Costituzione di un broodstock di astice europeo (Homarus gammarus) e prove di riproduzione controllata ai fini del ripopolamento attivo della fascia costiera
Author(s)
Saraga, Eleonora
Date Issued
March 21, 2012
Type
Doctoral Thesis
Abstract
This work aimed to set up methodologies for rearing juvenile lobsters (Homarus gammarus) for restocking purposes. A number of parameters for achieving the production of good individuals for restocking actions have been evaluated, trying to circumvent the most critical limiting factor, intra-specific cannibalism, which is usually reduced by individual rearing. The thesis work has consisted of: (i) investigation on the status of the species, especially in Italy; (ii) planning and validation of the necessary structures and equipments for housing both adult females and juveniles; (iii) experimentation of different rearing techniques; (iv) localization of appropriate sites for release. Particular focus has been given to the rearing environment both in quantitative (optimization of procedures) and qualitative (e.g. evaluation of condition and behaviour of the individuals) aspects. It was possible to obtain a high number (thousands) of benthonic individuals, similar to what already obtained in Northern Europe, with a survival rate above 80%. Moreover, specific experiments have shown that communal rearing of hundreds of individuals is possible in enriched environments with shelters, rocks or material to hide that minimizes cannibalism. The behavioural analyses suggest that the juveniles are neophilic and perform active shelter search in the first weeks, while they become neophobic, and presumably more aggressive, after the second week of their benthonic life. Enrichment procedures (shelter in the rearing environment) during ontogenesis seem to confer a better development of motor, sensory and cognitive abilities, thus improving the quality of the individuals.
Additional information
Dottorato di ricerca in Ecologia e gestione delle risorse biologiche
Subjects
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esaraga_tesid.pdf
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