dorsal tentacle or gill originates on setiger four (Webster and Bene- 

 dict 1887: Laubier 1963; Day 1967). 



DISTRIBUTION: Listed by Gosner (1971) as a boreal species, 

 found between Cape Cod and the Bay of Fundy. Also collected in 

 the New York Bight and reported from Denmark, the North Atlan- 

 tic. Greenland, the coast of Chile, and the Sea of Japan (Webster 

 and Benedict 1887: Curtis 1977; Pearce, Rogers, Caracciolo, and 

 Halsey 1977). 



HABITAT: Inhabitant of mud and sandy mud in depths of 1 1-22 

 m (Webster and Benedict 1887; Day 1967; Gosner 1971). Fauchald 

 (1977) says cossurids are common in sand and especially in deep 

 slope abyssal muds. 



In the New York Bight apex, Cossura longocirrata was collected 

 in depths ranging from about 23 to 46 m. It was characteristic of the 

 highest organic fine sandy and silty sediments (Fig. 53; Table 1). 

 Summer and winter distributions were almost identical. 



FEEDING ECOLOGY: Cossurids appear to be burrowing 

 deposit feeders, using the eversible, soft, unarmed pharynx in feed- 

 ing. The dorsal tentacle also appears to be sensory and, addition- 

 ally, may be respiratory in function since it is well equipped with 

 blood vessels (Day 1967; Fauchald 1977). 



REPRODUCTION AND GROWTH: Curtis (1977) collected C. 

 longocirrata in Greenland, however, no gametes were seen and the 

 reproductive biology of the species remains unknown. 



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Order Terebellida 



Ampharete arctica Malmgren, 1866 



DESCRIPTION: Tubicolous worms, inhabitating a membranous 

 tube covered with mud. sand grains, or foreign matter (Day 1967; 

 Gosner 1971). In our collections, length averaged 15-18 mm. 



DISTRIBUTION: Cosmopolitan (Hartman 1969). 



HABITAT: In the New York Bight apex, Ampharete arctica was 

 collected in depths from 10.9 to 45.6 m. It was usually associated 

 with fine to medium sandy sediments with low to medium organic 

 content, although it did occur in low densities (10/m-) in high 

 organic areas (Fig. 54; Table 1). 



FEEDING ECOLOGY: The Ampharetidae are sessile deposit 

 feeders which gather food particles from the surface of sand or mud 

 by means of buccal tentacles which can be extruded from the mouth 

 (Day 1967; Jumars and Fauchald 1977). 



Yablonskaya (1976) has found that the food of Ampharetidae 

 from the Azov and Caspian Seas (U.S.S.R.) consists of flocculent 

 organic-mineral particles with some remains of diatoms, blue- 

 green and green algae. Most small ampharetids either collected par- 

 ticles of plant detritus from the sediment surface or filtered them 

 from the water layer immediately above the sediment. 



REPRODUCTION AND GROWTH: Little information was 

 available on the reproduction and growth of A. arctica, however, 

 Thorson (1946) stated that its wide distribution in Arctic seas indi- 

 cated nonpelagic development because pelagic development is sup- 

 pressed in nearly all Arctic species. 



Figure 54.— Distribution and abundance of Ampharete arctica in the New York 

 Bight apex. 



Hutchings (1973) studied reproductive patterns of a related spe- 

 cies, Mellina cristata. The Northumberland (England) population 

 of M. cristata breeds annually over a period of about 2 wk at the end 

 of December and beginning of January. Benthic larvae are pro- 

 duced which metamorphose into juveniles within 2 to 3 wk of 

 spawning. Mellina cristata is potentially capable of breeding for 

 the first time when 2 yrold. The majority of worms survive spawn- 

 ing and M. cristata probably breeds annually for several years. In 

 this population, not all potential breeders spawn, some resorb their 

 gametes and release another batch of gametes into the coelom. The 

 Northumberland population of M. cristata is near the southernmost 

 limit of the species distribution, which indicates that environmental 

 conditions for this population are not optimum. The population 

 appears to maintain itself by producing fewer oocytes and by only 

 part of the population spawning. 



Asabellides oculata (Webster, 1880) 



DESCRIPTION: Sessile worms, dwelling in membranous tubes. 

 In our collections, lengths reached 20 mm. 



DISTRIBUTION: Cape Cod to Cape Hatteras (Gosner 1971). 



HABITAT: Depths of 5-15 m (Gosner 1971). In the New York 

 Bight apex, we found Asabellides oculata in depths of about 10-46 

 m. It was present in all sediment types but reached peak abundance 

 in fine sand. Its total abundance was highest in low organic areas, 

 reaching moderate abundance in high organic areas. However, the 



37 



