Reproductive cycles of Mugil cephalus, Liza ramada and Liza aurata (Teleostei: Mugilidae)

Carbohydrates in photoreceptor segments in the retina of the firemouth cichlid Thorichthys meeki are described and compared. The present periodic acid-Schiff (PAS) and lectin results revealed the occurrence of neutral carbohydrates, composed mainly of glycosamine and mannose and glucose, in the light absorbing segments in rods and cones in this species. Unlike in mammals, the retina in this teleost seems to be poor in galactose and galactose-galactosamine units in the light absorbing segments.     

Three species of Dendromonocotyle Hargis, 1955 (Monogenea: Monocotylidae) collected from Japanese rays

Systematic Parasitology - Eighteen species of Dendromonocotyle Hargis, 1955 (Monogenea: Monocotylidae) have so far been described from elasmobranchs worldwide. In this paper, two new species are...     

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 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.     

A new species of Saturnius Manter, 1969 (Digenea: Hemiuridae) from Mediterranean mullet (Teleostei: Mugilidae)

A new hemiurid digenean, Saturnius gibsoni n. sp., is described from the stomach lining of Mugil cephalus L. off Oran, Mediterranean coast of Algeria. Characteristic morphological features of the new species include small size of the body which is comprised of six pseudosegments, small ventral sucker, weakly developed mound-shaped flange at the level of the ventral sucker, and eggs being large in relation to the size of the body. Saturnius gibsoni n. sp. resembles S. minutus Blasco-Costa, Pankov, Gibson, Balbuena, Raga, Sarabeev & Kostadinova, 2006 and two unidentified Saturnius spp. in the small size of the body and most metrical features. However, in spite of the presence of five transverse septa resulting in six pseudosegments and the range overlap of some metrical features, the ventral sucker in S. minutus is much larger, the ventral sucker muscular flange is more prominent, the last pseudosegment is narrower in relation to body width and more rounded, and the eggs are smaller (mean 21 × 10 vs 25 × 12 μm). Furthermore, the partial sequences of the 28S rRNA gene region (domains D1–D3; 1,195 nt) obtained from two isolates of S. gibsoni n. sp. differed by 11 nt (0.9%) from that of S. minutus. Both unidentified forms of Saturnius are clearly distinguishable from S. gibsoni n. sp. by the presence of six stout, transverse muscular septa, forming seven pseudosegments (vs five septa forming six pseudosegments). Bayesian inference analysis of partial 28S rDNA sequences based on a total of 15 species from the families Hemiuridae and Lecithasteridae depicted the Bunocotylinae Dollfus, 1950 as a strongly supported basal clade, with Bunocotyle progenetica (Markowski, 1936) as the closest sister taxon to Saturnius spp.     

A new species of Neoheterocotyle Hargis, 1955 (Monogenea: Monocotylidae) from the gills of Pristis clavata Garman (Pristidae) from Darwin,Australia

Neoheterocotyle darwinensis n. sp. is described from between the secondary gill lamellae of the dwarf sawfish Pristis clavata Garman (Pristidae) collected at the mouth of Buffalo Creek near Darwin, Northern Territory, Australia. This is only the second monocotylid species to be described from northern Australia. N. darwinensis is distinguished from the other seven valid species in the genus by the morphology of the hamuli, the dorsal haptoral accessory sclerites and the male copulatory organ. The similarities between N. darwinensis and Nonacotyle pristis Ogawa, 1991 from the gills of the freshwater sawfish Pristis microdon Latham collected in Papua New Guinea are discussed.     

Saturnius minutus n. sp. and S. dimitrovi n. sp. (Digenea: Hemiuridae) from Mugil cephalus L. (Teleostei: Mugilidae), with a multivariate morphological analysis of the Mediterranean species of Saturnius Manter, 1969

Three species of the bunocotyline genus Saturnius Manter, 1969 are described from the stomach lining of mugilid fishes of the Mediterranean and Black Seas. Two of the species are new: S. minutus n. sp. occurs in Mugil cephalus off the Mediterranean coast of Spain; and S. dimitrovi n. sp., a parasite of M. cephalus off the Bulgarian Black Sea coast and the Spanish Mediterranean coast, was originally described as S. papernai by Dimitrov et al. (1998). In addition, S. papernai Overstreet, 1977 is redescribed from M. cephalus off the Spanish Mediterranean coast and from Liza aurata and L. saliens off the Bulgarian Black Sea coast. The three species are distinguished morphometrically using univariate and multivariate analyses. These results were verified using Linear Discriminant Analysis which correctly allocated all specimens to their species designations based on morphology (i.e. 100% successful classification rate) and assigned almost all specimens to the correct population (locality). The following variables were selected for optimal separation between samples: the length of the forebody, ventral sucker and posterior testis, the length and width of the posteriormost pseudosegment, and the width of the muscular flange at ventral sucker level.     

