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An economically important species of Citharus linguatula was investigated in the Sea of Marmara (Eastern Mediterranean, Turkey). Length-weight relationships, growth parameters, reproductive time, and first sexual maturity length of the species were determined. A total of 236 individuals were analyzed, total length and weight varied from 7.5 to 26.5 cm TL (17.11±3.62 cm) and 2.67 to 180.81 g (44.07±1.84 g), respectively. The length-weight relationship was calculated as W=0.0047*TL3.17 in total. The growth type was positive allometry for both sexes. Total individuals were ranged in age between 1 and 4. According to sexes, von Bertalanffy growth parameters were calculated as L∞=23.44 cm, K=0.74 per year, and t0=-0.09 year for females and L∞=20.75 cm, K=0.56 per year, and t0=-1.14 year for males. The size at first maturity was 17.6 cm TL for males, and 16.7 cm TL for females. When sexual maturity, K, and GSI values were evaluated together, the reproduction period of C. linguatula was determined between September and December.

Some biological parameters of Spotted Flounder Citharus linguatula (Linnaeus, 1758), fished in Mostaganem bay were described based on 144 fishes, that were collected between January, March and April 2015. The study of sex ratio, showed that the females (61. 07%) were more numerous than males (38.93%). The total vertebral number of is ranged from 31 to 32. The length-weight relationship of C. linguatula, indicated a negative allometry (b

A total of 252 spotted flounder, Citharus linguatula (Linnaeus, 1758) were caught in the Iskenderun Bay from October 2012 to September 2013 using a commercial bottom trawler. Length-weight relationships (LWRs), sex ratio and condition factor of the fish specimens were investigated. Within collected C. linguatula samples, most of the individuals ranged from 10.0 to 15.0 cm (80.15%), the minimum and maximum total lengths of the specimens were 7.0 and 18.5 cm, respectively. Negative allometric growth were observed for male, female and both sexes. The sex ratio (females: males) was 1:1.04. Length-weight relationships for females, males and both sexes, were calculated as W= 0.0099 TL2.874, W= 0.0086TL2.920 and W= 0.0092TL2.896 , respectively Fulton’s condition factor (KF) values for female (0.7228) and male (0.7095) specimens also showed significant variations (P

Marine coastal areas are highly productive due to the presence of various inputs of organic matter, including terrestrial material, which fuels food webs. However, the ecological mechanisms underlying the productivity of benthic and demersal fish species in estuarine areas are poorly understood. By means of C and N stable isotope analysis and Bayesian mixing models, we investigated the trophic niches of three common fish species: Citharus linguatula, Pegusa lascaris (flatfish) and Liza ramada (mullet) in the Gulf of Gaeta (Italy). Fish were collected from the north-western area and the south-eastern area of the Gulf of Gaeta, the latter affected by organic inputs from the Garigliano River. The results highlighted the riverine terrestrial origin of the organic matter at the base of the food web in the south-eastern area and marine autochthonous input in the north-western area. All fish species increased their trophic specialisation in proximity to the river mouth. L. ramada specialised on seston of terrestrial origin, reducing its niche overlap with C. linguatula and P. lascaris. Away from the river mouth, all species were characterised by longer individuals, increased intraspecific diet variability and higher interspecific similarity in resource use. Organic input from the river represented a complementary trophic niche axis that enabled lower interspecific niche overlap in the south-eastern area, where fish populations were found at higher densities. In conclusion, this study provided information about the effects of the flow of material from the basal compartment up to abundant fish species in areas enriched by organic matter of varying origin.

WOS: 000406894400018, Size selectivity of 40 mm square mesh 50 mm diamond mesh and 44 mm nominal diamond mesh codends were determined in terms of commercial situations in the east Mediterranean bottom trawl fishery to assess the size selectivity for red mullet (Mullus barbatus), goldband goatfish (Upeneus moluccensis), brushtooth lizardfish (Saurida undosquamis), common pandora (Pagellus e;ythrinus) and spotted flounder (Citharus linguatula). Data was achieved by the covered codend model and was analyzed with logistic equation by the maximum likelihood method. L-50 values for 44 mm diamond and 40 mm square mesh codends were 13.19 and 14.14 for M barbatus, respectively. 44 mm diamond codend appeared to have rather high L50 rate for U. moluccensis. A fairly high catch length was obtained with diamond mesh for P. erythrinus on account of its body shape. Square mesh codends were suitable for P. etythrinus. High escape rates and L-50 values were attained with all the three codends for S. undosquamis, which has the highest economic capacity in deep trawl fishing in the region. As to 50 mm diamond mesh codends, these seemed rather too wide meshes for these species.

International audience; The demersal trawl fishery of the north Tunisian coast primarily targets the deep-water rose shrimp, Parapenaeus longirostris, and secondarily a variety of demersal fish species. These fishes include hake (Merluccius merluccius), common pandora (Pagellus etythrinus), red mullet (Mullus barbatus), surmullet (Mullus surmuletus), Atlantic horse mackerel (Trachurus trachurus), bogue (Boops boops), picarel (Spicara smarts) and spotted flounder (Citharus linguatula). A bioeconomic model was used to test management measures through scenarios that ran over eleven years to estimate the viability of the fishery according to biological and economic results. The most beneficial scenario was the combination of several management measures including a temporal closure of two months, the replacement of the 40 mm diamond mesh codend with 40 mm square mesh, the removal of both the biological recovery tax and of fuel subsidies, and an 83% reduction in fishing capacity. This results in an annual private profit higher by 9.3 M TND (Tunisian Dinar) (6.9 M USD) that of 2008, and an economic rent that was higher by 13.3 M TND (9.9 M USD) than by the end of the projected period. Shrimp and fish biomasses have doubled compared with 2008, and trawling damages would be reduced to the equivalent of a five-fold reduction in fishing effort. This study shows that the objectives of improving demersal ecosystems and improving individual and collective wealth can be achieved through the synergistic effects of various regulatory measures. (C) 2016 Elsevier B.V. All rights reserved.

