New Fisheries-related data from the Mediterranean Sea (October 2015)

In this third Collective Article, with fisheries-related data from the Mediterranean Sea, we present the historical length distribution of Lophius budegassa in the catch of commercial trawlers in the Greek seas; length-weight and length-length relationships of five flatfish species (Lepidorhombus boscii, L. whiffiagonis, Platichthys flesus, Pegusa lascaris and Solea solea) from different coastal areas of Turkey (Black Sea and Eastern Mediterranean Sea); growth of settled Polyprion americanus and length-weight relationships of this species and of Deltentosteus quadrimaculatus, Capros aper and three commercially important groupers in the Eastern Mediterranean Sea; the age, growth and mortality of Zosterisessor ophiocephalus in the Eastern Adriatic Sea; the length-weight relationship and condition factor of Atherina boyeri in a Central Mediterranean semi-isolated lagoon, and also the length-weight and length-length relationships of three Alburnus species from different inland waters in Turkey

New Fisheries-related data from the Mediterranean Sea (April 2015)

In this second Collective Article with fisheries-related data from the Mediterranean Sea we present the evaluation of bony structures in aging of Barbus tauricus, otolith dimensions-body length relationships for two species (Trachinus draco and Synchiropus phaeton), information on the growth of juvenile Thunnus thynnus and of Ruvettus pretiosus, weight-length relationships for three species (Aulopus fiamentosus, Thunnus thynnus and Tylosurus acus imperialis) and data on feeding habits and reproduction of Aulopus fiamentosus

New Mediterranean Biodiversity Records (April, 2014)

According to reports, the following 16 species have extended their distribution to other Mediterranean areas or have made a new appearance in other regions. The first category includes the following organisms: The rare and common Indo-Pacific seaweed Codium arabicum (Lebanese coasts), the acari Thalassarachna affinis (Marmara Sea), and the non-indigenous nudibranch Flabellina rubrolineata, which has also been found in many other areas of the Aegean Sea. In addition, the rare sea slug Thecacera pennigera (Piccolo of Taranto), the fangtooth moray Enchelycore anatina (National Marine Park of Zakynthos, Ionian Sea), the carangid Seriola fasciata (Gulf of Antalya), Lagocephalus sceleratus (SE. Ionian Sea), the reticulated leatherjacket Stephanolepis diaspros (Slovenia, N. Adriatic Sea), the marbled stingray, Dasyatis marmorata (NE Levantine), the starry smooth-hound Mustelus asterias (Iskenderun Bay, NE Mediterranean), the cephalopod Ommastrephes bartramii (Ionian Sea) have also been reported. The Atlantic crab Dyspanopeus sayi has expanded to many Italian areas and the blue crab Callinectes sapidus to a lake in N. Greece and in the S. Adriatic Sea. Finally, Farfantepenaeus aztecus has been found in the Ionian Sea, thus showing its wide expansion in the Mediterranean. The larval stages of Faccionella oxyrhyncha have been found, after many years, in the Aegean Sea and the first report of an existence on intersexual acari Litarachna duboscqi in Split(Adriatic Sea) was reported

Age and growth of the phaeton dragonet, Synchiropus phaeton (Actinopterygii: Perciformes: Callionymidae), from the Gulf of Iskenderun, north-eastern Mediterranean, Turkey

