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Gyrodactylus molweni sp. n. is described from the body surface and fins of the South African mullet, Chelon richardsonii (Smith, 1846) collected from Table Bay Harbour, Cape Town and is compared to five other Gyrodactylus species described from grey mullets globally namely G. zhukovi Ling, 1963 and G. mugili Zhukov, 1970 from Planiliza haematocheila (Temminck and Schlegel, 1845); G. mugelus Rawson, 1973 from Mugil cephalus L.; G. curemae Conroy and Conroy, 1985 from Mugil curema Valenciennes, 1836 and G. xiamenensis Zang,Yang and Liu, 2001 from Planiliza macrolepis (Smith, 1846). Morphologically, G. molweni sp. n. has prominent ventral bar processes that near cover the hamulus roots, marginal sickles with large rhomboid heels, slender shafts and fine points that extend beyond the sickle toes. Gyrodactylus molweni sp. n. can, however, be readily differentiated: G. mugili and G. xiamenensis have ventral bars with small ventral processes; G. zhukovi has marginal hooks sickles with slender shafts and proportionately short points and open-faced blades; G. mugelus possesses marginal hook sickles with deep, rounded heels, forward slanting shafts and an angular, square line to the inner face of the blades. Although the length of the marginal hooks of G. curemae are similar to G. molweni sp. n., their hamuli are double the size. A GenBank BlastN search with the 931 bp sequence covering ITS1, 5.8S and ITS2 gave no close hits; the nearest species for which sequences are available is G. nipponensis Ogawa and Egusa, 1978 (identity 96.56%, 899/931 bp). The proposal of G. molweni sp. n. as a new species, therefore, is well supported by both the molecular and morphological analyses presented herein. This Gyrodactylus species is the first to be described from C. richardsonii and only the second Gyrodactylus species to be described from the marine environment off the African continent.

Simple Summary The thick-lipped grey mullet (Chelon labrosus) has good potential for aquaculture diversification in Europe. However, research studies about this species are scarce, particularly focusing on the nutritional attributes of wild and cultivated thick-lipped grey mullets that might help to optimize its feeding regime. In order to determine the nutritional composition of thick-lipped grey mullet juveniles, wild and cultivated specimens were collected and compared. To do so, the liver fatty acids, muscle proximate composition, fatty acids and amino acids were analyzed. The wild specimens had higher levels of polyunsaturated fatty acids and a higher content of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids than the farmed specimens. Furthermore, all the amino acid scores were above 100% compared to the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) standard. This study provides new knowledge and contributes to understanding the nutritional attributes of wild and cultured C. labrosus and helps to design diets according to their nutritional demands. Abstract The thick-lipped grey mullet (Chelon labrosus) is a nominee fish species for aquaculture diversification in Spain because it is an omnivore and euryhaline species, but limited knowledge about the nutritional attributes of this species is available. This study aimed to characterize the chemical composition of wild and cultured fish. The muscle proximate composition, and fatty acid and amino acid profiles were assessed. The cultivated specimens showed a higher lipid content and lower protein and ash contents compared with the wild specimens. The predominant tissue fatty acids in both the wild and cultivated fish were palmitic acid (16:0), oleic acid (18:1n-9) and docosahexaenoic acid (DHA, 22:6n-3). A higher content of arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (20:5n-3) and DHA were detected in the muscle of wild mullets, while the fish supplied with commercial pellets showed higher quantities of monounsaturated fatty acids, and lower quantities of saturated fatty acids and polyunsaturated fatty acids (PUFAs). Regarding PUFAs, n-3 fatty acids were predominant in wild mullets, while n-6 and n-9 were more abundant in farmed fish. In terms of amino acid composition, except for histidine in wild specimens, the amino acid amounts were higher than the FAO/WHO standard. In conclusion, C. labrosus may contribute to improving the dietary intake of highly polyunsaturated n-3 fatty acids, with a benefit to human health, owing to that fact that a 100-g fillet portion of cultivated and wild C. labrosus can provide 770 mg and 1160 mg of EPA and DHA, respectively, which exceeds the 250 mg dietary daily intake recommended by the FAO/WHO.

The long-chain (≥C20) polyunsaturated fatty acid biosynthesis capacity of fish varies among species, with trophic level hypothesised as a major factor. The biosynthesis capacity is largely dependent upon the presence of functionally diversified fatty acyl desaturase 2 (Fads2) enzymes, since many teleosts have lost the gene encoding a Δ5 desaturase (Fads1). The present study aimed to characterise Fads2 from four teleosts occupying different trophic levels, namely Sarpa salpa, Chelon labrosus, Pegusa lascaris and Atherina presbyter, which were selected based on available data on functions of Fads2 from closely related species. Therefore, we had insight into the variability of Fads2 within the same phylogenetic group. Our results showed that Fads2 from S. salpa and C. labrosus were both Δ6 desaturases with further Δ8 activity while P. lascaris and A. presbyter Fads2 showed Δ4 activity. Fads2 activities of herbivorous S. salpa are consistent with those reported for carnivorous Sparidae species. The results suggested that trophic level might not directly drive diversification of teleost Fads2 as initially hypothesised, and other factors such as the species' phylogeny appeared to be more influential. In agreement, Fads2 activities from P. lascaris and A. presbyter were similar to their corresponding phylogenetic counterparts Solea senegalensis and Chirostoma estor., Te present study was funded by Ministerio de Economía y Competitividad (AGL2015-70994-R). Dr Covadonga Rodríguez is a member of the Instituto de Biotecnología de Canarias (ITB).