Summary Sampling was carried out on a seasonal basis during 2007–2009, using a conventional bottom trawl net with 44 mm codend mesh size in Izmir Bay, Aegean Sea. A total of 116 valid hauls: 27 in autumn, 28 in winter, 35 in spring and 26 in summer, were conducted at depths ranging from 30 to 70 m. A total of 112 species: 15 Chondrichthyes, 83 Osteichthyes, 11 Cephalopoda and 3 Crustacea were obtained in the trawl codend. All captures were separated into commercial (C) and non-commercial (NC) species. The C ratio was 69.6%, while NC (i.e. discards) was 30.4%. Diplodus annularis was the most abundant species in all seasons, followed by Mullus barbatus, Merluccius merluccius, Citharus linguatula, Serranus hepatus, Lepidotrigla cavillone, Spicara maena, Myliobatis aquila, Diplodus vulgaris, and Trisopterus minutus in decreasing order of abundance. These top ten species constituted 75% of total catch weight. Biomass ratios of total discards to commercial species were 0.44 : 1.

teristic and its relation with body weight has been extensively documented in fisheries research (Froese et al. 2011). The Length–weight (L–W) relation of a species depends on many factors (i.e. sex, size range, habitat, food availability, and fishing pressure), but may also vary seasonally (Froese 2006, Karachle and Stergiou 2008, Liousia et al. 2012). However, studies focusing on seasonal L–W relations are rather limited compared with those on annual estimates, because most of the estimates are based on samplings conducted during short-term periods in an annual basis. In Greek fisheries, L–W relations are mostly derived from sampling conducted in open sea (using trawls and purse seines; for reviews see: Stergiou and Moutopoulos 2001, Karachle and Stergiou 2008) than in coastal waters (smallscale fishery; Moutopoulos and Stergiou 2002), despite of the multi-gear nature of the fishery. Small-scale fishery is of great importance to the Greek fishery contributing 57.3% to the total Greek fisheries landings (Moutopoulos and Stergiou 2012). It involves approximately 30 000 fishers characterized by low income, elementary education and living in small and isolated islands (Tzanatos et al. 2005). Likewise, in the study area (Korinthiakos Gulf) the small-scale fishery component is highly contributing to providing approximately 74% of the total landings (Moutopoulos and Stergiou 2012). In the presently reported study, we calculated annual and seasonal estimates of L–W relations for the most abundant fish species caught by a professional small-scale vessel in Korinthiakos Gulf during a full annual fishing period: European hake, Merluccius merluccius (Linnaeus, 1758); white seabream, Diplodus sargus (Linnaeus, 1758); common pandora, Pagellus erythrinus (Linnaeus, 1758); bogue, Boops boops (Linnaeus, 1758); surmullet, Mullus surmuletus Linnaeus, 1758; Mediterranean horse mackerel, Trachurus mediterraneus (Steindachner, 1868); large-eye dentex, Dentex macrophthalmus (Bloch, 1791); annular seabream, Diplodus annularis (Linnaeus, 1758); spotted flounder, Citharus linguatula (Linnaeus, 1758); red mullet, Mullus barbatus Linnaeus, 1758; common two-banded seabream, Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817); blotched picarel, Spicara maena (Linnaeus, 1758); stargazer, Uranoscopus scaber Linnaeus, 1758; comber, Serranus cabrilla (Linnaeus, 1758); blue whiting, Micromesistius poutassou (Risso, 1827); European pilchard, Sardina pilchardus (Walbaum, 1792); red porgy, Pagrus pagrus (Linnaeus, 1758); picare, Spicara smaris (Linnaeus, 1758); black scorpionfish, Scorpaena porcus Linnaeus, 1758; golden grey mullet, Liza aurata (Risso, 1810); round sardinella, Sardinella aurita Valenciennes, 1847; European barracuda, Sphyraena sphyraena (Linnaeus, 1758); greater weever, Trachinus draco Linnaeus, 1758; saddled seabream, Oblada melanura (Linnaeus, 1758); salema, Sarpa salpa (Linnaeus, 1758); red scorpionfish, Scorpaena scrofa Linnaeus, 1758; common dentex, Dentex dentex (Linnaeus, 1758); flathead grey mullet, Mugil cephalus Linnaeus, 1758; black ACTA ICHTHYOLOGICA ET PISCATORIA (2013) 43 (1): 57–64 DOI: 10.3750/AIP2013.43.1.08

Bu çalışmada, İzmir Körfezi'nde kancaağız pisi balığının Citharus linguatula ,(L., 1758) bazı biyolojik özellikleri tespit edilmiştir. Ocak 2005-Mayıs 2006 tarihleri arasında, İzmir Körfezi'nden Egesüf Araştırma Gemisi'nden trol ağı ile aylık olarak toplam 2555 adet elde edilmiştir. Bireylerin I-VI yaş grupları arasında dağılım gösterdiği saptanmıştır. Minimum, maksimum ve ortalama total boy sırasıyla, 9,1cm, 23,9cm ve 15,90±0,096 cm'dir. Minimum, maksimum ve ortalama ağırlık sırasıyla, 5,02g, 105,34g ve 32,06±0,61 g'dır. Total boy-ağırlık ilişkisi esas alınarak hesaplanan boy ağırlık ilişkileri, W=0,005*L314, r= 0,98 olarak tespit edilmiştir. von Bertalanffy büyüme parametreleri tüm bireyler için Lt = 27,38 * [1-e-0,2142 (t+1,6353)] olarak hesaplanmıştır, In this study, some biological features of spotted flounder Citharus linguatula (L.,1758) were investigated from İzmir Bay. 2555 specimens were captured with bottom trawl net by R/V Egesuf between January 2005-May 2006. It is determined that the samples of population distributed between I-VI age groups. Minimal, maximal and mean total length were established as 9.1cm, 23.9 cm and 15.90±0.096 cm, respectively. Minimal, maximal and mean weights were found as 5.02g, 105.34g and 32.06±0.61g, respectively. The weight-length relationships and von Bertalanffy growth equations were calculated as W=0.005*L3.14, r= 0.98, Lt = 27.38 * [1-e-0.2142 (t+1.6353)]

