FISHERY BULLETIN: VOL. 69, NO. 4 



americana. These indigenous species are all 

 inhabitants of warm-temperate to troi)ical areas; 

 none are subarctic or boreal. Presumably mem- 

 bers of this group have been unable to bridge 

 the ocean because of unfavorable water tem- 

 peratures across the northern rim of the At- 

 lantic Ocean where water depths are favorable. 

 Amblyops abbreviata and Metenjthrops robmta. 

 in addition to having an amphi-Atlantic distri- 

 bution, are also widely distributed in the North 

 Pacific Ocean. Only Aiirhidliiid tijpica, which 

 occurs in the Atlantic and Pacific Oceans, and 

 Promysis atldjificd, which occurs in the North 

 and South Atlantic Oceans, do not fall into the 

 two main categories above. 



The Euroi^ean si)ecies Praiuuis flexHonuti. 

 now well established in the coastal waters of 

 New England, may have been introduced rather 

 recently by the activities of man (discu;:sion on 

 pages 735 and 73G). 



The information presented herein supple- 

 ments our scanty knowledge of the biology of 

 individual sjiecies and also ])rovides a general 

 review of the kinds of mysids in the western 

 Atlantic, their distribution, relative abundance, 

 and relations with some environmental char- 

 acteristics. 



MATERIALS AND METHODS 



Three million specimens i'ei)resenting 19 spe- 

 cies and 16 genera were collected during 19.53-69 

 from the continental shelf and slope off the east- 

 ern coast of the United States between Canada 

 and southern Florida. 



Two-thirds of the samples were collected from 

 the offshore New England region, between Nova 

 Scotia, Canada, and Long Island, N.Y. (Figure 

 1). About 2,000 samples were analyzed from 

 this region. Sparse sampling (1,000 samples) 

 was conducted between New York and Key 

 West, Fla. Most of the collections were taken 

 by six oceanograiihic research vessels: Alba- 

 tross III, Albatross IV. Blueback, and Delaware, 

 all operated by the National Marine Fisheries 

 Service; and Asterias and Gosnold, operated by 

 the Woods Hole Oceanographic Institution, 

 Woods Hole, Mass. Collection data and biologi- 

 cal information for each sample of nivsids in 



the NMFS collection are given in Burns and 

 Wigley." The collection data include: latitude 

 and longitude, water depth, date, sampling gear, 

 vessel name, cruise and station number. The 

 biological information consists of the number 

 of specimens, summary of body length by spe- 

 cies, sex, and stage of maturity. 



The 12 kinds of sampling instruments used 

 in collecting mysids were: bottom skimmer, 

 Cam!)bell gral:>, diii net, 30-cm ring net, 1-m 

 i-ing net, plankton net, naturalists dredge, otter 

 trawl, sled-mounted ring net, Smith-Mclntyre 

 grab, shrimj) trawl, and Van Veen grab. A few 

 sjiecimens were obtained from fish stomachs. 

 The kinds of gear mo.st successful in catching 

 mysids were ring nets, grab samjjlers, the bot- 

 tom skimmer (a combination dredge and plank- 

 ton net), and dredges with fine-mesh nets. Only 

 occasional siiecimens were obtained with bot- 

 tom trawls and dredges with coarse mesh 

 nets. 



Mysids were preserved in Formalin at sea 

 and transferred to ethyl alcohol at the time 

 the sami)les were sorted in the laboratory 

 ashore. 



In classifying larvae according to their 

 stage of development, we have followed Nair 

 (1939). 



A total of 5,-566 specimens were examined 

 under low-power magnification with a binocular 

 microscojie to determine sex and stage of 

 maturity and to measure size. Body length 

 was measured from the anterior margin of the 

 carapace to the posterior end of the telson, 

 using an ocular micrometer in the micro- 

 scope. 



SYSTEMATIC ARRANGEMENT 



For the .systematic arrangement and termi- 

 nology we have followed Tattersall and Tatter- 

 sall (1951). The list of species in their respec- 

 tive groupings are as follows: 



= Burns, Bruce R., and Roland L. Wigley. 1970. Col- 

 lection and bioloRical data pertaining to my.sids in the 

 collection at the BCF Biological Laboratory, Woods Hole. 

 Lab. Ref. No. 70-2, 36 p. Bur. Comnicr. Fi.sh. Biol. 

 Lab., Wood.s Hole, .Mass. (Unpublished manuscript.) 



718 



