Éditeur(s) : HAL CCSD Paris : Muséum national d'histoire naturelle
Résumé : International audience
To increase understanding of the chromosomal diversity among cichlid species, karyotypes of 19 species of Cichlidae belonging to 15 genera (Paratilapia polleni, Chromidotilapia guntheri guntheri, Hemichromis fasciatus, Steatocranus irvinei, Stomatepia pindu, Altolamprologus compressiceps, Julidochromis transcriptus, Neolamprologus tetracanthus, N. brevis, Gnathochromis permaxillaris, Eretmodus cyanostictus, Astatoreochromis alluaudi, Haplochromis callipterus, H. paludinosus, Ninzbochromis livingstonii, N. polystigma, Pseudocrenilabrus multicolor victoriae, P. philander and Ctenochromis horei) were investigated for the first time. In spite of the variation in the karyotypes of cichlid fishes (from 2n = 42 to 2n = 48 chromosomes), the modal chromosome number was 2n = 44. Cytogenetic mapping of the 18S ribosomal RNA (18S rRNA) gene was accomplished.
ISSN: 0399-0974

hal-01544902
https://hal.archives-ouvertes.fr/hal-01544902

Éditeur(s) : EDP Sciences
Résumé : Twelve diel surveys were carried out in three reservoirs of Sri Lanka viz. Minneriya, Udawalawe and Victoria, to investigate diel feeding patterns, daily ration and relative food consumption in fish populations. Stomach content weights of different size classes of various fish species in the three reservoirs in 12 diel surveys were analysed using an iterative method, MAXIMS. Predominantly herbivorous or detritivorous fish species such as Amblypharyngodon melettinus and Oreochromis niloticus exhibited one peak in the diel feeding pattern. Two peak feeding periods were evident in predominantly insectivores and/or zooplanktivores (e. g., Puntius chola and Rasbora daniconius) and interestingly in macrophyte feeders (i.e., Etroplus suratensis, Puntius filamentosus and Tilapia rendalli). It might be possible that all species with two feeding peaks in diel feeding patterns rely on vision for feeding. Food consumption per biomass (Q/B ratio) defined as amount of food consumed per unit weight of an age-structured population of fish was estimated on the basis of the average quantities of food consumed over a long period of time by various size classes in order to minimize the bias of estimates.
Douze séries d'échantillonnage ont été effectuées dans trois lacs-réservoirs du Sri Lanka : Minneriya, Udawalawe et Victoria, afin d'étudier le modèle journalier d'alimentation, les rations journalières et à la consommation relative des populations de poissons. Les poids des contenus stomacaux de différentes classes de taille ont ainsi été analysés en utilisant une méthode itérative, MAXIMS. Les espèces herbivores ou détritivores telles que Amblypharyngodon melettinus et Oreochromis niloticus montrent un pic dans l'activité de nutrition. Tandis que les espèces détrivores et/ou zooplanctivores en présentent deux (ex., Puntius chola et Rasbora daniconius) de même que des espèces se nourrissant de macrophytes (ex., Etroplus suratensis, Puntius filamentosus et Tilapia rendalli). Il est possible que la vision joue un rôle chez ces espèces présentant deux pics journaliers d'alimentation. La consommation de nourriture par rapport à la biomasse (le rapport Q/B) est défini comme la quantité d'aliment consommé par unité de poids d'une population de poissons structurée en âge, sur la base de quantités moyennes de nourriture consommée sur une longue période de temps et par diverses classes de taille, afin de minimiser les biais dans les estimations.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2006-07 , Vol. 19 , N. 3 , P. 229-237

Droits : 2006 EDP
http://archimer.ifremer.fr/doc/2006/publication-2134.pdf
DOI:10.1051/alr:2006023
http://archimer.ifremer.fr/doc/00000/2134/

Éditeur(s) : HAL CCSD Springer Verlag (Germany)
Résumé : 5 pages
International audience
This study investigates the recent evolution of a rich parasite community associated with one of the world's most invasive species, the cichlid fish Oreochromis mossambicus. Populations from the species' native range (Mozambique) are compared to a population from New Caledonia (Wester Pacific), an island where the species was introduced in 1954. The results support the complete local extinction of the gill parasite community in the course of the invasion process. Up to six gill parasite species per locality were documented in the O. mossambicus native range, and previous surveys consistently reported at least one parasite species introduced along African cichlid species established out of Africa. The absence of parasites in New Caledonia is therefore exceptional. This can be attributed to local factors, such as a strong initial population bottleneck, the likely absence of multiple host introductions, and the frequent occurrence of brackish watersheds that might enhance the probability for natural deparasitation.
ISSN: 0932-0113

hal-01356378
https://hal.archives-ouvertes.fr/hal-01356378
PUBMED : 27334451
DOI : 10.1007/s00436-016-5168-1

Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 68, pp.751-755
Résumé : If warmwater finfish protein requirements as level in diet is low, absolute intake per day is similar to those of coldwater species. But relation of this requirement with specific growth rate differs for strictly warmwater fishes as Tilapias. Analysis of partition between protein and non-protein energy retention shows that these species with Clarias make a better use of non-protein energy provided and consequently improve their protein retention. Better carbohydrate digestibility and metabolism are propounded as part of the explanation.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/acte-1424.pdf
http://archimer.ifremer.fr/doc/00000/1424/