Monogeneans on native and introduced freshwater fishes from Cuba with the description of a new species of Salsuginus Beverley-Burton, 1984 from Limia vittata (Poeciliidae)

During a parasitological survey carried out between March and September 2003 in Cuba, the following monogeneans were found on the gills of freshwater fishes: Salsuginus cubensis n. sp. on the Cuban molly Limia vittata Guichenot (Poeciliidae); Cichlidogyrus sclerosus Paperna & Thurston, 1969 and C. tilapiae Paperna, 1960 on the African cichlid Tilapia rendalli Boulenger (Cichlidae); Haplocleidus dispar Mueller, 1936 and Pterocleidus acer Mueller, 1936 (all Dactylogyridae) on the sunfish Lepomis macrochirus Rafinesque (Centrarchidae) (new geographical records); and Gyrodactylus sp. (Gyrodactylidae) on the biajaca Nandopsis tetracanthus Valenciennes (Cichlidae) (new host and geographical record). Salsuginus cubensis differs from all other species of the genus in the size and morphology of the copulatory complex. The occurrence of C. sclerosus, C. tilapiae, H. dispar and P. acer in their respective hosts is due to the introduction of these hosts to Cuba. A review of the species composition of the Monogenea in native and introduced freshwater fish from Cuba is presented and the zoogeographical distribution of the species found is briefly discussed.     

New species of Rhabdosynochus Mizelle and Blatz 1941 (Monogenoidea: Diplectanidae) from the gills of centropomid fishes (Teleostei) off the Pacific Coast of Mexico

In the course of the investigations into the fish parasites in the Tres Palos Lagoon in the State of Guerrero off the Pacific coast of Mexico, the following diplectanid species (Monogenoidea) from the gills of centropomids were found: Rhabdosynochus alterinstitus n. sp. from Centropomus nigrescens; Rhabdosynochus lituparvus n. sp., Rhabdosynochus volucris n. sp., and Rhabdosynochus siliquaus n. sp. from Centropomus robalito (Centropomidae). The apparent synapomorphic character supporting a sister relationship of these diplectanids is a single, sheathlike accessory piece comprising 3 distal branches of the male copulatory organ. The origin of the present diplectanid on centropomids is discussed, and it is suggested that this may be the result of allopatric speciation as a result of the uplift of the Panamanian Isthmus, thereby separating the Pacific and Atlantic Oceans during Pleistocene (3-5 million yr ago).     

New and previously described species of Urocleidoides (Monogenoidea: Dactylogyridae) infecting the gills and nasal cavities of Hoplias malabaricus (Characiformes: Erythrinidae) from Brazil

During an investigation of the biodiversity and structure of parasite communities among native populations of the erythrinid fish Hoplias malabaricus (Characiformes) from 7 rivers in Brazil, the following monogenoidean (Dactylogyridae) species were found: Urocleidoides malabaricusi n. sp., Urocleidoides naris n. sp., Urocleidoides cuiabai n. sp., Urocleidoides brasiliensis n. sp., and Urocleidoides eremitus Kritsky, Thatcher, and Boeger, 1986. Specimens considered as a new genus of Dactylogyridae were also found. The new species are mainly distinguished from the other 14 species of Urocleidoides in the general morphology of their copulatory and anchors/bar complexes. These new species and the new dactylogyrid genus are described, as well as supplemental observations and new illustrations of U. eremitus are provided. The present findings expand the known geographical distribution of species of Urocleidoides to southeastern and midwestern Brazil. A high speciation of this genus in the tropics is hypothesized, and it is briefly discussed.     

Systematic status and first description of male of Dujardinia cenotae Pearse, 1936 [= Hysterothylacium cenotae (Pearse, 1936) Moravec et al., 1995] (Nematoda: Anisakidae)

A new collection of adult anisakid nematodes from the intestine of the catfish Rhamdia guatemalensis from two cenotes (= sinkholes) and a cave in the Yucatan Peninsula, southeastern Mexico, has shown that they are conspecific with those inadequately described as Dujardinia cenotae Pearse, 1936. The female is redescribed and the male is described for the first time. The morphology of this species shows that it belongs to the genus Hysterothylacium. This is the only Hysterothylacium species recorded from freshwater fishes in Mexico and it may well be endemic to cenotes and caves of the Yucatan Peninsula.     