The diet composition and possible relationships between mouth area and intestine length with feeding were investigated for seven flatfish species in the North-North-West Aegean Sea. Samples were obtained from commercial fisheries (trawls and gillnets) on a seasonal basis, and a total of 444 individuals was analysed. The two most abundant species, Arnoglossus laterna and Citharus linguatula , preyed mainly on fish, and there were no differences in the feeding habits of the two species with season or sex. The remaining five species fed on small benthic invertebrates, mainly Crustacea and Polychaeta. Multivariate analysis showed that, based on their diet, the seven species formed three distinct groups. The mean mouth area and relative gut length differed significantly between the three groups, indicating differences in some of the morphological characteristics in order to avoid trophic overlap. The estimated trophic levels of these species (from 21 literature sources) ranged from 3.00 for Symphurus nigrescens to 4.49 for A. laterna and C. linguatula , indicating that flatfish span all trophic levels above 3. Keywords : diet, gut length, mouth, Pleuronectiformes, trophic overlap African Journal of Marine Science 2011, 33(1): 67–78

The usefulness of fish parasite communities as bioindicators of environmental stress was tested on two benthic fish species, the red mullet ( Mullus barbatus ) and the spotted flounder ( Citharus linguatula ), during the spring of 2006 at two sites of the Catalan coast (northwestern Mediterranean): an anthropogenic-impacted area located close to the city of Barcelona, and a less polluted area close to Blanes (Girona). Gonadosomatic and hepatosomatic indices and condition factor were determined for the fishes caught. Prevalence, mean intensity, mean abundance and species richness of the parasites found in the survey were calculated for both species and locations, and the main histological alterations were recorded. Cysts of unknown aetiology and intestinal coccidians were reported only in red mullets from the area close to Barcelona, which were highly parasitized by the digenean Opecoeloides furcatus and the nematode Capillaria sp. However, a higher prevalence of Ichthyophonus sp. was reported in the spotted flounder from Blanes. Cysts of unknown aetiology, some nematodes and Ichthyophonus sp. may be associated with pollution.

Spotted flounder Citharus linguatula (Linnaeus, 1758) is one of the most abundant species within demersal fish assemblages next to the continental shelf (up to 200 m depth) of the Mediterranean Sea. In spite of the ecological importance of this species in the central Tyrrhenian Sea, many aspects of its biology (e.g. feeding behaviour) are poorly described. In order to analyze how feeding habits are related to the ontogenetic changes in this species, 2636 specimens (between 9 and 26 cm of total length TL) were collected from November 2000 to January 2002. During ontogenetic development spotted flounder occupied different trophic levels: diet shifted from mysids, predominantly in the smaller spotted flounder ( 19 cm TL). Before the transition to the icthyophagous phase, a more generalist foraging behaviour including decapods ( Processa sp., Alpheus glaber ), molluscs ( Turitella sp.) and benthic fish ( Lesuerigobius spp., Gobius niger, Callionymus spp., Arnoglossus laterna ) dominated the diet. Seasonal analysis of the diet showed an increase in the presence of mysids in summer and autumn, and of decapods in summer and spring. Teleosteans are present throughout the year without significant variations. Daily ration values, computed from the Eggers method, ranged from 1.57% to 2.83% wet body weight, showing a negative relationship between reproduction and daily consumption rate.

Four flatfish species were collected between January 2003 and June 2005 from commercial fishing vessels operating with gill nets and bottom trawls along the Portuguese coast in order to examine feeding habits, age and growth and reproduction. Citharus linguatula (Linnaeus, 1758), Lepidorhombus boscii (Risso, 1810) and Microchirus azevia (de Brito Capello, 1867) fed mainly on crustaceans, whereas Platichthys flesus (Linnaeus, 1758) fed mainly on echinoderms and crustaceans. Feeding activity was highest in spring and summer; females and small individuals showed the lowest vacuity index values. For all the species, significant differences were found in the proportion of prey items according to season, sex and size class. M. azevia had the largest diet spectrum. Ages were determined from sagittal otoliths. The von Bertalanffy growth equation coefficients differed between sexes. The asymptotic length L∞ of females was higher than that of males, except in C. linguatula. The lowest growth coefficient was obtained for P. flesus (k=0.11 for males and k=0.10 for females) and M. azevia showed the highest growth coefficient estimates (k=0.40 for females and k=0.30 for males). The highest proportion of individuals at spawning stage was recorded in winter for L. boscii, P. flesus and M. azevia, and in autumn for C. linguatula. Cuatro especies de peces planos fueron capturadas desde enero de 2003 hasta junio de 2005 por embarcaciones comerciales operando con redes de enmalle y arrastre de fondo, a lo largo de la costa portuguesa, con objeto de examinar los hábitos alimenticios, la edad, el crecimiento y el ciclo sexual. Citharus linguatula (Linnaeus, 1758), Lepidorhombus boscii (Risso, 1810) y Microchirus azevia (de Brito Capello, 1867), se alimentaron sobre todo de crustáceos. La dieta de Platichthys flesus (Linnaeus, 1758) estuvo compuesta principalmente por equinodermos y crustáceos. La mayor actividad alimenticia se observó en la primavera y el verano. Las hembras y los individuos más pequeños presentaron valores de índices de vacuidad más bajos. Para todas las especies se encontraron diferencias significativas en la proporción de ítems alimenticios según la estación, el sexo y la talla. M. azevia presentó el espectro más amplio de dieta. Las edades fueron determinadas a partir de los otolitos sagittae. Los coeficientes de la ecuación de crecimiento de von Bertalanffy fueron diferentes para los dos sexos. La talla asintótica L∞ de las hembras fue mayor que la de los machos, excepto para C. linguatula. El coeficiente de crecimiento más bajo se observó para P. flesus (k=0.11 para los machos y k=0.10 para las hembras), M. azevia presentó el mayor coeficiente de crecimiento (k=0.40 para hembras y k=0.30 para machos). La mayor proporción de individuos maduros en L. boscii, P. flesus y M. azevia se observó en invierno y en C. linguatula en otoño.

