بررسي ساختار سني و رشد گاوماهي Neogobius fluviatilis pallasi در نهر مادرسو پارك ملي گلستان

Investigation on age structure and growth of Neogobius fluviatilis pallasi in Madarsoo Stream, Golestan National Park.

The age structure and growth of Neogobius fluviatilis Pall asi were studied using 320 specimens from Madarsoo Stream, from 1997 to 1998 in Golestan National Park. Females made up 24.7 % and males 75.3 % of the individuals (p<0.05). The total length- weight relationships were JF = 0.004Z,3 32 and J^ = 0.001 Z4 02 for male and female, respectively. The age data, derived from otolith reading. The result showed that 3+ was the oldest age group for both sexes. The most abundant ages was 2+ years, The age data were used to estimate the growth parameters of the Von Bertalanffy equation: L(t) = 26.78 0 ,(ʹ+1776 )) and iv) = 29.o.4