Millora de procediments de reproducció ex situ de nàiades

Abstract

The long freshwater mussel (Unio mancus, Lamarck 1819) is a threatened mollusc in Catalonia. Because of this, and taking part of the LIFE Potamo Fauna project, the “Consorci de l’Estany” creates a freshwater mussel’s breeding laboratory, where this specie is breeded in captivity in order to carry out reintroductions and population reinforcements. The aim of this study is make improvements on the in vitro culture, a technique which allows the breeding in captivity of this specie without the use of a host fish. The glochidia will be cultured in a medium with 3 essential components; M199 medium, rabbit or carp serum and a mixture of antibiotics and antimicotics. In addition, another goal of this study is to prevent the fungal contamination caused by oomicets, because of this, malachite green will be used. The glochidia will be cultured in an incubator controlling the temperature and the CO2 %, fact that allows a greater pH stability. Besides that, it is pretended to study the in vitro protocol and to make improvements on it, so two techniques are proposed here: the use of vials or the use of petri dishes. The goal here is to figure out which one is the best. Every day a change of the 50% of medium will be done, and the fungal contamination will be removed. A monitoring of glochidia is done after few days to see how they develop. The results of this study indicate on one hand that malachite green has a significant effect on the oomycete contamination and it could be used to remove that contamination. On the other hand, the glochidia did not complete their metamorphosis and most of them died, so some aspect of the culture has failed (precariousness medium, contamination of mediums, extended exhibition of glochidia to clean medium MEM, or overdose of antibiotics or antimycotic). The methodology with the best results is the use of vials, with more advantages than the use of petri dishes. The advantages are, for instance, less contamination, less dirty in the medium, more pH stability and more facility when manipulating the samples. For this reasons, it is proposed for future studies the use of vials, and the implementation of some improvements, such as the use of vials with porous top or the less exhibition of glochidia to MEM medium