Acanthocephalans belonging to the species Neoechinorhynchus agilis were collected from two mullets, Mugil cephalus and Chelon ramada from Ichkeul Lagoon in northern Tunisia. Collected parasites, as well as tissues of their hosts (muscle, liver and intestine), were analysed for trace elements (silver, arsenic, cadmium, cobalt, copper, iron, manganese, nickel (Ni), lead (Pb), selenium, vanadium (V), zinc) using inductively coupled plasma mass spectrometry. Our results showed different accumulation patterns of trace elements in fish tissues and parasites. Among the host tissues, liver accumulated the highest metal amounts. Acanthocephalans showed Ni, Pb and V in significantly higher concentrations compared to their host's tissues. Further, the calculated bioconcentration factors demonstrated a 390-fold higher Pb accumulation in the parasite compared to fish muscle. This study is the first field survey in Tunisia dealing with elements’ uptake in parasites and their hosts. Our results corroborate the usefulness of the acanthocephalans for biomonitoring of metal pollution in aquatic ecosystems and promote more research in order to understand host–parasite systems in brackish waters of the Mediterranean area.

Pesticides are frequently applied to agricultural activities to improve harvest, in terms of yield and product quality. Useful tools for ecotoxicological studies of marine ecosystems are based on biomarker application on bioindicator key fish species. The main aim of the present study was to detect the potential presence of pesticides in a polluted coastal marine environment, namely Milazzo Gulf, situated in the north eastern coast of Sicily (Italy), by measuring the enzymatic activities of the ecotoxicological biomarkers acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in brain and blood samples of Chelon labrosus. Also, Marinello Reserve was selected as a reference site. The data showed a significant inhibition in AChE (81%) and BChE (71%) activities in fish from Milazzo Gulf in respect to those from the reference site. The esterase inhibition is primarily due to the presence of organophosphorus insecticides and carbamates that resulted, in Milazzo Gulf, higher in concentration in respect to the reference quality standard decree (D.M. 260, 2010). The results obtained in this study confirm the suspected presence of insecticides in waters and fish from Milazzo Gulf, which may lead to a considerable hazard to humans. This study confirms the relevant advantages of the biomarker approach on fish species in the ecotoxicological evaluation of marine environments.

International audience

For several years Tunisia has opted to breed freshwater fish in reservoirs and artificial lakes, created for irrigation, as a strategy of providing high quality aquatic protein to the interior regions and providing work opportunities for local communities. The aim of this study was to summarize the main results accumulated by the last 20 year efforts made by the members of the National Institute for Marine Science and Technology (INSTM)-Aquaculture Laboratory to develop thicklip (Chelon labrosus) and flathead (Mugil cephalus) grey mullets fry production from captive broodstocks intended for stocking inland reservoirs (artificial lakes) and grow-out purposes Administration of human chorionic gonadotropin (hCG) at a priming dose of 10.000 IU kg−1 female bw, followed by 10.000 IU hCG and (100 or 200 μg kg−1 female bw of thicklip or flathead grey mullet respectively) as resolving dose resulted at the highest egg production for both species. Mean fecundity was 494.655 eggs kg-1 bw for thicklip grey mullet and 418.945 eggs kg-1 bw for flathead grey mullet. Fertilization rate of eggs produced was high (mean rate 83 % and 63 % for thicklip and flathead grey mullet respectively) and larvae hatched from those eggs at high rates (77 % and 88 %, respectively). The green method was more efficient than clear method to produce thicklip and flathead grey mullet fry, (i.e larvae had higher growth rate and better survival rates). The results of this study demonstrate the possibility to control reproduction and produce grey mullet fry in captivity. However, further research is needed to optimize the production protocol of eggs and fry of both grey mullet species.

Thinlip mullet Chelon ramada is the most abundant mullet species found in the Comacchio lagoons (northern Adriatic Sea, Italy). Histological and ultrastructural sections of the intestine of C. ramada showed that over 83% of 48 mullets were infected with the intestinal parasite Myxobolus mugchelo (Myxozoa). In histological sections, plasmodia of M. mugchelo containing mature spores were situated closer to mucosal folds and were surrounded by numerous mast cells (MCs). Mature spores, generally oval in shape, were observed in the paracellular space among the enterocytes or within them. Near the infected epithelial cells, several MCs, rodlet cells and few neutrophils occurred. In intestinal epithelium, large cells resembling macrophages, some with spores of M. mugchelo inside, were observed. These macrophage-like cells were foamy and possessed elongate striated granules. The number of MCs and macrophages in the intestinal epithelium was significantly higher in parasitized fish. In some parasitized intestines, portions of epithelium were displaced by spores, or the spores were observed inside the damaged enterocytes. Immunohistochemical analysis of C. ramada infected or uninfected intestinal tissue revealed the presence of histamine, serotonin (5-HT), leu-enkephalin and inducible-nitric oxide synthase in epithelial macrophages. Several epithelial cells positive to proliferating cell-nuclear antigen were also observed in the proximity of the macrophages. The current study is the first to record the occurrence of intraepithelial macrophages which engulf myxozoan spores. A hypothesis on migration of spores from pancreas via intestinal wall to gut lumen is presented.

A survey was performed to investigate the infection status of zoonotic trematode (ZT) metacercariae in fish from a local market in Yangon City, Myanmar. A total of 264 fish (12 species) were collected through 4 times from December 2013 to June 2015. All collected fish were transferred to our laboratory on ice and examined by the artificial digestion method. More than 7 species of ZT metacercariae, i.e., Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus spp., Stellantchasmus falcatus, Pygidiopsis cambodiensis, and Procerovum sp. were detected. Metacercariae of H. taichui were collected in 58 (42.3%) out of 137 fish (5 species), and their average density was 42.9 per fish infected. Metacercariae of H. pumilio were detected in 96 (49.0%) out of 196 fish (9 species), and their average density was 23.6 per fish infected. H. yokogawai metacercariae were found in 40 (50.0%) out of 80 fish (5 species), and Centrocestus spp. metacercariae in 91 (50.8%) out of 179 fish (8 species), and their densities were 306 and 25.8 per fish infected, respectively. Metacercariae of S. falcatus and P. cambodiensis were detected only in mullets, Chelon macrolepis. A total of 280 Procerovum sp. metacercariae were found in 6 out of 12 climbing perch, Anabas testudineus. Morphological characteristics of adult flukes recovered from experimental animals were described. It has been first confirmed that fish from Yangon, Myanmar are commonly infected with various species of ZT metacercariae.

