A new genus and three new species of dactylogyrids (Monogenea), gill parasites of the threadfin bass,Pronotogrammus multifasciatus Gill (Perciformes: Serranidae) in the Southeastern Pacific Ocean off Peru

Pronotogrammella n. g. is erected to accommodate Pronotogrammella boegeri n. sp. (type-species), Pr. scholzi n. sp. and Pr. multifasciatus n. sp. (Monogenea: Dactylogyridae). The new species are gill parasites of the threadfin bass Pronotogrammus multifasciatus Gill (Perciformes: Serranidae), a demersal teleost collected from off the coastal zone of Puerto Pizarro, Tumbes, Peru. Pronotogrammella n. g. is mainly characterised by having broadly fork-shaped dorsal anchors, which have an accessory anchor sclerite articulated to the tip of the superficial roots. Pronotogrammella n. g. is also characterised by having: (i) a tubular tapered-shaped male copulatory organ (MCO), filamentous distally, with a clockwise coil at distal end or not, lacking accessory piece; (ii) a dorsal bar with an anteromedial delicate umbelliform membrane supported by two processes; (iii) hooks with upright blunt thumb and uniform shank; (iv) a vaginal aperture dextrolateral; (v) a subquadrangular haptor, with inconspicuous lateral flaps and lacking haptoral reservoirs; and (vi) eye-spot or chromatic granules absent. Pronotogrammella boegeri n. sp. is characterised by its crosier-shaped MCO having a clockwise coil at distal end and by its dorsal bar with a straight anteromedial processes. Pronotogrammella scholzi n. sp. is typified by possessing of a dorsal bar with the anteromedial processes like cow horns, hoof-shaped deep roots of the dorsal anchors and a broader shaft of the MCO. Pronotogrammella multifasciatus n. sp. differs from all congeners by having a tubular MCO with twisted shaft and a base with a short and broad arm and by having an almost dumbbell-shaped ventral bar.

     

Morphological and molecular data of new species of Characithecium and Diaphorocleidus (Monogenea: Dactylogyridae) from Neotropical characid fishes

The present study describes three new species of monogenean parasites of characid fishes from the Upper Paraná River basin, Brazil: Characithecium paranapanemense n. sp. on Psalidodon paranae and Psalidodon bockmanni, Diaphorocleidus magnus n. sp. on Astyanax lacustris and Psalidodon fasciatus, and Diaphorocleidus neotropicalis n. sp. on Astyanax lacustris and P. bockmanni. An amendment for Diaphorocleidus is proposed, since additional characters observed in the new species required to extend the generic diagnostic features mainly to include: articulation process connecting the base of the MCO with accessory piece present or absent, and accessory piece with variable shapes (plate-like, pincer-shaped, wrench-shaped, sheath-shaped), divided or not into subunits. Characithecium paranapanemense n. sp. can be distinguished from other congeners by the morphology of its MCO and accessory piece. Diaphorocleidus magnus n. sp. differs from most of its congeners by the morphology of its accessory piece, the presence of articulation process connecting the base of the MCO with accessory piece, and the morphology of the sclerotized structures of the haptor. Diaphorocleidus neotropicalis n. sp. can be easily distinguished from its congeners by the morphology of the accessory piece, the sclerotized structures of the haptor and the morphology of the vagina. Molecular data of the new species (partial 28S rDNA and mitochondrial cytochrome oxidase I) were obtained and the first phylogenetic analysis based on 28S rDNA gene sequences for species of Characithecium and Diaphorocleidus are provided. Although Diaphorocleidus and Characithecium share some morphological similarities, phylogenetic analysis indicates that species of these two genera are not closely related.     

Bicentenariella n. g. (Monogenea: Dactylogyridae) including descriptions of three new species and two new combinations from serranid fishes (Actinopterygii: Serranidae: Anthiinae) in the South American Pacific Ocean

Systematic Parasitology - Bicentenariella n. g. is proposed to accommodate three new species of dactylogyrid monogeneans found on the gills of the threadfin bass Pronotogrammus multifasciatus Gill...     

