Dactylogyridean monogeneans of the siluriform fishes of the Old World

Abstract

This is a catalogue and discussion of the known dactylogyridean monogenean genera of siluriform fishes of the Old World. Of a total of 38 nominal genera, only 19 are considered valid. Seventeen of these 19 genera are currently in the Ancyrocephalidae (containing the Ancyrocephalinae and Ancylodiscoidinae), whilst the other two (Neocalceostoma and Neocalceostomoides) are in the Neocalceostomatidae. The 17 genera are Anchylodiscus, Ancylodiscoides, Bagrobdella, Bifurcohaptor, Bychowskyella, Chauhanellus, Cornudiscoides, Hamatopeduncularia, Mizelleus, Paraquadriacanthus, Pseudancylodiscoides, Protoancylodiscoides, Quadriacanthus, Schilbetrema, Schilbetrematoides, Synodontella and Thaparocleidus. Clariotrema Long, 1981 and Neobychowskyella Ma, Wang & Li, 1983 are considered synonyms of Bychowskyella Akhmerov, 1952, Anacornuatus Dubey, Gupta & Agarwal, 1992 is considered a synonym of Quadriacanthus Paperna, 1961, Mizellebychowskia Gupta & Sachdeva, 1990 is considered a synonym of Neocalceostoma Tripathi, 1959 and Hargitrema Tripathi, 1959 is treated as a synonym of Hamatopeduncularia Yamaguti, 1953. It is proposed that the Ancylodiscoidinae be raised to family status within the order Dactylogyridea to accommodate these 17 'ancyrocephalid' genera from siluriforms, together with Malayanodiscoides and Notopterodiscoides from notopterids. A key and the diagnostic characteristics of the 19 recognised dactylogyridean genera from catfishes plus two from notopterids, together with a list of species and synonyms, are included. New combinations made in this work are Thaparocleidus avicularia (Chen, 1987) n. comb., T. calyciflorus (Chen, 1987) n. comb., T. choanovagina (Luo & Lang, 1981) n. comb., T. dissimilis (Chen, 1988) n. comb., T. leiocassis (Reichenbach-Klinke, 1959) n. comb., T. meticulosa (Chen, 1987) n. comb., T. parasoti (Zhao & Ma, 1999) n. comb., T. persculpus (Chen, 1987) n. comb., T. valga (Chen, 1987) n. comb. and T. wulingensis (Yao & Wang, 1997) n. comb. [all from Silurodiscoides] and Bychowskyella glyptothoraci (Ma, Wang & Li, 1983) n. comb. [from Neobychowskyella].

Monogeneans from Pangasiidae (Siluriformes) in Southeast Asia: IV. Five new species ofThaparocleidusJain, 1952 (Ancylodiscoididae) fromPangasius krempfi,P. kunyit,P. mekongensisandP. sabahensis

“…mekongensis Gustiano et al, in press and P. sabahensis Gustiano et al, in press (Siluriformes, Pangasiidae). One has been previously described (see "Dis cussion" below) on Pangasius bocourti Sauvage, 1880 (T. vietnamensis Pariselle et al, 2002) and was found also on P. mekongensis, five are considered new (see descriptions below), their anatomy (soft and hard parts) complies with that of Tbaparocleidus Jain, 1952 (Monogenea, Ancylodiscoididae) as defined by Lim (1996) and Lim et al (2001) The morphology of hard parts is identical to T. hume rus n. sp. except for the penis which presents a distal third with a reduced diameter and a thin velum-like expansion, and for the sclerotised vagina which is shorter.…”

Monogeneans from Pangasiidae (Siluriformes) in Southeast Asia: VIII. Four new species ofThaparocleidusJain, 1952 (Ancylodiscoididae) fromPangasius polyuranodonandP. elongatus

“…Two species are represented by too few individuals to be conclusively described (from two to five individuals among the 988 worms collected). The four remaining species are considered new (see descriptions below), their anatomy (soft and hard parts) complies with that of the diagnosis of Thaparocleidus (Monogenea, Ancylodiscoididae) as defined by Lim (1996) and Lim et al (2001 Adults: 649 ± 121 (423-959) long, 103 ± 18.5 (66-145) wide at the level of the penis. Pharynx: 45 ± 7.4 (27-56) wide.…”

Redescription and phylogenetic analyses of Thaparocleidus gomtius and T. sudhakari (Monogenea: Dactylogyridae) from Wallago attu (Siluriformes: Siluridae) in India

“…With the span of time, there have lots of work being done on the correct evaluation of all these genera. Up to now, assessment of these 20 dactylogyridean genera indi- cates that only 7 are valid, while the other monogenean genera are listed as synonymous (Lim and Lerssutthichawal, 1996;Lim, 1998;Lim et al, 2001). It is very well known that molecular data is used to establish differentiation within species that showing a high degree of morphological similarities.…”

“…In all the genera harboring W. attu, Thaparocleidus Jain, 1952b is the most dominant and species rich genus. Sixteen nominal species of Thaparocleidus have been described from W. attu in India till now and many of them are considered as species inquirendae by Lim et al, 2001 as their descriptions were inadequate. The examination of monogenean from gill fi laments of W. attu from Ganga River in India revealed the presence of two species of Thaparocleidus i.e., T. gomtius (Jain, 1952) Lim, 1996 and T. sudhakari (Gusev, 1976) Lim, 1996.…”