Efecto de la temperatura en el desarrollo embrionario y larval del mejillón, Mytilus galloprovincialis (Lamarck, 1819)

Abstract

The Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) has been recently registered for the Chilean coast, from Concepcion (36°S) to the Magellan Strait (54°S). To determine the feasibility of the massive culture of M. galloprovincialis in Chile, a study of the temperature effects on the early development was carried out. Embryos and larvae were raised at 12, 16 and 20°C in laboratory facilities at Coliumo Bay (36°S), Chile, from where adults mussels were collected. Embryonic development followed the common sequence exhibited by other bivalves. Trocophores turned into veligers at 45 h post fertilization, followed by D-larvae (99 ± 6 μm length, initial size), with a large ciliated velum, a well-developed stomach and concentric growth lines in the shell; 15 days post-fertilization, umbonate larvae developed eye-spots and adductors muscles; pediveliger larvae (265 ± 2 μm initial length size) developed a pedal organ and gill filaments. Both embryonic and larval stages were accelerated at higher temperatures. The larval growth rates at 20°C (9.1 μm*d-1) were significantly larger than at 12 and 16°C (6.7 μm*d-1 and 7.4 μm*d-1, respectively). In comparison with Mytilus chilensis, M. galloprovincialis showed better growth rates at the same temperatures. This fact suggests that in Chile M. galloprovincialis seed can be produced under controlled conditions for its massive cultivation.