Gobioecetes biwaensis n. g., n. sp. (Monogenea: Dactylogyridae) from the gills of a freshwater gobiid fish, Rhinogobius sp. BW Takahashi & Okazaki, 2002, with a redescription of Parancyrocephaloides daicoci Yamaguti, 1938

Abstract

A description is given of Gobioecetes biwaensis n. g., n. sp. (Monogenea: Dactylogyridae) on the gills of a freshwater gobiid fish, Rhinogobius sp. BW Takahashi & Okazaki, 2002 from Lake Biwa, Shiga Prefecture and Rhinogobius sp. from Sento Imperial Palace, Kyoto Prefecture, Japan. This monogenean is most similar to Parancyrocephaloides rhinogobius Ling, 1973, proposed here as Gobioecetes rhinogobius n. comb., collected from the gills of Rhinogobius giurinus (Rutter, 1897) in Hupei Province, China, but can be differentiated from it in that ventral hamuli of G. biwaensis are larger than those of G. rhinogobius and in that in G. biwaensis, ventral hamuli are larger than dorsal ones, but in G. rhinogobius, ventral and dorsal hamuli are almost equal in size. The new genus is characterized by the absence of a bar supporting dorsal hamuli. Parancyrocephaloides daicoci Yamaguti, 1938, the type species of the genus, is redescribed based on newly collected specimens from a marine dactylopterid, Dactyloptena peterseni (Nyström, 1887) and the type specimens, revealing that it has a pair of vestigial bars supporting dorsal hamuli. The generic diagnoses of Gobioecetes n. g. and Parancyrocephaloides are given and systematic position of these genera in Dactylogyridae is discussed in this paper.

Dactylogyridae 2022: a meta-analysis of phylogenetic studies and generic diagnoses of parasitic flatworms using published genetic and morphological data

“…Furthermore, confirmation biases might affect which taxa are included in phylogenetic studies as prior expectations of researchers could affect taxon selection (see Jermiin et al, 2020). For instance, DNA sequences of species of Gobioecetes and Parancyrocephaloides (Ogawa and Itoh, 2017) were absent from a study on species formerly and presently considered as belonging to 'Haliotrema' (Soo, 2019), despite their close relationship to the 'Haliotrema' group (clade A8). (Tan et al, 2011) and endoparasitic (Theisen et al, 2017 worms were not considered in a study on the new genus Characidotrema and its phylogenetic position among Dactylogyrinae (macroclade A) (Řehulková et al, 2019), despite the importance of these groups as major lineages within the subfamily.…”

Phylogenetic position of Ancyrocephalus (sensu lato) curtus Achmerov, 1952 (Monopisthocotylea, Dactylogyridae), a parasite of fish Perccottus glenii Dybowski, 1877(Gobiiformes: Odontobutidae)

“…2023). At the same time, A. mogurndae clusters with representatives of Eutrianchoratus Paperna, 1969 , Gobioecetes Ogawa & Ito, 2017 , Heteronchocleidus Bychowsky, 1957 , Pseudodactylogyrus Gussev, 1965, and Trianchoratus Price & Berry, 1966, confirming the polyphyly of Ancyrocephalus sensu lato (Wu et al . 2006; Mendoza-Palmero et al .…”

“…are evident in the morphology of the sclerotised male copulatory organ and the absence of the vaginal armament. These parasite species have a penis shaped as a long, coiled and/or sinuous tube with a conspicuous inflation at the base, and an accessory piece shaped as a separate, distinctly concaved plate, which is not connected to the proximal end of the penis (Gussev 1955; Ogawa and Itoh 2017; Nitta and Nagasawa 2020). The most pronounced differences between A. curtus and Gobioecetes spp.…”

“…The former species has both the dorsal and the ventral haptoral bar, whereas Gobioecetes spp. have only the ventral bar (Gussev 1955; Ogawa and Itoh 2017; Nitta and Nagasawa 2020).…”

Characterization and phylogenetic analysis of the complete mitochondrial genome of Rhinogobius sp. (Perciformes, Gobiidae)

“…Most species of genus Rhinogobius are under the threat due to overfishing and habitat destruction, and some species are classed as vulnerable species on the IUCN Red List (http://oldredlist.iucnredlist.org/details/169498/0). In addition, taxonomy within the genus Rhinogobius has long been a question debated among scientists (Ogawa and Itoh 2017;Yamasaki et al 2015). The mitochondrial genome of Rhinogobius sp.…”