); 2) antennule, 

 Ai, length: generally > 22 segments (usually half the 

 length of the body) in the calanoids, generally between 10 

 and 22 segments (not reaching to the end of prosome) in 

 cyclopoids although some have fewer segments, and very 

 short and < 10 segments in the harpacticoids; and 3) 

 structure of the antennae, A , (biramous in the calanoids 

 and harpacticoids and uniramous, i.e., lacking an exo- 

 pod, in the cyclopoids). See Kaestner (1969, Chapter 7) 

 for an overview of the Copepoda. 



The urosome in harpacticoids starts with the somite 

 that bears the fifth legs. The last urosomal somite, on 

 which the anus opens, has a pair of setose projections, the 

 caudal rami, which bear caudal setae. The generalized 

 harpacticoid is linear in shape with the prosome slightly 

 wider than the urosome and the entire body gradually 

 tapering posteriorly. There is, however, a wide variety of 

 body shapes and forms ranging from slender, elongate 

 vermiform organisms to oval, dorsoventrally flattened 

 ones. Nine general body shapes are defined in Figure 1 

 (see legend). They represent most, but by no means all, 

 the body shapes exploited by the harpacticoids. In the 

 key that follows, each genus is defined as to general body 

 shape, which should help the reader visualize the gross 

 morphology of the animal. 



I caution the reader and user of the key not to use body 

 shape as the only criterion for distinguishing the genera. 

 The body forms in Figure 1 are given as generalizations 

 and four or more families may have the same body form 

 which, then, might include some 40 or more genera. For 

 example, the body form "fusiform prehensile" is found in 