The term intersex describes alterations in gonadal development with the simultaneous presence of male and female reproductive stages in the same gonad of a gonochoristic species. In coastal and estuarine environments, euryhaline fish living in polluted waters such as Mugilidae can frequently show these sexual anomalies. In this work, we analysed adult specimens of three species of euryhaline mullets (Chelon labrosus, Liza aurata and Mugil cephalus) from two Sardinian lagoons (Marceddì and San Teodoro) devoted to extensive aquacultural practices, in order to identify putative alterations in gonads and in gamete development. Overall, 13 of the 158 mullets examined (8.2%) were affected by gonadal disorders: four subjects (one C. labrosus, two L. aurata and one M. cephalus) exhibiting an intersex condition were found in the Marceddì lagoon and the other nine (five C. labrosus, two L. aurata and two M. cephalus) in the San Teodoro lagoon. Twelve of these gonads were classified as testis-ova (TOs) and one, belonging to a C. labrosus specimen, was a mixed gonadal tissue (MGT). Intersex condition was evaluated using an intersex index and all the recorded values showed a mild Ovotestis Severity Index (OSI). However, our findings suggest that fish gonadal disorders may be underestimated in extensive reared fish species, particularly in coastal brackish environments polluted by intensive agriculture and animal husbandry activities.

The southern mullet Chelon richardsonii (Mugilidae) is the main target species of the inshore net fishery (gillnet and beach-seine) on the west coast of South Africa. The stock has displayed symptoms of overfishing, with a 28% reduction in the standardised catch per unit effort (CPUE) between 2008 and 2016, and a 36.5-mm reduction in mean total length (TL) of fish in the commercial catch between 1998 and 2017. The socioeconomic importance of the inshore net fishery and concern regarding stock status necessitated an assessment of the C. richardsonii stock. This work presents an update of the life-history parameters and the first stock assessment of C. richardsonii at the centre of its distribution—Saldanha Bay and Langebaan Lagoon—using CPUE standardisation and per-recruit analysis. The sexes exhibited distinctive growth, with females growing larger, and their length-at-first-maturity was estimated at 205 mm TL, corresponding to age 2 years. Estimated natural mortality was 0.718 y–1, total mortality was 1.599 y–1, and fishing mortality was 0.881 y–1. Current spawnerbiomass- per-recruit was estimated at 24.5% of the pristine (unfished) levels, indicating a stock at risk of recruitment failure. An increase in the minimum stretched mesh size of the gillnets to 51 mm and a reduction in fishing mortality to 0.60 y–1 (approximately 30%) would facilitate the recovery of the spawner biomass to the target of 40% of pristine (SB40).Keywords: CPUE, fishery management, gillnets, life history, mortality, Mugilidae, spawner biomass

Among polychlorinated biphenyls (PCBs), dioxin-like PCBs (DL-PCBs) are of the most concern for human health. In this study, the levels of 12 DL-PCBs congeners were measured in 125 fish samples of the Caspian Sea, Iran. Five fish species (Oncorhynchus mykiss, Vimba vimba, Cyprinus carpio, Rutilus frisii kutum and Chelon saliens) were collected from 5 coastal cities of the Caspian Sea (25 samples per each city). Duncan's multi-scope test was used to compare the mean of DL-PCBs in different fish species and different cities. Probabilistic risk of exposure to DL-PCBs and sensitivity analysis were assessed using Monte Carlo simulation approach. The average (standard deviation) of DL-PCBs in fish samples ranged from 232 (16) to 1156 (14) pg/g lipids. The total maximum concentration was detected in Cyprinus carpio from Bandar Anzali, the minimum in Vimba vimba from Chalos. In all samples, non-carcinogenic risk of exposure to DL-PCBs was in safe level (Hazard Quotient 1). In contrast, the lifetime cancer risk estimated for Bandar Anzali, Bandar Torkaman, and Rasht exceeded the threshold value of 1 × 10

Redlip mullet (Chelon haematocheilus) is distributed in coastal waters of the North-Western Pacific Ocean and is a cultured fish in Korea. A hydroacoustic technique constitutes a useful method to assess the biomass and spatial distribution of mullet in sea cages or in coastal waters, and acoustic target strength (TS) information of the target fish is an essential parameter in using this method. In this study, ex situ TS measurements of 16 live mullets were made in an aquaculture sea cage in Korea. The split-beam scientific echo-sounder used for measurements was comprised of 38, 120, 200, and 420 kHz frequencies. An underwater video camera was simultaneously used to observe the mullets&rsquo, behavior during the TS measurements. The mullet TS data was analyzed from a wide range of total fish length (FL: 14.3&ndash, 40.3 cm). As results for all frequencies, the frequency dependence of the mean TS values were relatively low, and the difference in mean TS was within 2.5 dB. When the slope of the least-squares regression line was forced to 20 into the TS equation, the resulting value for the constant term (b20) at each frequency was &minus, 67.0 dB, &minus, 68.3 dB, &minus, 66.3 dB, and &minus, 68.5 dB, respectively. The data tended to be frequency dependent. Additionally, the maximum TS appeared between tilt angles of 0&deg, and 10&deg, These results indicate that TS measurements can be applied to estimate the biomass of the mullet in sea cages or in coastal waters.

