Sur la présence de Mylesinus paraschomburgkii Jégu et al., 1989 (Characiformes, Serrasalmidae) dans le bassin du rio Jari (Brésil, Amapa)

Des récoltes postérieures à la description de #Mylesinus paraschomburgkii permettent d'étendre son aire de distribution au bassin du Jari et au principal affluent du Uatuma. Une analyse en composantes principales sur 18 descripteurs morphologiques montrent que la morphologie générale de la population du Jari est différente de celle des populations du Trombetas et du Uatuma. L'isolement de la population du Jari serait donc plus ancien que la séparation des populations du Trombetas et du Uatuma. La dispersion de #Mylesinus paraschomburgkii le long de la marge sud du plateau des Guyanes serait reliée aux transgressions marines du Quaternaire. (Résumé d'auteur

Neotropical Monogenoidea. 21. Trinigyrus mourei sp.n. (Dactylogyridae) from the gills of the Amazonian catfish Hypostomus marginatus (Loricariidae)

Trinigyrus mourei sp. n. (Dactylogyridae) is described from an Amazonian armoured catfish, Hypostomus emarginatus (Loricariidae) in Brazil. The new species closely resembles T. hypostomatis HANEK, MOLNAR & FERNANDO, 1974, from which it differs mainly by having: 1) a more robust copulatory organ; 2) a non-articulated accessory piece; and 3) comparatively longer haptoral appendages

UNE NOUVELLE ESPÈCE DE TOMETES (TELEOSTEI : CHARACIDAE : SERRASALMINAE) DU BOUCLIER GUYANAIS, TOMETES LEBAILI N. SP.

Tometes lebaili n. sp. diffère de Tometes trilobatus Valenciennes, 1850, par la position de la bouche, oblique et dirigée vers le haut. T. lebaili présente 7 à 8 dents à la série labiale du dentaire contre 5 chez T. trilobatus. T. trilobatus, citée des rapides de l’Araguari (Amapá, Brésil) à l’Oyapock (Guyane française), est remplacée plus à l’ouest par T. lebaili n. sp., décrite de la Mana (Guyane fr.) au Commewine (Surinam) et peut-être présente dans le Sinnamary. La taille maximale observée pour T. lebaili est de 512 mm LS

Tometes makue n. sp. (Characidae : Serrasalminae), une nouvelle espèce du bouclier guyanais décrite des bassins du Rio Negro (Brésil) et de l'Orénoque (Vénézuéla)

Tometes makue is a new species of Tometes Valenciennes, 1850 from Guiana shield. Previously identified as a Mylesinus species by Kner (1860), Sepulveda (1984) and Jégu et al. (1989), T. makue presents the main characteristics of T. trilobatus Valenciennes, 1850, type species of Tometes, and T. lebaili Jégu et al., 2002. T. makue differs from Mylesinus by stronger and shorter tri- and bicuspid teeth, two last sigmoid premaxillary teeth, a shorter lateral premaxillary processus and the two median lingual teeth bracked together. T. makue differs from T. trilobatus and T. lebaili by a smaller number of prepelvic serrae, which are often absent in the larger specimens (0-9 in adults vs. 11-24 in T. trilobatus and 19-26 in T. lebaili). T. makue differs from T. trilobatus by a greater number of dentary teeth on the labial series (6-11 vs. 5-6 in T. trilobatus). T. makue and T. trilobatus present an horizontal and terminal mouth, whereas it is oblique and upturned in T. lebaili. Juveniles of T. makue present 6 to 10 vertical black stripes on the sides and a humeral black spot between 40 and 85 mm SL. Larger specimens are uniformly grey. Observations on stomach contents indicate that T. makue feed mainly on Podostemaceae. T. makue, which can reach 379 mm SL, is an endemic rheophilic species from Orinoco basin, in Venezuela, and rio Negro basin, in Brazil. T. makue, T. trilobatus, T. lebaili and Mylesinus paraschomburgkii form a group of large phytophagous serrasalmins endemic of the Podostemaceae meadows of Guiana shield, from Caroni river in Venezuela to Maroni river in French Guiana

Sur la présence de Mylesinus paraschomburgkii Jégu et al., 1989 (Characiformes, Serrasalmidae) dans le bassin du rio Jari (Brésil, Amapa)

Des récoltes postérieures à la description de #Mylesinus paraschomburgkii permettent d'étendre son aire de distribution au bassin du Jari et au principal affluent du Uatuma. Une analyse en composantes principales sur 18 descripteurs morphologiques montrent que la morphologie générale de la population du Jari est différente de celle des populations du Trombetas et du Uatuma. L'isolement de la population du Jari serait donc plus ancien que la séparation des populations du Trombetas et du Uatuma. La dispersion de #Mylesinus paraschomburgkii le long de la marge sud du plateau des Guyanes serait reliée aux transgressions marines du Quaternaire. (Résumé d'auteur

Mebendazole dietary supplementation controls Monogenoidea (Platyhelminthes: Dactylogyridae) and does not alter the physiology of the freshwater fish Colossoma macropomum (Cuvier, 1818)

This study evaluated the efficacy of mebendazole treatment in supplemented diet against the monogeneans Anacanthorus spathulatus, Notozotecium janauachensis and Mymarothecium boegeri gill parasites of an important native farmed characid fish Colossoma macropomum as well as its effect on the fish physiology. Fish were fed supplemented diet with 0, 0.5, 1.0 and 2.0 g mebendazole (MBZ)·kg-1 dry ration for 14 days. Parasitological analysis and blood collection were performed at 7 and 14 days after feeding. Anacanthorus spathulatus was more resistant to than N. janauachensis, and M. boegeri was more sensitive to treatment. On the other hand, good results in terms of disease control were found when analyzing the parasitological index (prevalence, mean intensity and mean abundance) and the fish physiological response. Fish fed 1.0 g MBZ·kg-1 dry ration for 14 days showed 89.2% of efficacy. Mebendazole treatment did not affect the glucose, hemoglobin, red blood cells count, sodium and potassium concentrations. Furthermore, has proved to be effective in controlling monogenea parasites in C. macropomum. Statement of relevance: Colossoma macropomum commonly known as tambaqui or cachama is one of the most native farmed characid fish in South America. North of Brazil has the main tambaqui production, however obstacles interfere in the fish health like ectoparasites. Besides the best management practices, alternative treatments must be pointed out to keep the homeostasis of the host under parasite infestation. This study focused the treatment of monogenean helminth parasites in the gills of C. macropomum and its effects on the hematological parameters and plasma ions. © 2016 Elsevier B.V