Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Diagnose : nombre de rayons des nageoires D1 : VI ; D2 : I+ 9 ; C : 21-22 ; A : I+ 8 ; P : 17-18 ; Pv : 10 ; nombres d'écailles sur la ligne latérale Éc : 27-28, de vertèbres V : 26. Il existe un dimorphisme sexuel des papilles urogénitales. Le système latéral a été observé en utilisant la microscopie électronique à balayage après fixation dans une solution de glutaraldéhyde à 2 % en eau de mer. Les canaux oculoscapulaires, préoperculaires, les pores muqueux, ainsi que les séries de neuromastes superficiels sont répertoriés et le nombre de neuromastes compté dans chacune. Les séquences codantes pour l'ARN ribosomique 18S sont identifiées.
ISSN: 1631-0691

hal-00749626
https://hal.univ-antilles.fr/hal-00749626

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