Ali Rıza Köşker

Tetrodotoxin levels in pufferfish (Lagocephalus sceleratus) caught in the Northeastern Mediterranean Sea.

The toxicity of tetrodotoxin (TTX) in pufferfish (Lagocephalus sceleratus) from Mersin Bay in the Northeastern Mediterranean Sea was measured using a mouse bioassay (MBA) and LC-MS-MS. Pufferfish were caught by trawl fishing, longlining and fishing line from December 2012 to October 2013. Changes in the levels of TTX in the gonads, livers, intestines, skins and muscles as a function of season and sex were determined. The gonads of female fish were toxic in all seasons (>2μg/g), whereas the gonads of male fish were only toxic in the spring and autumn. The highest TTX levels in gonads, livers, intestines and skins of female fish were 52.1, 46.2, 7.64 and 3.43μg/g, respectively, using LC-MS-MS. The TTX level in the muscle of female fish in winter was 2.83μg/g but was otherwise below the toxic limit. Consequently, it can be dangerous to consume pufferfish, including the edible muscle, from the Eastern Mediterranean Sea.

The effects of sex and season on the metal levels and proximate composition of red mullet (Mullus barbatus Linnaeus 1758) caught from the Middle Black Sea

ABSTRACT The effects of seasonal and sexual differences on the levels of macro, trace element, and toxic metal levels in Mullus barbatus were investigated using the ICP-MS. The quantity relationships of macro elements were found as K>P>Na>Ca>Mg for male, P>K>Na>Ca>Mg in female; the quantity relationships of trace elements were determined as Fe>Zn>Mn>Mo>Se>Cu>Ni>Co in male, Fe>Zn>Mn>Se>Cu>Ni>Mo>Co in female; and the quantity relationship of toxic elements were found as As>Pb>Cd in both male and female. Macro, trace, and toxic metal levels showed no significant differences (p > .05) in terms of sexuality, but demonstrated seasonal differences (p > .05). Overall, the highest level of macro elements was determined in the autumn, while the high level of trace elements was measured in the winter. The As, Cd, and Pb levels in the muscle tissue of red mullet fish were higher than acceptable limits. However, when the Estimated Daily Intake (EDI) and Estimated Weekly Intake (EWI) of both toxic metals are considered, they appear to be below acceptable limits. As a result, it was determined that the red mullet had been contaminated with toxic metals (Cd and Pb) but their levels according to EDI and EWI were below the limit.

First report on TTX levels of the yellow spotted pufferfish (Torquigener flavimaculosus) in the Mediterranean Sea

ABSTRACT The differences of tetrodotoxin (TTX) levels in various parts of pufferfish (Torquigener flavimaculosus) were examined in conjunction with the seasonal and sexual variations. The TTX levels in gonads, liver, intestines, skin and muscle tissue were determined using the Q‐TOF LC/MS. Instrumental analysis revealed that all examined tissues from T. flavimaculosus contained high TTX concentrations. TTX levels in the gonads, liver, intestines, skin and muscle tissue of pufferfish were within the range of 5.03–100.71, 7.04–106.80, 12.59–86.30, 33.95–139.88 and 15.88–86.07 (&mgr;g/g), respectively. It was determined that in all seasons, except for summer, female individuals had higher TTX levels than males. Among all seasons, the highest level of TTX was found in winter and the lowest in autumn. Consequently, T. flavimaculosus is a highly toxic pufferfish that is dangerous for human consumption and should not be consumed under any circumstances. HIGHLIGHTSThe first report is on the TTX content of T. flavimaculosus (pufferfish) in the Mediterranean Sea.TTX content in pufferfish was determined by using the Q‐TOF LC/MS analysis.All seasons except for summer, female individuals had higher TTX levels than males.Regardless of gender, this species is a highly toxic pufferfish that is dangerous for human consumption.

The effects of age and individual size on metal levels of Serranus cabrilla (Linnaeus, 1758) from the Yeşilovacık Bay (Northeasthern Mediterranean, Turkey)

In this study, the relationships were determined between the macro (Na, Mg, P, K, Ca), potential toxic metal, As, and trace element, Zn, levels of the muscle tissue and fish size (length and weight) in Serranus cabrilla (Linnaeus, 1758) caught via bottom trawl boat from the Yesilovacik Bay (Northeastern Mediterranean, Turkey). The potential toxic metal, macro and trace element levels of the muscle tissue of S. cabrilla were determined. Besides, the relationships between fish size and metal levels were investigated. For this study, S. cabrilla individuals of 0-1, 1-2 and 2-3 age groups were used. Min-Max total length of the age groups was determined as 10.5-11.8, 13.0-15.5 and 15.8-16.5 cm; Min-Max weights were 15.34-23.66, 30.41-43.82 and 41.89-58.18 g respectively. There was no statistical difference between the age groups according to the macro and trace element levels of muscle tissue. The Arsenic levels of the muscle tissue were high and in general displayed variation with age. The present study firstly reported the relationship between mineral-metal levels and individual size-age of S. cabrilla.

The Effects of Sex and Seasonality on the Metal Levels of Warty Crab (Eriphia verrucosa) in the Black Sea

ABSTRACT The present paper examines the impacts of gender and season variables on the nutritional composition and metal levels of warty crab caught in the central Black Sea region (Ordu). Crab samples were caught over four seasons, using gillnets, trammel net, and SCUBA diving. Results of chemical analysis showed that protein, lipid, moisture, and total mineral substance level ranges of male crabs were 20.45–22.64%, 0.95–1.27%, 75.44–77.09%, and 1.63–2.08%, while these ranges in female individuals were determined as 19.45–21.46%, 0.63–0.92%, 75.44–77.44%, and 2.08–3.28%, respectively. Macro and trace element levels in crab muscle tissue were determined as K > P > Na > Ca > Mg and Zn > Fe > Cu > Mn > Se > Ni > Mo > Co, respectively. Cd and Pb levels in crab muscle tissue were determined to be lower than the limit values given in codices independent of the seasonal variables. However, as the levels were found to be above the limit values, metal concentrations in crabs were also evaluated based on provisional tolerable daily intake and provisional tolerable weekly intake limits.

Seasonal Changes in the Chemical Composition of the Beadlet Anemones (Actinia equina) from Mersin Bay, Northeastern Mediterranean coast of Turkey

In this study, the effects of seasonal variation in proximate composition and fatty acid profile as a component of chemical compositions of Mediterranean Sea anemone species (Actinia equina L.,1758) living in Mersin Bay were investigated. Chemical composition analysis of anemone samples showed that while the highest levels of protein and water were obtained in winter, the highest lipid and total mineral substance (TMS) levels were obtained in autumn. In terms of fatty acid analysis, during all four seasons the dominant saturated fatty acids (SFA) were palmitic (C16:0) and stearic acids (C18:0), the dominant monounsaturated fatty acids (MUFA) were oleic (C18:1n9) and vaccenic acids (C18:1n7) and the dominant polyunsaturated fatty acids (PUFA) were linoleic acids (C18:2n6), linolenic acid (C18:3n3), gamma linolenic acid (C18:3n6), arachidonic acid (C20:4n6), eicosapentaenoic acid (EPA, 20:5n3) and docosahexaenoic acid (DHA, C22:6n3) for A. equina. The highest values of gamma linolenic acid, EPA and DHA levels were obtained in autumn as 0.44%, 14.83% and 14.10%, respectively.