Food is an important factor for the survival of juvenile fish. Knowledge of the diet of co-existing species helps clarify their relationships with each other. A number of Mugilidae species are known to co-exist in estuarine systems, raising the question of whether they compete for food resources. The feeding behaviours of five juvenile Mugilidae species were studied in the estuaries of Strymonikos (North Aegean Sea) using stomach content analysis. It was found that the speciesChelon labrosus, Liza saliensandMugil cephaluspresented high feeding activity during summer and autumn andL. ramadaandL. aurataduring winter and spring. The diet overlap between the species was generally moderate to low and the pairL. saliens–M. cephalusexhibited the highest overlap in Richios estuarine system. The species do not appear to compete for common resources, probably because there is not always a spatiotemporal overlap, enough food is available or they exploit different resources. Four out of the five species exhibited similar patterns of feeding strategies with varying levels of specialization at an individual level and a rather generalized pattern at the population level. This more generalized feeding strategy may permit them to co-exist. OnlyM. cephalusshowed a more specialized feeding behaviour, with a strong preference for microalgae. The absence of a general pattern for the trophic levels according to seasons, sizes or locations, also imply the opportunistic character of the species. Both season and fish size influenced the variation in the diet composition.

The main ontogenetic and functional changes of the digestive and visual systems of Chelon labrosus during the first three months from fertilization until 99 days post-hatch (dph) are described. An extended slow growth pattern (3.93%) during the first three weeks of larval life was discernible. A long transitional period of mixed endo-exogenous feeding was noticeable until 13 dph. The majority of organ systems and structures (eye, digestive system, liver, pancreas, thyroid and others) were developed and functional before first feeding (mouth opening at 4 dph). First differentiation of gastric glands was detected at 16 dph, with the appearance of a noticeable pyloric muscular portion or typical gizzard and first developed pyloric caeca from 23 dph. The presence of pinocytotic supranuclear vesicles (5 dph) was still visible in the posterior intestine until the third month of life. The eyes exhibited early differentiation and functionality (pigmentation, first cone-type photoreceptors) during the lecithotrophic phase (2 dph), and development of all typical retinal layers containing different retinal cell types was progressively discernible from 16 dph onwards. From this time, rod photoreceptor precursor cells were incorporated into the basal region of the outer nuclear layer, and increases of two types of photoreceptors (cones and rods) were detected from 23 dph. El objetivo del trabajo se centró en describir los principales cambios ontogénicos y funcionales de los sistemas digestivo y visual de Chelon labrosus, durante los primeros tres meses de vida larvaria, desde la fertilización hasta 99 dias después de eclosionar (dde). Se observó un largo periodo de reducido crecimiento (3.93%) durante las tres primeras semanas de vida, y una amplia fase de alimentación endo-exotrófica (hasta 13 dde). La mayoría de sistemas, órganos y estructuras tisulares (ojo, digestivo, hígado, páncreas, tiroides, entre otros) se evidenciaron desarrollados y funcionales antes de iniciarse la primera alimentación (apertura de la boca a los 4 dde). Las glándulas gástricas se desarrollaron a partir de 16 dde y la porción pilórica muscular o típica molleja y los ciegos pilóricos eran visibles a los 23 dde. La presencia de vesículas proteicas supranucleares pinocitóticas era evidente en el intestino posterior (5 dde) y hasta el tercer mes de vida. Los ojos presentaron una precoz diferenciación y funcionalidad (pigmentación, fotorreceptores tipo conos) durante la fase lecitotrófica (2 dde) y se observó un desarrollo progresivo de todas las capas retinales, y conteniendo los diferentes tipos celulares desde los 16 dde. A partir de este periodo, algunos precursores de fotorreceptores tipo bastones se incorporaron en la región basal de la capa nuclear externa, y a partir de 23 dde se evidenció una proliferación de ambos tipos de fotorreceptores -conos y bastones-.

The purpose of the study was to obtain preliminary data on the effect of dietary protein on the growth of the thick-lipped grey mullet (Chelon labrosus) juveniles reared in net sea-cages. The juveniles (6.2 ± 0.61 g) were obtained from the wild and were stocked into net sea-cages at a stocking rate of 100 juveniles per cubic meter and fed with experimental diets including 25, 30, or 35% crude protein for 87 days. The highest mean weight and specific growth rate (SGR) were 39.5 g and 2.13% day-1, respectively, at protein levels of 30%. The diet also resulted in the most efficient feed conversion ratio of 1.61. CORRESPONDING AUTHOR: M. Altunok [+] Limburger Str. 4, 35260, Stadtallendorf, Germany e-mail: muhammet.altunok@hotmail.de Osman Ozden Ege University, Faculty of Fisheries, Bornova-Izmir 35100, Turkey

Accurate identification of fish and fish products, from eggs to adults, is important in many areas. Grey mullets of the family Mugilidae are distributed worldwide and inhabit marine, estuarine, and freshwater environments in all tropical and temperate regions. Various Mugilid species are commercially important species in fishery and aquaculture of many countries. For the present study we have chosen two Mugilid genes with different phylogenetic signals: relatively variable mitochondrial cytochrome oxidase subunit I (COI) and conservative nuclear rhodopsin (RHO). We examined their diversity within and among 9 Mugilid species belonging to 4 genera, many of which have been examined from multiple specimens, with the goal of determining whether DNA barcoding can achieve unambiguous species recognition of Mugilid species. The data obtained showed that information based on COI sequences was diagnostic not only for species-level identification but also for recognition of intraspecific units, e.g., allopatric populations of circumtropical Mugil cephalus, or even native and acclimatized specimens of Chelon haematocheila. All RHO sequences appeared strictly species specific. Based on the data obtained, we conclude that COI, as well as RHO sequencing can be used to unambiguously identify fish species. Topologies of phylogeny based on RHO and COI sequences coincided with each other, while together they had a good phylogenetic signal.

