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).     

Neotropical Monogenoidea. 46. Three new species from the gills of introduced aquarium fishes in India,the proposal of Heterotylus n. g. and Diaphorocleidus n. g., and the reassignment of some previously described species of Urocleidoides Mizelle & Price, 1964 (Polyonchoinea: Dactylogyridae)

Three new species of the Dactylogyridae are described from aquarium fishes collected in India and two new genera are proposed: Heterotylus heterotylus n. g., n. sp. from Hypostomus sp. (Loricariidae), Diaphorocleidus armillatus n. g., n. sp. from Gymnocorymbus ternetzi (Characidae) and Urocleidoides vaginoclaustrum n. sp. from Xiphophorus helleri (Poeciliidae). Heterotylus n. g. is characterised by species having overlapping gonads (testis posterodorsal to the ovary), a mid-ventral vaginal aperture, a copulatory complex consisting of a relatively straight copulatory organ unarticulated to a complex accessory piece, erect acute hook thumbs, unexpanded hook shanks, dorsal and ventral anchor/bar complexes and absence of well-defined basal roots of the ventral anchors. Diaphorocleidus n. g. includes species with overlapping gonads (testis posterodorsal to the ovary), submarginal sinistral vaginal pore, a copulatory complex comprising a coiled (counterclockwise) copulatory organ unarticulated to an accessory piece, protruding depressed hook thumb, hook shank with two subunits (proximal subunit expanded), dorsal and ventral anchor/bar complexes and V-shaped bars. The following new combinations are proposed: D. affinis (Mizelle, Kritsky & Crane, 1968) n. comb. (syn. U. affinis Mizelle, Kritsky & Crane, 1968), D. kabatai (Molnar, Hanek & Fernando, 1974) n. comb. (syn. U. kabatai Molnar, Hanek & Fernando, 1974) and D. microstomus (Mizelle, Kritsky & Crane, 1968) n. comb. (syn. U. microstomus Mizelle, Kritsky & Crane, 1968).     

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 species of Demidospermus (Monogenea: Dactylogyridae) of pimelodid catfish (Siluriformes) from Peruvian Amazonia and the reassignment of Urocleidoides lebedevi Kritsky and Thatcher, 1976

Three new species of Demidospermus Suriano, 1983 were found in mixed infections on the gills of 4 pimelodid catfish collected in the Amazon River basin around Iquitos, Peru, namely, Demidospermus peruvianus n. sp. from Pimelodus ornatus Kner, Pimelodus blochii Valenciennes, Pimelodus sp. (type host), and an unidentified pimelodid. Demidospermus peruvianus n. sp. (type host, Pimelodus sp.) is characterized by the presence of the male copulatory organ with 2 lateral, thickened projections, and the vagina with a loop at its middle. Demidospermus curvovaginatus n. sp. from P. ornatus , Pimelodus sp. (type host), and Pimelodidae gen. sp. differs from its congeners by the presence of a funnel-shaped vagina directed posteriorly and a male copulatory organ with a small lateral projection at its base. Demidospermus striatus n. sp. from P. blochii and Pimelodus sp. (type host) is distinguished by a cup-shaped vagina with conspicuous ridges at the perimeter of the aperture with a short tube directed anteriorly. In addition, Urocleidoides lebedevi Kritsky and Thatcher, 1976 , a parasite originally described from the gills of Pimelodus grosskopfii (type host) from Colombia, is transferred to Demidospermus , based on morphological characters that we observed in type specimens.     

Six new species of Rhamnocercus Monaco,Wood & Mizelle, 1954 (Monogenea: Diplectanidae) infecting the gills from South American sciaenid fishes