Background. Synchiropus phaeton (Günther, 1861) is a sexually dimorphic, benthic species that inhabits mud bottoms. This fish is one of the important by catch species in the trawl fishing. There is no commercial value. But it has ecological importance in this area. The information about the biology of S. phaeton is very limited. This study was conducted to investigate the age and growth relation of phaeton dragonet inhabiting the Gulf of Iskenderun, north-eastern Mediterranean coast of Turkey. t_abstract=' Materials and methods. A total of 289 phaeton dragonets were collected as discards during the commercial trawl fishing at the depth range of 100–150 m in the Gulf of Iskenderun, north-eastern Mediterranean. The fish age was determined from sagittal otoliths. The age readings were performed using Leica S8APO microscope and were documented with the Leica Application Suite (Ver. 4.8.0) software. The index of the mean percentage error (IMPE) was calculated to assess the precision of the age determination between two independent readers. Growth parameters for all specimens were subsequently determined by fitting the observed and the length-at-age data using the von Bertalanffy growth equations. Total length–weight relations (LWRs) and the condition factor (CF) were determined. Results. The total length and weight of S. phaeton ranged from 7.0 to 19.0 cm and from 2.01 to 22.0 g, respectively. The age of the studied individuals ranged from 2 to 7 years. The parameters of von Bertalanffy growth fitted to the mean observed total lengths-at age for each sex separately and were estimated as L∞ = 23.358 cm, K = 0.248 year–1, t0 = –0.501 years for females and L∞ = 26.543 cm,  K = 0.156 year–1, t0 = –0.662 years for males, respectively. The overall growth performance index (G) value was determined as 3.46 for the combined sexes. The total length–weight relations were determined as W = 0.0121TL2.55, R² = 0.94; 95% confidence intervals of b = 2.395–2.687, t-test P < 0.05 for females and W = 0.0094TL2.64, R2 = 0.93; 95% confidence intervals of b = 2.470–2.803, t-test P < 0.05 for males. The types of growth were found negatively allometric (b < 3). The highest condition factor was found at the age of 2 (0.62), while the lowest was found at the age of 6 (0.26). Conclusion. The presently reported study provides the first data on the age and growth of the S. phaeton that had not been studied previously in the Gulf of Iskenderun, north-eastern Mediterranean of Turkey. This study will contribute significantly to the conservation and management strategies of the species of S. phaeton in the future

Preliminary study on age, growth and reproduction of Mustelus mustelus (Elasmobranchii: Carcharhiniformes: Triakidae) inhabiting the Gulf of Iskenderun, north-eastern Mediterranean Sea

Background. Shark populations within the eastern Mediterranean are declining due to overfishing. Unfortunately, our knowledge on the biology of sharks and specifically dogfishes within eastern Mediterranean is extremely limited due to the lack of landings. Mustelus mustelus (Linnaeus, 1758) is one of such deficiently known cartilaginous fishes and the relevant information on its age and growth in the eastern Mediterranean is missing. The understanding of growth and reproductive behaviour is important for management and conservation of this species. The presently reported study was intended to determine age, growth, and some reproductive parameters of Mustelus mustelus collected in the Gulf of Iskenderun, the north-eastern Mediterranean Sea. Materials and methods. In this study, a total of 155 Mustelus mustelus were caught in the north-eastern Mediterranean Sea between March 2012 and October 2015. Fish age was determined based on band counts of sectioned vertebrae. The periodicity of band pair formation was examined using the marginal increment analysis. Growth parameters for all specimens were then determined by fitting the observed and the length-at-age data using the von Bertalanffy Growth Equation. The size and age at which 50% of both sexes reached maturity was estimated by a logistic model for maximum likelihood process and the gonadosomatic index was determined. Results. The total length and weight of the specimens examined ranged from 44.3 to 162.6 cm and from 241.3 to 12 060 g, respectively. The presently reported study provides new maximum lengths (162.6 cm) for M. mustelus from the north-eastern Mediterranean. The fish studied represented age groups from 0 through 25. The observed sex ratio was 1 ÷ 1.04 (females ÷ males). Von Bertalanffy growth parameters were estimated to be L∞ = 195.13 cm, W∞ = 20 060 g, K = 0.06, and t0 = −4.27 for all specimens. Length–weight relation was found to be W = 0.0027L3.0054 (R2 = 0.98) and 95% confidence intervals of b = 2.936–3.075, t-test P < 0.05. All studied specimens of M. mustelus represented isometric growth (b = 3). Condition factor ranged from 0.148 to 2.87 for females and from 0.103 to 1.024 for males. The length at 50% maturity and the age at 50% maturity were 109 cm and 8 in females and 92 cm and 7 in males, respectively. It was observed that mean GSI values were low in September and July, reaching a maximum in January to February. Conclusion. The results of this study could give useful insight for management plans and conservation of M. mustelus in the Mediterranean coast of Turkey

A study on the pelagic and demersal fishes of iskenderun Bay [I§skenderun Körfezi Baliklari Üzerine Bir Araştirma]

