بررسي صفات زيست سنجي و شمارشي ماهي گامبوزيا (Gambusia holbrooki) در سه منطقه سيجوان، مصب گرگانرود و تالاب گميشان

The morphometric and meristic characters survey of population Gambusia holbrooki in Sijual Basein,Gorgan-Rood estuary and Gomishan Wetland

The study was conducted to determine variation in morphological characters of Gambusia holbrooki Givord, 1859 in Sijual Zone (freshwater), Gorgan-Rood Estuary (2-3ppt), and Gomishan Wetland (13ppt) during summer, 2006. In this study, 8 morphometric and 5 meristic characters were used. Morphometric characteristics corrected and standardized before analysis for reducing error of allometric growth. There was no significant difference in head length, eye orbit diameter, distance between two eyes orbits, pre-anal and pre-ventral fins in two Sijual Basein and Gorgan-Rood Estuary, but had with Gomishan Wetland (P<0.05). Scatter plot based on extracted factors 1 and 2 revealed that there was high similarity in Sijual Basein and Gorgan-Rood Estuary. They differ significantly from the ones in Gomishan population. Soft rays of anal, dorsal, ventral and pectoral fins were 10, 8, 6 and 11.The scales on the assumed lateral line were significantly lowest in Gomishan population than in other two studied populations. Results revealed that the salinity and other environmental parameters could be factors affecting morphometric characters in Gambusia holbrooki.