Sonia Ternengo

Ultrastructure of spermiogenesis and the spermatozoon of Monorchis parvus Looss, 1902 (Digenea, Monorchiidae), a parasite of Diplodus annularis (Pisces, Teleostei)

Abstract The present paper describes the characteristic ultrastructural features of spermiogenesis and the spermatozoon of Monorchis parvus (Trematoda, Digenea, Monorchiidae). This spermiogenesis is characterized by a flagellar rotation of about 120° and the formation of a novel ultrastructural element: a centriolar extension. It nevertheless follows the general pattern of digeneans. It begins with the formation of a differentiation zone, comprising striated rootlets associated with two centrioles and an intercentriolar body. The mature spermatozoon presents features allowing the distinction between M. parvus and other digenetic trematodes. It possesses an original anterior extremity. The two central elements of the axonemes appear prior to the peripheral doublets. The external ornamentations of the cell membrane are formed parallel to the central elements. Another peculiarity of the male gamete is the presence of two mitochondria. M. parvus, therefore, differs distinctly from other digenetic trematodes.

Spermiogenesis and sperm ultrastructure of Diphterostomum brusinae (Digenea, Zoogonidae), a parasite of Diplodus annularis (Pisces, Teleostei)

This paper constitutes the first ultrastructural study of spermiogenesis and the spermatozoon of a Digenea belonging to the family Zoogonidae, Diphterostomum brusinae. Spermiogenesis follows the general pattern found in the digeneans. It begins with the formation of a differentiation zone in the spermatid. The two centrioles give rise to flagella. These two flagella undergo a rotation of 90° and fuse with the median cytoplasmic process. The proximo-distal fusion occurs at the level of attachment zones. The mature spermatozoon of D. brusinae presents all the features found in the digeneans gametes: two axonemes, mitochondrion, nucleus and two bundles of parallel cortical microtubules. Nevertheless, several characteristics distinguish the spermatozoon of D. brusinae from other digeneans, in particular the external ornamentations of the plasma membrane and the anterior and posterior extremities. The description of the ultrastructural features of reproduction in this species would contribute to the understanding of the phylogenetic relationships in the Zoogonidae family.

Sperm ultrastructure of the gall bladder fluke Anisocoelium capitellatum (Digenea: Cryptogonimidae), a parasite of Uranoscopus scaber (Pisces: Uranoscopidae)

Ultrastructure of mature spermatozoon of Anisocoelium capitellatum is described with transmission electron microscopy. The description gave evidence of some characteristics of this digenean. The male gamete presents features allowing the distinction between A. capitellatum and other digenetic trematodes. It is characterized by original anterior and posterior extremities. The peripheral doublets appear prior to the central cores in the anterior extremity of axoneme. In the distal part of the spermatozoon, these ultrastructural features are also the first elements disappearing in the axoneme 1 and the last remaining in the axoneme 2. Another important peculiarity of the spermatozoon is the presence of three mitochondria.

Site influence in parasite distribution from fishes of the Bonifacio Strait Marine Reserve (Corsica Island, Mediterranean Sea)

The spatial distribution of parasite communities from teleost fishes (Diplodus vulgaris, Mullus surmuletus, Pagellus erythrinus, Phycis phycis, Scorpaena scrofa and Symphodus tinca) was studied in the Bonifacio Strait Marine Reserve (Corsica Island) with different protection levels. Canonical correspondence analysis was used to study spatial patterns and to quantify the importance of site influence on parasite communities. To supplement these results, we used the indicator species analysis (Indval) to identify parasite species as bioindicators of a given ecosystem. Moreover, fish spatial distribution in the marine reserve was evaluated in order to link parasite species occurrence and fish abundance. Several parasite species were associated with a specific site, and some of them were considered as site bioindicators, especially in the western part of the protected area (Bruzzi and Moines Islands). However, the relative abundance of fish followed a different spatial pattern. Stronger fish abundance was observed in the eastern part of the reserve (Lavezzi Islands). The parasite species were correlated to sites inside as well outside the reserve. The parasite distribution seemed not to be influenced by the protection status of the site. Furthermore, in our study, most of the parasite species were not linked to a site. The most important factor influencing their distribution was host specificity. This suggested that the parasite life traits history remained a fundamental determinant in the community composition.

Three species of Philometra (Nematoda, Philometridae) from marine fishes off Corsica, France

Gravid or subgravid females of the following three species belonging to the nematode genus Philometra were collected from marine perciform fishes of the Bonifacio Strait Marine Reserve, Corsica, France: Philometra justinei sp. nov. (prevalence 1.5%, intensity 11) and Philometra sp. (prevalence 3%, intensity 2) from the abdominal cavity and gonads, respectively, of the striped red mullet Mullus surmuletus (Mullidae), and Philometra serranellicabrillae Janiszewska, 1949 (prevalence 27%, intensity 2–6) from the gonads of the comber Serranus cabrilla (Serranidae). The newly described species, P. justinei, is mainly characterized by the absence of an anterior bulbous inflation of the oesophagus, body length of the gravid female (196 mm), conspicuously large amphids, number and distribution of cephalic papillae, and the morphology of larvae. It is the second known species of Philometra parasitizing fishes of the family Mullidae and the ninth species of this genus reported from marine fishes of the Mediterranean region. P. serranellicabrillae, studied for the first time by SEM, is redescribed.

