Morphometric variability between and within species of Ligophorus Euzet & Suriano, 1977 (Monogenea: Ancyrocephalidae) in the Mediterranean Sea

Monogeneans belonging to the genus Ligophorus Euzet & Suriano, 1977 are parasitic on the gills of several fish species of the family Mugilidae (mullets). At present, 12 species belonging to this genus have been described in the Mediterranean Sea and each host species is infected by a number of Ligophorus species that are not found on other mullets. A multivariate study using principal component and canonical variate analyses was carried out, with the aim of investigating the extent of morphometric variability within and between the 12 Mediterranean species of Ligophorus. Significant intraspecific morphometric variation was detected between two allopatric populations of L. angustus Euzet & Suriano, 1977 parasitic on Chelon labrosus from Sardinia; however, the existence of a new species of Ligophorus needs further evidence. Analysis of interspecific variation confirms the validity of the morphological keys used at present for the identification of Ligophorus at the species level and provides a picture of the relationships between species, indicating that the two species parasitising Mugil cephalus, L. chabaudi Euzet & Suriano, 1977 and L. mugilinus (Hargis, 1955) are the most differentiated. The hypothesis that strict host-parasite ecological relationships may be the result of co-speciation processes is briefly discussed.     

Ligophorus pilengas Sarabeev & Balbuena, 2004 (Monogenea: Ancyrocephalidae) is proposed as the senior synonym of L. gussevi Miroshnichenko & Maltsev, 2004

Ligophorus pilengas Sarabeev & Balbuena, 2004 and L. gussevi Miroshnichenko & Maltsev, 2004, both recently described as new species from the so-iuy mullet Mugil soiuy in the Sea of Azov and Black Sea, were compared. A morphometric analysis of both forms strongly suggests that they represent the same species. According to the 'Principle of priority', L. pilengas is proposed as a senior synonym of L. gussevi.     

Ligophorus pilengas Sarabeev & Balbuena, 2004 (Monogenea: Ancyrocephalidae) is proposed as the senior synonym of L. gussevi Miroshnichenko & Maltsev, 2004

Ligophorus pilengas Sarabeev & Balbuena, 2004 and L. gussevi Miroshnichenko & Maltsev, 2004, both recently described as new species from the so-iuy mullet Mugil soiuy in the Sea of Azov and Black Sea, were compared. A morphometric analysis of both forms strongly suggests that they represent the same species. According to the ‘Principle of priority’, L. pilengas is proposed as a senior synonym of L. gussevi.     

Descriptions of eight new species of <Emphasis Type="Italic">Ligophorus</Emphasis> Euzet &; Suriano, 1977 (Monogenea: Ancyrocephalidae) from Red Sea mullets

Eight new species of Ligophorus Euzet &; Suriano, 1977 (Monogenea: Ancyrocephalidae) are described from two species of mullets from the Red Sea. Ligophorus bykhowskyi n. sp. and L. zhangi n. sp. from Crenimugil crenilabris (Forsskål) differ from other species of the genus in the structure of the male copulatory organ, which has a simple accessory piece and a wide copulatory tube that arises from a large, single-chambered, expanded base. Ligophorus simpliciformis n. sp., L. bipartitus n. sp., L. campanulatus n. sp., L. mamaevi n. sp., L. lebedevi n. sp. and L. surianoae n. sp. from Liza carinata (Valenciennes) are differentiated on the basis of the morphometrics of the hard parts of the haptor and male copulatory organ. The eight species represent the first records of species directly attributed to Ligophorus from the Red Sea. Measurements of the haptoral hard-parts and the male copulatory organ of the new species are analysed with the aid of Principal Component Analysis. Three morphological types of male copulatory organ, five types of anchor, and two types of ventral and three types of dorsal bars were distinguished among these species. L. bykhowskyi and L. zhangi from C. crenilabris have the same type of male copulatory organ and anchors. Those species from Liza carinata have only one common morphological character, a thick copulatory tube, but have two types of accessory piece, four types of anchors and three types of bars. All species of Ligophorus found on mullets in the Red Sea have an accessory piece without a distal bifurcation and thus differ from most species of this genus from other regions of the world’s oceans.     

