Morphology, growth and reproduction of the non-indigenous topmouth gudgeon Pseudorasbora parva (Temminck et Schlegel, 1846) in the wetland of Alma-Gol, Northern Iran.

摘要

Observation of topmouth gudgeon was actually the first record of its being in this wetland, indicating increasing of its distribution in new habitats. So, morphological characters, growth and reproduction of this species as newly introduced non-indigenous fish into Iran were studied in the Alma-Gol wetland (northern Iran) during a period from September 2000 to August 2002. Inter-sexual comparison of morphological characters revealed that there are significant differences in total length, head width, A-C distance and dorsal fin rays between sexes. The maximum age of the fish studied was 3+ years and 4+ for females and males respectively. Observed lengths-at-age were different between sexes, with males longer and heavier than females in all age groups. The slope of the total length-weight relationships differed significantly between sexes, being negative allometric for both sexes. The overall ratio of males to females was 1.625: 1. The highest average values of GSI were 11.93 and 6.98 for females and males respectively in spring samplings. Absolute fecundity estimates ranged from 965 to 2930, with a mean value of 2214.34+or-445.24(SD) eggs.