Table 2. --Relative abundance (% of specimens) in samples from the coralline 

 algal turf habitat in 1984. * = all juveniles with disc diameter 

 less than 5 cm. 



Total number recovered 

 Al gal vol ume (ml ) 



Ophiocomel la ophiactoides 

 Amphiphol is squamata 

 Amphiura stimpsoni 

 Ophiactis savignyi 

 Ophiostigma isacanthum 

 Ophiacti s algicola 

 Ophiocoma pumila* 

 Ophiothrix oerstedi* 

 Ophioderma appressum* 

 Ophiolepis paucispina 



0.6 



details of their sizes, appearances, and reproductive modes. Of the four 

 species present in 1981, Ophiocomel la ophiactoides was the most abundant and 

 Ophiostigma isacanthum , the least. Further samples from this habitat in 1984 

 (table 2) show that the pattern is consistent over time, although in these 

 later samples rather more occasional species were taken and Amphiura stimpsoni 

 was moderately abundant. Four of the six most common species ( 0. ophiactoides , 

 Ophiactis savignyi , Ophiactis algicola , and 0. isacanthum ) in the latter 

 col lections are fissiparous, able to reproduce asexual ly by cross-disc division, 

 and two ( Amphipholis squamata and A. stimpsoni ) are brooders. The fissiparous 

 species are members of three different families (Ophiocomidae, Ophiactidae, 

 Amphiuridae). The species represented as juveniles may be found in abundance 

 as adults elsewhere in Discovery Bay. 



A rather similar group of species of brittle stars was found in the samples 

 taken (in 1981 only) from the detritus surrounding the Thalassia testudinum 

 shoots and, to a small extent, the axils of Thalassia leaves (table IB). Of 

 the seven species found, all except Ophioderma cinereum were also in the algal 

 turf. However, the relative abundances of these species are very different in 



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