Two new species of Halysioncum Caira, Marques, Jensen, Kuchta et Ivanov, 2013 (Cestoda, Diphyllidea) from Indo-Pacific rays of the genus Aetomylaeus Garman (Myliobatiformes, Myliobatidae)

Abstract: Recent collections of cestode parasites from two species of the myliobatid genus Aetomylaeus Garman from several localities in the Pacific Ocean resulted in the discovery of two new species of Halysioncum Caira, Marques, Jensen, Kuchta et Ivanov, 2013. Halysioncum gibsoni sp. n. from Aetomylaeus maculatus (Gray) in the South China Sea off Borneo differs from all of its congeners in having the following combination of characters: 27 apical hooks (14 type A and 13 type B hooks), 11?12 lateral hooklets, 22?28 spines per column on the cephalic peduncle, testes distributed in a single column and an internal seminal vesicle. Halysioncum arafurense sp. n., recovered from Aetomylaeus cf. nichofii 2 (sensu Naylor et al. 2012b) in the Arafura Sea off the Wessel Islands, Northern Territory, Australia, can be distinguished from its congeners based on the following combination of characters: 23 apical hooks (12 type A and 11 type B hooks), the number of lateral hooklets (9?11), the number of spines per column on the cephalic peduncle (20?24), the number and distribution of the testes (13?15 testes in two irregular columns), and the distribution of vitelline follicles (interrupted dorsally at the level of the ovarian lobes). Both species represent the first verified records of diphyllideans from eagle rays of the genus Aetomylaeus and formally extend the host associations of diphyllideans to include a third genus of Myliobatiformes. The myliobatiforms are indeed an understudied group of available hosts for diphyllideans and represent interesting target hosts if the diversity of diphyllidean tapeworms is to be fully estimated and understood.Fil: Ivanov, Veronica Adriana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Caira, Janine N.. University Of Connecticut; Estados Unido

Three new species of Cichlidogyrus Paperna, 1960 (Monogenea, Ancyrocephalidae) parasitic on Tylochromis jentinki (Steindachner, 1895) (Pisces, Cichlidae) in West Africa

Trois monogènes nouveaux : #Cichlidogyrus berrebii n. sp., #C. pouyaudi n. sp. et #C. kothiasi n. sp., parasites branchiaux de #Tylochromis jentini (Cichlidae), sont décrits en Afrique de l'Ouest (Côte d'Ivoire et Guinée). Ces trois nouvelles espèces sont considérées comme primitives à cause de la morphologie caractéristique de la barre transversale dorsale du hapteur, mais elles sont cependant situées dans le genre #Cichlidogyrus$. (Résumé d'auteur

Cichlidogyrus Paperna, 1960 (Monogenea, Ancyrocephalidae) : gill parasites from West African Cichlidae of the subgenus Coptodon Regan, 1920 (Pisces), with descriptions of six new species

Une étude des parasites branchiaux de poissons appartenant au sous-genre #Coptodon Regan, 1920 (#Cichlidae) : #Tilapia coffea Thys van den Audenaerde ; #T. dageti Thys van den Audenaerde ; #T. guineensis (Bleecker) ; #T. louka Thys van den Audenaerde ; #T. walteri Thys van den Audenaerde ; and #T. zillii (Gervais) ; provenant de différentes localités en Afrique de l'Ouest (Burkina Faso, Congo, Côte d'Ivoire, Guinée, Mali et Sénégal) a révélé la présence de 19 espèces du genre #Cichlidogyrus Paperna, 1960 (#Monogenea, #Ancyrocephalidae). Six sont considérées comme nouvelles : #C. amphoratus n. sp., #C. levequei n. sp., #C. microscutus n. sp., #C. ornatus n. sp., #C. ouedraogoi n. sp. et #C. yanni$ n. sp. Nous discutons de la spécificité de ces parasites. (Résumé d'auteur

Ligophorus pilengas n. sp. (monogenea: ancyrocephalidae) from the introduced so-iuy mullet, mugil soiuy (teleostei: mugilidae), in the sea of Azov and the Black sea

The monogenean Ligophorus chabaudi was originally described on the gills of the flathead mullet, Mugil cephalus, and was subsequently reported on the So-iuy mullet, Mugil soiuy. However, the morphology of sclerotized parts and multivariate statistical analyses suggest that the form from the So-iuy mullet represents a new species. This study provides a description of the new species Ligophorus pilengas n. sp. and provides additional morphological data concerning the morphology of the ventral bar that might be useful for the diagnosis of Ligophorus. Ligophorus pilengas n. sp. is the second species of Ligophorus reported on the So-iuy mullet. Zoogeographical records indicate that L. pilengas n. sp. was probably introduced to the Black Sea and the Sea of Azov from the western Pacific Ocean together with its host.Balbuena Diaz-Pines, Juan Antonio, [email protected]

Can host body size explain the parasite species richness in tropical freshwater fishes ?

The variability of monogenean gill ectoparasite species richness in 19 West African cyprinid species was analyzed using the following seven predictor variables : host size, number of drainage basins, number of sympatric cyprinid species, host diversity, association with mainland forest, host ecology, and monogenean biological labelling. The size of the host species accounted for 77% of the variation in the number of parasite species per host, and host ecology and additional 8%. Together the effects of host size and host ecology accounted for 85% of the variation in monogenean species richness. This study shows that the deciding factors for explaining monogenean species richness in West African cyprinid fishes are host species size and host ecology. These results were compared with main factors responsible for parasite species richness in fish communities. Other possible explanations of monogenean community structure in West African cyprinids are discussed. (Résumé d'auteur

The biotope of branchial ectoparasites of fishes : factors of variations in the pattern sea bass - monogeneans

International audienceFor the analysis of functional structure of communities, the ecologists are obliged to extend their investigations to the heterogeneity of their environment and colonized biotopes. The gills of sea bass Dicentrarchus labrax serve as a biotope for several ectoparasites ; some aspects of the heterogeneity of this biotope were studied quantitatively. The models expressing the variations of number of branchial filaments, and branchial area that can be colonized by monogeneans, were established in function of the lenght of fishes. Such biotopes being subjected to significant physical modifications, the effects of the latter over the organization of parasitic settlements are then discussed