18 pages, 9 figures, 3 tables, This study assesses the effects of commercial trawling on benthic fauna, by analysing differences in the population structure and diet of benthic organisms inhabiting fishing grounds. The study is focused on two epifaunal species collected from a fishing ground in the north-western Mediterranean, which included a portion of un trawled seabed used as a reference of undisturbed community. The selected species were the flatfish Citharus linguatula, more abundant at the undisturbed site and previously characterised as a surface predator and vulnerable to trawling, and the starfish Astropecten irregularis, which dominated the epibenthic community and had been characterised as an opportunistic species with low vulnerability to trawling. Both species were selective feeders and ingested similar prey species at each of the two sites, although differences in the relative prey abundance found in the stomachs occurred between sites. A. irregularis at the fished site mainly ingested gastropods, whereas higher proportion of bivalves was ingested at the undisturbed site. C. linguatula diet mainly composed of crustaceans at both sites, but there was an increase in the ingestion of small fish at the fished site. Moreover, prey ingestion of these two species generally increased with fishing activity. Trawling appears to modify the diet of these two species in terms of relative abundance of ingested prey, nevertheless, increased opportunism due to trawling disturbance was not detected and the density of these predators over fishing grounds was more closely related to their vulnerability to trawling, This study was funded by the EU project (RESPONSE, Q5RS-2002-00787), and S. de Juan is supported by a fellowship from “Departament d'Universitats, Recerca i Societat” from the Catalan government

U ovom radu obrađen je utjecaj selektivnosti pridnene povlačne mreže koće na primjeru sviju vrsta: patarače platušice i tabinje bijelice

The population differentiation of seven flatfish species, Citharus linguatula , Lepidorhombus boscii , Platichthys flesus , Microchirus azevia , Solea lascaris , Solea senegalensis and Solea solea , widely distributed along the eastern north Atlantic and occurring in sympatry along the Portuguese coast was studied using morphological and parasitological data. Fish were obtained from commercial fishing vessels operating in three locations along the Portuguese coast (north, centre and south) between January 2003 and June 2005. Eleven morphometric and seven meristic characters were considered in morphological analyses. Size effect was removed from morphometric measurements by principal component analysis and a multivariate discriminant analysis was performed to investigate the differences between populations using both morphometric and meristic data, separately. Individuals were examined for macroparasites infections according to standard procedures, and a multivariate discriminant analysis was also applied to investigate population differences. Analyses of both types of data (morphological and parasitological) revealed a similar pattern of a generally low differentiation evidenced by the high overlap of individuals in the ordination diagrams. However, some differentiation was found between samples from the west (north and centre) and the south Portuguese coast evidencing the existence of an ecological differentiation along the Portuguese coast. Broad scale population studies should, therefore, take into account the information provided by such data, especially with regard to fisheries’ management policies and stock definition.

Fishing with experimental gill-nets was carried out during 1994 and 1995 off the western coast of Portugal, using mesh sizes between 40 and 90 mm. Most sets were concentrated in the region between Setubal and Lisbon in shallow waters up to 100 m, with about 1/4 being carried out at greater depths. A total of 88 species were captured over the 2 years, of which the majority had small or no commercial value. The most important commercial species (hake, Merluccius merluccius, pouting, Trisopterus luscus, axillary seabream, Pagellus acarne, red mullet, Mullus surmuletus, and horse mackerel, Trachurus trachurus) accounted for about 12% of the catch weight in the 40 mm mesh panels, between 32 and 44% for mesh panels ranging between 60 and 80 mm, and 70% in the 90 mm mesh panels. The estimation of selectivity was carried out for the latter five species and also for the dogfish, Scyliorhinus canicula, wedge sole, Dicologlossa cuneata, and spotted flounder, Citharus linguatula, applying the SELECT method to the data pooled over both years. In the case of hake, pouting and dogfish, sufficient data were available to estimate selectivity on a yearly basis. Four different uni-modal and a bi-modal (bi-normal) models were fitted, with the bi-normal always providing the best fit as given by the smallest value of the ratio deviance/degrees-of-freedom. The exception was the wedge sole where the bi-normal model did not converge and the gamma was the unimodal model providing the best fit. The 40 mm mesh panels mostly retained species of low or no commercial value and undersized hake and pouting. Mesh size panels of 60, 70 and 80 mm proved to be the most efficient in catching the commercially valuable species over the length range available, with virtually no catch of undersized fish. The 90 mm panels retained mainly valuable species, but the overall catches were poor, with the exception of the axillary seabream. These results highlight the difficulties of managing multispecies fisheries based only on mesh size, since the optimal mesh varies considerably among the target species.

