Age, length-weight relationships and condition factors of endemic Antalya barb Capoeta antalyensis (Battalgil, 1943)

The aim of this study was to determine the length-weight, length-length relationships (LWR and LLR) and condition factors of Antalya barb Capoeta antalyensis, an endemic species to Turkey. The specimens (N = 125) were caught using the gill nets in the Sorgun Dam (Aksu, Isparta). The age of the study specimens varied between one and six years. The total length and body weight of the specimens varied from 17.7 – 36.7 cm and 57.03 – 526.91 g respectively. A negative allometric growth (b = 2.7743) was recorded for the species whereas the LWR and total length (TL) – fork length (FL) equations were W = 0.0203 × TL2.7743 (R2 = 0.95) and TL = 0.402 + FL × 1.061 (R2 = 0.99) respectively. The condition factor was determined for every specimen. In light of the results obtained in the study this species may be considered for aquaculture ensuring sustainable population in the wild. This study provides new information that can play an important role in the sustainable management this species

Variations of Some Growth Characteristics and Length-Length Relationships of Sakarya Bleak (Alburnus esherichii Steindachner, 1897) in Different Habitats

In this study, some growth characteristics and relationships of Sakarya bleak inhabiting different water habitats (dam, pond and creek) in the Bilecik Province of Türkiye were examined. Sample weights ranged from 0.17 to 111.25 g. Total lengths were measured between 2.70 and 19.80 cm. According to the localities, the b values varied between 2.9469±0.07 and 3.2548±0.03. R2 values were computed between 0.850 and 0.996. The relative condition factor values were similar to each other, while the Fulton’s condition factor values ranged from 0.79±0.01 to 1.29±0.03. The length-weight (LWR) and length-length relationships (LLRs) of samples were examined. According to localities, growth type of the length - weight relationships were either isometric or positive allometric

Evaluation Of The Ecological And Economical Results Of The Introduced Alien Fish Species In Lake Egirdir, Turkey

Lake Egirdir is the second largest lake in Turkey and its fish fauna in 1950's was consisted of Barbatula mediterraneus, Cobitis turcica, Capoeta pestai, Cyprinus carpio, Hemigrammocapoeta kemali, Pseudophoxinus egridiri, Pseudophoxinus handlirschi, Vimba vimba and Aphanius anatoliae. Sander lucioperca were introduced to the lake and a considerable amount of pikeperch fishery become possible during the 1970s. However, during the 1980's, most of the native fish species in the lake disappeared due to predatory effects of the pikeperch. Cannibalism rate of pikeperch increased (96%) and their size in the catch decreased because of unsufficient prey fish and overfishing. Moreover, with the collapse of crayfish stock because of a fungal infection, the lake fishery became deteriorated. In the followed years, Gambusia affinis, Knipowitschia caucasica, Tinca tinca, Carassius gibelio, Alburnus chalcoides, Seminemacheilus ispartensis, Atherina boyeri and Pseudorasbora parva were introduced to the lake and cannibalism rate in pikeperch population decreased to 96%. Annual catch in the lake decreased to 38-450 tons in the last five years from 2000 tons in the years of 1970s. At the time of this research 13 fish species was present in the lake and 7 of these were native while 6 were alien species. Consequently, the alien fish species introduced to Lake Egirdir have caused a change in the lake's native fish fauna, destroyed its endemic species as well as giving damage to both the food-chain structure of the lake's ecosystem and the socioeconomic structure of the region.Wo

Eğirdir Gölü Makrofitlerinin Gelişme ve Yayılma Özelliklerinin Sualtı Gözlemleri ile İzlenmesi

Bu çalışmada; Eğirdir gölündeki makrofitlerin gelişme ve yayılma özellikleri sualtı görüntüleme çalışmaları ile tespit edilmiştir. Ayrıca suyun fiziko-kimyasal değerleri de tespit edilerek bitki bioması üzerine etkili parametre belirlenmiştir. 2011 ve 2012 yıllarında ortalama sıcaklık 21 °C, oksijen 11,48 mg/l, pH 9,4, elektriksel iletkenlik 385,6 μS/cm, organik madde 21,9 mg/l, klorofil-a 0,7 mg/m3, görünürlük, 2,73 m, ortalama biomas 413,4 g/m2 olarak bulunmuştur. Su derinliği 2011 yılında 52 cm ve 2012 yılında 55 cm azalmıştır. Bitkilerin gelişimi ve yayılması üzerine etkili parametrenin derinlik azalması olduğu belirlenmiştir

İznik Gölü (Bursa/Türkiye)’ndeki Gümüşi Havuz Balığının (Carassius gibelio Bloch, 1782) Büyüme Özellikleri

Bu çalışmada, İznik Gölü’nde bulunan Gümüşi Havuz Balığı (Carassius gibelio Bloch, 1782)’nın büyüme özellikleri belirlenmiştir. Ocak - Aralık 2006 tarihleri arasında yakalanan 3114 adet (1060 erkek, 2054 dişi) balığın yaş ve eşey kompozisyonu, yaş-boy, yaş-ağırlık, kondisyon faktörü, oransal boy ve ağırlık artışları tespit edilmiştir. Populasyondaki bireylerin 0-VI yaşlar arasında dağılım gösterdiği, II. yaş grubunun diğer yaşlara oranla daha baskın olduğu saptanmıştır. Yaş gruplarına göre ortalama boy ve ağırlığın 8,8±0,021 cm ile 30,9±0,271 cm ve 14,4±0,079 g ile 764,8±13,733 g arasında değiştiği saptanmıştır. Populasyonu oluşturan bireylerin boy-ağırlık ilişkisi W=0,015756L3,125 ve kondisyon faktörü 2,350±0,014 olarak bulunmuştur