Ligophorus abditus n. sp. (Monogenea: Ancyrocephalidae) and other species of Ligophorus Euzet & Suriano, 1977 infecting the flathead grey mullet Mugil cephalus L. in the Sea of Japan and the Yellow Sea

As a result of the re-examination of museum slides and new material of monogeneans collected from Mugil cephalus L. in the Sea of Japan, the estuary of a river which flows into the Sea of Japan, the Yellow Sea (off Zhifu, at the boundary of the Bohai Sea) and the East China Sea (off the Ryukyu Islands), five species of Ligophorus Euzet & Suriano, 1977 were identified, one of which is new. The known species are L. chabaudi Euzet & Suriano, 1977, L. cheleus Rubtsova, Balbuena & Sarabeev, 2007, L. domnichi Rubtsova, Balbuena & Sarabeev, 2007 and L. pacificus Rubtsova, Balbuena & Sarabeev, 2007, which are reported from the Yellow Sea; in addition, L. domnichi is reported for the first time from the East China Sea. Ligophorus abditus n. sp., from the Sea of Japan, differs from its most similar congeners, L. pacificus and L. domnichi, in the shapes of the dorsal anchors and the accessory piece of the male copulatory organ. A comparison of all of the species of Ligophorus recovered from M. cephalus in the Sea of Japan was carried out using Principal Component Analysis, and their distribution and origin are discussed.     

Physiological characterization of four model Lotus diploid genotypes: L. japonicus (MG20 and Gifu), L. filicaulis, and L. burttii under salt stress

The genus Lotus comprises a heterogeneous group of annual and perennial species. Lotus japonicus (with MG20 and Gifu ecotypes) has been adopted as one of the model legumes in genetic and genomic studies. Other Lotus species, such us Lotus burttii and Lotus filicaulis, have also been used in genetic and genomic studies because of their capacity to produce fertile progenies in crosses with L. japonicus. In the present work, physiological responses to salt stress in four Lotus genotypes were evaluated on the basis of growth and associated parameters, such as photosynthesis, ions, relative water content, oxidative damage and antioxidant system responses, using two NaCl levels applied by acclimation for up to 28 and 60 d. Growth responses varied with plant developmental stage in the four Lotus genotypes. L. japonicus MG20 was found to be a salt-tolerant genotype, mainly when exposed to salt stress at the young plant stage. The capacity of Lj MG20 to sustain growth under salt stress was correlated with enhancement of Superoxide dismutase and Glutathione reductase activities, as well as with increases in total and reduced glutathione content and lower Na⁺ accumulation in leaves. These results suggest that enhancement of antioxidant responses in Lj MG20 contributed to improve salt stress tolerance at early stages. On the other hand, after long-term high NaCl stress treatment, L. filicaulis exhibited lower biomass reduction, lower oxidative damage and Na⁺ accumulation in leaves than the control treatment; hence, this genotype was considered salt-tolerant. These apparently ambiguous results remark that salt tolerance, as a development-related process, was differentially expressed among the Lotus genotypes and depended on stress duration and plant phenological stage.     

A redescription of Pseudorhabdosynochus epinepheli (Yamaguti, 1938), the type-species of Pseudorhabdosynochus Yamaguti, 1958 (Monogenea: Diplectanidae), and the description of P. satyui n. sp. from Epinephelus akaara off Japan

Pseudorhabdosynochus epinepheli (Yamaguti, 1938) has been recorded from a variety of hosts, mainly groupers. All type-specimens of Diplectanum epinepheli Yamaguti, 1938, Pseudorhabdosynochus epinepheli Yamaguti, 1958 and Cycloplectanum hongkongensis Beverley-Burton & Suriano, 1981 are figured: it is concluded, as did Kritsky & Beverley-Burton (1986), that the three species are synonymous. In addition, numerous monogenean specimens from a deep-sea grouper, Epinephelus chlorostigma, collected off New Caledonia, South Pacific, were prepared using various methods and described. These specimens are also conspecific with P. epinepheli (Yamaguti, 1938) and represent a new geographical record. This species has a sclerotised vagina with a very characteristic primary chamber. The simultaneous presence of P. lantauensis (Beverley-Burton & Suriano, 1981) and P. epinepheli was noted in both type-slides of D. epinepheli from Japan (host: E. akaara) and C. hongkongensis from Hong Kong (host: E. bruneus). Several causes are suspected for the alleged ‘generalist’ character of P. epinepheli, including the misidentification of either fish or monogeneans and the accidental exchanges of monogeneans between fishes of different species kept alive in the same tank. Finally, the confirmed list of hosts of P. epinepheli includes E. akaara, E. awoara and E. chlorostigma; it is suggested that the latter, a widespread deep-sea fish, serves as a reservoir for the infection of the other species, which are associated with shallow waters. P. satyui n. sp. is described from two specimens found on slides from E. akaara (from the Inland Sea of Japan) deposited by Yamaguti; the new species has a sclerotised vagina with characteristic spherical chambers.

