A COST-BENEFIT ASSESSMENT OF TWO MULTI-SPECIES ALGAE DIETS FOR JUVENILES OF Mytilus galloprovincialis

作者：Aghzar; Minambres M; Alvarez P; Presa P^*

来源：Thalassas: An International Journal of Marine Sciences , 2013, 29(1): 9-16.

• Chaetoceros gracilis
• cost-benefit assessment
• multi-species algae diets
• Mytilus galloprovincialis
• Phaeodactylum tricomutum

The optimisation of productivity in mussel hatchery requires the assessment of multi-species algae diets to enhance growth and survival during retention time. The present study monitored shell length in Mytilus galloprovincialis juveniles using diets of four microalgae, Tetraselmis suecica, Isochrysis galbana, Phaeodactylum tricornutum and Chaetoceros gracilis. The experiment lasted 116 days to assess shell length response, used a full-sib mussel progeny to minimise familiar effects on growth variance, and enforced a mini-raft suspension system to assure equal food deliverance to all juveniles under treatment. Shell-length increment in the 26% C. gracilis-based diet was not different from the 26% P. tricornutum-based diet except in two samplings. None differences between diets were observed neither in the growth trend nor in survival (99%). Present data indicate that multi-species algae diets incorporating C. gracilis have a slight non-significant positive effect on growth of M galloprovincialis juveniles and that such growth gain is not compensated by its higher production cost (4 times) as compared to diets composed by cheaper and easy-culturing species such as P. tricornutum. The global cost required to fill a whole raft (ca 200 ropes) using two-month old hatchery-produced mussel juveniles (One month retention time after fixation i.e. juveniles 2,000 mu m in length) fed P. tricornutum was less (1,892 (sic)/raft) than that fed C. gracilis (7,551 (sic)/raft) or its equivalent from rocky scrapping (2,000 (sic)/raft).

• 出版日期2013-1