Three new species of Dactylogyrus Diesing, 1850 (Monogenea: Dactylogyridae) from the gills of the bala sharkminnow Balantiocheilos melanopterus (Cyprinidae) from Thailand

Three new species of Dactylogyrus are described from the gills of the cyprinid fish Balantiocheilos melanopterus (Bleeker) imported from Thailand via the aquarium trade. They are D. coartatus n. sp., D. macrocolpius n. sp. and D. melanopteri n. sp. The double-bar species, D. coartatus n. sp. and D. melanopteri n. sp., are characterised by hooks that are markedly large in relation to the size of the anchors. Clip-like anchors with a sharply recurved, long point are a unique feature of D. coartatus n. sp. The single-bar species, D. macrocolpius n. sp., is characterised by having a copulatory organ composed of a spiral copulum and a medial accessory piece with thorns.     

New and previously described species of Dactylogyridae (Monogenoidea) from the gills of Panamanian freshwater fishes (Teleostei)

During an investigation of the diversity of metazoan parasites of 7 freshwater fish species from 3 localities in central Panama, the following gill dactylogyrid (Monogenoidea) species were found: Aphanoblastella chagresii n. sp. from Pimelodella chagresi (Heptapteridae); Aphanoblastella travassosi (Price, 1938) Kritsky, Mendoza-Franco, and Scholz, 2000 from Rhamdia quelen (Heptapteridae); Diaphorocleidus petrosusi n. sp. from Brycon petrosus (Characidae); Gussevia asota Kritsky, Thatcher, and Boeger, 1989, from Astronotus ocellatus (Cichlidae); Sciadicleithrum panamensis n. sp. from Aequidens coeruleopunctatus (Cichlidae); Urocleidoides flegomai n. sp. from Piabucina panamensis (Lebiasinidae); and Urocleidoides similuncus n. sp. from Poecilia gillii (Poeciliidae). Consideration of the comparative morphology and distribution of these parasites along with the evolutionary history of the host fishes suggests that diversification may be associated with geotectonic events that provided isolation of the Central American fauna with the uplift of the Panamanian Isthmus during early Pliocene (3 mya).     

New and known species of Dactylogyrus Diesing, 1850 (Monogenea,Dactylogyridae) from Iranian freshwater cyprinid fishes

Three new Dactylogyrus species, D. rectotrabus n. sp. and D. acinacus n. sp. from Garra rufa plus D. carassobarbi n. sp. from Carassobarbus luteus are described from River Dez (Persian Gulf Basin) of Iran. Three known species, D. haplogonus from Rutilus frisii kutum, D. chalcalburni from Alburnus alburnus and Alburnoides bipunctatus, and D. pavlovskyi from Barbus sharpeyi are recorded from the Rivers Sefid (Caspian Basin), Zayandeh (Central Iran) and Dez (Tigris-Euphrates Basin), respectively. Comments on the monogenean fauna of Iranian freshwater fishes are presented.     

Two new species of chimaeroid fishes from the southwestern Pacific Ocean (Holocephali, Chimaeridae)

 Two new species of chimaeroid fishes from the family Chimaeridae are described on the basis of morphological characters. The carpenter's chimaera is a large-bodied species of Chimaera distinguished from its congeners by massive head with blunt snout; firm, nondeciduous skin; purplish color; preopercular and oral lateral line canals branching together; and pelvic claspers that are divided for the distal one third of length, purple at the base with white fleshy tips. The pale ghost shark is a species of Hydrolagus distinguished from its congeners by a dorsal fin spine that reaches to the origin of the second dorsal fin when depressed; elongate second dorsal fin not indented along its length; preopercular and oral lateral line canals sharing a common branch; long, stout caudal filament; and pale silvery-gray coloration fading to white ventrally. The pale ghost shark has long been recognized as a new species from New Zealand, and formal taxonomic recognition of this species will prove important for fishery management. Received: October 15, 2001 / Revised: May 1, 2002 / Accepted: May 29, 2002 Acknowledgments I am grateful to Peter Last, Alastair Graham (CSIRO, Dept. of Marine Research), Clive Roberts, Andrew Stewart (NMNZ, Wellington), and Mark McGrouther and Doug Hoese (AMS, Sydney), for their hospitality and support of this research. This work was funded by grants from the National Science Foundation (NSF DEB-9510735) and the National Geographic Society (no. 5414–95), and also funded in part by the New Zealand Foundation for Scientific Research and Technology, Biosystematics of NZ EEZ Fishes Project, contract MNZ603, C. Roberts, program leader.     

