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1 



Figure 48.— Distribution and abundance of Drilonereis longa in the New York 

 Bight apex. 



Figure 49.— Distribution and abundance of Magelona cf riojai in the New York 

 Bight apex. 



carnivorous (Pettibone 1963: Day 1967; Gosner 1971). However, 

 Sanders et al. (1962) considered D. tonga to be a sediment ingestor 

 after finding sand, diatoms, and algae to be the main contents of its 

 gut. It may be that D. longa exhibits both types of feeding behavior, 

 each under different environmental conditions. 



REPRODUCTION AND GROWTH: No information was found 

 on the reproduction and growth of this species. However, plank- 

 tonic larvae of this family (Arabellidae) were not found by Fewkes 

 (1883). Thorson (1946). or Rasmussen (1956). and brooding has 

 been recorded for another Arabellidae. Noiocirnis spinifents. (Pet- 

 tibone 1957). These facts tend to support the idea that the Arabelli- 

 dae exhibit nonpelagic development. 



Order Magelonida 



Magelona cf riojai Jones, 1963 



DESCRIPTION: A slender-bodied, small worm with a spadelike 

 head. 



DISTRIBUTION: Maine to North Carolina (Kinnerand Maurer 

 1978). 



Bight apex. Magelona cf riojai was found in low numbers in fine to 

 medium sandy, low organic areas (<3%). and was restricted to 

 depths of <25 m (Fig. 49: Table 1). 



FEEDING ECOLOGY: Jumars and Fauchald (1977) classify the 

 Magelonidae as surface deposit feeders: Day (1967) and Jones 

 ( 1968) believed them to be burrowers. using the spadelike head and 

 large distensible proboscis to force their way through the substrate. 

 They feed on microscopic debris, diatoms, organic particles, and 

 small plants and animals. While feeding. Magelona sp. utilizes the 

 papillae of its paired prostomial tentacles. Food material adheres to 

 distal papillae and is transferred to more proximal papillae when a 

 loop is formed by the tentacle: by repetition of this activity, food 

 material is passed stepwise toward the mouth (Day 1967: Jones 

 1968). 



REPRODUCTION AND GROWTH: Specimens of M. rosea (a 

 closely related species) collected from Cape Cod. Mass.. by Moore 

 (1900)" during the latter part of August contained nearly ripe eggs 

 in the middle segments of the body. Bhaud (1972) reported larvae 

 of Magelona sp. present in the plankton of the Danish Oresund 

 from January through May. 



HABITAT: Jones ( 1968) has observed that Magelona sp. lives in 

 a well-sorted, hieh energv. sand environment. In the New York 



"Moore, J. 1900. The polychaetous annelids of the Woods Hole region. Unpubl. 

 manuscr.. 1032 p. U.S. Nail Mus . Wash.. D.C. 



34 



