Euzetia occultum n. g., n. sp. (Euzetiinae n. subf.), a monocotylid monogenean from the gills of Rhinoptera neglecta (Rhinopteridae) from Moreton Bay,Queensland, Australia

Euzetia occultum n. g., n. sp. (Monogenea: Monocotylidae) is described from the gills of the Australian cownose ray Rhinoptera neglecta Ogilby collected in Moreton Bay, Queensland, Australia. Euzetia has one central and ten peripheral loculi, which is similar to species in Decacotyle Young, 1967. However Euzetia is distinguished from other genera in the family by the presence of an additional loculus on either side of the central loculus. Because Euzetia does not fit into any of the six existing subfamilies in the Monocotylidae Taschenberg, 1879, as currently recognised, we propose the Euzetiinae n. subf. to accommodate the new genus. Euzetia occultum is described and illustrated fully. This is the first published record of a monocotylid from a species of Rhinoptera Cuvier.     

Neotropical Monogenoidea. 52. Diechodactylus joaberi n. g., n. sp. from the banded knifefish Gymnotus carapo (Gymnotiformes: Gymnotidae) in southeastern Brazil

Diechodactylus joaberi n. g., n. sp. is described from the body surface of the banded knifefish Gymnotus carapo L. (Gymnotiformes: Gymnotidae) from southeastern Brazil. The new genus is proposed to accommodate species with five pairs of hooks in anterior bilateral clusters on the haptor, three pairs of hooks in a single cluster on the posterior margin of the haptor, sclerites R1 associated with the superficial bar, and confluent intestinal caeca. The presence of five pairs of hooks in two bilateral clusters anterior in the haptor permits the differentiation of species of Diechodactylus from species of all known genera of the Gyrodactylidae. The genus is likely a member of a clade of the Gyrodactylidae comprising genera with a similar hook distribution.     

Macrouridophora halargyrea n. sp. (Monogenea: Diclidophoridae) from Halargyreus johnsonii (Moridae) in the North-eastern Atlantic

Macrouridophora halargyrea n. sp. (Monogenea: Diclidophoridae) is described from the gills of the morid teleost Halargyreus johnsonii caught off the Faroe Islands in the North-eastern Atlantic. This new species is differentiated from ten other species in the genus Macrouridophora Rubec & Dronen, in press, by its: specialised heart-shaped haptor distinctly set-off from the body proper; inverted orientation of the first three anterior pairs of clamps; distinct spinulation covering the isthmus and haptor; small body size; small numbers of testes; and host.     

<Emphasis Type="Italic">Decacotyle cairae</Emphasis> n. sp. (Monogenea: Monocotylidae) from the gills of <Emphasis Type="Italic">Pastinachus</Emphasis> sp. (Elasmobranchii: Dasyatidae) from the South China Sea off Sarawak,Borneo, Malaysia

Decacotyle cairae n. sp. (Monogenea: Monocotylidae) is described from the gills of an unidentified species of Pastinachus collected in the South China Sea off Sematan and Mukah, Sarawak, Borneo, Malaysia. D. cairae can be distinguished from the other six members of the genus by the presence of two simple unsclerotised accessory structures on the dorsal surface of the haptor in combination with a long, narrow, looping male copulatory organ. The host specimens of Pastinachus collected in Borneo also appear to be a new species and the monogenean data support this conclusion. A key to species of Decacotyle is given and their host-specificity is discussed.     

Two new species of mazocraeid monogeneans from Clupanodon punctatus (Temminck & Schlegel) (Clupeiformes: Clupeidae) found in Daya Bay, South China Sea, with the proposal of Chelimazocraes n. g.

