species studied were small cryptic forms. Three species were fissiparous (see 

 also Mladenov, et al . , 1983) and produced relatively small eggs; two of these 

 broadcast "exceedingly small numbers of larvae." Two non-f issiparous species 

 produce and brood a small number of relatively large eggs which undergo direct 

 devel opment. 



Mladenov noted that of approximately 2,000 extant ophiuroid species, only 

 57 are known brooders (Hendler, 1979) and 37 undergo fission (Emson and Wilkie, 

 1980; Emson, et a! . , 1985). While 65% of those exhibiting fissiparity and 

 12% of the brooders are found in the tropics, brooders like Amphipholis squamata 

 and fissiparous species like Ophiactis savignyi are among the most widespread 

 and abundant" tropical ophiuroids. At Discovery Bay, the three fissiparous 

 ophiuroid species were numerically dominant. Emson, et al . (1985) speculate 

 that populations of these species have been "maintained almost solely by asexual 

 reproduction." 



Among colonial species, growth, fission, fusion, and fragmentation are 

 important asexual life history processes (e.g., Bak and Engel , 1979; Hughes and 

 Jackson, 1980; Karlson, 1980, 1983; Bothwel 1 , 1981; Tunnicliffe, 1981; Lasker, 

 1983; Rylaarsdam, 1983; Hughes, 1984). More critical evaluation of the importance 

 of sexual reproduction to these colonial species is currently underway. There 

 has been a relatively recent increase in this particular research area. At the 

 Third International Coral Reef Symposium held in 1977, there were no presentations 

 on this topic. Four years later at the Fourth International Coral Reef Symposium, 

 there were six such presentations (Bothwell, unpub. data; Karlson, 1981; Kojis 

 and Quinn, 1981; Richmond, 1981; Van Moorsel , 1981; Yamazato, et a_L , 1981). 

 Data from the Van Moorsel presentation have now been published - ("Van Moorsel, 

 1983). An excellent review of this subject dealing with over 100 scleractinian 

 coral species has also just been published by Fadallah (1983); also see Harrison, 

 et al. (1984). Fadalallah (1983) and Szmant-Froel ich, et aK (1983) suggest the 

 need for further work on reproductive cycles, reproductive modes, relative 

 fecundity, and reproductive effort in order to satisfactorily evaluate the 

 importance of sex to coral reef organisms. At this point we know virtually 

 nothing about the relationship between reproductive effort and the actual input 

 of settled larvae into adult populations; this point also is stressed by 

 McFarland (1985). 



The original purpose of this discussion group was to compare growth and 

 life history patterns of solitary and colonial organisms on shallow and deep 

 reefs. We did, in part, deal with depth-related variation in coral growth 

 form, growth rate, and life history patterns. Furthermore, we briefly discussed 

 some general differences and similarities between colonial and solitary species 

 (see Jackson, 1977). The remarkable success of fissiparous echinoderms and 

 colonial corals, sponges, gorgonians, and zoanthids has been noted. This is 

 suggestive of some level of evolutionary convergence favoring asexual strategies 

 even in solitary organisms. My own work with zoanthids emphasized low colonial 

 integrity in two very successful species. These species may be more similar to 

 aggregating solitary organisms (e.g., barnacles, anemones, polychaetes, and 

 mussels) than to more highly organized colonial forms. One curious and 

 potentially significant difference between solitary and colonial organisms is 

 the ability of colonial species to fuse (Teissier, 1929; Stephenson, 1931; 

 Schijfsma, 1939; Ivker, 1972; Hughes and Jackson, 1980; Buss, 1982). It is 



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