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Résumé   Pseudorhabdosynochus epinepheli (Yamaguti, 1938) a été mentionné chez différents h?tes, surtout des mérous. Tous les spécimens-types de Diplectanum epinepheli Yamaguti, 1938, Pseudorhabdosynochus epinepheli Yamaguti, 1958 et Cycloplectanum hongkongensis Beverley-Burton & Suriano, 1981 sont figurés, et on conclut, comme Kritsky & Beverley-Burton (1986), que les trois espèces sont synonymes. De plus, de nombreux spécimens de monogènes collectés chez un mérou de profondeur, Epinephelus chlorostigma, de Nouvelle-Calédonie, Pacifique Sud, ont été préparés avec des méthodes variées. Ces spécimens sont aussi conspécifiques de P. epinepheli (Yamaguti, 1938) et la Nouvelle-Calédonie représente une nouvelle mention géographique. L’espèce a une vagin sclérifié avec une chambre primaire très caractéristique. La présence simultanée de P. lantauensis (Beverley-Burton & Suriano, 1981) et P. epinepheli a été notée dans les lames-types de D. epinepheli du Japon (h?te, E. akaara) et de C. hongkongensis de Hong-Kong (h?te, E. bruneus). Plusieurs causes sont soup?onnées pour le caractère prétendument ‘généraliste’ de P. epinepheli, dont les mauvaises identifications de poissons, des monogènes, et l’échange accidentel de monogènes chez des poissons gardés vivants ensemble dans un même contenant. Finalement, la liste des h?tes confirmés de P. epinepheli comprend E. akaara, E. awoara et E. chlorostigma. On fait l’hypothèse que E. chlorostigma, espèce de profondeur, a servi de réservoir pour l’infestation des autres espèces, plus associées aux eaux peu profondes. P. satyui n. sp. est décrit de deux spécimens trouvés dans des lames de parasites de E. akaara (de la mer intérieure du Japon) déposées par Yamaguti. La nouvelle espèce a un vagin sclérifié avec des chambres sphériques caractéristiques.

     

Glyphidohaptor safiensis n. sp. (Monogenea: Ancyrocephalidae) from the white-spotted rabbitfish Siganus canaliculatus (Park) (Perciformes: Siganidae) off Oman,with notes on its phylogenetic position within the Ancyrocephalidae Bychowsky & Nagibina, 1968 (sensu lato)

A new ancyrocephalid monogenean is described from the gills of wild White-spottedrabbitfish Siganus canaliculatus (Park) based on morphological and molecular analyses. Glyphidohaptor safiensis n. sp. can be distinguished from other members of the genus by the shape of the accessory piece of the male copulatory organ (MCO). Unlike its congeners, the rod-shaped accessory piece of G. safiensis n. sp. is distally broad and flattened. The MCO of G. safiensis n. sp. is curved, enclosed in a heavy sheath with a terminal flap. Partial large subunit (LSU), partial small subunit (SSU) and the partial SSU, entire internal transcribed spacer region 1 (ITS1) and partial 5.8S rDNA of the new species and two species of Tetrancistrum Goto & Kikuchi, 1917 from the same host and locality were sequenced and subjected to phylogenetic analysis. The LSU rDNA analysis grouped G. safiensis n. sp. with Tetrancistrum sp. from the gills of Siganus fuscescens Houttuyn from Australia, indicating a possible misidentification of the latter. Sequences of the SSU rDNA of the new species were most similar to those for Pseudohaliotrema sphincteroporus Yamaguti, 1953, demonstrating the close relatedness of the genera Pseudohaliotrema Yamaguti, 1953 and Glyphidohaptor Kritsky, Galli & Yang, 2007 within the Ancyrocephalidae. The comparison of the partial SSU (424 bp) and entire ITS1 and partial 5.8S rDNA (246 bp) sequences obtained for G. safiensis n. sp. with the only available sequence of another member of Glyphidohaptor Kritsky, Galli & Yang, 2007, G. pletocirra Paperna, 1972 (HE601931-HE601933) yielded on average 1.08% dissimilarity (a difference of 7 bases), with a p-distance of 0.010 ± 0.004%. This is the first record of a species of Glyphidohaptor from S. canaliculatus and from the Persian Gulf, the Gulf of Oman and the Arabian Sea.

     

Description of a new species of Aethycteron Suriano & Beverley-Burton, 1982 (Monogenea: Ancyrocephalidae) on the gills of the rare striated darter,Etheostoma striatulum Page & Braasch (Perciformes: Percidae), from the Duck River,Tennessee, USA

Systematic Parasitology - The striated darter (Etheostoma striatulum Page &amp; Braasch) is a rare fish species restricted to the Duck River system in Maury County, Tennessee, USA. In this...     

