Van Gölü Havzası su kaynaklarında yaşayan siraz (Capoeta capoeta, Gülden staedt, 1773) balıklarının populasyon yapısı ve büyüme özellikleri

Abstract

ÖZ: Bu çalışmada Van Gölü havzasında yeralan Dönerdere göleti, Koçköprü Baraj gölü, Karasu ve Bendimahi Çaylarında yaşayan Siraz (Capoeta capoeta) populasyonlarının yapılan, büyüme ve kondisyon özellikleri incelenmiştir. Örneklemeler 1995 - 1997 yıllan arasında, fanyalı ağlar, ığnp, çevirme ağı ve serpme ağ ile yapılmış, toplam 670 fert incelenmiştir. Örnekler üzerinde çatal boy, vücut ağırlığı ve cinsiyet belirlenmiş, yaş tayini operkulum ve pullardan yapılmıştır. İncelenen Capoeta capoeta öreneklerinde çatal boy 4 ila 47 cm. ağırlık 1.2-1273.0 g, yaş I ile Xlllarasinda bulunmuştur. Avlamp pazarlanabilecek boya sahip fertlerin oram % 8 ile % 41 arasında değişmiştir. Cinsiyet oranı erkek:dişi 1:0.85 şeklinde hesaplanmıştır. Boy-ağırlık ilişkisi AG=0.01688xÇB2-9449 (N=670, r=().982).olarak belirlenmiş, populasyonlar ve örnekleme dönemleri arasında önemli bir farklılık bulunmamıştır. Kondisyon faktörü Dönerdere için 1.461, Karasu için 1.370, Bendimahi için 1.456 ve Koçköprü için 1.303, populasyon genelinde ise 1.411 olarak bulunmuştur. Kondisyon değeri bakımından populasyonlar ve aynı populasyon içinde örnekleme dönemleri bakımından bazı farklılıklar görülmüştür. Anahtar Kelimeler: Capoeta capoeta, Van Gölü Havzası, Büyüme A STUDY ON POPULATION STRUCTURE AND GROWTH PROPERTIES OF THE CAPOETA CAPOETA ( CYPRINIDAE) POPULATIONS LIVING IN SOME WATERS OF LAKE VAN BASIN, TURKEY. ABSTRACT: This study was carried out to investigate population structures and growth properties of the Capoeta capoeta living in some water bodies of Lake Van basin. The species has economic importance in distribution areas. In the basin two stagnant water bodies Koçköprü dam lake. Dönerdere irrigation reservoir and two running water Karasu and Bendimahi rivers which flowing into Lake Van were selected. The fish samples were taken in year 1995 and 1997 by using commercial trammel nets, hand nets and beach seine. On the sampled specimens, fork length, body weight and sex were determined. Opercular bone and scales were taken from the specimens for age determination. Size and age compositions, sex ratios, length-weight relations, condition factors, growth in length and weight were determined for the populations. The fork length were found to be varied between 4 to 47 cm. The ratio of exploitable specimens of the populations ( â 20 cm fork length) were found between 8% -41%. The weight were found between 1.2-1270.0 g and most abundant weight groups were varied among to habitat and according to sampling gears. The age were found between I-XIII but the specimens which are VIII and older were rare. The overall sex ratio of the populations was found for male: female as 1:0.85 In the samples the ratios of the juveniles were high and was found as 62.78 % Length-weight relationships for whole specimens was found as: W = 0.01688 x FL 2.9449 (>j=670. r=0.982). No significant difference were found among the populations and seasons. The condition factor value ( K ) was determined as 1.461 for Dönerdere. 1.370 for Karasu, 1.456 for Bendimahi and 1.303 for Koçköprü populations and 1.41 1 for the basin. Some differences were found in K values among populations and seasons. While growth in length and weight by age were found slightly better in. Bendimahi and Koçköprü populations, the growth of the Karasu population was found slowest In Dönerdere a good management and encouraging of fishing and measurements for habitat improvement are needed in Karasu, v* Key Words: Capoeta capoeta. Van Lake Basin. Growth