RESUMEN
Due to their high specificity, monogenoids from fish provide an interesting model to study historical associations of hosts and parasites. High agreement between host and parasite phylogeny is often interpreted as evidence of cospeciation. However, cophylogenetic signal may also arise from other, either adaptive or non-adaptive, processes. We applied the recently developed Cophylospace Framework to better understand the evolutionary relationship between monogenoids and marine catfish from the Atlantic coast of South America. The associations between 12 marine catfish and 10 monogenoid species were assessed. Molecular data of host and parasite species were used for phylogenetic reconstruction. We used anchor morphology based on Procrustes coordinates to evaluate whether closely related hosts are associated with morphologically similar parasites. To assess the association between parasite phylogeny and host morphology, we produced a distance matrix based on morphological characters of catfishes. Agreement between phylogenies and between phylogeny and morphology was measured using Procrustes R2 computed with PACo. The parasite phylogeny obtained in this study represents the first complete phylogenetic hypothesis of monogenoids parasitizing ariids from South America. The Cophylospace analysis suggested that phylogenetic and morphological distance of monogenoids contributes similarly to explain the pattern of hostparasite associations, whereas parasite phylogeny is more strongly associated with the morphological traits of the hosts than with host phylogeny. This evidence suggests that cospeciation is not a major force accounting for diversification in the monogenoids studied. Rather host morphological traits seem to be a more important driver, which conforms with evidence from other hostâmonogenoid systems.
Asunto(s)
Bagres , Parásitos , Trematodos , Animales , Filogenia , Bagres/parasitología , Evolución Biológica , Interacciones Huésped-Parásitos , América del SurRESUMEN
The present study describes Udonella brasiliensis n. sp., an epibiont found on Caligus sp., a parasite the ariids Genidens barbus (Lacepède) and Aspistor luniscutis (Valenciennes), caught on the coast of the state of São Paulo, Brazil. Morphological and molecular analyses (partial 18S rDNA) were carried out. The morphological data showed that U. brasiliensis n. sp. can be distinguished from current valid species by its morphometric attributes (e.g., body, pharynx, ovary and testis), while the molecular information supports the proposal of a new species. The 18S rDNA phylogenetic analysis shows a close relationship between the new species and Udonella australis Carvajal & Sepulveda, in a subclade formed of species that parasitize South American fish. Finally, this study also discusses a scenario of initial irradiation for udonellids.
Asunto(s)
Bagres , Copépodos/parasitología , Enfermedades de los Peces/epidemiología , Simbiosis , Trematodos/anatomía & histología , Trematodos/genética , Infecciones por Trematodos/veterinaria , Animales , Brasil/epidemiología , Enfermedades de los Peces/parasitología , Filogenia , ARN de Helminto/análisis , ARN Ribosómico 18S/análisis , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/parasitologíaRESUMEN
Based on a taxonomic approach, combining morphological characters with DNA sequences (i.e.,18S rDNA, ITS1, 5.8S rDNA and ITS2), Susanlimocotyle n. gen. is proposed to accommodates Susanlimocotyle narina n. sp. from the nostrils of the ariid Sciades herzbergii (Bloch) from the coast of the state of Pará, Brazil. Susanlimocotyle n. gen. is characterized by species possessing: an intestinal ceca confluent posteriorly; a male copulatory organ, comprising a variable tube, articulated with the accessory piece; a sclerotized vagina, vaginal aperture dextro-ventral; an onchium; a robust ventral bar; two dorsal bars; a ventral anchor with elongated shaft and a dorsal anchor with deep root expanding into wings. In addition, new molecular data of Chauhanellus spp. are also provided and used for the evaluation of the phylogenetic relationships among monogenoids parasitizing siluriforms. Susanlimocotyle n. gen. exhibited a higher genetic divergence level for 18S rDNA (4.6 to 7.2% [83-130 bp]) with respect to Chauhanellus spp. despite sharing S. herzbergii as a host, than Hamatopeduncularia spp., (4.1 to 5.8% [75-110 bp]) from Oriental ariids. For the 18S rDNA, 5.8S rDNA, ITS1 and ITS2 regions, C. boegeri and C. susamlimae were observed to have the smallest interspecific distances, and C. velum was revealed to be the most genetically distant species to Chauhanellus. The proposal for Susanlimocotyle n. gen. is also supported by phylogenetic analysis based on the 18S rDNA gene, which supports the close relationship between the new genus and Hamatopeduncularia and Chauhanellus from ariids from the South America and Oriental regions. Moreover, the patterns towards the shared diversification between monogenoids and their ariid hosts were addressed.
