Life Histories and Distributions of 

 Dominant Benthic Invertebrates 



Phvlum Coelenterata 



Class Anthozoa 



Edwardsia spp. 

 son, 1854 



elegatis Verrill, 1869 and sipunculoides Stinip- 



DESCRIPTION: Small, slender, solitary anemones between 75 

 and 150 mm in length. They burrow in the sediment with their 

 tapering "foot" and are often encrusted with sand and other foreign 

 material. Sixteen to 36 mobile tentacles surround the mouth (Miner 

 1950). 



DISTRIBUTION: These two species of Edwardsia occur from 

 the Bay of Fundy to at least Chesapeake Bay (Boesch et al. 1977). 



by ciliary currents, to larger organisms, captured by mucous secre- 

 tions or nematocysts (Barnes 1963: Gosner 1971). No specific 

 information on Edwardsia spp. was available. 



REPRODUCTION AND GROWTH: No information specific 

 to E. elegans or E. sipunculoides was available in this category. 

 However, anemones can reproduce both asexually and sexually. 

 Asexual reproduction is chiefly by longitudinal fission (budding). 

 Sexual reproduction can involve individuals which are males, 

 females, or protandric hermaphrodites. A free-living larval form 

 called the planula is produced in sexual reproduction. This larva 

 eventually attaches to a substrate and metamorphoses into the adult 

 benthic form (Barnes 1963; Gosner 1971). 



The larvae of some species of Edwardsia are parasitic on the sur- 

 face or in the gastrovascular system of medusae and ctenophores 

 (Mnemiopsis sp.). adhering by means of the mouth margin and tak- 

 ing food particles from their hosts by means of the siphonoglyph 

 current (Hyman 1940: Gosner 1971). 



HABITAT: Gosner (1971) reported that Edwardsia elegans 

 occurs between the littoral and 117 m. while Edwardsia sipuncu- 

 loides is found in deeper water of 87-1 17 m. In this study, these 

 species were found in depths between 23 and 46 m in abundances of 

 10-60/m : . They were most abundant in high organic fine sands or 

 silts (Fig. 12; Table 1). 



FEEDING ECOLOGY: Anemones, in general, feed on live or 

 dead animal material ranging from plankton and detritus, collected 



Ceriantheopsis americanus [Ceiianthus americanus] (Verrill, 

 1866) 



DESCRIPTION: A smooth-bodied, brownish, elongate (up to 

 200 mm), burrowing anemone. It inhabits a distinctive heavy 

 mucous tube, constructed in part with its own nematocysts. The 

 inner surfaces of the tubes are purple or lavender. One hundred or 

 more tentacles, in each of two circlets, surround the mouth (Miner 

 1950; Gosner 1971). 



V 



4030 



y / 



. j° ; 



20 ! 

 \ 



•■yj 



'10^-, i I 



V. i i I 



/ 



40 20- 



60 



(10 | 



LT 



4010 



7350' 

 I i 



7340' 



Figure 12.— Distribution and abundance of Edwardsia spp. (E. elegans and E. 

 sipunculoides) in the New York Bight apex. 



DISTRIBUTION: Gosner (1971) considered Ceriantheopsis 

 americanus to be a Virginian species, occurring from Cape Cod to 

 Cape Hatteras. However, Pratt (1935) and Miner (1950) gave its 

 range as Cape Cod to Florida. 



HABITAT: Gosner (1971) reported occurrence of this species 

 from the littoral zone to 2 1 m. Sanders (1956) reported it to be part 

 of the typical soft bottom community in Long Island Sound; the 

 species was also common in the sewage sludge disposal area of the 

 New York Bight apex (National Marine Fisheries Service footnote 

 2). In the present study, C. americanus was collected in depths up 

 to about 46 m in all sediment types. However, it was most abun- 

 dant, occurring in numbers up to 340/m : , in high organic fine sands 

 to silt (Fig. 13; Table 1). The Cerianthidae are often found buried in 

 the sediment with only the tentacles and oral disc protruding: their 

 tubes may confer some protection from stressed environments. 



FEEDING ECOLOGY: C. americanus. like most smaller anem- 

 ones, is thought to be a suspension feeder, with its mucous secre- 

 tions and nematocysts aiding in the capture of small planktonic 

 organisms. An extracellular and extracorporeal contact digestion 

 has also been demonstrated in species of Ceriantheopsis. This 

 digestion occurs when prey come into contact with enzymes pro- 

 duced in the ectodermal layer of the labial tentacles (Barnes 1963: 

 Tiffon 1975). 



Since C. americanus is able to withdraw rapidly into its mucous 

 tube, it avoids being preyed upon by many finfish. However, it has 

 been shown by Wobber (1970) that California species of genus 

 Ceiianthus, closely related to genus Ceriantheopsis. are often the 

 prey of a nudibranch, Dendronolus iris. Dendronotus iris feeds on 

 Ceiianthus spp. tentacles, but because it consumes an average of 

 only 2-10 tentacles per anemone, it does minor damage to the 

 anemone. 



