FISHERY BULLETIN: VOL. 76. NO. 1 



characters which were used to separate these two 

 species were the specialized thoracic hooks and the 

 abdominal papillae. Curtis documented the ap- 

 pearance of first hooks, then papillae, with the 

 increasing size of the animals. He also observed 

 various intermediate stages with the population. 



Paraonidae 



In a revision of the family Paraonidae by Strel- 

 zov(1973), Mcintosh's species of Sco/eco/epzWes (?) 

 jeffreysii was shown to be an indeterminable 

 Aricidea sp. The records of A . jeffreysii from New 

 England (Pettibone 1963a) and from the Chesa- 

 peake Bay (Wass 1972) were referred to A. 

 catherinae Laubier by Strelzov (1973:91). The rec- 

 ord by Day ( 1973) of A. cerruti (not Laubier) from 

 North Carolina should also be referred to A. 

 catherinae. Strelzov (1973:108) also has referred 

 Cirrophorus lyriformis (Annekova) to C. bran- 

 chiatus Ehlers. The species collected in our mid- 

 shelf collection thus was referred to C. bran- 

 chiatus. Both species were recorded by Day ( 1973) 

 from North Carolina. These specimens probably 

 require further examination. 



Sabellidae 



Banse (1970, 1972) revised the generic descrip- 

 tions of both Chone spp. and Euchone spp. em- 

 phasizing the branchial crown, setae, and anterior 

 abdominal segments (Euchone). 



There were many specimens of Euchone spp. 

 and Chone spp. on the continental shelf off Dela- 

 ware. We experienced difficulty in distinguishing 

 the species because many of our specimens were 

 juvenile forms. Our specimens of Euchone spp. 

 appear to have more variability than those re- 

 ported by Banse. In addition, many specimens 

 were damaged or lacked branchial crowns so the 

 number of radioles and the palmate membrane 

 could not be observed. The specimens of Euchone 

 compared most favorably with E. incolor and E. 

 elegans, and the specimens of Chone spp. were 

 most like C. duneri. 



ZOOGEOGRAPHY 



Some 125 species of polychaetes (and 8 other 

 species identified only to genus) were collected in 

 the Delaware Bay area. Based on the literature, 

 116 species have been collected in areas off New 

 England (Table 2, column 1). Sixty-seven species 



were cited from Chesapeake Bay (Wass 1972; 

 Table 2 , column 3 ). The number of species common 

 to the Chesapeake and Delaware Bay areas is 

 lower than expected, considering their proximity. 

 This was mainly because many of the offshore 

 species encountered in our work were not included 

 in Wass's list. However, work in progress on the 

 mid-Atlantic shelf is expected to change this (D. 

 Boesch, pers. commun.). Ninety-one of the species 

 were common to North Carolina (Hartman 1945; 

 Day 1973; Gardiner 1975; Table 2, column 4). 



Examination of the local species revealed that 

 for 11 of them, this was the southern extent of 

 their range; i.e., they were reported for New En- 

 gland, but not from Chesapeake Bay or North 

 Carolina (Table 2). Only three species were found 

 to be at the northern limit of their range in the 

 Delaware Bay area, having been found in 

 Chesapeake Bay or North Carolina, but not New 

 England. It appears that the polychaete fauna 

 from the Delaware Bay area is more closely re- 

 lated to the northern than the southern fauna. 

 Two of the species with their northern range in 

 this area, Prionospio cristata and Clymenella mu- 

 cosa., were offshore species. The probability of lar- 

 vae being carried north into the area by the Gulf 

 Stream is great, as Lear and Pesch^^ have shown 

 the intrusion of this water from offshore during 

 the winter and summer months. 



Data from Hartman (1965) and Hartman and 

 Fauchald (1971) showed that 14 species, which 

 were collected in depths >200 m, were also found 

 in our samples (Table 2, column 2). Seven of these 

 species were recorded only in our offshore samples 

 (J). The remaining seven species, Brania clavata, 

 Paradoneis lyra, Lumbrineris fragilis, Ampharete 

 arctica, Heteromastus filiformis, Chaetozone 

 setosa, and Glycera americana, were also found in 

 the estuary. It was interesting to note that of these 

 seven species, H. filiformis and C. setosa belong to 

 particularly difficult families taxonomically. In 

 our work, H. filiformis was found in salinities as 

 low as 5%o. The species was reported in depths of 

 >1,000 m by Hartman (1965) and Hartman and 

 Fauchald ( 1971). Lumbrineris fragilis, L. latrielli, 

 Aricidea suecica, Prionospio steenstrupi, and 

 Exogone dispar are other species given wide dis- 

 tributions in the literature (M. Pettibone pers. 

 commun.). The distribution of species over such a 



i^Lear, D. W., and G. G. Pesch. 1975. Effects of ocean disposal 

 activities on the mid-continental shelf environment off Dela- 

 ware and Maryland. EPA Reg. Ill Rep., 78 p. 



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