International audience; In the past several years, all numerical models have forecasted an increase in extreme climatic events linked to global change. Estuarine waters at the interface of marine and freshwater bodies are among the most volatile ecosystems, particularly for aquatic species, and will be strongly influenced by the temperature with extreme flooding events. This study aimed to quantify the acclimation capacity of coastal fish species to estuarine plume modifications. The thicklip mullet (Chelon labrosus) and European seabass (Dicentrarchus labrax) were selected as representative species of estuarine ecological guilds. These fish were subjected to an experiment mimicking a brief freshwater intrusion (35–5). These experiments were conducted at two different temperatures that these two species would encounter during their incursion from the sea through estuarine waters to freshwater habitats. The experimental results confirmed the high capacity for acclimation of both species to changes in salinity and temperature. Interspecific differences were observed. For example, the salinity has a greater effect on the metabolism of the seabass than on that of the mullets. Meanwhile, the temperature has a greater effect on the mullets. These differences in metabolic responses to fluctuating salinities and temperatures may modify the use of estuarine waters by these species and should be considered when predicting future specific distribution areas in the context of global change

Three localities, representing three distinct coastal areas, were investigated: 1. the mouth of the Sutorina River; 2. the mouth of the Jaska River; 3. the mouth of the Bojana River (right branch). Regarding the composition of young mullet assemblages, Lisa saliens, Lisa ramada and Lisa aurata were dominant at the first locality; L. aurata and Chelon labrosus at the second; and at the third L. ramada was clearly dominant, Mugil cephalus occupied the subdominant position, while L. aurata was absent. The seasons of the first appearance of migratory fry were October, April, November, October and July, for M. cephalus, C. labrosus, L. ramada, L. aurata and L. saliens, respectively. Migratory periods varied from 2 (C. labrosus) to 7 (L. ramada) months.

A stratified study of microhabitat use by grey mullet on the island of Minorca (Balearic archipelago, western Mediterranean) showed that the distribution of all the species was dramatically affected by salinity. Sites with a salinity level under 15 were positively selected in spring and summer by those species whose growth performance was the best in oligomesohaline water (Liza ramado and Mugil cephalus) but also by a species whose growth was not affected by salinity (Chelon labrosus). Liza aurata concentrated in polyhaline and euhaline sites, where growth was improved, a pattern also exhibited by Liza saliens. Both species avoided fresh water sites all year round. As a consequence, community structure was correlated with salinity. The above reported electivity patterns often disappeared in autumn, when most grey mullets migrate off-shore. Se ha realizado un estudio estratificado sobre el uso del hábitat por parte de los mugílidos en Menorca (Islas Baleares, Mediterráneo occidental). El análisis de los datos ha revelado la importancia de la salinidad para explicar la distribución de las cinco especies de mugílidos presentes en los estuarios mediterráneos. Las zonas con una salinidad inferior a 15 fueron seleccionadas positivamente en primavera y verano por aquellas especies cuyo crecimiento se maximiza en aguas oligomesohalinas (Liza ramado y Mugil cephalus), e incluso por una especie cuyo crecimiento no se ve afectado por la salinidad (Chelon labrosus). Liza aurata se concentró durante todo el año en lugares con una salinidad polihalina o euhalina, ya que su crecimiento se maximiza en dicho rango. El mismo patrón de distribución se observó para Liza saliens. Ambas especies evitaron los ambientes dulceacuícolas durante todo el año. Como consecuencia de lo anterior, la estructura de las comunidades de mugílidos durante la primavera y el verano está relacionada con la salinidad. Los patrones de electividad arriba descritos desaparecieron con frecuencia en otoño, cuando una fracción importante de la población de todas las especies emigra al mar.

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Thicklip grey mullet, Chelon labrosus, is an important commercial fish species and has been studied worldwide. However, no recent studies have been made regarding polychlorinated biphenyls (PCBs) in wild C. labrosus. Due to that, the concentration of 13 PCBs congeners was measured in muscles and livers, of males and females, of C. labrosus of different ages, allowing the estimation of PCB bioaccumulation throughout the species lifespan, in the Mondego estuary, a southern European temperate estuary. Male muscle sample concentrations ranged from 32 to 96ngg-1(lipid wt.) and in females from 32 to 62ngg-1(lipid wt.). In male liver sample concentrations ranged from 106 to 158ngg-1(lipid wt.), while female concentrations ranged from 88 to 129ngg-1(lipid wt.). The most abundant congeners presenting higher percentages in all samples were CB 138, 153 and 180. No significant differences were found between the concentrations in both sexes, but muscle and liver PCB concentrations in males tended to increase with age whereas in females concentrations remained stable throughout the species lifespan. Significant differences were found between concentrations in muscle and liver. The authors wish to thank all the colleagues who helped in the field and laboratory work. This work was supported by FCT (Fundação para a Ciência e Tecnologia) through a PhD grant attributed to J. Baptista (SFRH/BD/48262/2008), funded by Programa Operacional Potencial Humano of QREN Portugal and by the Portuguese Budget through the Ministry of Science, Technology and Education. P. Pato acknowledges a postdoctoral fellowship from FCT (SFRH/BPD/35068/2007). The authors, also, wish to thank the reviewers for their comments, who helped in improving the manuscript. published

