264 



CUTRESS AND ROWE 



TABLE 1 (cont'd) 



Family STICHOPODIDAE 



Stichopus chhronotus Brandt: Lawrence, 1980. 

 'Stichopus horrens Selenka, 1867. 

 'Stichopus txiriegatus Semper, 1868. 

 'fStichopus ?uariegatus juvenile. 



Thelenota ananas (Jaeger): Humes, 1973; Lamberson, 1978. 

 Thelenota anax H. L. Clark: Rowe and Doty, 1977; Lamberson, 1978. 

 Order APOPIDA 



Family CH1RIEX)TIDAE 



Chiridota rigida Semper: Lawrence, 1980; Lawrence and Guille, 1982. 

 Family SYNAPTIDAE 

 'Euapta godeffroiii (Semper), 1868. 

 ' Pendekaplectana nigra (Semper), 1868. 

 Svnapta maculata (Chamisso and Eysenhardt): Bakus, 1968, 1973. 



'New published Enewetak record. 

 fVery small specimen. 



ntauhtiana, and Stichopus horrens at Enewetak. Bakus 

 (1968, 1973) reported on defense mechanisms and the 

 ecology of several species. Enewetak was one site for a 

 study (Bakus and Green, 1974) on changes in toxicity of 

 hoiothurians with relation to various latitudes, water tem- 

 peratures, and habitats. Presence of a tumor in one of 10 

 specimens of H. (Mertensiothuria) leucospilota was 

 repHDrted by Smith et al. (1973). Humes (1973) recorded a 

 parasitic cojjepod on Thelenota ananas. In their report on 

 Guam hoiothurians, Rowe and Doty (1977) included 

 Enewetak in the general distribution of T. anax. Some 

 aspects of the biology of H. (H.) atra were studied by 

 Webb et al. (1977) and Ebert (1978). Lawrence (1980) 

 recorded numbers and biomass of eight species of 

 hoiothurians on the Enewetak reef flat. The organic com- 

 position of the body wall of six species of Enewetak 

 hoiothurians was analyzed by Lawrence and Guille (1982). 



BIOGEOGRAPHY 



According to distribution summaries for various Indo- 

 Pacific species (H. L. Clark, 1921, 1946; A. M. Clark and 

 Rowe, 1971), 18 of the 20 holothurian species known at 

 present from Enewetak Atoll are widely distributed 

 throughout the Indo-West Pacific. The other two, 

 Thelenota anax and Chiridota rigida, range from northern 

 Australia northward to the Philippines and eastward to the 

 West and Central Pacific. 



Of the 18 Indo-West Pacific sptecies, those most widely 

 distributed are Hohthuria (Plati/perona) difficilis (Red Sea 

 to the Hawaiian and Easter islands), H. (Thymiosycia^ aren- 

 icola (Red Sea to the Hawaiian, Galapagos, and Cocos 

 Islands; Caribbean; Bermuda) and H. (T.) impatiens (Red 

 Sea to Hawaii, Caribbean, Mediterranean). Twelve other 

 species range from the shores of East Africa or the Red 



Sea to the Central Pacific: Actinopiiga mauritiana, 

 H. (Halodeima) atra, H. (T.) hilla, H. (Mertensiothuria) per- 

 vicax. H. (M.) leucospilota. Stichopus chhronotus, 

 S. horrens, and Euapta godeffro\ji to the Hawaiian Islands; 

 Stichopus uariegatus, Thelenota ananas, and Si/naptula 

 maculata to the Line and (or) Society islands; and 

 Pendaplectana nigra to the Marshall Islands. The other 

 three have not been reported from Africa or the Red Sea. 

 Afrocucumis africanus ranges from Mauritius to Fiji; 

 Bohadschia argus, from the Seychelles islands to the 

 Marshall Islands, and Labidodemas semperianum, from the 

 Maldives to the Hawaiian and Society islands. 



Of the 78 holothurian species recorded from Pacific 

 islands (A. M. Clark and Rowe, 1971), only 20 (26%) are 

 represented at Enewetak. On the other hand, a vast major- 

 ity (90%) of the Enewetak species also ranges into the 

 Indian Ocean, compared with 68% of the total Pacific 

 species recorded by Clark and Rowe. With t:ie possible 

 exception of the surprisingly low number of species found, 

 the composition of the holothurian fauna at Enewetak 

 could be predicted from the geographical position of that 

 atoll and may be indicative of the reproductive strategies 

 of the widespread species. Unfortunately, little is known of 

 larval development of the species or length of larval life. 

 Incidentally, it may be noted that Oshima (1916) reported 

 brood-care in Afrocucumis africana in Japan, which is 

 unusual for a widespread, tropica[ cchinoderm^ 



Juvenile specimens of three species {Actinopy/ga ?mau- 

 ritiana, Labidodemas ? semperianum, and Stichopus 

 ?variegatus) have been collected at Enewetak, and figures 

 of their spicules have been included. Due to the element of 

 doubt regarding their identification and the distinctiveness 

 of their color and spicules, all three forms have been 

 included in the key that follows. 



