アカウニ×ムラサキウニの交雑と雑種幼生の形態

抄録

Crossbreeding between Pseudocentrotus depressus egg and cryopreserved Anthocidaris cras-sispina sperm were performed, in order to obtain several information concerning the influence of maturation of egg and sperm donors on the morphological appearance of parental characters in hybrids. Hybrid larvae were reared up to metamorphosis at 20°C, and Chaetoceros gracilis was used as the food. Skeletal structure of hybrid larvae exhibited intermediate characters, such as incomplete compound basket body structure, structural differences in postoral rod, postero dorsal rod and posterior transverse rod. Utilization of cryopreserved sperm in the experiment, permitted the use of sperm collected during the breeding season of the paternal species. This in turn is thought to have enhanced the probability of producing intermediate characters in the hybrid larva.