Journals / Turkish Journal of Veterinary and Animal Sciences / 2005 / Cilt: 29 - Sayı: 2
Age, Growth and Diet Composition of the Resident Brown Trout, Salmo trutta macrostigma Dumeril 1858, in Fırnız Stream of the River Ceyhan, Turkey
- Pages
- 285–295
- DOI
- —
Abstract
It was aimed to describe some population charactersitics of Salmo trutta macrostigma from Fırnız Stream of the River Ceyhan. The age, growth, length-weight relationship and diet composition were investigated from May 2000 to February 2001. The ratio of male to female of 197 brown trout caught by electroshocker was 0.67:1.00 and their fork lengths varied from 8.0 to 48.5 cm and the majority of them were in the 11.0-17.0 cm length group. Total weights varied from 7.4 to 1441.0 g and age distribution ranged between 0 and 9. The length-weight relationships were estimated as W = 0.0149*FL3.009 (r = 0.994) for males and W = 0.0163*FL2.971 (r = 0.995) for females. The von Bertalanffy growth parameters were estimated as L\infity = 51.00 cm, k = 0.131, t0= - 1.220, W\infity = 2034.96 g for males and L\infity = 72.75 cm, k = 0.097, t0 = - 0.910, W\infity = 5421.51 g for females. The condition factor of 197 brown trout ranged from 1.13 to 1.85 and the differences between females and males in the same age groups were not significant (P > 0.05). A total of 15 prey groups were identified in the diets of brown trout and most abundant were Coleoptera, Trichoptera, Ephemeroptera, Plecoptera, Malacostraca, Diptera, Acarii, Heteroptera, fish, fish eggs and plant seeds. According to the Index of Relative Importance (IRI%), five food items represented more than 99% of the total diet, with the most important being Gammarus sp. (43.96%), Nemoura sp. (18.85%), Hydropsychidae (13.44%), Isoperla sp. (12.83%) and an unidentified Diptera sp. (10.26%).
Özet
Ceyhan Nehri, F›rn›z Çay›’ndaki Salmo trutta macrostigma’n›n baz› populasyon özelliklerinin tan›mlanmas› amaçlanm›flt›r. Yafl, büyüme, boy-a¤›rl›k iliflkisi ve diyet kompozisyonu May›s 2000 ve fiubat 2001 tarihleri aras›nda incelenmifltir. Elektroflokerle yakalanan 197 adet alabal›kta erkeklerin diflilere oran› 0,67:1,00 ve çatal boylar 8,0-48,5 cm aras›nda de¤iflmifl ve ço¤unlu¤u 11,0- 17,0 cm boy grubunda yer alm›flt›r. Total a¤›rl›klar 7,4-1441,0 g, yafl kompozisyonu ise 0 ile 9 aras›nda de¤iflmifltir. Boy- a¤›rl›k iliflkileri erkeklerde W = 0,0149*FL3,009 (r = 0,994), diflilerde ise W = 0,0163*FL2,971 (r = 0,995) olarak hesaplanm›flt›r. Von Bertalanffy Büyüme parametreleri erkekler için L∞ = 51,00 cm, k = 0,131, t0 = - 1,220, W∞ = 2034,96 g, difliler için ise L∞ =72,75 cm, k = 0,097, t0 = - 0,910, W∞ = 5421,51 g fleklinde hesaplanm›flt›r.‹ncelenen 197 adet alabal›kta kondisyon faktörü 1,13 – 1,85 aras›nda de¤iflmifl ve ayn› yafl grubunda erkek ve difller aras›nda istatistiki aç›dan önemsiz bulunmufltur (P > 0,05). Alabal›klar›n diyetlerinde toplam 15 adet besin çeflidi tesbit edilmifl ve bunlar›n en çok Coleoptera, Trichoptera, Ephemeroptera, Plecoptera, Malacostraca, Diptera, Acarii, Heteroptera, bal›k, bal›k yumurtas› ve bitki tohumu gruplar›na ait olduklar› görülmüfltür. K›smi Önemlilik Indeksine (% IRI) göre 5 besin organizmas› grubunun toplam diyetin % 99 undan fazlas›n› oluflturdu¤u tesbit edilmifltir. En önemli besin organizmalar›; Gammarus sp. (% 43,96), Nemoura sp. (% 18,85), Hydropsychidae (% 13,44), Isoperla sp. (% 12,83) ve cinsi teflhis edilemeyen bir Diptera sp. (% 10,26) dir.