The link between climate-driven river runoff and sole fishery yields observed in the Gulf of Lions (NW Mediterranean) was analysed using carbon- and nitrogen stable isotopes along the flatfish food webs. Off the Rhone River, the main terrestrial (river POM) and marine (seawater POM) sources of carbon differed in delta(13)C (-26.11 per thousand and -22.36 per thousand, respectively). Surface sediment and suspended POM in plume water exhibited low delta(13)C (-24.38 per thousand and -24.70 per thousand, respectively) that differed more from the seawater POM than from river POM, demonstrating the dominance of terrestrial material in those carbon pools. Benthic invertebrates showed a wide range in delta(15)N (mean 4.30 per thousand to 9.77 per thousand ) and delta(13)C (mean -23.81 per thousand to -18.47 per thousand ), suggesting different trophic levels, diets and organic sources. Among the macroinvertebrates, the surface (mean delta(13)C -23.71 per thousand ) and subsurface (mean delta(13)C -23.81 per thousand ) deposit-feeding polychaetes were particularly (13)C depleted, indicating that their carbon was mainly derived from terrestrial material. In flatfish, delta(15)N (mean 9.42 to 10.93 per thousand ) and delta(13)C (mean -19.95 per thousand to -17.69 per thousand ) varied among species, indicating differences in food source and terrestrial POM use. A significant negative correlation was observed between the percentage by weight of polychaetes in the diet and the delta(13)C of flatfish white muscle. Solea solea (the main polychaete feeder) had the lowest mean delta(13)C, Arnoglossus laterna and Buglossidium luteum (crustacean, mollusc and polychaete feeders) had intermediate values, and Solea impar (mollusc feeder) and Citharus linguatula (crustacean and fish feeder) exhibited the highest delta(13)C. Two different benthic food webs were thus identified off the Rhone River, one based on marine planktonic carbon and the other on the terrestrial POM carried by the river. Deposit-feeding polychaetes were responsible for the main transfer of terrestrial POM to upper trophic levels, linking sole population dynamics to river runoff fluctuations.

This study reports weight–length relationships for 50 selected fish species of the Algarve coast (southern Portugal). Specimens were caught during fishing surveys with different types of fishing gears (trawls, nets, long-lines and traps) or sampled during whole fish market sampling operations. A total of 22 825 individuals were sampled, belonging to 50 fish species from 25 families. The best represented was family Sparidae (13 species), distantly followed by Scombridae and Triglidae (four species), Carangidae (three species), and by Gadidae, Haemulidae, Scyliorhinidae, Serranidae and Soleidae (two species). In numerical terms, the most important species were Trachinus draco and Diplodus bellottii , with 2767 and 2144 individuals, respectively, followed by Citharus linguatula (1844), D. vulgaris (1206), Microchirus azevia (1165), Scorpaena notata (1118) and Pagellus erythrynus (1075). To the author’s best knowledge, this study presents the first references on weight–length relationships for six fish species worldwide, for 15 species for the northeastern Atlantic, for 20 species for Portuguese waters and for 25 species for the Algarve coast (southern Portugal).

Obtaining data to study fish biology can be a challenge if a stock is fished by a variety of gears with different effort units and different selectivity, particularly if these gears only partially overlap in space and time. In this work, we attempted to study the biology of the spotted flounder Citharus linguatula in the Patraikos Gulf and the adjacent central Ionian Sea (eastern Mediterranean) and to evaluate the current fisheries management. We characterized age composition and growth, length-at-maturity, and catch-per-unit-effort (CPUE) of spotted flounder from the catches of bottom trawls, gillnets and trammel nets for the period autumn 2013–2014. Variation of fish total length, gonadosomatic index, hepatosomatic index and condition factor was analyzed using generalized additive models (GAMs) with regard to sex, date, fishing gear and depth. We also modeled CPUE fluctuations of each gear by date, depth, longitude and latitude using GAMs. Fish age ranged from 1 to 5 years. A slightly allometric growth was documented with females attaining larger sizes than males. Length-at-maturity was 163 mm for females and 169 mm for males. The seasonal change of gonad maturity stages and the gonadosomatic index indicated spawning in late summer-autumn. Changes in length frequencies indicated that recruitment to the fisheries occurred in late spring-early winter in shallow depth (

* Citharus linguatula (Linnaeus, 1758) – Atlantic spotted flounder; Carta-de-bico ①, ③, Published as part of Carneiro, Miguel, Martins, Rogélia, Landi, Monica & Costa, Filipe O., 2014, Updated checklist of marine fishes (Chordata: Craniata) from Portugal and the proposed extension of the Portuguese continental shelf, pp. 1-73 in European Journal of Taxonomy 73 on page 60, DOI: 10.5852/ejt.2014.73, http://zenodo.org/record/3866515

The present study was conducted in the Thracian Sea, seasonally, from autumn 1996 until May 1998, using professional fishing bottom trawlers, and focuses mainly on the discarded catches and, to a lesser extent, on marketable ones, with emphasis on fishes. Sampling was conducted following normal commercial fishing practises. The duration of the fishing trips ranged from one to three days, whereas haul duration ranged from 35 to 385 min. Overall, 114 hauls were performed at depths ranging from 18.7 to 355.6 m. The total catch was 24376 kg (13137 kg fishes, 4410 kg crustaceans, 2141 kg cephalopods and 4688 kg of other invertebrates) in 262.6 hours of fishing. From those, 44.9% were marketable, whereas 55.1% were discarded. In all cases fishes dominated the catch, with 52.8% of the mean catch being composed of fishes, 14.7% of crustaceans, 9.7% of cephalopods and 22.8% of other invertebrates. The discard rates did not vary significantly between the two years of study. Seasonally, the greatest discard rate was observed in autumn, while, concerning the depth zones, the lowest discard rate was recorded at depths > 300 m (36.3%), where only one haul was performed, whereas in the zones 0 – 150 and 150 – 300 m the mean discard rates were 56.7 and 53.5%, respectively. In total, 141 fish species, belonging to 53 families, were caught. Of those, 17 were exclusively marketable, 58 discarded, and 66 species had individuals in both, the marketable and discarded fraction. The number of fish species caught did not differ with year, whereas it was much lower during spring (86 species) when compared to winter and autumn (120 and 117 species, respectively), despite the fact that haul duration was approximately the same for all seasons. The species number was negatively related to hauling depth. The most abundant fish species caught were Serranus hepatus, followed by Arnoglossus laterna, Trachurus mediterraneus, Lepidopus caudatus, Merluccius merluccius and Citharus linguatula. At greater depths, the dominant species was Gadiculus argenteus argenteus. There was a small variation of the dominant marketable and discarded species, with respect to the year of study. Length frequency distributions were constructed for the most, numerically, abundant species, both discarded and marketable, per season and depth zone. The estimation of the discarding length, i.e. the length at which 50% of the individuals of a marketable species is being marketed, revealed that a large number of small individuals of highly marketable species, such as Merluccius merluccius, are being caught and marketed. The relationship between mean and maximum total body length and depth of capture was examined for 27 fish species and the prevailing trend was “bigger – deeper”. The number of species and families and the (number of species) / (number of families) ratio were both negatively related to depth. From the abundance – depth relationship of 55 species it was revealed that, for the majority of fish species,%%%%Η παρούσα έρeυνα πραγματοποιήθηκe στο Θρακικό Πέλαγος, σe…

