Diplectanum Diesing, 1858

Domingues, Marcus V. & Boeger, Walter A., 2008, Phylogeny and revision of Diplectanidae Monticelli, 1903 (Platyhelminthes: Monogenoidea), Zootaxa 1698, pp. 1-40 : 24-25

Diplectanum Diesing, 1858

Synonymy: Dactylogyrus Wagener, 1857 , partim, nec 1850; Lepidotes Johnston & Tiegs, 1922 ; Neodiplectanum Mizelle & Blatz, 1941 ; Lamellodiscoides Yamaguti, 1963 ; Pseudolamellodiscoides Gupta & Krishna, 1979

Diagnosis: Tegument smooth or scaled. Genital pore opening posterior to male copulatory organ (MCO). Genital atrium muscular. Vas deferens intercaecal or looping left intestinal caecum. MCO tubular, composed of 2 nested tubes; external tube uniform. Accessory piece absent. Prostatic reservoir separated into three zones [43]. Accessory copulatory organ present [44]. Vaginal atrium muscular. Vaginal aperture marginal. Squamodiscs, ventral, dorsal; anterior rows of rodlets with open rings. Superficial root of ventral anchor reduced. Parasites of freshwater and marine actinopterygian fishes ( Perciformes , Siluriformes ).

Type species: D. aequans ( Wagener, 1857) Diesing, 1858 from Dicentrarchus labrax (Linnaeus) (type host), Dicentrarchus punctatus (Bloch) (Moronidae) , and Bagrus sp. ( Bagridae ).

Other species: See comments below.

Remarks: Kritsky et al. (2000) questioned the monophyly of Diplectanum based on the greatly variable morphology of its species (e.g., presence/absence of accessory piece, MCO morphology). The comparative morphology and cladistic analysis did not support monophyly of Diplectanum (see comments above). Thus, Diplectanum is presently restricted to species possessing the combination of the following characteristics: (1) male copulatory organ formed by two nested tubes; (2) accessory copulatory organ; (3) prostatic reservoir separated into three zones; (4) two squamodiscs. Diplectanum stricto sensu contains the type species, D. aequans ( Wagener, 1857) Diesing, 1858 from Dicentrarchus labrax , Dicentrarchus punctatus , and Bagrus sp.; D. aculeatum Parona & Perugia, 1889 from Sciaena umbra Linnaeus , and Umbrina cirrosa (Linnaeus) (Sciaenidae) ; D. banyulense Oliver, 1968 from Umbrina canariensis Valenciennes ; D. belengeri ( Chauhan, 1945) Chauhan, 1954 from Johnius belangerii (Cuvier) , Johnius carutta Bloch (Sciaenidae) , and Congresox talabonoides (Bleeker) (Muraenesocidae) ; D. bocqueti Oliver, 1980 from Argyrosomus regius (Asso) (Sciaenidae) ; D. chabaudi Oliver, 1980 from Umbrina cirrosa ; D. dollfusi Oliver, 1980 from Argyrosomus regius ; D. glandulosum Williams, 1989 from Argyrosomus hololepidotus (Lacépède) ; D. jamestownense Obiekezie, 1988 from Pseudotolithus typus Bleeker ; D. labourgi Oliver, 1974 from Umbrina canariensis ; D. minutum Tripathi, 1957 from Johnius glaucus (Day) , and Nibea maculata (Bloch & Schneider) (Sciaenidae) ; D. oliveri Williams, 1989 from Argyrosomus hololepidotus ; D. sciaenae , van Beneden & Hesse, 1863 from Argyrosomus regius ; D. simile Bychowsky, 1957 from Sciaena umbra , and Argyrosomus regius . Except for the type species, members of Diplectanum stricto sensu were reported from perciform fishes, which seem to represent their natural hosts group. However, Diplectanum aequans has been reported also from Bagrus sp. ( Bagridae , Siluriformes ) ( Paperna & Kohn 1964), but this probably represents a misidentification of the parasite species, as already noted by Oliver (1968).

