DETERMINATION OF MONTHLY LENGTH-WEIGHT RELATIONSHIPS AND LENGTH COMPOSITION OF WHITING (Merlangius merlangus euxinus) CAPTURED FROM THE BLACK SEA COASTS (SİNOP-SAMSUN)

Abstract

ÖZBu çalışmada Karadeniz'de avlanan mezgit (Merlangius merlangus euxinus) balığının aylık olarak boy-ağırlık ilişkisi ve boy kompozisyonu belirlenmiştir. Araştırma verileri Kasım 2012-Ekim 2013 tarihleri arasında Sinop ve Samsun bölgelerinde avcılık yapan ticari balıkçı gemilerinden (dip trolü ve uzatma ağı) elde edilmiştir. Örneklenen mezgit balıklarının total boy ve ağırlık ölçümleri kaydedilmiş ayrıca balıklarda cinsiyet tespiti yapılmıştır. Araştırma süresince tüm veriler genel, dişi, erkek ve belirsiz olmak üzere değerlendirilmiştir. Türün genel, dişi, erkek, belirsiz olarak ortalama total boyu 13.25 ±0.04 cm, 13.72 ±0.05 cm, 13.01 ±0.04 cm, 10.78 ±0.12 cm ve genel boy-ağırlık ilişkisi W=0.0068L3.0202 (n=2173; R=0.987) şek-linde hesaplanmıştır. Mezgit balığının boy kompozisyonu ve boy-ağırlık ilişkisinin aylık olarak farklılık gösterdiği (p<0.05), "b" değerinin aylara göre <3 yada >3 şeklinde değiştiği tespit edilmiştir. Türün genel olarak izometrik bir büyümeye sahip olduğu, Aralık 2012, Ocak, Şubat, Ağustos ve Eylül 2013 aylarında pozitif allometrik büyüme, diğer aylarda ise negatif allometrik büyüme gösterdiği saptanmıştır. Balıklarda boy-ağırlık ilişkisi çalışmalarının belirli bir veya birkaç dönem dikkate alınarak yapılması "b" değeri üzerinde yanıltıcı olabilmektedir. Balığın yaşamı boyunca birçok iç ve dış faktörler (beslenme, üreme, büyüme, tür içi ve dışı rekabet, yaşam sahası, mevsim, sıcaklık, tuzluluk ve kirlilik gibi) nedeniyle etkilenebileceğin-den populasyon dinamiği çalışmalarında daha geniş ölçekli ve detaylı veri alımına dikkat edilmelidir.Anahtar Kelimeler: Mezgit (Merlangius merlangus euxinus), Boy-ağırlık ilişkisi, Boy kompozisyonu, Aylık izleme, Karadeniz ABSTRACT DETERMINATION OF MONTHLY LENGTH-WEIGHT RELATIONSHIPS AND LENGTH COMPOSITION OF WHITING (Merlangius merlangus euxinus) CAPTURED FROM THE BLACK SEA COASTS (SİNOP-SAMSUN)Monthly length-weight relationship and length composition of whiting (Merlangius merlangus euxinus) were determined from the Black Sea coasts in the study. Study data were obtained between November 2012 and October 2013 from commercial fishing vessels (demersal trawl and gillnets) in the Samsun and Sinop regions. Total length and weight of sampled whiting were measurement and also determined gender of fishes. Mean length for general, female, male, unsexed and general lengthweight relationship of whiting were calculated 13.25 ±0.04 cm, 13.72 ±0.05 cm, 13.01 ±0.04 cm, 10.78 ±0.12 cm and W=0.0068L 3.0202 (n=2173; R=0.987) respectively. It was determined that length composition and length-weight relationship of whiting monthly differed. Values of "b" for the months were found to change as <3 or >3. Whiting has as generally isometric growth but positive allometric growth showed for December 2012, January, February, August and September 2013 and negative allometric growth showed for other months were established. It may be inaccurate on the value of "b" that the studies of length-weight relationship in fishes is done considering specific or several periods. Because of...

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