The Mondego estuary fish assemblage was studied for the accumulation of PCBs. Three sampling stations were visited along an estuarine salinity gradient, and, in total, 15 species were collected. Analysis of PCBs revealed no significant differences among the sampling stations, although differences were observed among the fish assemblages. Fish assemblages could be divided into three groups. The first group comprised those with higher concentration (more than 10ngg-1, dw), included the species Gobius niger, Sardina pilchardus, Anguilla anguilla, Pomatoschistus microps, Chelidonichthys lucerna and Liza ramada; the second group with medium concentration (5-10ngg-1, dw), included the species Pomatoschistus minutus, Dicentrarchus labrax, Atherina presbyter, Chelon labrosus, Diplodus vulgaris, Platichthys flesus and Cilata mustela; and a third group with low concentration (less than 5ngg-1, dw), included the species Solea solea and Callionymus lyra. A positive correlation was found between lipid content and PCB concentrations. To evaluate the influence of the residence time of species on the accumulation of PCBs, species were divided into two groups: species that spend more than 3years in the estuary, and species that spend less than 3years in the estuary. Species that spend more than 3years in the estuary presented higher concentrations than species that spend less than 3years in the estuary. CBs 138 and 153 had higher concentration, and tended to increase with time spent in the estuary. The authors wish to thank all the colleagues that helped in the field and laboratory work. This work was supported by FCT (Fundação para a Ciência e Tecnologia) through a PhD grant attributed to J. Baptista (SFRH/BD/48262/2008), funded by Programa Operacional Potencial Humano of QREN Portugal and by the Portuguese budget through the Ministry of Science Technology and Education. P. Pato acknowledges a postdoctoral fellowship from FCT (SFRH/BPD/35068/2007). The authors, also, wish to thank the reviewers for their comments, which helped improve the manuscript. published

Polychlorinated biphenyls (PCBs) are lipophilic contaminants that tend to accumulate in organisms. PCBs were detected in Chelon labrosus, Liza aurata and Liza ramada, along different age groups. L. ramada presented the highest concentration, and it increased with age, whereas C. labrosus and L. aurata concentration remained constant. L. ramada high concentration can be attributed to its ecological niche, since this species is able to accumulate PCBs along its different age groups even in low environmental contamination conditions. PCBs 101, 118, 138, 149, 153, 170 and 180 were the congeners that more contributed to these species contamination, being PCB 138 and 153 the congeners with higher concentration. Mullets are edible in many countries, being important in fisheries and aquaculture. L. ramada is the most common mullet for capture and human consumption. All species presented concentrations below the regulation limit establish by the European Union, and therefore safe for human consumption. The authors wish to thank all the colleagues that helped in the field and laboratory work. This work was supported by FCT (Fundação para a Ciência e Tecnologia) through a PhD grant attributed to J. Baptista (SFRH/ BD/ 48262/ 2008), funded by Programa Operacional Potencial Humano of QREN Portugal and by the Portuguese budget through the Ministry of Science Technology and Education. P. Pato acknowledges a postdoctoral fellowship from FCT (SFRH/ BPD/ 35068/ 2007). The authors, also, wish to thank the reviewers for their comments, which helped improve the manuscript. published

International audience; A comprehensive mitochondrial phylogeny of the family Mugilidae (Durand et al., Mol. Phylogenet. Evol. 64 (2012) 73-92 [1]) demonstrated the polyphyly or paraphyly of a proportion of the 20 genera in the family. Based on these results, here we propose a revised classification with 25 genera, including 15 genera currently recognized as valid (Agonostomus, Aldrichetta, Cestraeus, Chaenomugil, Chelon, Crenimugil, Ellochelon, Joturus, Mugil, Myxus, Neomyxus, Oedalechilus, Rhinomugil, Sicamugil and Trachystoma), 7 resurrected genera [Dajaus (for Agonostomus monticola), Gracilimugil (for Liza argentea), Minimugil (for Sicamugil cascasia), Osteomugil (for several species currently under Moolgarda and Valamugil, including M. cunnesius, M. engeli, M. perusii, and V. robustus), Planiliza (for Indo-Pacific Chelon spp., Indo-Pacific Liza spp., and Paramugil parmatus), Plicomugil (for Oedalechilus labiosus), and Squalomugil (for Rhinomugil nasutus)] and 3 new genera: Neochelon gen. nov. (for Liza falcipinnis), Parachelon gen. nov. (for L. grandisquamis) and Pseudomyxus gen. nov. (for Myxus capensis). Genus Chelon was shown to include exclusively Chelon spp. and Liza spp. from the Atlantic and the Mediterranean, and Liza spp. species endemic to eastern southern Africa. Genus Crenimugil should now include C. crenilabis, Moolgarda seheli and V. buchanani. Genus names Liza, Moolgarda, Paramugil, Valamugil and Xenomugil should be abandoned because they are no longer valid. Further genetic evidence is required to confirm or infirm the validity of the genus Paracrenimugil Senou 1988. The mitochondrial phylogeny of the 25 genera from the present revision is the following: [(Sicamugil, (Minimugil, Rhinomugil)); Trachystoma; ((Myxus, Neomyxus), (Cestraeus, Chaenomugil, (Agonostomus, Dajaus, Joturus), Mugil)); (Aldrichetta, Gracilimugil); Neochelon gen. nov.; (Pseudomyxus gen. nov., (Chelon, Oedalechilus, Planiliza, Parachelon gen. nov.)); ((Squalomugil, (Ellochelon, Plicomugil)), (Crenimugil, Osteomugil))]. Agonostomus monticola and several species with large distribution ranges (including Moolgarda seheli, Mugil cephalus and M. curema) consist of separate lineages whose geographic distribution suggests they are cryptic species, thus warranting further taxonomic work in the Mugilidae at the infra-generic level.