Background. Understanding the reproduction of the spotted flounder, Citharus linguatula (Linnaeus, 1758), has been considered a major step toward understanding its population dynamics, especially, in the northern Aegean Sea. So, the presently reported study aimed to study the reproductive biology of C. linguatula and provided the first data of its fecundity. Materials and methods. T his study was carried out between September 2006 and September 2008 in Saros Bay (Northern Aegean Sea, Turkey), which had been closed to trawl fishing since 2000. The gonadosomatic index, length at maturity (L50), and absolute fecundity were analysed. Results. The elevated GSI values observed, suggested the spawning period was from September to November. The length at maturity (L50) was at 15.0 cm TL for females and 14.0 TL cm for males. The relations between the absolute f ecundity and total length, total weight, and age of the spotted flounder females were estimated as Fa = 0.1878TL 3.29 , Fa = 58.515TW + 36.453, and Fa = 887.59A - 389.43, respectively. Conclusion. The identification of reproductive strategy is necessary to obtain a better understanding of its biology.

Two frequently reported but poorly known hemiurid digeneans, Lecithochirium musculus (Looss, 1907) (Lecithochiriinae), from the stomach of Trachinus draco and Citharus linguatula, and Ectenurus lepidus Looss, 1907 (Dinurinae), from the stomach of Spicara maena, are redescribed based on material from off the Barcelona coast of the western Mediterranean. The two species are commented upon, and Lecithochirium israelense Fischthal, 1980 is considered a synonym of L. musculus. Records of the two species in the Mediterranean Basin and North East Atlantic region are summarised.

The composition of the diet of Citharus linguatula (L.) off the coast of the Gulf of Valencia, Spain, was determined between October 1989 and October 1990. The percentage of empty stomachs remained constant throughout the year, except for the period August to September, when a maximum was recorded coinciding with the reproductive period. Crustaceans (Mysidacea and Decapoda) and teleosts constituted the main prey. The composition of the prey ingested varied with predator size; small specimens contained a greater number of mysids in their stomachs, while decapods and fishes were more abundant in the stomachs of larger specimens. Diets varied seasonally: mysids were more important during autumn, whereas decapods were more important during winter and spring. Fishes were numerically most important in the diet in summer, but the frequency of occurrence was constant throughout the year.

On the Atlantic Moroccan coast, two species of pleuronectiform fish coexist, wedge sole (Citharus linguatula) a temperate species, and spotted flounder (Dicohgoglossa cuneata) a tropical one. These two species are the definitive host for Bothriocephalus andresi and Acanthocephaloides propinquus, respectively. A negative binomial fits the dispersion of B. andresi in the population of C. linguatula. The fish become parasitized between their first and third year, while still immature, with the highest abundances in the third year. After the fish become ichthyopagous, the level of infection drops drastically. We postulate that copepods are the sole source of infection. The presence of B. andresi in both Atlantic and Mediterranean populations of C. linguatula shows that the parasite follows the host during its migration along the Mediterranean coasts. The prevalence of A. propinquus remains above 50% as a consequence of the large numbers of amphipods included in the diet of D. cuneata, regardless of the age of the fish or the season. The amphipods, Phtisica marina and Pariambus typicus are an important food and represent potential intermediate hosts for A. propinquus. The population dynamics of A. propinquus on the Atlantic Moroccan coasts are similar to those observed in parasite populations of Gobius niger in the Gulf of Lion (French Mediterranean). The observation of B. andresi and A. propinquus in both Moroccan Atlantic and Mediterranean fishes highlights the problem of the evolution of these parasite populations during the colonization of the Mediterranean by the hosts.