Phylogeny of the Atlantic and Pacific species of Ligophorus (Monogenea: Dactylogyridae): Morphology vs. molecules

Within ectoparasitic fish monogeneans, the genus Ligophorus contains a high number of species from which several were recently described. The precise determination of their taxonomic status requires robust diagnostic morphologic features that rely predominantly on a restricted set of sclerotized structures. In the present study, these morphological characters were used for the reconstruction of a phylogenetic tree, which was compared with a tree built from molecular data (28S and ITS1 DNA sequences). Thirty-eight morphological characters were used in 29 species of Ligophorus from the Atlantic and Pacific regions and 5 species within close genera of Dactylogyridae. The morphological and molecular phylogenetic trees are congruent and suggest that the genus Ligophorus is monophyletic, and that species parasitizing Liza spp. and Chelon labrosus occupy basal positions. The present study suggests that host switching is a common event in this host–parasite association, because about half of the species infecting the same host species are not close relatives. Following host switching, dispersal with vicariance is probably an important force shaping the present distribution and diversity of Ligophorus. The pattern of occurrence of Ligophorus spp. on Mugil cephalus supports that reproductive isolation and therefore parallel speciation are taking place among these parasitic organisms.     

Molecular phylogeny of species of Ligophorus (Monogenea: Dactylogyridae) and their affinities within the Dactylogyridae

The taxonomic framework of Ligophorus, monogenean specialists of the gills of grey mullets (Mugilidae), is evaluated and its interspecific relationships are assessed for the first time using molecular data. The position of Ligophorus within the paraphyletic Ancyrocephalinae is re-assessed based on newly sequenced species. Furthermore, the relationship between morphometric and genetic interspecific similarities is evaluated. Partial 28S and complete ITS1 rDNA sequences from representatives of 14 of the 16 nominal species of Ligophorus from the Mediterranean, Black and Azov Seas were analysed together with published sequences of members of the Dactylogyridae. The phylogenetic analyses of the Dactylogyridae (i) confirmed the position of Ligophorus within the marine Ancyrocephalinae; (ii) revealed a sister relationship between Ergenstrema and Ligophorus, whose species are all exclusive parasites of grey mullets; and (iii) substantiated the affinities of Ergenstrema with the marine Ancyrocephalinae. The phylogenetic analysis restricted to Ligophorus confirmed the distinct status of the included species. The ITS1 region provided the highest divergence between species and phylograms with the strongest branch support. Both the 28S and ITS1 phylograms revealed two main clades. One included species from hosts with Mediterranean and NE Atlantic distribution and another was formed by species parasitising several Liza spp., including Lz. haematocheilus from the Northwestern Pacific, and Mugil cephalus, which suggests an origin outside the Mediterranean for the latter clade. The phylogenetic evidence presented herein indicated that a combination of host-switching and lineage duplication events accounted for the diversification of this genus in the Mediterranean basin. The agreement between molecular and morphological interspecific similarities observed in Ligophorus supports the validity of morphometric characters used for species identification.     

A new species of Euryhaliotrematoides Plaisance & Kritsky, 2004 (Monogenea: Dactylogyridae) from the gills of the spotted rose snapper Lutjanus guttatus (Steindachner) (Perciformes: Lutjanidae)

Euryhaliotrematoides mehen n. sp. (Monogenea: Dactylogyridae) is described based on specimens collected from the gills of the spotted rose snapper Lutjanus guttatus (Steindachner) off Mazatlan, Sinaloa, on the northwestern coast of Mexico. The synapomorphy of this genus is the presence of a funnel-shaped base of the male copulatory organ. This new species differs from all other species of the genus by possessing a male copulatory organ with a base with a thickened margin and a membranous accessory piece resembling a scarf and covering about 60% of its distal region. PCR products of the 28S rRNA (831 bp) and 18S rRNA (662 bp) genes were sequenced and submitted to GenBank (accession numbers HQ615997 and JF938069, respectively). BLASTn searches revealed no 100% identical hits with the previously registered monogenean sequences.     

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).     

Four new species of Asteraceae from Peru

Four new species of Asteraceae are described from Peru:Dasyphyllum brevispinum andOnoseries chrysactinioides (Mutisieae), andGynoxys congestiflora andSenecio miniauritus (Senecioneae). These species are described, illustrated, and their relationships discussed.