Determination of generation time and asexual fecundity of doliolids (Tunicata, Thaliacea)

Abstract

The goal of this study was to provide temporal information on the generation time of Dolioletta gegenbauri and some of the life cycle's components. At 20°C and ~90 μg Cl-1 of ingestible phytoplankton, D.gegenbauri's life cycle is completed in 20.5 days. Phorozooids ≥ 5 mm produce on average 11.0 gonozooids day-1 over a period of 8-18 days. Utilizing field data on the abundance and size distribution of an assemblage of phorozooids and nurses, in conjunction with experimentally obtained rates, indicates that asexual production per cubic meter by phorozooids with that of nurses should result in rapid colonization of a wide shelf by doliolids, as observed during July and August 1981 on the southeastern continental shelf of the USA.