A parasitological survey searching diplectanids (Monogenea: Diplecatnidae) infesting the gills of marine fishes from South America was carried out during the 2019–2020 period. The gills of four sciaenid species, 2 Cheilotrema fasciatum Tschudi, 1 smalleye croaker Nebris microps Cuvier, 2 royal highhat Pareques lanfeari (Barton), and 1 minor stardrum Stellifer minor (Tschudi), were sampled. Six new species of Rhamnocercus Monaco, Wood & Mizelle, 1954 were described: Rhamnocercus chacllae n. sp. and Rhamnocercus chaskae n. sp. from P. lanfeari, Rhamnocercus fasciatus n. sp. from C. fasciatum, Rhamnocercus microps n. sp. from N. microps, and Rhamnocercus rimaci n. sp. and Rhamnocercus tantaleani n. sp. from S. minor. Rhamnocercus chacllae n. sp. can be differentiated from its congeners by its L-shaped male copulatory organ (MCO) and by having an anteromedial slight notch at ventral bar. Rhamnocercus chaskae n. sp. differs from the other species of the genus by its long and straight MCO with bifid distal end and by having haptoral accessory spines at level of ventral bar with quadrifid distal portion. Rhamnocercus fasciatus n. sp. is characterized by possessing a straight and long MCO with truncated distal end, haptoral accessory spines at level of ventral bar with bifid distal portion, dorsal bars with a knob at lateral extremity, and a large vagina with bell-shaped. Rhamnocercus microps n. sp. differs from all congeners mainly by having a short and straight MCO with the distal end of internal tube spatulate and uncovered by external tube. Rhamnocercus rimaci n. sp. is can be distinguished from all other species of Rhamnocercus by having an almost J-shaped MCO with the distal end of external tube slight expanded and the distal end of internal tube narrow and uncovered by external tube. Rhamnocercus tantaleani n. sp. is mainly characterized by its MCO, which is tubular and straight, having the distal end of external tube bifurcated (right branch well-expanded and left branch narrow) and the distal end of internal tube enveloped by left branch of the external tube. This is the first data on the parasites of P. lanfeari, a little known, but popular fish in local markets from Peru. Rhamnocercus microps n. sp. is the first described species of Rhamnocercus in Brazil. The present finding brings to 12, the number of known species of Rhamnocercus. A key to Rhamnocercus species is provided.

     

Three new species of Philocorydoras Suriano, 1986 (Monogenoidea: Dactylogyridae) infecting the gills of callichthyids (Actinopterygii: Callichthyidae) from the Peruvian Amazonia

During a research on gill ectoparasites of callichthyids fishes from the Peruvian Amazonia, the following monogenoideans were found: Philocorydoras peruensis n. sp. from Corydoras splendens (Castelnau); Philocorydoras multiradiatus n. sp. and Philocorydoras jumboi n. sp. from Brochis multiradiatus (Orcés, V.). All new species described herein are mainly differentiated from their congeners based on the morphology of the copulatory complex. In P. peruensis n. sp. the cirrus is “J”-like shaped tube slightly tilted to one side, while in P. jumboi n. sp. is “J”-like shaped tube in a straight position and in P. multiradiatus n. sp. the cirrus is an arced tube with inflated base and distally narrow. Brochis (Orcés, V.) represents a new genus hosting species of Philocorydoras. All new species presented in this work represent the first species of Philocorydoras reported for Peru.

     

Monogenea of marine fishes from Hainan Island, China. VIII. Two new species of Euryhaliotrema Kritsky & Boeger, 2002 (Dactylogyridae) from Lutjanus argentimaculatus (Teleostei: Lutjanidae)

This paper reports two new species of Euryhaliotrema Kritsky & Boeger, 2002 collected from the gills of Lutjanus argentimaculatus (Forsskål). E. xinyingense n. sp. is similar to Euryhaliotrema atlanticum Kritsky & Boeger, 2002 in the structure of copulatory apparatus, but differs from the latter in the shape of anchors and the structure of vagina. E. hainanense n. sp. also closely resembles E. atlanticum Kritsky & Boeger, 2002, but differs from the latter in the structure of haptor and the shape of accessory piece.     

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.     

