The Migratory Pattern and Condition of Tiny Scale Barb, Thynnichthys thynnoides (Bleeker, 1852) at Rui River, Perak, Malaysia

Abstract

A study on the migratory behavior and condition of potamodramous Thynnichthys thynnoides and its environmental attributes was studied from May to October 2015 in Rui River, the main tributary of Perak River. The migration pattern and condition of T. thynnoides were examined by using two catch techniques which are active (scoop net) and passive (gill net) sampling, while water quality parameters were determined by using standard methods. Thynnichthys thynnoides were caught between August and October as the migration season began, with peak migration occurring in September and October. The longest observed migration from the refugee habitat to the possible spawning ground was 52 km. There was a significant variation in turbidity concentration between spawning and non–spawning seasons (F = 13.23, P < 0.05). The length–weight relationships of T. thynnoides exhibited isometric body growth, and the condition of T. thynnoides declined over the spawning migration. From these results, it was concluded that the migration of T. thynnoides was dependent on environmental conditions.