Rev. biol. mar. oceanogr. 49(3): 607-614

Nota Científica

Crecimiento y supervivencia de larvas D, pedivéligeras y postlarvas de Gari solida (Mollusca: Psammobiidae), provenientes de reproductores acondicionados

Ramiro A. Contreras-Guzmán¹, Claudia E. Puebla-Arce¹, Elisa G. Pacheco-Sánchez¹ y Francisco J. Contreras-Saldaña¹

¹Instituto de Ciencia y Tecnología, Universidad Arturo Prat, Ejército 443, Puerto Montt, Chile

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Adults of Gari solida were maintained at a room temperature of around 14°C for approximately 90 days, fed with a microalgae mix 300,000 cell ml^-1, after which spawning was induced in 20 specimens. The oocytes obtained were fertilized at a 10:1 sperm/oocyte ratio and the embryos were incubated in a specially designed system (‘hatching system’) for a period of 96 h, until D-shape larvae without gelatinous coating were obtained. Larval culture was undertaken in cylindrical 200 L tanks at 13 ± 1.3°C, with seawater filtered to 1 µm and UV irradiation, at an initial density of 9.7 larvae ml^-1, with water renewal every 2-3 days; D-shape larvae were fed with Isochrysis aff. galbana and throughout the umbonate, pediveliger and postlarval stages, with a mix of Isochrysis aff. galbana and Chaetoceros calcitrans (7:3), where concentration was proportioned in accordance with culture density. The umbonate larval stage was detected at day 11 of culture and the pediveliger stage, at day 22, starting from the free-swimming D-shape larvae. Metamorphosis was induced with an epinephrine bath at 0.005 N concentration and postlarvae obtained at day 26 of culture were subsequently cultured up to day 35. Average sizes reached were 122 ± 13 mm, 158 ± 12 mm, 185 ± 5 mm and 216 ± 24 mm for the ‘D’, umbonate, pediveliger and postlarval stages, respectively. Survival up to postlarvae stage was 0.005%. Development of G. solida larvae and postlarvae culture is in its initial phases and improvements in all stages are necessary, from breeder conditioning onwards.

Key words:  Bivalves, larval development, clams