Dactylogyrids (Monogenoidea: Polyonchoinea) parasitising the gills of snappers (Perciformes: Lutjanidae): Species of Euryhaliotrema Kritsky & Boeger, 2002 from the golden snapper Lutjanus johnii (Bloch) off northern Australia, with a redescription of Euryhaliotrema johni (Tripathi, 1959) and descriptions of two new species

Three species of Euryhaliotrema Kritsky & Boeger, 2002 (Monogenoidea: Dactylogyridae) were collected from the gills of four golden snapper Lutjanus johnii (Bloch) (Lutjanidae) from the marine and brackish waters off Darwin, Northern Territory, Australia. Type-specimens of Ancyrocephalus johni Tripathi, 1959 apparently have not survived and the possibility existed that the species was based on specimens representing more than one species. Euryhaliotrema johni (Tripathi, 1959) (sensu Young, 1968) was redescribed and determined to most likely represent A. johni, originally described from the River Hooghly, Diamond Harbour, India. Two new species were described. Euryhaliotrema longibaculoides n. sp. was most similar to Euryhaliotrema longibaculum (Zhukov, 1976) Kritsky & Boeger, 2002 from Lutjanus spp. from the western Atlantic Ocean. It differed from E. longibaculum by having a male copulatory organ (MCO) with an elongate comparatively delicate shaft and a bulbous base (MCO U- or J-shaped with funnel-shaped base in E. longibaculum). Based on the comparative morphology of the haptoral sclerites, Euryhaliotrema lisae n. sp. was most similar to Euryhaliotrema cryptophallus Kritsky & Yang, 2012 from the gills of the mangrove red snapper Lutjanus argentimaculatus (Forsskål) from the South China Sea. Euryhaliotrema lisae differed from E. cryptophallus by having a copulatory complex with an obvious weakly sclerotised J-shaped MCO (MCO cryptic, delicate, and with a shaft comprising about one counterclockwise ring in E. cryptophallus).     

Correction to: Three new species of Philocorydoras Suriano, 1986 (Monogenoidea: Dactylogyridae) infecting the gills of callichthyids (Actinopterygii: Callichthyidae) from the Peruvian Amazonia

Systematic Parasitology -     

Three new Procamallanus (Spirocamallanus) species from freshwater fishes in Mexico

The following 3 new species of Procamallanus (Spirocamallanus) are described from the intestines of freshwater fishes in Mexico, all belonging to the morphological group characterized by the presence of wide caudal alae, 3 pairs of subventral preanal papillae, and unequal spicules in the male: Procamallanus (Spirocamallanus) jaliscensis n. sp. (type host: Agonostomus monticola) and Procamallanus (Spirocamallanus) gobiomori n. sp. (hosts: Gobiomorus maculatus [type host], Gobiomorus polylepis and Eleotris picta) from 2 rivers in Jalisco State, western Mexico, and Procamallanus (Spirocamallanus) mexicanus n. sp. (type host: Cichlasoma geddesi) from Xalapa District, Veracruz State (Gulf of Mexico region), southeastern Mexico. Procamallanus jaliscensis is characterized by the length of the spicules (606-900 microm and 282-354 microm), number (15-16) of spiral ridges in the buccal capsule, and the digit-like protrusion with 1 terminal cuticular spike on the female tail; P. mexicanus by the length of the spicules (456-480 microm and 231-233 microm), number (10-12) of spiral ridges in the capsule, and the shape of the female tail (conical with a suddenly narrowed distal part, without any terminal spikes); and P. gobiomori by the length of spicules (318-348 microm and 156-192 microm), number (8-10) of spiral ridges and by the digit-like protrusion with 2 terminal cuticular spikes on the female tail.     

New species of Ergasilus von Nordmann, 1832 (Copepoda: Ergasilidae) from the gills of freshwater fishes in Patagonia,Argentina

Systematic Parasitology - A new parasitic copepod, Ergasilus yandemontei n. sp., is described based on 10 adult females collected from the gills of the atherinid silverside Odontesthes hatcheri...     

Evolutionary relationships of sibling tapeworm species (Cestoda) parasitizing teleost fishes

DNA/DNA hybridization and sequencing of rDNA (partial 18S rDNA and ITS1) were used to investigate phylogenetic relationships among seven host-specific Bothriocephalus parasites (Cestoda, Pseudophyllidae). The small nucleotide divergence between six of the seven bothriocephalids suggests that isolation and differentiation of Bothriocephalus lineages in the different host species probably occurred recently and over a short time span. Comparison of the molecular phylogeny of the parasite species to the phylogeny of their hosts (teleostean fishes) revealed little congruence between the branching patterns of hosts and parasites, suggesting that bothriocephalids have not cospeciated with their hosts.      

