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.).

Paradiplozoon cirrhini n. sp. (Monogenea, Diplozoidae), a gill parasite of Cirrhinus molitorella (Cyprinidae, Labeoninae) in South China.

Paradiplozoon cirrhini n. sp. (Monogenea, Diplozoidae) is described from the gills of mud carp, Cirrhinus molitorella (Valenciennes, 1844) (Cyprinidae, Labeoninae), collected in Wuzhou, Guangxi Province, and Conghua, Guangdong Province as part of an ongoing survey of the diplozoid fauna in the Pearl River basin of China. The new Paradiplozoon species is distinguished from congeners by the structure of median plate and its outgrowth sclerites. The ITS2 sequences of the new species differ from all known available diplozoid sequences by 22.04%-38.34%. The new species is the first diplozoid species parasitic on Labeoninae in China. Molecular phylogenetic analyses using rRNA ITS2 placed Paradiplozoon cirrhini n. sp. in a sister position to the other Chinese Paradiplozoon, implying that Labeoninae represents an early and potentially ancestral host group for China Paradiplozoon. We also provided ITS2 sequences for four other diplozoids species, namely P. megalobramae Khotenovsky, 1982, P. saurogobionis (Jiang, et al., 1985) Jiang, Wu & Wang, 1989, Sindiplozoon hunanensis Yao & Wang, 1997, and Sindiplozoon sp., and validated their phylogenetic position. The results confirm that all diplozoid species are spilt into two major clades and show monophyly of Sindiplozoon but paraphyly of Paradiplozoon.

Title: Paradiplozoon cirrhini n. sp. (Monogenea, Diplozoidae), parasite des branchies de Cirrhinus molitorella (Cyprinidae, Labeoninae) dans le sud de la Chine. Abstract: Paradiplozoon cirrhini n. sp. (Monogenea, Diplozoidae) est décrit à partir des branchies de la carpe de vase Cirrhinus molitorella (Valenciennes, 1844) (Cyprinidae, Labeoninae), collectée à Wuzhou, province du Guangxi, et à Conghua, province du Guangdong dans le cadre d'une enquête en cours sur la faune des Diplozoidae du bassin de la Rivière des Perles en Chine. La nouvelle espèce de Paradiplozoon se distingue de ses congénères par la structure de la plaque médiane et ses sclérites d'excroissance. Les séquences ITS2 de la nouvelle espèce diffèrent de toutes les séquences de Diplozoidae disponibles connues de 22,04 % à 38,34 %. La nouvelle espèce est la première espèce de Diplozoidae parasite de Labeoninae en Chine. Les analyses phylogénétiques moléculaires utilisant l'ARNr ITS2 ont placé Paradiplozoon cirrhini n. sp. dans une position sœur des autres Paradiplozoon chinois, ce qui implique que les Labeoninae représente un groupe d'hôtes précoce et potentiellement ancestral pour les Paradiplozoon de Chine. Nous avons également fourni des séquences ITS2 pour quatre autres espèces de Diplozoidae, à savoir P. megalobramae Khotenovsky, 1982, P. saurogobionis (Jiang, et al., 1985) Jiang, Wu & Wang, 1989, Sindiplozoon hunanensis Yao & Wang, 1997 et Sindiplozoon sp. et validé leur position phylogénétique. Les résultats confirment que toutes les espèces de Diplozoidae sont réparties en deux clades majeurs et montrent la monophylie de Sindiplozoon mais la paraphylie de Paradiplozoon.

Redescription of Paradiplozoon opsariichthydis (Jiang, Wu et Wang 1984) Jiang, Wu et Wang, 1989 (Monogenea, Diplozoidae).

Paradiplozoon opsariichthydis (Jiang, Wu et Wang, 1984) Jiang, Wu et Wang, 1989 (Platyhelminthes, Monogenea, Diplozoidae) is blood-feeding parasite from the gills of Asian cyprinid fish Opsariichthys bidens Günther, 1873. In this study, we present a morphological redescription of P. opsariichthydis neotype main morphological features e.g. size of body and clamps due to the fact that the type material is missing. We decided to supplement morphological descriptions by the relevant molecular data (internal transcribed spacer - ITS2) related to P. opsariichthydis adult worm isolates and other representatives of genus Paradiplozoon to cross verify our findings. In addition to that, this study also brings an attention to the host identification. Thus, parasite data were complemented by the determinant cytochrome oxidase b (cytb) sequences of its hosts. All novel sequences are deposited in GenBank. This combination of the morphological and molecular data related to both the parasite and its host seems to be the optimal approach to the general process of (re)description of highly host-specific parasitic organisms, which can then lead to a meaningful phylogenetic analysis.