Grey mullet occur in abundance around sea bream and sea bass farms where they for- age on waste fish feed, a behaviour that could modify their natural movement pattern and distribu- tion. In this study, we used visual census to record grey mullet aggregations at fish farms in the west- ern Mediterranean Sea. We also mapped the movements of 2 species (Liza aurata and Chelon labrosus) between farms and adjacent coastal fishing areas, using acoustic telemetry. Grey mullet were frequently observed in the vicinity of the aquaculture cages and represented an important abundance and biomass at the farms. The presence and swimming depth of the tagged mugilids at any of the farms were neither significantly related to the time of the day nor the feeding period, except for C. labrosus, which showed a tendency towards deeper waters (~15 m) during feeding peri- ods. Some of the tagged fish stayed in the vicinity of the farms for longer periods and also moved fre- quently to other farms and nearby commercial fishing areas. Other tagged fish remained at the release location for shorter periods, before they moved out of the study area or possibly were caught by local fishermen. This is the first study using acoustic tagging in wild fish around Mediterranean fish farms that demonstrates that offshore aquaculture farms and local fishing grounds in the western Mediterranean Sea are connected through movements of wild fish. These farms attract and affect large numbers of commercially important fish species; probably causing ecological changes not only in the immediate proximity of farms but also several kilometres away from the farms.

The main objectives of this investigation were to test the effects of (i) the presence of periphyton substrates, (ii) rearing density and (iii) supplemental feeding with dry feed on the growth and production of golden mullet (Liza aurata) juveniles. Twenty-six 1 m(2)-cages were installed in a French marine pond from April till June 2008. Mullets were stocked in cages with or without substrate at a density of 0, 20,40 or 60 individuals per cage. Each treatment was carried out in triplicate. In addition, 20 fish were put in three tanks and fed ad libitum with dry feed. The results showed that (i) although mullets were seen to graze on periphyton substrates, their presence did not affect,mullet growth and production. In future studies, meshed substrates could be attached on hard structures to improve the efficiency of mullet grazing; (ii) individual growth was higher at low density due to a lower competition for space and food. Production increased with rearing density reflecting that food availability was not limiting in control cages; (iii) growth and net yield of mullets were lower in fed tanks than in natural ponds where food seemed to be more appropriate for wild mullet juveniles and where stress factors were lower. Finally, in contrast to the individual growth rate, the net fish yield in this experiment was greater than that recorded in other extensive and semi-intensive systems. It was equivalent to yields observed in other periphyton-based systems. Periphyton developed on the meshed walls of cages probably increased the natural productivity of the pond. As part of sustainable aquaculture development, the effluents of intensive farms could be exploited to produce periphyton on inflexible substrates and to rear mullet adults, which are more herbivorous than juveniles. This type of integrated system could be developed with other mullet species, such as Chelon labrosus or Mugil cephalus, whose growth rates are higher than L aurata. Mullet production could be exploited by the sale of fillets and dried roe. (C) 2010 Elsevier B.V. All rights reserved.

This study reports the first description of the karyotype of Agonostomus monticola, a species belonging to a genus which is considered to be the most primitive among living mugilid fish. Specimens from Panama and Venezuela were cytogenetically analysed by conventional chromosome banding (Ag and base-specific-fluorochrome staining, C-banding) and by fluorescent in situ hybridization (FISH). Agonostomus monticola showed a chromosome complement of 2n = 48, composed of 23 acrocentric and one subtelocentric chromosome pairs and a pericentromeric distribution of the C-positive heterochromatin in all chromosomes. Major ribosomal genes were found to be located on the short arms of the subtelocentric chromosome pair number 24 and minor ribosomal genes in a paracentromeric position of a single medium-sized chromosome pair. All these observed cytogenetic features are similar to those previously described in four representatives of two genera, Liza and Chelon, which are considered to be among the most advanced in the family. Thus, this karyotypic form might represent the plesiomorphic condition for the mullets. This hypothesis regarding the plesiomorphic condition, if confirmed, would shed new light on the previously inferred cytotaxonomic relationships for the studied species of Mugilidae, because the karyotype with 48 acrocentric chromosomes, which has been so far regarded as primitive for the family, would have to be considered as derived.

International audience; This work describes the ontogeny of the digestive tract in thick lipped grey mullet (Chelon labrosus) larvae reared until day 36 post-hatching with the semi-extensive technology in mesocosms. Diet was constituted by live preys, rotifers, Arternia and wild zooplankton, then compound diet was added from day 20 (p. h.). Linear growth, weight growth and digestive enzymes specific activities were studied during larval ontogeny. Pancreatic enzymes (trypsin and amylase) and intestinal enzymes (leucine-alanine peptidase "Leu-ala", aminopeptidase N "AN" and alkaline phosphatase "AP") were assayed in larvae sampled throughout the rearing trial to evaluate gastrointestinal maturation along the development. The trypsin specific activities were very high during the first two weeks and then declined as observed in marine fish species. A following increase in trypsin specific activity from day 20 was attributed notably to ingestion of particle compound diet. In contrast to the pattern generally described in fish larvae, amylase specific activity showed a continuous increase. This could be attributed to the fact that C. labrosus is an omnivorous species and suggests that the fish might be able to use efficiently diets containing higher levels of starch or other carbohydrates since the end of larval development. Relative expression of intestinal brush border membrane enzymes (AP and AN) and cytosolic enzyme (Leu-ala), showed an abrupt increase of both AP/leu-ala and AN/leu-ala ratios at day 8 (p. h.), indicating that maturation of intestinal tract in C. labrosus larvae is particularly precocious. It is assumed that larvae of C. labrosus might support early co-feeding and weaning strategies, which could reasonably be initiated since mouth opening. (c) 2008 Elsevier B.V. All rights reserved.