A new Huffmanela species (Nematoda: Trichosomoididae) parasitizing atherinid fishes in north Patagonian Gulfs, Argentina

Huffmanela moraveci n. sp. (Nematode: Trichosomoididae) is described from the skin of fins and gills of the silversides Odontesthes smitti Lahille, 1949, and Odontesthes nigricans Richardson, 1848 (Pisces: Atheriniformes), from southwestern Atlantic coast, on the basis of the morphology of adults and eggs found in the host tissues. Huffmanela moraveci n. sp. can be distinguished from Huffmanela carcharini, H. banningi, H. japonica, H. mexicana, H. paronai, H. schouteni, H. shikokuensis, H. branchialis, H. filamentosa, H. ossicola, and H. lata by the size and shape of the eggs. The adult stage of H. moraveci n. sp. can be differentiated from H. hufmani and H. canadensis by the position of the nerve ring and by the total esophagus length/body length ratio. Huffmanela moraveci n. sp. also differs from H. huffmani by the presence of bacillary bands and by the body length. This is the first report of a species of Huffmanela in South America, the first report of a species of Huffmanela with Odontesthes spp. as host, and the third known adult form in the genus.     

Neotropical Monogenoidea: Euryhaliotrema dontykoleos n. sp. (Dactylogyridae) from the gills of the freshwater sciaenid, Pachyurus junki (Perciformes)

Euryhaliotrema dontykoleos n. sp. (Monogenoidea, Polyonchoinea, Dactylogyridae) is described based on specimens collected from the gills of Pachyurus junki (Teleostei, Sciaenidae, Pachyurinae) in the Rio Tocantins and its tributaries, State of Tocantins, Brazil. The new species, the first species of Monogenoidea reported from a pachyurine, is easily differentiated from its congener by the presence of toothlike projections in the border of the vaginal opening and by having a trapezoidal anteromedial projection on the ventral bar. Phylogenetic analysis indicates that the new species is not a member of the clade that includes the Euryhaliotrema spp. from Plagioscion spp., a second lineage of freshwater sciaenids in South America. Euryhaliotrema dontykoleos shares an immediate ancestor with the clade formed by parasites infecting marine Paralonchurus spp., (Sciaenidae), and those of Plagioscion spp.     

Five new cryptic freshwater gastropod species from New Caledonia (Caenogastropoda,Truncatelloidea, Tateidae)

During the course of a project aiming at the reconstruction of the colonization of the South Pacific islands by tateid gastropods based on molecular data we discovered five new species on New Caledonia belonging to the genera Hemistomia and Leiorhagium, respectively. We describe these species based on morphological, anatomical and genetic data. All five species are morphologically cryptic as they closely resemble or are even indistinguishable from known species stressing the importance of a comprehensive taxonomic approach integrating several methods. As a consequence of their small and fragmented geographic ranges and the rapidly progressing anthropogenic land cover changes on New Caledonia, all five species qualify as critically endangered according to the criteria of the IUCN.     

Monogenoidean parasites of the gill lamellae of the sheepshead Archosargus probatocephalus (Walbaum) (Perciformes: Sparidae) from the Indian River Lagoon, Florida, with descriptions of four new species of Euryhaliotrema Kritsky & Boeger, 2002 (Dactylogyridae)

Examination of the gill lamellae of three sheepshead Archosargus probatocephalus (Walbaum) from the Indian River Lagoon in Florida revealed six species of Monogenoidea: Microcotyle archosargi MacCallum, 1913 (Microcotylidae); Neobenedenia sp. (Capsalidae); and four new species of Euryhaliotrema Kritsky & Boeger, 2002 (Dactylogyridae). The prevalence of all helminths was 100%, except for Neobenedenia sp., which was represented by a single immature specimen. The four new species, Euryhaliotrema carbuncularium n. sp., E. dunlapae n. sp., E. amydrum n. sp. and E. spirulum n. sp., are described and with E. carbunculus (Hargis, 1955) Kritsky & Boeger, 2002 apparently constitute a monophyletic clade of Euryhaliotrema spp. that parasitise sparid hosts in the western hemisphere. The Indian River Lagoon in Florida represents a new locality record for M. archosargi, and the sheepshead is apparently a new host record for a member (Neobenedenia sp.) of the Capsalidae.