The usefulness of fish parasite communities as bioindicators of environmental stress was tested on two benthic fish species, the red mullet (Mullus barbatus) and the spotted flounder (Citharus linguatula), during the spring of 2006 at two sites of the Catalan coast (northwestern Mediterranean): an anthropogenic-impacted area located close to the city of Barcelona, and a less polluted area close to Blanes (Girona). Gonadosomatic and hepatosomatic indices and condition factor were determined for the fishes caught. Prevalence, mean intensity, mean abundance and species richness of the parasites found in the survey were calculated for both species and locations, and the main histological alterations were recorded. Cysts of unknown aetiology and intestinal coccidians were reported only in red mullets from the area close to Barcelona, which were highly parasitized by the digenean Opecoeloides furcatus and the nematode Capillaria sp. However, a higher prevalence of Ichthyophonus sp. was reported in the spotted flounder from Blanes. Cysts of unknown aetiology, some nematodes and Ichthyophonus sp. may be associated with pollution., Se ha comparado la utilidad de las comunidades parasíticas de peces como bioindicadores de estrés ambiental en dos especies bentónicas de peces , el salmonete de fango Mullus barbatus y la solleta Citharus linguatula, durante la primavera de 2006 en dos lugares de la costa catalana (Mediterráneo NO): un área fuertemente impactada cerca de la ciudad de Barcelona, y una menos contaminada cerca de Blanes (Girona). Se determinó el índice gonadosomático, el índice hepatosomático y el factor de condición de los peces capturados. Se calculó la prevalencia, intensidad media, abundancia media y riqueza específica de los diferentes parásitos encontrados por especie y localidad, y se analizaron las principales alteraciones histológicas. Se han encontrado quistes de etiología desconocida y coccidios intestinales tan sólo en los ejemplares de M. barbatus de Barcelona, los cuales también estaban altamente parasitados por el digeneo Opecoeloides furcatus y el nematodo Capillaria sp. Se ha detectado Ichthyophonus sp. tan sólo en los ejemplares de C. linguatula, presentando una mayor prevalencia en los ejemplares de Blanes. Los quistes de etiología desconocida, algunos nematodos e Ichthyophonus sp. podrían estar relacionados con la contaminación

Bu araştırma, İzmir Körfezi’nden Ocak 2002-Mayıs 2002 tarihleri arasında yakalanan Kancaağız pisi balığının (Citharus linguatula) bazı morfometrik özelliklerini belirlemek amacıyla yapılmıştır. Toplam 195 adet balık örneği 44 mm göz açıklığına sahip dip trol ağlarıyla yakalanmıştır. Yakalanan balıkların boy değerleri minimum 110 mm, maksimum 207 mm’dir. Total boy-standart boy ilişkisi TL=1.1496*SL+9.3824 (r2=0.937) olarak hesaplanmıştır. Örneklerden toplam 8 adet morfometrik ölçüm alınmıştır bunlar sırasıyla; dorsal boy uzunluğu (DBU), ağız ucu-solungaç arası mesafe (ASM), pre-pektoral uzunluk (PPU), pre-orbital uzunluk (POU), göz çapı (GÇ), post-orbital mesafe (POM), gözlerarası mesafe (GAM) ve vücut genişliği (VG) olup bu ölçümler arasındaki istatistiksel ilişkinin varlığı incelenmiştir.

Dietary studies of seabirds provide information on food webs and oceanographic variability. Studying fatty acid signatures (FAS), which reflect changes in the composition of the diet, has several advantages over traditional methods. In the context of the Mediterranean marine ecosystem, we studied tissue FAS in captive-fed and wild seabirds. Yellow-legged gulls Larus michahellis were experimentally fed either pelagic (sardine Sardina pilchardus) or demersal (spotted flounder Citharus linguatula) fish for 8 wk, and FAS in the birds’ plasma and adipose tissue were studied. The FAS developed patterns characteristic of the sardine or flounder diet, showing the reliability of both types of samples. In addition, plasma samples of 20 endangered wild Balearic shearwaters Puffinus mauretanicus and their most likely prey items from the Mediterranean Sea were collected and analyzed for FAS. Based on FAS of Mediterranean fish, and the results from the feeding experiment, the diet of the endangered wild shearwaters was estimated. In terms of the composition of polyunsaturated fatty acids, the plasma FAS of the shearwaters resembled those of the captive gulls kept on a sardine diet, suggesting that pelagic feeding resources dominate shearwater diet. However, the high level of 20:1n-11, likely metabolized from 22:1n-11 by the birds themselves, suggested that the diet also contained a demersal component rich in 22:1n-11. Contrary to the situation in the open oceans, the levels of the C20 and C22 monounsaturated fatty acids are low in the Mediterranean food web and characteristic of most demersal species. Our results support the findings of previous field studies that the diet of the shearwaters is frequently supplemented by demersal fish from fishery discards.

SUMMARYMacroparasites are generally aggregated within their hosts with infection and aggregation levels resulting from a continuous arms race between maintaining high mating probability and host mortality low for which host and environmentally related factors contribute to some extent. Here, infection and aggregation patterns of the macroendoparasites infecting the flatfish Citharus linguatula, Arnoglossus laterna, Lepidorhombus boscii, Scophthalmus rhombus and Platichthys flesus in 3 areas along the Portuguese coast were analysed. Of the 21 macroendoparasite species found only 1 infected all hosts and most were host or area exclusive. For each host-parasite system, values of the indices varied between areas and macroendoparasites were not always aggregated; in fact, some macroendoparasites were generally uniformly distributed, which can be related to specific density-dependent regulation mechanisms. No general pattern was found for infection or aggregation levels of the 3 species infecting more than 2 hosts along the Portuguese coast, i.e. Lecithochirium rufoviride, Nybelinia lingualis and Anisakis simplex s.l., suggesting that regulation mechanisms are not species specific but are locally determined, with host ecology playing a significant role.

Citharus linguatula (Linnaeus, 1758) Sea of Marmara: 23800-468 (4 spc.), 01.09.1961; 23800-463 (1 spc.), 16.06.1991, Offshore of Mimarsinan, 175 m, N. Meriç, L. Eryilmaz. Mediterranean Sea: 23800-723 (2 spc.), January 2003, Iskenderun Bay, trawl, C. Dalyan.

