Volume 70

Temporal Variations in the Development, Growth, and Survival of the Larvae of Queen Conch Strombus gigas Under Experimental Cultures


Authors
Brito-Manzano,N.P;D.AldanaAranda
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Date: November, 2017


Pages: 241-245


Event: Proceedings of the Seventy Annual Gulf and Caribbean Fisheries Institute


City: Merida, Yucatan


Country: México

Abstract

Larvae of Strombus gigas from egg masses of natural ovoposition were reared under laboratory conditions for one year during the reproductive season (from March to September) in Chinchorro Bank. The same types of rearing containers and techniques were employed. Egg masses are incubated for 3-5 days in 25-L containers, and cultured in 4-L containers. Larvae were fed with Tetraselmis suecica at a concentration of 1,000 algal cells/ml, density of 200 larvae/L, temperature of 29º ± 1º C, and a natural photoperiod. At hatching, the larvae from March, April, May, and September cultures presented 2 velar lobes, 1.5 shell whorls, and right tentacle (1-3 days), whilst the June, July and August, developed 4 velar lobes, 2.0 shell whorls, and right tentacle (1-3 days). The mean shell length at hatching was 300 ± 1.52 μm for all culture months. The development of proboscis began between 11 to 16 days, for June to August cultures and in 19-21 days for March, April, May, and September cultures. Settlement was first observed at 27 days in larvae from June to August cultures (42%); for March, April, May, and September cultures it was in 29 days in 29% of larvae. The maximum shell lengths have been obtained in August and September (908 μm both), whilst the minimum was registered for April with 867 μm. The growth rate varied from 22.33 μm/day to 30.00 μm/day. With regard to survival, the percentages obtained in June and July (38%) were highest in relation to September values (20%). For the other months, survival was 22% for March culture, 34% in April, 37% for May, and 28% in August culture. The results obtained in this work, demonstrate that the development, growth, and survival of the larvae from the intermediate months (June to August) of the reproductive season were much better (F = 4.01, p < 0.05, Tukey < 0.01), than in early and later months (March, April, May, and September), which can be related to the parents maturity.

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