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.     

Parasite prevalence and intensity in Mugil cephalus (Pisces: Mugilidae), from Colorado River, Baja California, Mexico

The parasitic prevalence and mean intensity in the striped mullet, Mugil cephalus, was seasonally determined during an annual cycle (February 1994 to February 1995) in the confluence of the Colorado and Hardy rivers, Baja California, México. Two species of parasites were identified, a nematode, Contracaecum multipapillatum (von Drasche, 1882) (Ascaridida: Anisakidae), and a copepod, Ergasilus versicolor Wilson, 1911 (Poecilostomatoida: Ergasilidae). The larvae of C. multipapillatum, which were represented by two size classes (A and B stages), had prevalences of 30% and 14.5%, respectively; while A. versicolor had a prevalence of 72.7%. The mean intensity of C. multipapillatum was 6.18 and 2.37 individuals per infected fish for A and B stages, respectively; and for A. versicolor, it was of 4.01. The number of parasites (taxa combined) increased with the size of fish (r = 0.22, p = 0.02), but it was independent of the host's condition factor (KSL).     

Eight new species ofHamatopeduncularia Yamaguti, 1953 (Monogenea: Ancyrocephalidae) from Ariidae of Peninsular Malaysia

Eleven species of Hamatopeduncularia Yamaguti, 1953 were found on six species of ariids caught off the west coast of Peninsular Malaysia. They are: H. arii Yamaguti, 1953 from Arius maculatus; H. thalassini Bychowsky & Nagibina, 1969 from A. thalassinus; H. simplex Bychowsky & Nagibina, 1969 from Osteogeneiosus militaris; H. isosimplex n. sp. from A. venosus, A. maculatus and A. sagor; H. malayanus n. sp. from A. caelatus; H. manjungi n. sp. from A. thalassinus; H. papernai n. sp. from A. maculatus; H. elongatum n. sp. from A. thalassinus; H. longicopulatrix n. sp. from A. venosus; H. venosus n. sp. from A. venosus; and H. malaccensis n. sp. from O. militaris and A. maculatus.     

Two species of Ergasilidae (Copepoda: Poecilostomatoida) parasitic on the gills of Mugil cephalus Linnaeus (Pisces: Teleostei), with proposition of a new genus Dermoergasilus

A new genus of Ergasilidae (Dermoergasilus) is proposed to accommodate Ergasilus amplectens Dogiel et Akhmerov, 1952; E. coleus Cressey, 1970; and E. semicoleus Cressey, 1970. Dermoergasilus amplectens (Dogiel et Akhmerov, 1952) and Nipergasilus bora (Yamaguti, 1939) are redescribed based on the specimens recovered from the gills of Mugil cephalus L. collected in Kojima Bay, Okayama Prefecture, Japan.     

Two new species of Dendromonocotyle Hargis, 1955 (Monogenea: Monocotylidae) from the skin of Taeniura meyeni (Dasyatidae) and Aetobatus narinari (Myliobatidae) from aquaria in Queensland,Australia

Dendromonocotyle pipinna n. sp. (Monogenea: Monocotylidae) is described from the dorsal skin surface of Taeniura meyeni Müller & Henle from a public aquarium in Mooloolaba, Queensland, Australia. D. torosa n. sp. was found on the dorsal skin surface of a heavily infected specimen of Aetobatus narinari (Euphrasen) during a post-mortem at the Mooloolaba aquarium and on a specimen of A. narinari kept in an aquarium in Cairns. Both of these new Dendromonocotyle species are distinguished from each other and others in the genus by the morphology of the terminal papillary sclerite and the male copulatory organ.     

A global review of the cosmopolitan flathead mullet Mugil cephalus Linnaeus 1758 (Teleostei: Mugilidae), with emphasis on the biology, genetics, ecology and fisheries aspects of this apparent species complex