This study was conducted in iskenderun Bay, Mediterranean Sea, between December 1994 and November 1996. Systematics of the fish species inhabiting the bay were examined. Out of 145 species of 111 genera of 67 families there were 19 species belonging to the Chondrictyes and 126 species belonging to the Osteictyes. Of all these species, 22 were Lessepsian migrant fish species

Age and growth of the common guitarfish, Rhinobatos rhinobatos, in Iskenderun Bay (north-eastern Mediterranean, Turkey)

Age and growth of the common guitarfish (Rhinobatos rhinobatos) were estimated from the north-eastern Mediterranean coast of Turkey. A total of 115 common guitarfish (66 females and 49 males) were sampled. Age determinations were carried out using vertebral sections. Alcian blue dying techniques were used to enhance the visibility of the band on vertebrae. The techniques have been used for the first time on elasmobranchs vertebrae successfully in this study. A total of 97 vertebrae of 115 were visible on the vertebral band in this study. Male and female common guitarfish ranged in age from 1 to 15 and 1 to 24 y respectively. Total length ranged from 42 to 147 cm for females and 39 to 124 cm for males. The relationships between total length (TL) and total weight (TW) were presented as TW = 0.0014*TL3.1672 (R2 = 0.98) for females, TW = 0.0012*TL3.1947 (R2 = 0.98) for males and TW = 0.0012*TL3.1915 (R2 = 0.98) for both sexes. The parameters for von Bertalanffy growth curves were estimated as Linf = 137.70±9.38 cm, K = 0.159±0.047, to = -2.180 ± 0.90 for pooled data. ©2008 Marine Biological Association of the United Kingdom

Ölçme Eşdeğerliği

In order to make a meaningful comparison, instruments must have similar measurement qualities across settings. Research on measurement invariance has typically focused on internal structure of multi-item instruments and external relations. In the recent literature, researchers have paid attention to four forms of invariance. The researchs which include the measurement invariance tests can detect psychometric problems that result from cultural biases in item content, translation errors, acquiescence biases, and other factors. Also Statistical techniques to define and assess measurement invariance are helpful and useful to develop a framework for theoretical definitio

A new record of Pontobdella muricata (Annelida: Hirudinea: Piscicolidae) from Iskenderun Bay, northeastern Mediterranean Turkey

The aim of this study is to report a new record of marine leech, Pontobdella muricata (Linnaeus, 1758) from Iskenderun Bay, northeastern Mediterranean. Fish samples were collected during a trawl fishing conducted at a depth ranging from 150 to 300 m in Iskenderun Bay, Turkey. Fish samples, infected with marine leech, was transferred to the ecophysiology laboratory in Fisheries Faculty of the Firat University. One infected fish was photographed and the parasite was removed from the host and fixed in ethanol for further morphological examinations and measurements. The parasite was identified as Pontobdella muricata. Dipturus oxyrinchus constitutes new host for Pontobdella muricata which is one of the most common species of leeches found on skates and rays. ©Biharean Biologist, Oradea, Romania, 2019Firat University Scientific Research Projects Management UnitAcknowledgement. This work was partially supported by Scientific Research Projects Coordination Unit of Fırat University. Project Number SUF.15.04

Some biological aspects of penaeid shrimps inhabiting Yumurtalik Bight in Iskenderun Bay (north-eastern Mediterranean)

The species composition, size frequency distribution and length/weight relationships for each sex, size at first sexual maturity, and spawning seasons of the commercially important shrimp species inhabiting Yumurtalik Bight of the Nort-eastern Mediterranean were studied. Two penaeid shrimp species, Penaeus semisulcatus and Metapenaeus stebbingi, dominated the catches. Only a few individuals of Metapenaeus monoceros were captured during the study. The minimum size at first maturity was estimated to be 130 mm total length (TL) for P. semisulcatus and 55-60 mm TL for M. stebbingi. The size which 50% of the population is mature is 36 mm carapace length (CL) for P. semisulcatus and 15.4 mm CL for M. stebbingi. The highest proportion of mature females was encountered between the early spring and summer months when mater temperatures were relatively high. Most mature spawners were captured at a water depth of 5-10 m for M. stebbingi and 20-30 m for P. semisulcatus. The results showed that while P. semisulcatus does not spawn in the bight in winter months, M. stebbingi was not present in the bight from September through the winter months