Floating seaweed is considered to be an important habitat for juvenile fishes due to the provision of food, shelter, a visual orientation point and passive transport. The importance of the presence of the highly dynamical seaweed clumps from the North Sea to juvenile neustonic fishes was investigated by analysing both neuston samples (without seaweed) and seaweed samples concerning fish community structure, and length-frequency distributions and feeding habits of five associated fish species. While the neustonic fish community was mainly seasonally structured, the seaweed-associated fish community was more complex: the response of the associated fish species to environmental variables was species specific and probably influenced by species interactions, resulting in a large multivariate distance between the samples dominated by Chelon labrosus and the samples dominated by Cyclopterus lumpus, Trachurus trachurus and Ciliata mustela. The results of the stomach analysis confirmed that C. lumpus is a weedpatch specialist that has a close spatial affinity with the seaweed and feeds intensively on the seaweed-associated invertebrate fauna. Similarly, C. mustela juveniles also fed on the seaweed fauna, but in a more opportunistic way. The shape of the size-frequency distribution suggested enhanced growth when associated with floating seaweed. Chelon labrosus and T. trachurus juveniles were generally large in seaweed samples, but large individuals were also encountered in the neuston. The proportion of associated invertebrate fauna in their diet was of minor importance, compared to the proportions in C. lumpus. Individuals of Syngnathus rostellatus mainly fed on planktonic invertebrates but had a discontinuous size-frequency distribution, suggesting that some of the syngnathids were carried with the seaweed upon detachment and stayed associated. Floating seaweeds can therefore be regarded as ephemeral habitats shared between several fish species (mainly juveniles) that use them for different reasons and with varying intensity.

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.

A total of 127 specimens of grey mullets (Teleostea: Mugilidae) from the Mistras Lagoon (Sardinia - western Mediterranean) were examined for metazoan parasites. Five species of grey mullets were found: Chelon labrosus, Liza aurata, L. ramada, L. saliens and Mugil cephalus. Forty-one species of parasites were identified: 14 monogeneans, 5 crustaceans, 18 digeneans, 3 nematodes and 1 acanthocephalan; 26 of them being reported from Sardinia for the first time. Findings of faunal interest are: Ergenstrema sp. (Monogenea) in L. saliens; Caligus pageti (Crustacea) in L. aurata and L. saliens; Saturnius sp. (Digenea) in C. labrosus, L. aurata and L. saliens; Capillaria sp. (Nematoda) in C. labrosus, L. aurata and M. cephalus. The dynamics and distribution of ectoparasites were partially influenced by salinity, while the interpretation of the results for endoparasites was more complex. The data obtained show the richness of the parasite fauna of grey mullets from the Mistras Lagoon, providing additional environmental information on this body of water., No disponible

This paper describes the embryonic and larval developmental stages of Chelon labrosus, a prominent species among the Mugilidae, a family of high interest in the ecological management of coastal extensive aquaculture systems. Its high commercial value makes it the most important mullet in the Italian northern Adriatic “vallicoltura”. The success of induced reproduction techniques enabled us to describe its developmental stages, which were recorded by camera lucida drawings and presented as developmental tables. Histological and scanning electron microscopy observations were also carried out. Development may be divided into four periods: embryonic, pre-larval, larval and juvenile, each one characterized by typical anatomical and physiological features. At hatching, C. labrosus larvae are rather underdeveloped, in comparison with other marine farmed species, but the sense organs develop rapidly as well as the mouth. At 12 days the larva already has a juvenile head on a larval body. The juvenile stage is reached precociously, at 60 days, so that C. labrosus had a high performance in the rearing trials which were carried out.

To monitor changes of fish assemblage, we selected 5 study sites in lower-middle part of the Mankyeong (3 sites) and the Dongjin (2 sites) River, and conducted field sampling 2 to 4 times per year from 2007 to 2009. Total sampled fishes were 66 species in 16 families. Cyprinidae (RA, 73.25%; 33 species) was dominant family. Dominant species was Zacco platypus (RA, 19.96%), and subdominant species was Chelon haematocheilus (RA, 11.11%). There were 18 Korean endemic species (RA, 12.56%) and one endangered species, Liobagrus obesus, was only found in the Mankyeong River. Three exotic species were found: Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus. Fish assemblages showed similar occurrence patterns around the sampling periods. As a result of species number comparison between before and after dike construction at MR1 and MR2, there was no huge difference. When fishes were classified into two types, primary freshwater and peripheral species, using habitat characteristics, number of primary freshwater species was increased from 14 to 21 after dike construction. Moreover, relative occurrence rate of primary freshwater species was increased to 53% compared with before construction (18%). On the other hand, number of peripheral freshwater species was decreased from 29 to 19 after dike construction. As a result of cluster analysis using Jaccard method, fish community before and after dike construction was distinguished each other.

Samples of mullet fry were taken hourly, for 24h, once a month, from September 1979 to October 1980. Five species were found to enter the estuary of the Arno river: Mugil cephalus, Liza ramada, Liza aurata, Liza saliens and Chelon labrosus. Seasonal occurrence and migrational peaks were determined for each species. Variations of standard length and of condition factor were studied during the migrational phase. Hourly samples gave further information on daily variations in the catches of juvenile mullets, on the influence of tidal movements and on feeding activity during the 24-h cycle. Our results showed that the greatest number of fry was caught at sunset, a second peak occurring in the morning hours. Furthermore, the catches seem to be affected by tidal movements, being higher during high tide. The variations of the vacuity coefficient (the percentage of empty stomachs in the total sample) related to dial rhythm, were considered to indicate the daily feeding activity of each species. The analysis showed that the trophic activity of L. saliens, L. ramada and L. aurata occurs mainly during daylight. On the contrary, M. cephalus seems scarcely to feed in this condition, but increases its activity slightly at dusk and in the first part of the night.

The daily feeding rhythms of five species of mullet fry (Liza ramada, Liza aurata, Liza saliens, Mugil cephalus and Chelon labrosus) were investigated by analyzing their stomach fullness during 24‐hour cycles. Light is the major abiotic factor influencing the feeding rhythm of the fry. Feeding activity occurs prevalently during day‐time with a clear unimodal feeding cycle. Only L. saliens fry show a bimodal feeding cycle, with a secondary peak around sunset. Differences in the feeding activity rhythm are probably due to larger individuals which, unlike the smaller individuals, show preferential twilight feeding. Tides and temperature play a secondary role and their influence is probably masked by the light effect.