Chelimazocraes liaoi n. g., n. sp. and Chelimazocraes ascidiformis n. sp. (Monogenea: Mazocraeidae) are described from the gills of Clupanodon punctatus (Temminck & Schlegel) in Daya Bay (South China Sea). The new genus is characterised by the following features: (i) the haptor is distinctly separated from the body proper, and the arrangement of the clamps is bilaterally symmetrical but longitudinally heteromorphic; (ii) the anterior three pairs of clamps are of the mazocraeid-type, whereas the fourth pair is of a non-mazocraeid type with three sclerites; (iii) all three pairs of clamps are similar in shape but their size gradually becomes smaller from the anterior to the posterior; (iv) the inner spines of the copulatory organ have a similar shape; and (v) the testes are numerous and arranged longitudinally posterior to the ovary. The two new species are easily distinguished from other members of the Mazocraeidae by the unique structure of the fourth pair of clamps; however, there are some noticeable differences between the two species. The major differences are as follows: (i) the body of C. liaoi n. sp. is significantly larger than that of C. ascidiformis n. sp.; (ii) the anterior three pairs of clamps consist of different sclerites in the two species; and (iii) the copulatory organ has one pair of outer spines and 15–16 pieces of inner spines in C. liaoi n. sp. (vs two pairs of outer spines and 22–26 pieces of inner spines in C. ascidiformis n. sp.).     

<Emphasis Type="Italic">Malalophus jensenae</Emphasis> n. g., n. sp. (Monogenea: Monocotylidae) from the gills of <Emphasis Type="Italic">Aetomylaeus vespertilio</Emphasis> (Myliobatidae) off northern Australia

Malalophus jensenae n. g., n. sp. is described from the gills of the ornate eagle ray Aetomylaeus vespertilio (Bleeker) collected off the eastern coast of the Gulf of Carpentaria, northern Queensland. The new genus is similar to Heliocotyle Neifar, Euzet & Ben Hassine, 1999, with which it shares a haptor bearing seven peripheral loculi and a single dorsal haptoral accessory structure. M. jensenae can be distinguished from species of Heliocotyle by the presence of numerous sclerotised sinuous ridges covering the ventral surfaces of the peripheral loculi of the haptor. It also lacks pseudosepta which are present on the haptor of Heliocotyle species. This is the first published record of a monogenean from an elasmobranch in the Gulf of Carpentaria, Australia.     

Neotropical Monogenoidea. 33. Three new species of Ancistrohaptor n. g. (Dactylogyridae,Ancyrocephalinae) on Triportheus spp. (Teleostei,Characidae) from Brazil,with checklists of ancyrocephalines recorded from neotropical characiform fishes

Three new species of Ancistrohaptor n. g. are described from the gills of three species of Triportheus (Characidae) collected from the environs of Manaus, Amazonas, Brazil: A. falcatum n. sp. from T. elongatus; and A. falciferum n. sp. and A. falcunculum n. sp. from T. angulatus, T. albus and T. elongatus. Ancistrohaptor n. g. is proposed for species possessing overlapping gonads, a dextral or dextroventral vaginal aperture, a coiled (counter-clockwise) male copulatory organ, two accessory pieces in the copulatory complex, and a haptor armed with two pairs of anchors (ventral anchor with elongate shaft), dorsal and ventral bars and 14 hooks; hook pair 1 (ventral) anterior to ventral bar, pairs 2–4 (ventral) lying bilaterally anterior to ventral anchor bases, pair 5 (ventral) associated with distal end of ventral anchor shafts, and pairs 6 and 7 (dorsal) bilateral about midway along haptoral length. Parasite-host and host-parasite lists of the Ancyrocephalinae from neotropical Characiformes are provided.     

Monogenea from the middle Yangtze Valley: Sinomazocraes changjiangensis n. g., n. sp. (Family Mazocraeidae Price, 1936) on a clupeiform fish from Hubei Province,China

Sinomazocraes changjiangensis n. g., n. sp. (Monogenea: Mazocraeidae) is described from the gills of the shortjaw tapertail anchovy Coilia brachygnathus collected from Jiayu and Huanggang Counties (Hubei Province), which are located in the middle reaches of the Yangtze River. The structure of the clamps and copulatory organ are similar to those of Heteromazocraes Mamaev, 1981. However, although Sinomazocraes also has four pairs of clamps, it is distinguished from other genera in the family by the fact that the three anterior clamps on one side of the body are significantly larger than the others. Variations in the form of the clamps in different species of the Mazocraeidae are discussed.     