Revision of the amphiamerican Neotetraonchus Bravo-Hollis, 1968 (Monogenoidea: Dactylogyridae), with a description of N. vegrandis n. sp. from the gill lamellae of the blue sea catfish Ariopsis guatemalensis (Siluriformes: Ariidae) off the Pacific Coast of Mexico

Neotetraonchus Bravo-Hollis, 1968 is revised and reassigned to the Dactylogyridae Bychowsky, 1933 based on examinations of specimens representing four species from the gill lamellae of sea catfishes (Ariidae). The monotypic Neotetraonchidae Bravo-Hollis, 1968 is placed in synonymy with the Dactylogyridae. Neotetraonchus bychowskyi Bravo-Hollis, 1968 (type-species), is redescribed from the tete sea catfish Ariopsis seemanni (Günther) (type-host) in the eastern Pacific Ocean off Panama (new geographical record). Neotetraonchus vegrandis n. sp. is described from the blue sea catfish A. guatemalensis (Günther) off the Pacific Coast of Mexico. Neotetraonchus bravohollisae Paperna, 1977 is redescribed from the hardhead sea catfish A. felis (L.) in the Gulf of Mexico off the Yucatan Peninsula. Neotetraonchus felis (Hargis, 1955) Paperna, 1977 is redescribed from A. felis in the Gulf of Mexico off Mississippi and the Yucatan Peninsula (new geographical record). Morphological similarities between species of Neotetraonchus suggest the likely presence of geminate species pairs flanking the Isthmus of Panama.

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A new diplectanid (Monogenea) genus and species from the gills of the black snook, Centropomus nigrescens (Perciformes: Centropomidae) of the Pacific coast of Mexico

Cornutohaptor nigrescensi n. sp. (Diplectanidae) is described from the gills of the black snook, Centropomus nigrescens (Perciformes: Centropomidae) from the Pacific coast of Mexico. Cornutohaptor n. gen. is proposed for this new species and is characterized by possessing 2 intestinal ceca terminating blindly; a germarium looping right intestinal cecum; bilobed testis; 2 seminal vesicles; 7 pairs of hooks, each with protruding thumb; a grooved ventral bar and coiled male copulatory organ (MCO); an accessory piece comprising a "baglike structure" with an appendage; dorsal bars associated parallelly to body midline; and no adhesive accessory organs on the haptor. Cornutohaptor differs from all confamilial genera by including species with anchors with straight and deep root longest, hook pair 1 reduced in size, MCO with counterclockwise rings, and by the morphology of the accessory piece. Cornutohaptor nigrescensi most closely resembles species of Murraytrema Price, 1937, Lobotrema Tripathi, 1937, and Murraytrematoides Yamaguti, 1958, because of the absence of squamodiscs or lamellodiscs on the haptor and tegumental scales on the posterior portion of the body. Cornutohaptor differs from these genera in the position and number of haptoral bars (2 bars in Lobotrema spp., dorsal bars transversally associated in Murraytrema and Murraytrematoides spp.) and in having a coiled MCO (copulatory organ is a comparatively straight, poorly sclerotized tube in Murraytrematoides spp.). This is the first diplectanid described from a centropomid along the Pacific coast of Mexico.     

