Modèle de distribution des nématodes chez le poisson chat (Clarias anguillaris (Linnaeus, 1758)) dans deux réservoirs du Burkina Faso (Afrique de l’Ouest)

Abstract

Paracamallanus cyathopharynx, Procamallanus laevichoncus, Rhabdochona congolensis, Contracaecum sp., Anisakis sp. et une espèce non identifiée. Les nématodes étaient plus nombreux dans le réservoir de Ziga. Cependant, la prévalence des nématodes n’a pas varié dans les deux sites. Les nématodes adultes étaient plus diversifiés dans le tube digestif et les larves étaient fréquentes dans la cavité et dans les tissus des organes. Parmi les espèces de nématodes étudiés, Anisakis sp. a été rencontrée chez les poissons pour la première fois au Burkina Faso. Cette investigation a permis de connaître les espèces de nématodes qu’héberge C. anguillaris au Burkina Faso. Ces espèces n’avaient pas la même distribution chez l’hôte de même que les différents stades. Les adultes étaient rencontrés dans le tube digestif et les larves dans les tissus et les mésentères
 English title: Nematode distribution pattern in catfish (Clarias anguillaris (Linnaeus, 1758)) in two reservoirs of Burkina Faso (West Africa)
 Clarias anguillaris is a fish widely consumed in Burkina Faso. Among the parasites of this fish, we note the nematodes whose diversity and preferred organs are not very well known. This work shows diversity and distribution of nematodes of C. anguillaris. The host fish were sampled in two reservoirs in Burkina Faso; namely the Loumbila dam and the Ziga dam. At each sampling, the host fish were examined for nematodes. The digestive tract, for its part, was separated from the secondary organs after dissection, and each part was examined for the collection of nematodes. A total of 268 Clarias anguillaris were examined. Of the fish examined, 74.63% were infected. 06 species of Nematodes were collected: Paracamallanus cyathopharynx, Procamallanus laevichoncus, Rhabdochona congolensis, Contracaecum sp., Anisakis sp. and an unidentified nematode. Nematodes were more abundant in Ziga dam. However, the percentage of nematodes infestation did not vary at both sites. Adults’ nematodes were more diverse in the digestive tract and larva were more found in the cavity and in the tissues. Among the species of nematodes studied, Anisakis sp. was encountered for the first time on fishes in Burkina Faso. This investigation allowed to discover the nematode species harbored by C. anguillaris in Burkina Faso. These species did not have the same distribution in the host nor the different stages of the nematodes. Adults were found in the digestive tract and larvae in tissues and mesenteries.

Study of some ecological parameters in nematode parasites of freshwater fish in the Senegal and Gambia rivers

“…This relationship is not verified in most of our host fish species. Our results corroborate those of Sinare et al (2021) [31] and Mujtaba et al (2018) [27] , according to whom, the number of nematodes is not related to the size or weight of the hosts. Moreover, Enyidi and Eneje (2015) [14] showed a decrease in prevalence with an increase in size in farms.…”

“…Similarly, the decrease in food resources exposes fish to consuming all sorts of food, thus increasing the risks of infestation. Our results confirm those of Sinare et al (2021) [31] , indicating that during the dry season, the reduction in water surface leads to contacts among different hosts, as well as those found in Otolithoides pama from the Bay of Bengal (Priyanka et al 2019) [30] and Mugil cephalus in Senegal (Dione et al 2014) [11] . However, the opposite has been reported by other authors (Olivero-Verbel et al 2013, Sinare et al 2021) [29,31] .…”

“…Our results confirm those of Sinare et al (2021) [31] , indicating that during the dry season, the reduction in water surface leads to contacts among different hosts, as well as those found in Otolithoides pama from the Bay of Bengal (Priyanka et al 2019) [30] and Mugil cephalus in Senegal (Dione et al 2014) [11] . However, the opposite has been reported by other authors (Olivero-Verbel et al 2013, Sinare et al 2021) [29,31] . Ibiwoye et al (2005) [19] note a high infestation of fish at the beginning of the rainy season due to their weakening during hibernation.…”

“…This has been reported by other authors. Thus, Sinare et al (2021) [31] showed that the difference in the number of nematode parasites of C. anguillaris between two collection localities was significant. Daoui and Chaheb (2021) [8] made a similar observation, highlighting that this parameter plays a very important role in the coexistence between hosts and parasites.…”