Pseudanthocotyloides heterocotyle (van Beneden, 1871) Euzet & Prost, 1969 (Monogenea: Polyopisthocotylea: Mazocraeidae), a parasite of herring Clupea harengus L. and sprat Sprattus sprattus L. (Teleostei: Clupeidae)

A total of 690 herring Clupea harengus L. and 88 sprat Sprattus sprattus L. caught off the west coast of Sweden, in the North Sea and off the west and south coasts of the United Kingdom, were examined for gill parasites. The monogenean Pseudanthocotyloides heterocotyle (van Beneden, 1871) Euzet & Prost, 1969 was found in 38 (5.5%) herring and one (1.1%) sprat. The parasite was significantly (P>0.05) more common off the west coast of Sweden than elsewhere and most specimens (62.5%) were found on the pseudobranchs. Only the smaller herring were infected. P. heterocotyle is redescribed and its taxonomy discussed, together with the possibility of host and parasite misidentification in previous reports.     

Haliotrema cupensis n. sp. (Monogenea, Ancyrocephalidae) from a marine gobiid (Teleostei, Perciformes) of the Mediterranean coast

We describe a new ancyrocephalid monogenean, Haliotrema cupensis n. sp., from a marine gobiid, Gobius cobitis (Pallas) from the Mediterranean Sea. This species differs from the other members of the genus by the morphology of the penis and accessory piece, the haptoral ornamentation and by possessing a larger testis. This is the first report of an ancyrocephalid on a marine gobiid and of a Haliotrema species in the Mediterranean Sea.     

Taxonomy, molecular phylogeny, and ultrastructural morphology of Olpidiopsis porphyrae sp. nov. (Oomycetes, straminipiles), a unicellular obligate endoparasite of Bangia and Porphyra spp. (Bangiales, Rhodophyta)

Olpidiopsis porphyrae sp. nov., a marine oomycete endoparasite that infects the commercially cultivated red alga Porphyra yezoensis, is described and its phylogenetic position based on molecular data and ultrastructural morphology is discussed. O. porphyrae infects the host Porphyra by means of encysted zoospores. Spherical-shaped holocarpic thalli develop within the cytoplasm of its algal host, which produce monoplanetic, subapically biflagellate zoospores. The characteristic features of this isolate are the ellipsoidal, unicellular thallus and simple holocarpic zoosporangial development, which show morphological similarity with the genus Olpidiopsis. Laboratory infection experiments with a wide range of green, brown, and red algae revealed that O. porphyrae infects several stages of the bangialean red algae (the genera Bangia and Porphyra). Molecular phylogenetic analyses inferred from both SSU rRNA and cox2 genes showed O. porphyrae branched before the main saprolegnian and peronosporalean lineages within the monophyletic oomycete clade, indicating its phylogenetic separation from them. A single or double K-body-like organelle, which contains tubular inclusions, is found located to one side of the zoospore nucleus and shows similarities to homologous organelles previously described in O. saprolegniae. The ultrastructural morphology of O. porphyrae with zoospore initials containing K-bodies and tubular mitochondrial cristae is characteristic of oomycetes. Group I intron-like multiple insertions were found in the SSU rRNA gene of O. porphyrae. This is the first report of SSU group I introns in the class Oomycetes.     

Lampteromyces bioluminescence : 3. Structure of lampteroflavin, the light emitter in the luminous mushroom, L. japonicus

The structure of lampteroflavin, the light emitter in the luminous mushroom (Lampteromyces japonicus), was determined to be a new riboflavin α- -riboside, its structure being elucidated on the basis of fast atom bombardment tandem mass spectrometry, NMR, and CD studies.     

Redescriptions of species of Tetrarhynchobothrium Diesing, 1850 and Didymorhynchus Beveridge & Campbell, 1988 (Cestoda: Trypanorhyncha), with the description of Zygorhynchus borneensis n. sp

Tetrarhynchobothrium tenuicolle Diesing, 1850 is redescribed from the type-specimens collected from Raja clavata Linnaeus in the Adriatic Sea. T. striatum (Wagener, 1854) is redescribed from voucher specimens from the type host, Myliobatis aquila Linnaeus, from the type-locality, off Naples, Italy. The two species are very similar in tentacular armature, but are provisionally maintained as independent species, since the armature of T. tenuicolle cannot be fully described and because all available specimens of T. striatum are immature, limiting comparisons of potential differences in segment anatomy. T. setiense Dollfus, 1969 is treated as a synonym of T. striatum. Zygorhynchus borneensis n. sp. is described from Himantura uarnacoides (Bleeker) and H. pastinacoides (Bleeker) off Sabah, Malaysia. The new species is distinguished from its congeners by the very small hooks present in the basal region and by the presence of a uterine pore. The metabasal tentacular armature of Didymorhynchus southwelli Beveridge & Campbell, 1988, described for the first time, is homeoacanthous and homeomorphous in form. However, it has a basal swelling with hook rows originating on the bothrial surface and terminating on the antibothrial surface of the tentacle.     