New species and geographical records of dactylogyrids (Monogenea) of catfish (Siluriformes) from the Peruvian Amazonia

Three new species of gill monogeneans (Dactylogyridae: Ancyrocephalinae) are described from siluriform catfish from Iquitos, Peru: Demidospermus mortenthaleri n. sp. from Brachyplatystoma juruense (Boulenger), Demidospermus brevicirrus n. sp. from Pimelodus sp., and Aphanoblastella aurorae n. sp. from Goeldiella eques (Müller & Troschel). Demidospermus mortenthaleri is characterized by a male copulatory organ (MCO) with a small loop at its middle portion; 2 types of hooks, of which pairs 5 and 6 are longer than the remaining hooks; a proximal subunit round and highly depressed thumb; and a sclerotized vagina with a round pad at the vaginal aperture. Demidospermus brevicirrus is distinguished from other congeners by the presence of a short, straight, and robust MCO and boot-shaped accessory piece with a hooked projection directed posteriorly. Aphanoblastella aurorae is the only species of the genus that possesses an arrow-shaped sclerotized vagina and a medial process on the dorsal bar. Another 6 dactylogyrids described previously are recorded for the first time from the Peruvian Amazonia: Cosmetocleithrum bulbocirrus Kritsky, Thatcher and Boeger, 1986 ; Vancleaveus fungulus Kritsky, Thatcher and Boeger, 1986 ; V. janauacaensis Kritsky, Thatcher and Boeger, 1986 ; V. platyrhynchi Kritsky, Thatcher and Boeger, 1986 ; Unilatus unilatus Mizelle and Kritsky, 1967 ; and U. brittani Mizelle, Kritsky and Crane, 1968 . Based on observations of specimens collected in the Peruvian Amazonia, new morphological data for these species are provided. Comparison of new specimens of U. unilatus and U. brittani with those of Unilatus brevispinus Suriano, 1985 and Unilatus longispinus Suriano, 1985 , both originally described from Brazil, has shown that they are conspecific. Therefore, the latter species were synonymized with U. unilatus and U. brittani , respectively. In addition, 56 undescribed monogeneans found in catfish from the Peruvian Amazonia, some of them probably belonging to new genera, are listed.     

First records of known endoparasitic species of Pseudempleurosoma Yamaguti, 1965 (Monogenoidea: Dactylogyridae) from tetraodontid and rachycentrid fish off the northern coast of the Yucatan Peninsula, Mexico

Monogenoideans infecting the rectum of the wild checkered puffer fish, Sphoeroides testudineus (Tetraodontidae), and the pyloric ceca of the cultured cobia, Rachycentron canadum (Rachycentridae), from the northern coast of the Yucatan Peninsula, Mexico, were morphologically identified as Pseudempleurosoma carangis Yamaguti, 1965 and Pseudempleurosoma gibsoni Santos, Mour?o and Cárdenas, 2001 (Dactylogyridae), respectively. Morphometric comparison between the paratypes of P. carangis and those from S. testudineus showed that the latter differ only in the length of the body, germarium, and dorsal anchors. Similarly, a small form of P. gibsoni based on body size was detected in the present study. These metric differences may be attributable to the host effect, i.e., S. testudineus/R. canadum versus Caranx lugubris (Carangidae) (type host of P. carangis) from Hawaii and Paralonchurus brasiliensis (Sciaenidae) (type host of P. gibsoni) from Brazil, or by the degree of maturity, or both. In view of these considerations, new illustrations and several supplemental observations for P. carangis and P. gibsoni are provided. The present findings also represent new geographical records, and new sites of infection, e.g., rectum and pyloric ceca, for species of Pseudempleurosoma, and the first known endoparasitic monogenoideans infecting tetraodontid and rachycentrid fishes in Mexico.     

Five new species of Urocleidoides (Monogenoidea) (Mizelle and Price 1964) Kritsky, Thatcher, and Boeger, 1986, parasitizing the gills of Panamanian freshwater fishes

During an investigation of gill monogenoidean parasites from freshwater fishes in central Panama, 5 new species of Urocleidoides (sensu stricto) were found: Urocleidoides cultellus n. sp., Urocleidoides visiofortatus n. sp., and Urocleidoides advenai n. sp. from the gymnotiform Brachyhypopomus occidentalis (Hypopomidae); Urocleidoides neotropicalis n. sp. and Urocleidoides piriatiu n. sp. from the characiforms Saccodon dariensis (Parodontidae) and Ctenolucius beani (Ctenoluciidae), respectively. Our findings represent the first known species of Urocleidoides from these fishes in Central America and demonstrate that they are morphologically linked to their South American congeners.