FECUNDITY AND EARLY LARVAL DEVELOPMENT OF THE ASCIDIAN ECTEINASCIDIA TURBINATA (ASCIDIACEA: PEROPHORIDAE) IN CUBA

Abstract

Zooids (the total amount of ovocytes, embryos, and larvae in larval release stage zooids), colonial (zooids mean fecundity per number of mature zooids on resorption or releasing larvae colonies) fecundity and the characteristics and duration of the early larval stages of the ascidian Ecteinascidia turbinata (Ascidiacea: Perophoridae) are given. The ascidian colonies were collected from non-estuarine mangroves in the NW region of Cuba. An average of 41 ± 12 ovocytes, embryos, and larvae were counted in 200 zooids of 17- 31 mm length from 20 colonies gathered during different months and sites. Ascidian colonies of 163 mm length and 252 zooids average produced 10590 larvae as average per colony during each generation-degeneration cycle that lasts about 40 days. Zooids and colonial fecundity were very variable in zooids and colonies with similar reproductive stage, but a high correlation (r = 0.84) between colonial fecundity and number of zooids per colony was found. Ascidian colonies prior to larvae release stage were placed in 10-liter glass aquaria. The experiments were carried out on September and November, 2000. Water temperature ranged between 23 and 30 ºC. The biggest larval release took place between 10:00 and 14:00 h. Average total length (TL) of larvae leaving the parental zooid was 2.7 mm. The larvae planktonic stage lasted 4 to 8 hours, attaining 3.1 mm (TL). Metamorphosis and larvae settlement lasted 8 to 12 hrs, and exogenous feeding began at 19 hrs. The juvenile zooid measured between 1.3 and 2.05 mm, and 9 % of the larvae completed the metamorphosis.