Monogenea of Chinese marine fishes. XVIII. Two monocotylids, including a new species, from the blotched fantail ray Taeniurops meyeni (Elasmobranchii: Dasyatidae) in the South China Sea.

Two monogenean species are recorded from a blotched fantail ray, Taeniurops meyeni (Müller et Henle) (Dasyatidae), kept in a public aquarium at the Guangzhou Ocean World. Heterocotyle taeniuropi sp. n. was obtained from the gills. It is similar to Heterocotyle similis Neifar, Euzet et Ben Hassine, 1998 and H. scotti Neifar, Euzet et Ben Hassine, 1998, both of which have a similar male copulatory organ, but it can be distinguished from these two species by aspects of the morphology of the male copulatory organ, which is tubular, straight or slightly curved with a sclerotized accessory piece and an asymmetrical funnel-shaped opening at the proximal end, and recurved at the distal end. Dendromonocotyle pipinna Chisholm et Whittington, 2002, which is a new record for Chinese waters, was collected from the body surface of the same host. Its main features are almost the same as in the original description, except that it exhibits a variable number of marginal papillae.

Neohexostoma gymnosardae n. sp. (Monogenea, Hexostomatidae), a gill parasite of Gymnosarda unicolor (Valenciennes) (Teleostei, Scombridae) in the South China Sea.

Parasite biodiversity of fish in coral reefs of the South China Sea is still incompletely explored. We describe here a new species of Neohexostoma (Monogenea: Hexostomatidae) from the gill filaments of the dogtooth tuna Gymnosarda unicolor (Scombridae), collected off Yongshu Reef, South China Sea. Neohexostoma gymnosardae n. sp. is distinguished from its congeners by the following features: (i) haptor clearly marked from body proper by a strongly constricted peduncle, divided in its posterior margin into two symmetrical lobes, (ii) vagina armed with scattered small blunt spines, (iii) eggs tied by their long polar filaments, (vi) esophagus with several lateral diverticula, (v) intestinal ceca unfused and extending into the haptor. We present an analysis of the relationships of this monogenean based on partial 28S rDNA sequences. An identification key for species of Neohexostoma is provided. This is the first member of the genus Neohexostoma known to parasitize a species of Gymnosarda.

TITLE: Neohexostoma gymnosardae n. sp. (Monogenea, Hexostomatidae), un parasite branchial de Gymnosarda unicolor (Valenciennes) (Teleostei, Scombridae) dans la mer de Chine méridionale. ABSTRACT: La biodiversité parasitaire des poissons dans les récifs coralliens de la mer de Chine méridionale est encore incomplètement explorée. Nous décrivons ici une nouvelle espèce de Neohexostoma (Monogenea, Hexostomatidae) des filaments branchiaux du thon à dents de chien Gymnosarda unicolor (Scombridae), collecté au large du récif de Yongshu, mer de Chine méridionale. Neohexostoma gymnosardae n. sp. se distingue de ses congénères par les caractéristiques suivantes : (i) hapteur clairement séparé du corps proprement dit par un pédoncule fortement resserré, divisé dans sa marge postérieure en deux lobes symétriques, (ii) vagin armé de petites épines émoussées éparses, (iii) œufs attachés par leurs longs filaments polaires, (vi) œsophage avec plusieurs diverticules latéraux, (v) caeca intestinaux non fusionnés et s'étendant dans le hapteur. Nous présentons une analyse des relations de ce monogène basée sur des séquences partielles d'ADNr 28S. Une clé d'identification des espèces de Neohexostoma est fournie. Ceci est le premier membre du genre Neohexostoma connu pour parasiter une espèce de Gymnosarda.

Paracaesicola nanshaensis n. gen., n. sp. (Monogenea, Microcotylidae) a gill parasite of Paracaesio sordida (Teleostei, Lutjanidae) from the South China Sea.