Dendromonocotyle lasti n. sp. from the skin and Monocotyle caseyae n. sp. (Monogenea: Monocotylidae) from the gills of Himantura sp. (Dasyatidae) in Moreton Bay, Queensland, Australia

Seven specimens of rays of the genus Himantura which could not be identified to species were collected from waters near Dunwich, Stradbroke Island, Moreton Bay, Queensland, Australia. The five smallest specimens of Himanturasp. (disc width 218-302 mm; four female, one male) had a banded tail and the dorsal surface was uniformly grey/brown. The two largest individuals of Himantura sp. (disc widths 460, 533 mm; female and male, respectively) also had a banded tail but the grey/brown dorsal surface had white spots. Two new monogenean species (Monocotylidae: Monocotylinae) are described from both the plain and white-spotted specimens of Himantura. Dendromonocotyle lastin. sp. is distinguished from other species in the genus by the number of papillae on the haptor, by the morphology of the male copulatory organ and by the morphology of the proximal portion of the vagina. The muscular sheath which surrounds the male copulatory organ is also unique having sclerotised spines at the distal end. Dendromonocotyle species are skin parasites, but a total of five juvenile specimens of D. lasti were found on the gills of four rays. Monocotyle caseyae n. sp. from the gills is characterised by the morphology of the male copulatory organ and its accessory piece. One specimen of M. spiremae Measures, Beverley-Burton & Williams, 1990, originally described from the gills of Himantura fai Jordan & Seale off Heron Island, Great Barrier Reef, Queensland, Australia, was also found on the gills of one Himantura specimen. The site and host-specificity of the parasites and the identity of the hosts are discussed.     

Triloculotrema japanicae n. g., n. sp. (Monogenea: Monocotylidae) from the olfactory sacs of the Japanese topeshark Hemitriakis japanica (Müller & Henle, 1839) (Carcharhiniformes: Triakidae)

Triloculotrema japanicae n. g., n. sp. (Monogenea: Monocotylidae: Merizocotylinae) is described. The parasite inhabits the olfactory sacs of the Japanese topeshark Hemitriakis japanica (Carcharhiniformes: Triakidae), and possesses a distinctive haptor with only three loculi. Some comments are made on the evolution of monocotylid monogeneans.     

Diplectanum squamatum n.sp. (Monogenea:Diplectanidae) fro the gills of Cynoscion guatucupa (Sciecidae) in southwest Atlantic waters

Diplectanum squamatum n. sp. is described from the gills of the sciaenid Cynoscion guatucupa collected off Mar del Plata, Argentina. The new species is distinguished from other species of the genus by the morphology of the hamuli and the male copulatory organ, and presence of scales on the haptor and body. This is the first species of Diplectanum to be reported from southwest Atlantic waters and, with the possible exception of D. cayennense Euzet & Durette-Desset, 1974, the only species from the Atlantic coast of South America.     

Monogeneans from the gills of glassfishes (Teleostei: Perciformes: Ambassidae) in India, with the proposal of Chandacleidus n. g. (Monogenea: Dactylogyridae)

Chandacleidus n. g. (Monogenea, Dactylogyridae) is proposed to include three species collected from the gills of Indian glassfishes (Ambassidae): Chandacleidus recurvatus (Jain, 1961) n. comb. (syn. Urocleidus recurvatus Jain, 1961) from Chanda nama and C. ranga (new host record) is redescribed; and Chandacleidus saiensis n. sp. and C. lucknowensis n. sp., both from Chanda nama and C. baculis, are described. Chandacleidus n. g. is characterised by species possessing: posteriorly united intestinal caeca; overlapping gonads (testis dorsal to ovary); a counterclockwise male copulatory organ; a grooved accessory piece; a dextro-marginal vaginal pore; a haptor with two lateral flaps and armed with dissimilar dorsal and ventral anchor/bar complexes and 14 similar hooks (dissimilar in size); and hook shanks comprised of two subunits.     

