Derya Bostanci

Otolith Biometry-Body Length Relationships in Four Fish Species (Chub, Pikeperch, Crucian carp, and Common Carp)

ABSTRACT Biometric data are presented for different fish species captured in four lakes of Turkey: crucian carp (Carassius gibelio), common carp (Cyprinus carpio), chub (Squalius cephalus), and pikeperch (Sander lucioperca). The length, breadth, and weight of otolith, (sagitta, asteriscus, and lapillus) were determined, and the relationships between otolith size and fork length were defined. All regressions were highly significant (P<0.05). In cyprinid fishes, (C. gibelio, C. carpio, and S. cephalus), asteriscus weight had the highest coefficient of determination among the asteriscus biometrics, and the lapillus length had the highest coefficient of determination among lapillus measurements for the same species. In S. lucioperca (Percidae), sagittal otolith weight was the best predictor of fish length.

Age Determination and Annulus Formation of Crucian Carp (Carassius gibelio) Inhabiting Egirdir Lake and Bafra Fish Lake, Turkey

ABSTRACT Age determination and annulus formation of the crucian carp (Carassius gibelio) obtained from Egirdir Lake between March 2001 and January 2003 and Bafra Fish Lake between January 2000 and September 2002 were evaluated by examination of scales, otoliths, vertebrae, opercular bones, and subopercular bones. The precision of age estimation was derived by percentage of reader agreement and coefficient of variation (CV). The highest agreement (70.3%) and lowest CV (7.0%) were with otoliths for Egirdir Lake specimens; in Bafra Fish Lake specimens, the highest agreement and lowest CV were with vertebrae 62.9% and 8.1%, respectively. We found that the most reliable bony structure for age determination varied in different populations of this species. Marginal increment analysis showed that annulus formation occured during October-April.

Morphological and Biometrical Characteristics on Otolith of Barbus tauricus Kessler, 1877 on Light and Scanning Electron Microscope

Se examino la morfologia de los otolitos, su biometria y la relacion entre el tamano de ellos y la longitud de los peces. Se registro el peso, longitud, grosor, area y perimetro para cada par de otolitos. Se calcularon y se identificaron en los graficos los valores de factor de forma, redondez, relacion de aspecto, circularidad, rectangularidad, elipticidad y las relaciones entre la longitud del otolito y los indices de la forma. De acuerdo con los resultados, la diferencia entre otolitos derechos e izquierdos fue estadisticamente significativo (P<0,05), excepto la longitud del otolito. Esta es la primera vez que se observa la diferencia de las variables de otolitos, no solo ente los pares de derecha e izquierda, sino tambien entre peces hembras y machos. Mientras que el peso de los otolitos tuvo el menor coeficiente de determinacion (R2), tales como 0,69; 0,59; 0,65, la longitud de los otolitos presento un R2 mas alto: 0,80; 0,81; 0.80, para hembras, machos y todas las muestras, respectivamente. Ademas, las imagenes de miscroscopia electronica de barrido son las primeras en mostrar los otolitos de B. tauricus para determinar la morfologia de estos.

Türkiye’deki üç Atherina boyeri Risso, 1810 popülasyonunun total boy ile otolit boyutları arasındaki ilişkilerinin bölgesel varyasyonu

This study focuses on the relationships between otolith measurements and total length; otolith shape indices and the total length; among otolith measurements for three Atherina boyeri populations (Lake Eğirdir, Lake İznik, and Hirfanlı Dam Lake) to determine regional variations of these populations in Turkey. 356 specimens with 41.0 103.6 mm total length of three A. boyeri populations were examined and their otoliths were extracted and measured. Otolith width is the strongest indicator for the three A. boyeri populations although the otolith length, width, and weight are good indicators for the fish length in the different populations. The linear relationship was determined between A. boyeri total length and sagittal otolith sizes in the three populations. However, the best model for the relationships among otolith sizes can be change depends on populations differentiation. Exponential model is the best model for Lake Eğirdir population while the linear model is the best model for Lake İznik and Hirfanlı Dam Lake populations.

Sagittal Otolith Morphology of Sharpsnout Seabream Diplodus puntazzo (Walbaum, 1792) in the Aegean Sea

Los indices morfologicos, biometria y la forma de los otolitos sagitales izquierdo y derecho se estudiaron para la especie sargo picudo, Diplodus puntazzo del mar Egeo. Se analizaron en 52 D. puntazzo la forma del surco acustico, las superficies proximal y distal y las regiones posteriores de los otolitos sagitales izquierdo y derecho. Ademas, se registraron para cada par de otolitos sagitales las mediciones morfometricas de peso, longitud, ancho y perimetro. Se calcularon en ambos otolitos sagitales los indices de forma, factor de forma, relacion de aspecto, circularidad, ortogonalidad y elipticidad. En el D. puntazzo que habita en el mar Egeo, el ancho y elipticidad de los otolitos fueron significativamente diferentes (P <0,05), para las mediciones de otolitos sagitales izquierdo y derecho, respectivamente. Existen gran variabilidad en las caracteristicas morfologicas de los otolitos de diferentes especies y poblaciones de peces, asimismo es limitada la informacion de los indices morfologicos y la forma de los otolitos sagitales. El presente estudio proporciono informacion suficiente sobre la morfologia y biometria de los otolitos izquierdo y derecho del sargo picudo en el Mar Egeo, lo que puede proporcionar una herramienta util para la discriminacion e identificacion de especies marinas de agua dulce y para nuevas investigaciones.

CURİ DERESİ (ORDU) BALIKLARI VE İSTİLACI BİR BALIK TÜRÜ Carassius gibelio (Bloch, 1782)

The research which aims to find out the fish species inhabiting in Curi Stream was done between June 2012 and June 2013 with seasonal. In catches of fish samples; fishing nets with different scales, fishing cast nets, fishing tackle and electroshocker are used. After the evaluation of totally 190 samples caught from the research area, 9 species belonging to 4 families (Cyprinidae, Gobiidae, Mugilidae, and Salmonidae) have been identified. They were determined as Alburnus chalcoides, Barbus tauricus, Carassius gibelio, Mugil cephalus, Neogobius cephalarges, Neogobius melanostomus, Squalius cephalus, Vimba vimba and Salmo labrax. The evaluation of captured specimens’ results, Carassius gibelio which is rising rapidly spreading invasive fish species from inland water of Turkey, was determined that they have started to spread in the Ordu.

A Comparison of Calcified Structures for Aging of Pikeperch (Sander lucioperca) in Bafra Fish Lake, Turkey

ABSTRACT Scales, otoliths, vertebrae, and opercular bones of pikeperch (Sander lucioperca) were evaluated to identify the best age determination structure. Neither vertebrae nor opercles provided material for consistent estimation of age. Marks on scales were typically clear and easy to read in younger fish, but the age determination from scales of older fish was difficult and subjective. Annuli of otoliths were very clear and easy to interpret. The precision of age estimation was derived by percentage of agreement of repetitive readings and the average percentage of error; these parameters were respectively highest (91.4%) and lowest (4.5%) for otoliths, indicating that they were the most reliable structures for age determination in pikeperch.