Four new species of Cichlidogyrus Paperna, 1960 (Monogenea,Ancyrocephalidae), all gill parasites from African mouthbreeder tilapias of the genera Sarotherodon and Oreochromis (Pisces,Cichlidae), with a redescription of C. thurstonae Ergens, 1981

A study of Oreochromis niloticus (Linnaeus), O. aureus (Steindachner), Sarotherodon caudomarginatus (Boulenger), S. galilaeus (Linnaeus) and S. galilaeus sanagaensis (Thys van den Audenaerde) (Teleostei, Cichlidae) from different locations in Africa (Burkina Faso, Cameroon, Guinea, Niger and Senegal) revealed the presence of 11 species of monogenean gill parasites. Four, belonging to Cichlidogyrus Paperna, 1960 and considered as new species, are described: C. rognoni n. sp., C. douellouae n. sp., C. giostrai n. sp. and C. njinei n. sp. They are distinguished by the shape and/or size of the sclerotised parts of the haptoral and copulatory complexes. C. thurstonae Ergens, 1981 from O. niloticus is redescribed.     

中国橐吾属(菊科-千里光族)的分类学研究(一)：狭舌橐吾的名实订正

由于对模式标本考证有误,狭舌橐吾(Ligularia angustiligulata C.C.Chang)长期以来被处理为沼生橐吾[L.lamarum(Diels)C.C.Chang]的异名。经我们考证,狭舌橐吾的主模式应为藏于PE的蔡希陶58004号标本(为唯一有狭舌橐吾的作者张肇骞先生所写定名签的标本),LBG藏有1份同号模式标本,它们与狭舌橐吾的原白完全吻合,而藏于KUN(2份)和SZ(1份)的同号标本与狭舌橐吾的原白在一些重要性状上相冲突,均非狭舌橐吾的模式标本;进而发现狭舌橐吾与叶状鞘橐吾(L.phyllocoleaHand.-Mazz.)在形态上没有本质区别,故应处理为后者的异名,而藏于KUN和SZ的3份标本均属于沼生橐吾。同时还指出长柄橐吾(L.longipes C.C.Chang)的名实有待进一步研究,其模式与叶状鞘橐吾有较大区别,似不宜将其处理为叶状鞘橐吾的异名。     

Morphological and histological study of the genital ducts ofCryptazeca monodonta (Pulmonata,Orthurethra), with special emphasis on the auxiliary copulatory organ

Summary The genital system ofCryptazeca monodonta is very similar to those reported for semidiaulic stylommatophores, but with some specific features. The fertilization pouch is simple and surrounded by subepithelial goblet gland cells. The spermoviduct has two different grooves: the oviductal channel and the spermatic groove, which run together with a blind-ending allospermiduct that opens into the lumen of the free oviduct. The vagina has a thick muscular wall with numerous pigmentary cells embedded in it. The vas deferens diverges from the spermiduct and becomes mainly glandular just before it joins the penis. This genital system is equipped with an auxiliary copulatory structure that consists of two independent and complementary organs. One of them is located just before the fusion of the free oviduct and the spermatheca stalk lumina and consists mainly of a thick mass of connective tissue. The other is a muscular sarcobellum located inside the penis. Both these organs are covered by small papillae whose connective cells are stacked. Each papilla has a solid spine on its top, which seems to be of mesenchymatous origin. As in other stylommatophores, the auxiliary copulatory organ is equipped with an adjoining gland, which inCryptazeca is next to the sarcobellum.Abbreviations ACO auxiliary copulatory organ - ag albumen gland - al allospermiduct - c connective aggregate of ACO - cc connective cells of ACO papillae - cf connective fibres - ep epiphalus - fo free oviduct - fp fertilization pouch - gl.c gland cells of sarcobellum - hd hermaphroditic duct (distal portion) - m muscle fibres - ov oviduct - p penis - pc penial caecum - pp papillae of ACO - pr prostatic gland - prm penial retractor muscle - p.sh penial sheath - s spermatheca - sc sarcobellum - SEM scanning electron micrograph - sov spermoviduct - sp spine - spd spermiduct - ss spermatheca stalk - v vagina - vd vas deferens