The Mytilus genus is composed by at least 5 species, M. californianus (Conrad 1837), M. edulis (Linnaeus 1758), M. galloprovincialis (Lamarck 1819), M. trossulus (Gould, 1850) and a recently corroborated as a valid species the chilean blue mussel M. chilensis. The Chilean native blue mussel M. chilensis, is an economically important marine resource in Chile. The M. chilensis aquaculture began in 1943 in Chiloé Island, southern Chile, and the aquaculture production increased rapidly from 3,864 t in 1993 to 398,274 t in 2018, equivalent of 29,3% of the total Chilean aquaculture production, occupying the second place after the salmonids exotic species aquaculture, which represent a 67,7% of the total aquaculture production in Chile. Therefore, and because the relative recent description of M. galloprovincialis and M. in Chilean waters, there is a need to carry out basic and applied studies to evaluate their actual and potential effects on their distribution, on the biodiversity along the coast and on the fasting growing mussel (Mytilus chilensis) aquaculture industry. Among some of the main features of these Mytilus species is the well-known capability to naturally hybridize among them in locations where their distributions overlap therefore, these alien mussel species could have also the potential for natural hybridization with the native mussel M. chilensis.
Adult mussels were collected from: M. chilensis from Yaldad Bay, Chiloé, M. galloprovincialis from Caleta Tumbes (Central Chile) and M. edulis platensis from Buque Quemado (Strait of Magellan). These sites were chosen on recently published evidence of presence of each of these species. Spawning was induced and male and female gametes were collected into 150 ml cups containing filtered seawater. Factorial crosses design was used to obtain embryos from pure and hybrid fecundation. Mantle tissue from each spawened mussel was removed and stored in 96% ethanol for genotyping. The objective was to determine if pure species crosses showed differences in compassion of hybrid crosses. Analysis of variance for fecundity (%) between these two types of crosses carried out at the laboratory showed no significant differences. The results indicate that ther is no intrinsic prezygotic barriers in externally fertilizing Mytilus mussels. Further research is needed to evaluate the growth and viability among the laboratory crosses to assess any differences in fitness between pure and hybrids crosses.
Research founded by FONDECYT 1170194.