Citharus linguatula (Linnaeus, 1758) Sea of Marmara: 23800-468 (4 spc.), 01.09.1961; 23800-463 (1 spc.), 16.06.1991, Offshore of Mimarsinan, 175 m, N. Meri��, L. Eryilmaz. Mediterranean Sea: 23800-723 (2 spc.), January 2003, Iskenderun Bay, trawl, C. Dalyan., Published as part of Nurettin Meri��, L��tfiye Eryilmaz & M��fit ��zulug, 2007, A catalogue of the fishes held in the Istanbul University, Science Faculty, Hydrobiology Museum., pp. 29-54 in Zootaxa 1472 on page 52

Anisakid nematodes belonging to the Anisakis simplex complex are highly prevalent in several fish species off the coast of Portugal and are an important zoonotic problem in the Iberian Peninsula. Two reproductively isolated sibling species of the Anisakis simplex complex were identified from Pleuronectiformes inhabiting the Portuguese coast using restriction fragment length polymorphism (RFLP). Recombinant genotypes corresponding to presumptive Anisakis simplex sensu stricto and Anisakis pegreffii hybrids were also detected by this technique, as well as the species Anisakis typica. Although 25 species of Pleuronectiformes were investigated, Anisakis spp. larvae were only found in seven: Arnoglossus imperialis, Arnoglossus laterna, Lepidorhombus boscii, Citharus linguatula, Platichthys flesus, Dicologlossa cuneata and Solea senegalensis. The occurrence of hybrids in relatively sedentary fishes such as the Pleuronectiformes suggests that the Portuguese coast may constitute an area of hybridization and, therefore, is of particular interest for the study of the process of hybridization and speciation for these anisakids.

Summary 1. To investigate the role of fish ecology in controlling terrestrial particulate organic matter (POM) uptake by benthic fish species and population responses to changes in continental inputs to coastal areas, depth distribution, diet and stable isotope ( δ 13 C and δ 15 N) data from the juveniles and adults of five important flatfish species ( Arnoglossus laterna , Buglossidium luteum , Citharus linguatula , Solea lascaris and S. solea ) were compared off the Rhone River delta (NW Mediterranean). 2. In moderate river discharge, isotopic signatures differed with fish species and benthic life stage, suggesting intra- and interspecific differences in trophic levels and food sources. Food web analysis indicated terrestrial POM uptake in all life stages of S. solea and A. laterna ( δ 13 C = − 20·1 to − 20·0‰ and − 18·9 to − 18·2‰, respectively), in the adults of B. luteum ( δ 13 C = − 19·0‰) and in the juveniles of S. lascaris ( δ 13 C = − 18·7‰), whereas all life stages of C. linguatula ( δ 13 C = − 17·6‰), S. lascaris adults ( δ 13 C = − 16·9‰) and B. luteum juveniles ( δ 13 C = − 17·5‰) exploited marine POM almost exclusively. 3. Fish diet and depth distribution accounted fully for the intra- and interspecific differences in terrestrial POM uptake observed. Greater terrestrial signatures were observed in fish eating larger quantities of deposit-feeding polychaetes (the main prey exploiting terrestrial POM for growth) and occurring mainly in the 30‐50 m depth zone (where river POM sedimentation and its uptake by the benthos were the highest). Due to intra- and interspecific differences in fish depth distribution and diet, Rhone River floods were predicted to have little effect on C. linguatula populations but to increase the other four species’ local stocks for several years, with a maximum impact on S. solea . 4. This study shows that the ability of benthic fish to exploit terrestrial POM inputs to the coastal zone depends strongly on their ecology. As this parameter will determine fish populations’ reactions to river floods, it must be assessed carefully before making hypotheses about the consequences of variations in river discharge on coastal fisheries’ production.

Information on distribution, relative abundance and size composition of the pleuronectiform species Citharus linguatula, Lepidorhombus boscii and Solea vulgaris was obtained during the MEDITS trawl surveys, carried out in a wide area of the Mediterranean Sea from 1994 to 1999. The three species showed a wide geographic distribution, as they were collected in all the macro-areas investigated, but with some differences in degree of presence among the 40 geographic sectors. Variations in abundance indices, analysed on a spatio-temporal basis with a Generalised Linear Model, were mostly related to the depth stratum and the macro-area. C. linguatula and S. vulgaris were especially found from 10 to 100 m depth, while L. boscii was most abundant on bottoms ranging from 100 to 500 m depth. The three species showed the highest abundance indices (kg/km2) in the Gulf of Lions, in the Greek Seas and along the Sardinian coasts. Especially for L. boscii and C. linguatula, the demographic structure showed that the sampled populations were mainly constituted by juveniles. The lowest biomass and abundance indices were obtained for S. vulgaris, whose catch was mainly composed of adult fish.

1. The subcellular distribution of mercury and possible presence of Hg binding proteins of low molecular weight were investigated by ultracentrifugation and gel filtration in liver and muscle of the flat fish Citharus linguatula and Lepidorhombus boscii from the northern Tyrrhenian sea, heavily contaminated by the metal. 2. For both tissues, Hg contents were higher in the pellet than in the supernatant. 3. In the eluate of supernatant from Sephadex G-75 of both tissues, Hg was mainly bound to high molecular weight ligands. 4. Differently from the muscle eluate, that from liver also contained a consistent amount of Hg bound to low molecular weight ligands.

The concentrations of Hg in superficial marine sediments and in muscle tissue of speciments of Citharus linguatula L. were determined in several zones of the northern Tyrrhenian sea. The average content of the metal found in the organism studied is very high and increases with the length of the specimens, displaying a different trend in the various zones. Additionally, an inverse relation was observed between Hg concentrations in C. linguatula and the metal content in the sediments of the studied zones. Consideration is given to the dangers of frequent consumption of this fish and to further research to understand the relation between the concentration of Hg in C. linguatula and in its environment.

10 pages, Larval development from the early stages to metamorphosis of the Pleuronectiform Citharus linguatula is described and illustrated for the first time; until now only its eggs and newly hatched larvae were known. The specimens used in this study were collected on plankton samples taken from the Catalan continental shelf (western Mediterranean) on two surveys made in September and October 1983. The descnption of larval development includes morphological and morphometnc characters and pigmentation. Relationships between various parts of the body and standard length during development are also considered. Information of their seasonal and spatial distribution along the studied area is provided. © 1988 IRL Press Limited