Extended pre feeding period in planktotrophic larvae of the bathyal echinoid aspidodiadema jacobyi
Young, C.M.; Cameron, J.L.; Eckelbarger, K.J.
Journal of the Marine Biological Association of the United Kingdom 69(3): 695-702
1989
ISSN/ISBN: 0025-3154
DOI: 10.1017/s0025315400031076
Accession: 007337840
Larvae of the deep-sea echinoid Aspidodiadema jacobyi Agassiz develop from opaque eggs 98 .mu.m in diameter. As in lecithotrophic echinoderm larvae originating from large eggs, mesenchyme cells fill the blastocoel during the blastula stage. Unlike other planktotrophic echinoderm larvae, the mouth does not open until 21 days after fertilization, approximately two weeks into the echinopluteus stage. Despite their small size, larvae of A. jacobyi can survive for up to eight weeks, apparently on yolk reserves, before becoming obligately plankotrophic. Thus nutritional flexibility may be an adaptation to patchy food resources in the deep sea.