Intensive infestations of Sciaenocotyle pancerii (Monogenea, Microcotylidae) on Argyrosomus regius (Asso) under fish-farming conditions

In the Mediterranean Sea, diversification in aquaculture is necessary because of overproduction and saturation of the market by sea bream and sea bass. Since 2004, Corsican aquaculturists started testproduction, under intensive rearing systems, of a new fish species, meagre, Argyrosomus regius (Asso) (Sciaenidae). Production of reared meagre is very limited thus far and confined to the Mediterranean Basin (southern France, Corsica, Spain, Italy and Morocco) (Jiménez, Pastor, Grau, Alconchel, Sánchez & Cárdenas 2005). Aquaculture can provide a suitable environment for the emergence of new pathogens (Murray & Peeler 2005). In summer 2005, heavy mortalities of meagre were reported in a Corsican farm (Gulf of Ajaccio). The fish examined were parasitized by a monogenean not reported from aquaculture, Sciaenocotyle pancerii (Sonsino) (Microcotylidae). That parasite was detected for the first time on the gills of Umbrina cirrosa (L.) and briefly described by Sonsino (1891) as Microcotyle pancerii. The species has since been reported from the Mediterranean Sea by Parona (1912) and Palombi (1949). Ktari (1970) recorded the parasite from shi drum and also from wild meagre in the Gulf of Tunis. Mamaev (1989) transferred M. pancerii to the genus Sciaenocotyle. This study highlights the transfer of a parasite from a wild to a reared population and describes the dynamics of the parasite population on farmed meagre during the autumn and winter of 2005 in coastal Corsica. From October 2005 to January 2006, reared meagre were collected from a farm in the south of Corsica. Mortalities at the farm started during August 2005. The farm included eight cages containing meagre and 12 cages with sea bass which are monitored weekly for parasites. Fish were fed with commercial food; salinity around the cages was 37%, and temperature ranged from 20 C at the beginning to 14 C at the end of the study. Monthly sampling consisted of 3–12 meagre selected randomly from the cages. In total, 50 cagereared specimens (58–4400 g in weight, 6 months to 2-year-old, of both sexes) were examined for parasites. Among these fish, three weighed more than 3000 g (2-year-old). All the other fish (n = 47) weighed less than 300 g (6-month-old), and were divided into two weight classes: one of specimens between 50 and 150 g and the second of fish between 150 and 250 g. The gill arches were sequentially dissected from the right side and placed into separate glass dishes for microscopic examination. For the three largest specimens (>3000 g) monogeneans were removed and counted only from the first gill arch of the right side. Each of the four right gill arches were examined from the smallest specimens (<300 g). Parasites were identified according to Ktari (1970). Infection was expressed Journal of Fish Diseases 2010, 33, 89–92 doi:10.1111/j.1365-2761.2009.01094.x

Chronic ulcerative dermatopathy in cultured marine fishes. Comparative study in sharpsnout sea bream, Diplodus puntazzo (Walbaum).

Chronic ulcerative dermatopathy (CUD) also known as chronic erosive dermatopathy, hole-in-the-head, head and lateral line erosion syndrome (HLLE) and lateral line depigmentation (LLD) is a chronic disease of unknown aetiology that affects the lateral line canals of the head and the trunk of various fish species. It has been described only in freshwater species although there are reports that it also affects marine fish. Here, we describe the disease in cultured sharpsnout sea bream using histology and scanning electron microscopy and identify several marine species as CUD sensitive. The results of this study correlate the development of the disease with the use of borehole water, indicating that the aetiology is probably associated with water quality rather than nutritional imbalance or infectious agents.

Atlas des Post-Larves de poissons de Méditerranée Occidentale

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Atlas des Post-Larves de poissons de Méditerranée Occidentale Romain Crec ’Hriou, Philippe Lenfant, Sylvia Agostini, Romain Bastien, Jérémy Bracconi, Eric D.H. Durieux, Laure-Hélène Garsi, Sonia Ternengo, Lisa Briot, Laura Lozano, et al.

Redescription of Caligus pagelli Delamare Deboutteville & Nuñes-Ruivo, 1958 (Copepoda: Caligidae) on the common pandora, Pagellus erythrinus (Linnaeus), in western Mediterranean waters off Corsica, France

Caligus pagelli Delamare Deboutteville & Nuñes-Ruivo, 1958, a rare and poorly known sea louse, is redescribed based on newly collected specimens of both sexes. The new material was collected from the common pandora Pagellus erythrinus (Linnaeus) caught in western Mediterranean waters off Corsica. The original and only available description of C. pagelli was incomplete and based only on females. Here we redescribe the female in detail, and describe the male for the first time.

Spatial variations in trace element concentrations of the sea urchin, Paracentrotus lividus , a first reference study in the Mediterranean Sea

A study on Trace Elements (TE) from sea urchin gonads has been conducted in the western Mediterranean Sea. Contamination data were used to determine a Trace Method Pollution Index (TEPI). TE concentrations varied considerably depending on the location of the sampling stations. The results showed that five trace elements (Zn, Fe, As, Al, Cu) are ubiquitous. The geographical area considered (Corsica) represents an important range of environmental conditions and types of pressure that can be found in the western Mediterranean Sea. TEPI was used to classify the studied sites according to their degree of contamination and allowed reliable comparison of TE contamination between local and international sites. TE contamination of the western Mediterranean Sea displayed a north-to-south gradient, from the Italian coasts down through the insular Corsican coasts to the north African littoral. Due to the increasing environmental pressure on the Mediterranean Sea, a regular monitoring of TE levels in marine organisms is necessary to prevent any further environmental deterioration.