Paracaesicola n. gen., is erected herein to accommodate a new microcotylid species, Paracaesicola nanshaensis n. sp., collected from the Yongshu Reef, South China Sea. This species is the first monogenean to be recorded from the gills of Paracaesio sordida. The new species is characterized by the following features: (i) haptor short, with clamps arranged in two equal bilateral rows; (ii) testes numerous, arranged in two roughly alternating longitudinal rows, extending into the haptor; (iii) genital atrium armed with 16 robust spines, which are vertically arranged on top of the sausage shaped muscular male copulatory organ; and (iv) single vagina, bottle-shaped, with a distinctly bulbous vaginal atrium. The terminals of the reproductive system discriminate Paracaesicola n. gen. from all other genera in the Microcotylidae. Molecular phylogenetic analyses, based on partial 28S rDNA, places Paracaesicola nanshaensis n. sp. within the microcotylid clade, but its sequence differs from all known available microcotylid sequences.

TITLE: Paracaesicola nanshaensis n. gen., n. sp. (Monogenea, Microcotylidae), parasite branchial de Paracaesio sordida (Teleostei, Lutjanidae) de la mer de Chine méridionale. ABSTRACT: Paracaesicola n. gen. est érigé ici pour accueillir une nouvelle espèce de Microcotylidae, Paracaesicola nanshaensis n. sp., collectée sur le récif de Yongshu, mer de Chine méridionale. Cette espèce est le premier monogène signalé des branchies de Paracaesio sordida. La nouvelle espèce est caractérisée par : (i) hapteur court, avec des pinces disposées en deux rangées bilatérales égales ; (ii) testicules nombreux, disposés en deux rangées longitudinales à peu près alternées, s'étendant jusqu'au hapteur ; (iii) atrium génital armé de 16 épines robustes, disposées verticalement au-dessus de l'organe copulateur mâle, musculaire et en forme de saucisse ; et (iv) vagin unique, en forme de bouteille, avec un atrium vaginal nettement bulbeux. Les parties terminales du système reproducteur distinguent Paracaesicola n. gen. de tous les autres genres de Microcotylidae. Les analyses phylogénétiques moléculaires, basées sur l'ADNr 28S partiel, placent Paracaesicola nanshaensis n. sp. au sein du clade des Microcotylidae, mais sa séquence diffère de toutes les séquences de Microcotylidae disponibles.

Redescription of Paradiplozoon hemiculteri (Monogenea, Diplozoidae) from the type host Hemiculter leucisculus, with neotype designation.

Paradiplozoon hemiculteri (Ling, 1973), a member of the Diplozoidae, parasitizes the gills of Asian fish. Not only is the type material unavailable for this species, the original description was poor and somewhat conflicting, and adequate molecular data were not available. What is more, the available morphological and molecular data are inconsistent and fluctuate significantly. Here, we present a redescription of P. hemiculteri based on morphological and molecular data from new isolates collected from the type host, the sharpbelly Hemiculter leucisculus (Basilewsky, 1855), captured at the neotype locality (Shaoguan, Guangdong Province, southern China); a neotype for P. hemiculteri was designated from this collection. The length and width of the body, buccal suckers, pharynx, attachment clamps, sickle and the central hook handle were all measured and the shape of the anterior and posterior part of the median plate and anterior and posterior joining sclerites accurately documented. Phylogenetic analyses based on the sequences of the second rDNA internal transcribed spacer (ITS2) indicated that all new samples clustered together and differed clearly from sequences attributed to P. hemiculteri, which are deposited in GenBank. Our results confirm that P. hemiculteri is the only diplozoid that has demonstrably been found on the gills of H. leucisculus to date.

PCR-SSCP as a molecular tool for the identification of Benedeniinae (Monogenea: Capsalidae) from marine fish.

PCR-based single strand conformation polymorphism (SSCP) analysis was used to characterize monogenean specimens of the subfamily Benedeniinae of morphologically uncertain specific status from different marine fish species, using Neobenedenia melleni, N. girellae and Entobdella corona for comparison. The first internal transcribed spacer (ITS-1) and the 5' terminal variable region (D1-D3 domains) of the large subunit ribosomal DNA (lsrDNA) were amplified separately from individual monogeneans, and the amplicons were subjected to PCR-SSCP analyses, followed by direct sequencing. Both SSCP patterns and the ITS-1 sequences data allowed specimens representing Entobdella spp. from the host Taeniura melanospilos to be unequivocally distinguished from those representing Neobenedenia spp. and those representing Benedenia spp. Neobenedenia girellae, a morphologically controversial species, had identical SSCP banding pattern and ITS-1 sequence to that of N. melleni, supporting the proposal that N. girellae is a synonym of N. melleni. Neobenedenia spp. and Benedenia spp. had identical SSCP patterns and ITS-1 sequences. These findings and the PCR-SSCP approach taken should have implications for the accurate identification and assessment of taxonomic validity of other important monogenean groups of the marine fish.