The phylogenetic position of the Loimoidae Price, 1936 (Monogenoidea: Monocotylidea) based on analyses of partial rDNA sequences and morphological data

Phylogenetic analyses of partial sequences of 18S and 28S rDNA of some monogenoids, including monocotylids and a specimen of Loimosina sp. collected from a hammerhead shark off Brazil, indicated that the Loimoidae (as represented by the specimen of Loimosina sp.) represents an in-group taxon of the Monocotylidae. In all analyses, the Loimoidae fell within a major monocotylid clade including species of the Heterocotylinae, Decacotylinae, and Monocotylinae. The Loimoidae formed a terminal clade with two heterocotyline species, Troglocephalus rhinobatidis and Neoheterocotyle rhinobatis, for which it represented the sister taxon. The following morphological characters supported the clade comprising the Loimoidae, Heterocotylinae, Decacotylinae and Monocotylinae: single vagina present, presence of a narrow deep anchor root, and presence of a marginal haptoral membrane. The presence of cephalic pits was identified as a putative synapomorphy for the clade (Loimoidae (T. rhinobatidis, N. rhinobatis)). Although rDNA sequence data support the rejection of the Loimoidae and incorporating its species into the Monocotylidae, this action was not recommended pending a full phylogenetic analysis of morphological data.     

Policlithrum ponticum sp. n. (Monogenea: Gyrodactylidae: Polyclithrinae) from Mugil cephalus from the Black Sea and problems of suprageneric systematics of the gydrodactylids

Polyclithrum ponticum sp. n. is described and P. mugilini Rogers, 1967 is redescribed. Both monogenean species are parasites of Mugil cephalus in the Black Sea. The new species differs from P. mugilini, P. alberti and P. boegeri by the lesser size of anchors, while it is distinguished from P. corallense by the larger size of these structures. P. ponticum sp. n. differs from all formerly described species by the greater length of dorsal connective bar. In both species from the Black Sea, "ear-like" structures situated near the external roots of anchors are described for the first time. It is suggested, that these structures take part in longitudinal, two-lobe folding of the haptor. The process of opening the haptor is probably performed by the additional bars of the haptor (bars 2 and 3 after: Rogers, 1967), joined to each other and with the anchors. The fifth pair of additional bars (Ernst e. a., 2000) derives from the "beard" of ventral connective bar and is united with its basal part. The sixth pair of additional bars (Ernst e. a., 2000) is considered as a typical "ribs" of the haptor, and therefore the "ribs" are represented by three pairs. Differences between marginal hooks of P. ponticum sp. n. and P. mugilini are insignificant, that probably depends on the presence of "ribs" of the haptor. Based on the subdivision of marginal hooks into two groups, the presence of additional supporting structure in the haptor, and the presence of the seminal receptacle, it is suggested that the subfamily Polyclithrinae Rogers, 1967 should include the genera Polyclithrum Rogers, 1967, Swingleus Rogers, 1969, Macrogyrodactylus Mamlberg, 1959, and probably Fundulotrema Hargis, 1955. Based on such characters as the lack of the anchors, the presence of suckers in the haptor, and ovipositing of eggs, it seems to be expedient to use the following taxa in systematics of gyrodactylids: Isancistrinae Fuhrmann, 1928 (genera Isancistrum, Anacanthocotyle); Gyrdicotylinae Vercammen-Grandjean, 1960 (Gyrdicotyle) and Ooegyrodactylinae Harris, 1983 (genera Phanerothecium, Ooegyrodactylus, Nothogyrodactylus, Hyperopletes).     

Neotropical Monogenoidea. 49. Four new species of the Diplectanidae (Dactylogyrinea) from the gills of some pachyurines (Teleostei: Sciaenidae) from the Rio Tocantins and Rio Doce Basins, with the proposal of Anoplectanum n. g. and Spinomatrix n. g.

