Éditeur(s) : HAL CCSD
Résumé : International audience
The subterranean environment is often described as “extreme” and food poor. Laboratory experiments have shown that blind Mexican tetra Astyanax mexicanus (De Filippi, 1853) cavefish are better at finding food in the dark than surface fish. Several morphological and behavioural attributes that could foster this obvious adaptive response to cave environments have been described. Nonetheless, it is currently unknown what young cavefish actually eat in their natural cave environment. Our results from the Pachón cave in México during the dry and rainy season show that fry are efficient predators in their natural cave environment. Their primary food item is aquatic crustaceans. The guts of post-larval, pre-juvenile stage individuals (n=9) contained an average of 17.9 water fleas (Cladocera), copepods, ostracods, and isopods. Thus, the fry in this cave are well-fed. The Pachón cave environment does not appear to be “food poor” for juvenile cavefish. Food regimes change between post-larval and adult stages to become more dependent on partially decomposed material, guano, or detritus from the mud. We discuss the data with regards to our current developmental and genetic understanding of cavefish morphological and behavioural evolution, particularly regarding its enhanced Vibration Attraction Behaviour (VAB).
Subterranean Biology

hal-01432027
https://hal.archives-ouvertes.fr/hal-01432027
DOI : 10.3897/subtbiol.21.11046

Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 43, pp.461-484
Résumé : Species with a very high potential for aquaculture, allowing development projects on a short terms basis: the seabass originating from S.E. Asia. Species, potentially interesting but presenting some drawbacks, as difficulties to perform larval rearing or presenting pathological problem. Species considered as difficult to rear and not retained like Siganus argenteus , Siganidae or Caranx ignobilis , Carangidae. The future development of finfish in Polynesia is emphasized and a project of sea bass netcage culture in Polynesian lagoon is presented.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/acte-1474.pdf
http://archimer.ifremer.fr/doc/00000/1474/

Éditeur(s) : Cambridge Univ Press
Résumé : Integrated Multi-Trophic Aquaculture takes advantage of the mutualism between some detritivorous fish and phytoplankton. The fish recycle nutrients by consuming live (and dead) algae and provide the inorganic carbon to fuel the growth of live algae. In the meanwhile, algae purify the water and generate the oxygen required by fishes. Such mechanism stabilizes the functioning of an artificially recycling ecosystem, as exemplified by combining the euryhaline tilapia Sarotherodon melanotheron heudelotii and the unicellular alga Chlorella sp. Feed addition in this ecosystem results in faster fish growth but also in an increase in phytoplankton biomass, which must be limited. In the prototype described here, the algal population control is exerted by herbivorous zooplankton growing in a separate pond connected in parallel to the fish-algae ecosystem. The zooplankton production is then consumed by tilapia, particularly by the fry and juveniles, when water is returned to the main circuit. Chlorella sp. and Brachionus plicatilis are two planktonic species that have spontaneously colonized the brackish water of the prototype, which was set-up in Senegal along the Atlantic Ocean shoreline. In our system, water was entirely recycled and only evaporation was compensated (1.5% volume/day). Sediment, which accumulated in the zooplankton pond, was the only trophic cul-de-sac. The system was temporarily destabilized following an accidental rotifer invasion in the main circuit. This caused Chlorella disappearance and replacement by opportunist algae, not consumed by Brachionus. Following the entire consumption of the Brachionus population by tilapias, Chlorella predominated again. Our artificial ecosystem combining S. m. heudelotii, Chlorella and B. plicatilis thus appeared to be resilient. This farming system was operated over one year with a fish productivity of 1.85 kg/m(2) per year during the cold season (January to April).
Animal (1751-7311) (Cambridge Univ Press), 2013-02 , Vol. 7 , N. 2 , P. 322-329

Droits : The Animal Consortium 2012
http://archimer.ifremer.fr/doc/00118/22955/20945.pdf
DOI:10.1017/S1751731112001279
http://archimer.ifremer.fr/doc/00118/22955/