%0 Journal Article
%T Early development, survival and growth rates of the giant clam Tridacna crocea (Bivalvia: Tridacnidae)
%A Miguel Mies
%A Felipe Braga
%A Marcello Santos Scozzafave
%A Daniel Eduardo Lavanholi de Lemos
%J Brazilian Journal of Oceanography
%D 2012
%I Universidade de S?o Paulo
%R 10.1590/s1679-87592012000200003
%X Tridacnid clams are conspicuous inhabitants of Indo-Pacific coral reefs and are traded and cultivated for the aquarium and food industries. In the present study, daily growth rates of larvae of the giant clam Tridacna crocea were determined in the laboratory during the first week of life. Adults were induced to spawn via intra-gonadal serotonin injection through the byssal orifice. After spawning oocytes were collected, fertilized and kept in 3 L glass beakers and raceways treated with antibiotics to avoid culture contamination. Larvae were fed twice with the microalga Isochrysis galbana and zooxanthellae were also offered twice during the veliger stage (days 4 and 6). Larval length was measured using a digitizing tablet coupled to a microcomputer. Larval mortality was exponential during the first 48 hours of life declining significantly afterwards. Mean growth rate was 11.3 ¦Ìm day-1, increasing after addition of symbionts to 18.0 ¦Ìm day-1. Survival increased to ca. 75% after the addition of zooxanthellae. The results describe the growth curve for T. crocea larvae and suggest that the acquisition of symbionts by larvae may be useful for larval growth and survival even before larvae have attained metamorphosis. Bivalves tridacn¨ªdeos s o habitantes consp¨ªcuos dos recifes da regi o do Indo-Pac¨ªfico e s o cultivados e comercializados para os mercados aliment¨ªcio e aquarista. No estudo apresentado foram determinadas as taxas de crescimento di¨¢rio durante a primeira semana de vida da larva do bivalve ornamental Tridacna crocea. As matrizes foram induzidas ¨¤ desova por meio de uma inje  o intragonadal de serotonina realizada atrav¨¦s do orif¨ªcio bissal. Ap¨®s desova, ov¨®citos foram coletados, fertilizados e mantidos em b¨¦queres de vidro e tanques de fluxo cont¨ªnuo tratados com antibi¨®ticos para evitar contamina  o. Larvas foram alimentadas em duas ocasi es com a microalga Isochrysis galbana e zooxantelas foram oferecidas tamb¨¦m por duas vezes. O comprimento larval foi medido atrav¨¦s de mesa digitalizadora conectada em um microcomputador. A mortalidade larval foi exponencial durante as primeiras 48 horas de vida, diminuindo em seguida. A taxa m¨¦dia de crescimento foi de 11,3 ¦Ìm dia-1, aumentando para 18,0 ¦Ìm dia-1 ap¨®s a adi  o de simbiontes. A sobreviv¨ºncia aumentou para 75% ap¨®s a adi  o de zooxantelas. Os resultados apresentam a curva de crescimento para a larva de T. crocea e sugerem que a aquisi  o de simbiontes pela larva pode ser importante para o crescimento larval e sobreviv¨ºncia mesmo antes delas completarem a metamorfose.
%K Tridacnidae
%K Ontog¨ºnese
%K Zooxantelas
%K Crescimento Larval
%K Simbiose
%K Cultura
%K Tridacnidae
%K Ontogenesis
%K Zooxanthellae
%K Early growth
%K Symbiosis
%K Culture
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000200003