Four new species of the Diplectanidae from the gills of freshwater sciaenid species (Pachyurinae) in Brazil are described and two new genera, Anoplectanum n. g. and Spinomatrix n. g., are proposed. These are: Diplectanum copiosum n. sp. from Pachyurus junki and Petilipinnis grunniens; Anoplectanum haptorodynatum n. g., n. sp. from Pachyurus junki and Petilipinnis grunniens, and A. microsoma n. g., n. sp. from Petilipinnis grunniens, all in the Tocantins Basin; and Spinomatrix penteormos n. g., n. sp. from Pachyurus adspersus in the Rio Doce Basin. Anoplectanum is proposed to accommodate diplectanids lacking squamodiscs and having a superficial root of the ventral anchor as long or longer than the deep root. Spinomatrix is proposed for species having a haptoral and peduncular armature composed of spines, hooks, anchors, squamodiscs and armed muscular pads.     

Five new monogenean species from the gills of Mulloidichthys vanicolensis (Perciformes: Mullidae) off New Caledonia, with the proposal of Volsellituba n. g. and Pennulituba n. g. (Monogenea: Dactylogyridae)

Three species of Volsellituba n. g. and two species of Pennulituba n. g. are described from the gills of the yellowfin goatfish Mulloidichthys vanicolensis (Valenciennes) off New Caledonia (South Pacific). Volsellituba and Pennulituba resemble dactylogyrid genera whose species lack eye-spots and possess tandem or slightly overlapping gonads, a single prostatic reservoir, a male copulatory organ without an accessory piece, a dextroventral non-sclerotised vagina, ventral and dorsal anchor/bar complexes, and hooks with shanks comprising a single slender unit. Volsellituba n. g. is characterised by its species having ventral tegumental folds at the level of the vaginal duct, a male copulatory organ with a subterminal basal opening and a two-piece dorsal bar. The following new species of Volsellituba are described: V. orchidea n. sp. (type-species), V. nabla n. sp. and V. elephantina n. sp. Pennulituba n. g. is distinguished by its species possessing a male copulatory organ with a wing-shaped membrane and a dorsal bar with a poorly to non-sclerotised medial part. This genus includes P. piratifalx n. sp. (type-species) and P. cymansis n. sp. A tabular summary of the species of Haliotrema Johnston & Tiegs, 1922 reported from mullids is provided.     

<Emphasis Type="Italic">Spicocleidus namae</Emphasis> n. g., n. sp. (Monogenea: Dactylogyridae) on <Emphasis Type="Italic">Chanda nama</Emphasis> (Hamilton) from Lucknow,India

Spicocleidus n. g. is proposed for S. namae n. sp., a new monogenean collected from the gills of an ambassid, Chanda nama (Ham.), in the River Sai near Lucknow, Uttar Pradesh, India. The new genus is characterised by a pair of modified dorsal anchors (spikes), the absence of a dorsal bar, alate lateral expansion of the anterior haptor and the post-ovarian position of the testis.     

Dactylomyza gibsoni n. g., n. sp. (Digenea: Opecoelidae) from Schuettea woodwardi (Waite) (Monodactylidae) from off Western Australia

An opecoelid digenean, Dactylomyza gibsoni n. g., n. sp. is described and figured from Schuettea woodwardi (Waite), a monodactylid from off the coast of Western Australia. The new genus conforms to the concept of the opecoelid subfamily Opecoelinae. The resemblance of the new genus to three other opecoelid genera, Pseudopecoeloides Yamaguti, 1940, Opecoeloides Odhner, 1928 and Poracanthium Dollfus, 1948, is discussed. Dactylomyza n. g. is distinguished from these morphologically similar worms on the basis of its median genital pore, ventral sucker appendages, uroproct and the absence of an accessory sucker. Pseudopecoeloides equesi Manter, 1947 is transferred to the new genus as Dactylomyza equesi (Manter, 1947) n. comb.