This study reviews published information on Mugil cephalus from around the world, with recent genetic studies indicating that the flathead mullet may indeed be a species complex. Disciplines that are covered range from the taxonomy, genetics and systematics, through a variety of biological and ecological attributes, to biomarker and fisheries studies. The eurytopic nature of M. cephalus is emphasized, with the migratory life history covering a succession of very different aquatic environments (e.g. rivers, estuaries, coastal lakes/lagoons, marine littoral, open ocean), each of which is occupied for varying lengths of time, depending on the population characteristics within a region and the life-history stage of the species. Interpretation of these movements over time has been greatly enhanced by the use of otolith micro-chemistry which has enabled scientists to map out the different habitats occupied by individual fish at the different life stages. The range of physico-chemical attributes within these environments necessitates a wide tolerance to differing conditions, especially with regard to salinity, turbidity, dissolved oxygen and temperature, all of which are discussed in this review. The importance of M. cephalus to the ecological functioning of coastal systems is emphasized, as well as the pivotal role that this species fulfills in fisheries in some parts of the world. The parasites range from internal trematode and cestode infestations, to external branchyuran and copepod parasites, which use M. cephalus as either an intermediate or final host. The value of the flathead mullet as a biomarker for the monitoring of the health of coastal habitats is discussed, as well as its potential as an indicator or sentinel species for certain ecosystems.     

Ultrastructural study of the esophagus of seawater-and freshwater-acclimated Mugil cephalus (Perciformes,Mugilidae), euryhaline marine fish

The esophagus of the common grey mullet Mugil cephalus shows a single mode of organization that is common to both seawater- and freshwater-acclimated specimens. A short anterior segment is lined by a stratified epithelium with mucous cells; posteriorly, this is progressively replaced by single-layered columnar epithelium. Ultrastructural features of the columnar epithelium are quite similar in the seawater- and freshwater-acclimated specimens. Apical microvillous projections, lamellar structures, and dilated intercellular spaces are observed. The present study suggests that the mullet esophagus is involved in active ion transport and water permeability, both in seawater and in freshwater environments. © 1993 Wiley-Liss, Inc.     

Twelve new species of dactylogyrids (Platyhelminthes,Monogenea) from West African barbels (Teleostei,Cyprinidae), with some biogeographical implications

Fifteen species of dactylogyrid monogeneans, belong to Dactylogyrus and Dogielius were observed in seven different African species of Barbus and Varicorhinus (Teleostei, Cyprinidae). The barbels examined in West Africa were: Barbus occidentalis Boulenger, 1911, known in the large Sahel-Sudan rivers and in Gabon: B. waldroni Nordman, 1935, B. petitjeani Daget, 1962, B. sacratus Daget, 1963, B. parawaldroni Lévêque, Thys van den Audenaerde & Traoré, 1987 and Varicorhinus wurtzi (Pellegrin, 1908) are distributed in various coastal rivers in the Gulf of Guinea. B. bynni (Forskal, 1775) the seventh species, is found in East Africa where it is known in the Nile Basin and the lakes connected with it. Three previously reported monogeneans were found: Dactylogyrus pseudanchoratus Price & Géry, 1968, was identified on all the host species studied; D. falcilocus Guégan, Lambert & Euzet, 1988, was found on V. wurtzi from Little Scarcies in Guinea; D. ruahae Paperna, 1973, was found on B. sacratus, B. parawaldroni and V. wurtzi in the rivers flowing from the Fouta Djalon mountains in Guinea to the Atlantic.Twelve new species of monogeneans are described. Eight belong to Dactylogyrus Diesing, 1850 and the four others to Dogielius Bychowsky, 1936. Seven of the dactylogyrids described display strict specificity for their host fish: Dactylogyrus clani n. sp. and D. petitjeanii n. sp. on B. petitjeani; Dactylogyrus sacrati n. sp. and Dogielius phrygieus n. sp. on B. sacratus; Dactylogyrus parawaldronii n. sp. on B. parawaldroni; and Dactylogyrus wurtzii n. sp. and Dogielius vexillus n. sp. on V. wurtzi. The remainder have a broader host spectrum: Dactylogyrus archaeopenis n. sp. on B. petitjeani, B. sacratus and B. parawaldroni; Dogielius pedaloe n. sp. on B. parawaldroni and V. wurtzi; Dactylogyrus aferoides n. sp. and Dactylogyrus sahelensis n. sp. on B. occidentalis, B. waldroni, B. petitjeani and B. bynni; and Dogielius djolibaensis n. sp. identified on B. occidentalis, B. petitjeani and B. waldroni.Characteristics of gill parasitism in three particular hosts, B. bynni, B. occidentalis and B. waldroni, confirm the current opinion of the existence of clinal variations in individual Barbus specific complexes belonging to isolated basins. We discuss the differences in the composition of gill parasitofauna of barbels from different catchment areas. Cyprinids in isolated catchments in Guinea, Sierra Leone and Liberia are parasitised in particular by interesting monogeneans which are true relic taxa. The problem of the use of these parasite groups as palaeo-ecological markers is raised.