Chapter 7 



OctocoralUa of Enewetak Atoll 



[Editor's Note: The section on the Octocorallia was compiled by 

 Dennis M. Dcvaney (B. P. Bishop Museum, Honolulu, Hawaii), 

 but the collection data listing was not completed due to his 

 untimely death. This unfinished section, with complete references, 

 is included in order to round out the categories of organisms 

 recorded from Enewetak. — B. L. Burch] 



STOLONIFERA 



Two widely distributed Indo-West Pacific stoloniferans 

 including the distinctive organ-pipe coral, Tubipora musica, 

 are present at Enewetak. This species occurs most abun- 

 dantly on windward reef flats or just behind the algal ridge 

 and less commonly on lagoon reefs (Wells, 1954). For 

 Pach};clavulaha violacea, see below. 



TELESTACEA 



One undetermined species of Telesto is represented in 

 the Mid-Pacific Research Laboratory (MPRL) reference col- 

 lection. It was found attached on the reef near the Medren 

 cargo pier. This appears to be the first record of Telesto 

 from the Marshall Islands; members of this genus may 

 occur on ship hulls and be distributed as fouling organisms. 



ALCYONACEA 



Alcyonaceans are the most numerous octocorals 

 represented in Enewetak shallow waters with approxi- 

 mately 20 species now known. The majority of these "soft 

 corals" recorded herein are from the lagoon and sub- 

 merged reef habitats. One alcyonacean was reported by 

 Odum and Odum (1956) as one of the organisms encoun- 

 tered during their earlier coral reef studies on the atoll. 

 Enewetak soft corals (Sarcophi;ton and Heteroxenia) were 

 utilized in work on the nerve net system of cnidarians (Bul- 

 lock and Thorson, 1962; Josephson, 1965). Six shallow- 

 water alcyonaceans and one stoloniferan were reported by 

 Verseveldt (1972) based on collections made in the search 

 for crustacean copepod symbionts in July 1969. The 

 stoloniferan, Pachi/clavulaha violacea, and three of the 

 alcyonaceans were hosts for several of these crustaceans 

 (Humes, 1973; Devaney, Chapter 19, Table 2, this 

 volume). 



Research at MPRL on marine natural products chemis- 

 try (Ciereszko et al., 1968; Schmitz et al., 1974; Van- 

 derah et al., 1978) has been based in part on soft corals. 

 In response to this work, eight alcyonaceans were deter- 

 mined from Enewetak by Verseveldt (1977) having been 

 collected mainly through projects by the University of 

 Hawaii's Department of Chemistry. In this publication, one 

 new species (Sinulaha sandensis) was described together 

 with other more widely distributed Indo-West Pacific 

 species all representing new records for the Marshall 

 Islands. This led to a revision of the genus Sinularia in 

 Verseveldt (1980). Furthermore, species identified by 

 Verseveldt for Ciereszko (University of Oklahoma) in 

 1975, include five that are new Enewetak records 

 (Table 1). Examples were depxssited in the MPRL refer- 

 ence collection. Nephthea, Sarcoph\jton, and Lobopln;tum 

 were genera reported in studies on the mucus chemistry 

 and zooxanthellae of reef animals (Ciereszko and 

 Ciereszko, 1978). 



COENOTHECALIA 



The blue-coral, Heliopora coerulea, distributed 

 throughout much of the Indo-Pacific, was found at 

 Enewetak and other Marshall Islands where colonics up to 

 many meters in area were reported on the seaward reef 

 flats (Wells, 1954). 



GORGONACEA 



The gorgonaceans (sea fans and sea whips) are 

 represented by at least eight species in the suborders 

 Scleraxonia and Holaxonia at depths from 5 to 45 m at 

 Enewetak. These are known by collections made together 

 with black corals to obtain information on their diversity 

 and to measure the concentration and distribution of skele- 

 tal radioiodine (Goldberg, 1975). He also included informa- 

 tion on colony form, color, habitat, and collection localities. 

 Determination of sp>ecies was made by F. M. Bayer and 

 updated in 1982. Representatives of all but one of these 

 taxa are in the United States National Museum (Smith- 

 sonian Institution). In another study of gorgonaceans from 

 the Marshall Islands, Bayer (1949) recorded several species 

 from Bikini Atoll. All but two of the Bikini specimens were 



63 



