Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil

Abstract

Four species ofCosmetocleithrum(three new) and one new species ofVancleaveusare described or reported parasitizing the gills of doradid catfishes (Siluriformes) from Xingu River and related tributaries:Cosmetocleithrumphryctophallussp. nov. andCosmetocleithrumbifurcumMendoza-Franco, Mendoza-Palmero & Scholz, 2016 fromHassarorestis;Cosmetocleithrumleandroisp. nov. fromHassargabiru;Cosmetocleithrumakuandubasp. nov. andVancleaveusklassenisp. nov. fromHassarorestisandH.gabiru.Cosmetocleithrumphryctophallussp. nov. differs from its congeners by possessing a male copulatory organ (MCO) with 2 ½ counterclockwise rings, and an accessory piece with an elongate torch-shaped blade.Cosmetocleithrumleandroisp. nov. has a MCO comprising a coil of about 3 ½ rings, a sigmoid accessory piece with a cup-shaped distal portion, a single type of hooks, and anchors with poorly differentiated roots.Cosmetocleithrumakuandubasp. nov. is characterized mainly by having a J-shaped MCO, an elongate accessory piece with sharp distal region, distal portion with a small gutter, and a heavily sclerotized vagina with short “S”-shaped vaginal canal.Vancleaveusklassenisp. nov. differs from the other species of the genus occurring in doradids by possessing anchors with triangular to subtriangular superficial root, developed deep root, and a coiled MCO with 2 ½ counterclockwise rings.Cosmetocleithrumbifurcumwas reported for the first time parasitizing doradids from Brazilian Amazon.

Una nueva especie de <i>Cosmetocleithrum </i>(Monogenea, Dactylogyridae) de las branquias de <i>Auchenipterichthys coracoideus</i> (Siluriformes: Auchenipteridae) de la Amazonía peruana

“…Twenty-two species of monogenoideans affiliated with Cosmetocleithrum have been documented in siluriform fishes, with 11 found in Doradidae species, one in Erythrinidae, one in Pimelodidae, and nine exclusively described in Auchenipteridae (Soares et al, 2018;Yamada et al, 2020). With the findings of our study, the tally of Cosmetocleithrum species increases to 23, and the count of monogenoidean species identified in auchenipterids rises from nine to ten.…”

“…Additionally, Cosmetocleithrum striatuli Abdallah, Azevedo & Luque, 2012 in Trachelyopterus striatulus Steindachner, 1877 (Cohen et al 2013);C. bulbocirrus Kritsky, Thatcher & Boeger, 1986 in Ageneiosus ucayalensis Castelnau, 1855 (Soares et al, 2018); C. laciniatum Yamada, Yamada, Da Silva & Dos Anjos, 2017 in T. galeatus (Yamada et al, 2017); C. berecae Cohen, Justo, Gen &Boeger, 2020, andC. nunani Cohen, Justo, Gen &Boeger, 2020 in A. nuchalis;C.…”

Dactylogyridae (Monogenoidea, Polyonchoinea) from the gills of Auchenipterus nuchalis (Siluriformes, Auchenipteridae) from the Tocantins River, Brazil

“…This reflects the incipient knowledge about the richness and composition of species in the group. Generic groupings are being recognized continuously, representing approximately 60 years of efforts of different scientists and research groups [3,19,29,30,35,36]. At early stages of faunal characterization, it is common to generate "catch-all" genera to accommodate morphologically similar species.…”

“…Subsequently, several other species were proposed [1,38]. Presently, 15 species of Cosmetocleithrum are known from Brazil, Argentina, and Peru [22,27,34,36,41] from siluriform hosts belonging mainly to the Doradidae but also the Auchenipteridae and Pimelodidae. A single report of a species of Cosmetocleithrum in Hoplias malabaricus (Bloch) (Erythrinidae, Characiformes) [13] requires confirmation due to the unexpected association.…”

Dactylogyrids (Platyhelminthes, Monogenea) from the gill lamellae of doradids (Siluriformes) with description of five new species of Cosmetocleithrum and new geographical distribution for known species from the Neotropical Region, Brazil

“…Ventral and dorsal anchors dissimilar in size and similar in shape, robust superficial and deep roots; deep root straight; superficial root pointed; evenly curved shaft, and short point. Ventral anchor outer 37 (35-39; n = 13); inner 32 (27-43; n = 13); base 23 (19)(20)(21)(22)(23)(24)(25)(26); n = 13). Dorsal anchor outer 29 (26-32; n = 13); inner 22 (18-25; n = 13); base 19 (16)(17)(18)(19)(20); n = 13).…”