Self-fertilization in Four Species of Giant Clam

Abstract

This experiment was carried out to demonstrate the possibility of sefl-fertilization using am monium-treated eggs and untreated sperm from a single individual and of development up to the D-shaped stage in obtained larvae of four species, Tridacna crocea, Tridacna squamosa, Tridacna maxima, and Hippopus hippopus. The injection of serotonin (5-hydroxytryptamine) creatinine sulfate into the gonads of T. crocea induced liberation of sperm and eggs. Fertilized eggs subsequently developed into D shaped larvae. This demonstrated the ability of self-fertilization in these species. Self-fertilized larvae of T. crocea, T. squamosa, and T. maxima were reared on cultured zo oxanthellae for about 2 weeks. When the larvae were found to be symbiotic with zooxanthellae, feeding was stopped. The sizes of the surviving larvae were 3.6mm, 10.6mm, and 0.2mm in shell length, respectively, for the species investigated. © 1993, The Japanese Society of Fisheries Science. All rights reserved.