Composition and Distribution of Macrobenthic Invertebrate Fauna 



205 



ably lower levels (0.1-2 g/m 2 ) in classes on either side 

 of these. 



Occurrence of ophiuroids in the samples was moder- 

 ate to moderately high (66-70%) in the two mid-range 

 content classes and in the absence of measurable car- 

 lion, and moderately low (23 to 47%) in the other 

 content classes they occupied (Table 30). 



Asteroidea — Starfishes constituted a moderately small 

 portion of the New England benthos. Their contribu- 

 tion to the total number of specimens was onlv 0.1%,, 

 but they provided 1.2% of the total biomass (Table 3). 



Representatives of three orders of the Asteroidea 

 were present in our samples: Phanerozonia, Spinulosa, 

 and Forcipulata. All three orders contained species that 

 were common in the samples. 



Starfishes exhibited considerable variation in color, both 

 inter- and intraspecificallv. The most brightly colored spe- 

 cies encountered was Porania iiisigiiis, which commonly 

 was a deep, rich claret color with patches of whitish and 

 yellowish papillae. Other specimens of the same species 

 and other species within the same genus were much paler, 



even a drab brownish-gray. Other colorful genera encoun- 

 tered were Hippasterias and Solaster. Many of the more 

 common genera, such as Asterias, Astropecten, and 

 Ctenodiscus, were predominantly tan, brown, or olive. 



Sizes ranged from juvenile specimens of various spe- 

 cies that were 2 to 3 mm in radius to large specimens of 

 Asterias and Solaster with radii of over 18 cm. Specimens 

 with radii over 8 cm were uncommon. 



Average weight of individual specimens was 1.4 g, 

 which was large compared with other taxonomic groups. 



The majority of starfishes in this region are carni- 

 vores, particularly the selective, predatory type of carni- 

 vore. Deposit feeding and filter feeding are adaptations of 

 only a few species, some of which are locally abundant. 

 Bivalve mollusks appear to be the principal food of New 

 England starfishes, although a variety of small inverte- 

 brate species, as well as dead fish, are consumed. A few 

 species of starfishes are serious predators of oysters, clams, 

 mussels, and other commercially valuable mollusks. 



Asteroids occurred in 144 samples (13% of the total). 

 Their density averaged 1.5/m 2 and their biomass aver- 

 aged 2.1 g/m 2 (Table 5). 