Diplectanum monticellii appears as a sister species of Pseudorhabdosynochus and Echinoplectanum in clade “X”. However, we decided not to propose a new genus for this taxon based on the absence of autapomorphic characters. Including this species, the present revision does not recognize the generic status of 51 species of Diplectanum , based on the redundant morphology of the accessory adhesive organ (i.e., presence of ventral and dorsal squamodiscs). Although the revision of Diplectanum is not within the scope of this work, we believe that some characteristics (e.g. morphology of reproductive structures) can be informative in the determination of generic groupings in future studies. Therefore, we consider the following species incertae sedis: D. bauchotae Oliver & Paperna, 1984 from Sphyraena flavicauda , and Argyrosomus regius ; D. bilobatus Hargis, 1955 from Cynoscion nebulosus (Cuvier) ; D. cayennense Euzet & Durette-Desset, 1974 from Plagioscion auratus (Castelnau) (Sciaenidae) ; D. collinsi ( Muller, 1936) Price, 1937 from Morone saxatilis (Waulbaum) (Moronidae) ; D. copiosum Boeger, Fehlauer & Marques, 2006 from Petilipinnis grunniens (Jardine & Schomburgk) (Sciaenidae) ; D. decorum Kritsky & Thatcher, 1984 from Plagioscion squamosissimus (Heckel) ; D. elongatum Obiekezie, 1988 from Pseudotolithus elongatus (Bowdich) (Sciaenidae) ; D. enyenibii Obiekezie, 1988 from Cynoglossus senegalensis (Kaup) (Cynoglossidae) ; D. fluviatile Johnston & Tiegs, 1922 from Macquaria ambigua (Richardson) (Percichthyidae) ; D. fujianensis Zhang, Liu , & Ding, 1995 from Argyrosomus amoyensis (Bleeker) , and Pennahia argentata (Houttuyn) (Sciaenidae) ; D. furcelamellosum Zhang, Liu, Ding & Chen, 2000 from Otolithes ruber (Bloch & Schneider) (Sciaenidae) ; D. fusiforme Oliver & Paperna, 1984 from Lutjanus kasmira (Forsskål) (Lutjanidae) ; D. grassei Oliver, 1974 from Umbrina cirrosa ; D. grouperi Bu, Leong, Wong, Woo & Foo, 1999 from Epinephelus areolatus (Forsskål) , and Epinephelus coioides (Hamilton) (Serranidae) ; D. gymnopeus Kritsky & Thatcher, 1984 from Plagioscion squamosissimus ; D. hilum Kritsky & Thatcher, 1984 from Plagioscion squamosissimus ; D. jaculator Mizelle & Kritsky, 1969 from Toxotes jaculatrix (Toxotiidae) ; D. jerbuae Gupta & Khanna, 1974 from Terapon jarbua (Forsskål) (Theraponidae) ; D. kuhliae Yamaguti, 1968 from Kuhlia sandvicensis (Steindachner) (Kuhliidae) ; D. lacustre Thurston & Paperna, 1969 from Lates niloticus (Linnaeus) (Latidae) ; D. laubieri Lambert & Maillard, 1974 from Dicentrarchus labrax , and Dicentrarchus punctatus ; D. lichtenfelsi Oliver & Paperna, 1984 from Polydactylus sextarius (Bloch & Schneider) (Polynemidae) ; D. maa Justine & Sigura, 2007 from Epinephelus malabaricus (Bloch & Schneider) ; D. maculatum Tripathi, 1957 from Otolithes ruber , and Pterotolithus maculatus (Cuvier) (Sciaenidae) ; D. magnodiscatum Zambrano, 1997 from Eugerres plumieri (Cuvier) (Gerreidae) ; D. megacirrus ( Maillard & Vala, 1980) Oliver, 1987 from Galeoides decadactylus (Bloch) (Polynemidae) ; D. melvillei Oliver & Paperna, 1984 from Umbrina cirrosa ; D. minousi ( Gupta & Khullar, 1967) Oliver, 1987 from Minous monodactylus (Bloch & Schneider) (Synanceiidae) ; D. monticellii Domingues & Boeger, 2003 from Cynoscion leiarchus (Cuvier) ; D. nagibinae Oliver & Paperna, 1984 from Umbrina cirrosa ; D. nanus Justine, 2007 c from Cephalopholis sonnerati (Valenciennes) ; D. narimeen Unnithan, 1964 from Lates calcarifer (Bloch) ; D. orissai ( Gupta & Krishna, 1979) Oliver, 1987 from Johnius borneensis (Bleeker) ; D. penangi Seng & Seng, 1991 from Lates calcarifer ; D. pescadae Kritsky & Thatcher, 1984 from Plagioscion squamosissimus ; D. piscinarius Kritsky & Thatcher, 1984 from Plagioscion squamosissimus ; D. polynemus Tripathi, 1957 from Eleutheronema tetradactylum (Shaw) , and Leptomelanosoma indicum (Shaw) (Polynemidae) ; D. puriense Tripathi, 1957 from Sillaginopsis panijus (Hamilton) , and Sillago chondropus Bleeker (Sillaginidae) ; D. secundum ( Tripathi, 1957) Yamaguti, 1963 from Terapon jarbua ; D. setosum Nagibina, 1976 from Psammoperca waigienis (Cuvier) , and Lates calcarifer ; D. spinosum ( Maillard & Vala, 1980) Oliver, 1987 from Galeoides decadactylus ; D. spirale Nagibina, 1976 from Lutjanus fulviflamma (Forsskål) , and Lutjanus russellii (Bleeker) ; D. squamatum Santos, Timi & Gibson, 2002 from Cynoscion guatucupa (Cuvier) ; D. sumpit Lim, 2006 from Toxotes jaculatrix ; D. tangzhongzhangi Zhang, Liu & Ding, 1995 from Argyrosomus amoyensis , Nibea albiflora (Richardson) , and Pennahia argentata ; D. toxotes Mizelle & Kritsky, 1969 from Toxotes jaculatrix ; D. uitoe Justine, 2007 b from Epinephelus maculatus (Bloch) ; D. umbrinum Tripathi, 1957 from Dendrophysa russelii (Cuvier) (Sciaenidae) , and Johnius dussumieri (Valenciennes) ; D. undulicirrosum Zhang, Liu, Ding & Chen, 2000 from Terapon theraps Cuvier , and Pelates quadrilineaus (Bloch) ; D. veropolynemi Nagibina, 1976 from Polydactylus plebeius (Broussonnet) , and Polydactylus sextarius ; D. wenningeri ( Mizelle & Blatz, 1941) Oliver, 1987 from Eucinostomus gula (Quoy & Gaimard) , and Gerres cinereus (Walbaum) (Gerreidae) .