Asunto(s)
Bagres , Enfermedades de los Peces/epidemiología , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , Brasil/epidemiología , Enfermedades de los Peces/parasitología , ARN de Helminto/análisis , ARN Ribosómico 18S/análisis , Trematodos/anatomía & histología , Trematodos/genética , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/parasitologíaRESUMEN
One new species of Rhinoxenus Kritsky, Boeger & Thatcher, 1988 from the nasal cavities and four new species of Mymarothecioides n. gen. from the gills are described in Hydrolycus armatus (Jardine & Schomburgk). They were collected in the Xingu River, Pará, Brazil. Rhinoxenus cachorra n. sp. is characterized by having a ventral anchor with inconspicuous roots, and point with fish-hook-like termination; copulatory complex comprising a spiraled male copulatory organ (MCO) with two counterclockwise coils, and an accessory piece with an expanded, bifurcated distal portion. Mymarothecioides n. gen. is proposed and characterized for species without eyes, with or without accessory chromatic granules; copulatory complex comprising articulated MCO, accessory piece; MCO a broad arcuate tube; an accessory piece with a hooked termination in the distal portion; a dextro or midventral non-sclerotized vagina; an anteromedial projection on the ventral bar. Mymarothecium whittingtoni Kritsky, Boeger & Jégu, 1996 is transferred to Mymarothecioides n. gen. as Mymarothecioides whittingtoni (Kritsky, Boeger & Jégu, 1996) n. comb.
Asunto(s)
Characiformes , Enfermedades de los Peces , Platelmintos , Trematodos , Infecciones por Trematodos , Animales , Brasil , Femenino , Branquias , Masculino , RíosRESUMEN
A parasitological survey of monogenoids infesting the gills of marine catfish (Ariidae) captured from the Atlantic coastal region of the Amazon Basin was carried out during the 2011-2013 period. The gills of 448 specimens involving twelve ariid species (29 Amphiarius rugispinis (Valenciennes), 52 Aspistor quadriscutis (Valenciennes), 74 Bagre bagre (Linnaeus), 16 Cathorops arenatus (Valenciennes), 13 Cathorops agassizii (Eigenmann & Eigenmann), 17 Cathorops spixii (Agassiz), 3 Cathorops sp., 13 Notarius grandicassis (Valenciennes), 14 Sciades couma (Valenciennes), 64 Sciades herzbergii (Bloch), 48 Sciades parkeri (Traill), 13 Sciades passany (Valenciennes), 92 Sciades proops (Valenciennes) were sampled. No monogenoids were found in Cathorops agassizi, Cathorops arenatus, Cathorops spixii, Cathorops sp. and Sciades parkeri, but the gills of the other sampled species were parasitized by at least one species of monogenoid. We identified four new species of Chauhanellus and one new species of Hamatopeduncularia: Chauhanellus hamatopeduncularoideum n. sp. from Amphiarius rugispinis and Sciades couma; Chauhanellus hypenocleithrum n. sp. from Sciades proops; Chauhanellus susamlimae n. sp. from Sciades herzbergii and Sciades passany; Chauhanellus velum n. sp. from Sciades couma, Sciades herzbergii and Sciades passany; and Hamatopeduncularia cangatae n. sp. from Aspistor quadriscutis and Notarius grandicassis. Four previously described species were reported for the first time parasitizing ariids from Atlantic Amazon: Chauhanellus neotropicalis Domingues & Fehlauer, 2006 from Amphiarius rugispinis, Aspistor quadriscutis, Notarius grandicassis and Sciades passany; Chauhanellus boegeri Domingues & Fehlauer, 2006 from Sciades couma and Sciades herzbergii; Hamatopeduncularia bagre Hargis, 1955 from Bagre bagre; and Neomurraytrematoides proops Zambrano & Añez 1993 from Sciades passany. The monotypic Neomurraytrematoides Zambrano & Añez 1993 was placed in synonymy with Neotetraonchus Bravo-Hollis, 1968 and its type-species, Neomurraytrematoides proops Zambrano & Añez 1993 was transferred to Neotetraonchus as Neotetraonchus proops (Zambrano & Añez 1993) n. comb. The morphology of the haptoral structures supports the transfer of Rhamnocercus seenghali Kumar, 2013 to Chauhanellus as Chauhanellus seenghali (Kumar, 2013) n. comb.