Morphological Variation of Wedge Clam (Donax faba Gmelin, 1791) and some Environmental Factors at Bang Hoi Beach and Bang Ruea Nak Beach, Songkhla Province

Abstract

Wedge Clam (Donax faba Gmelin, 1791) is bivalve which found along the coastal beach. It is a traditional food in local community, diverse in shell characteristics and little of data on its morphological variation, especially at Singhanakorn district, Songkhla province. Then the D. faba were collected between June to August 2020 from 4 stations to study the morphology and some environmental factors within its habitats. The results showed that there were 8 patterns of shell at Bang Hoi Beach and Bang Ruea Nak Beach. Colors and patterns of shells in form F which were yellowish to reddish brown with horizontal lines, radial purple and yellowish brown lines from shell apex was the most common. The average shell size was 21.99±2.37 mm in width, 14.04±1.94 mm in height and average weight was 1.85±0.61 g. Soil and water temperature, pH and salinity were quite similar in study area. The organic content ranged from 0.01 – 0.21% and the sandy beach mainly consisting of fine to very coarse sand particles. When comparing the shell size of D. faba between 8 types, it was found that the mean shell width and weight were not significantly different, while the mean shell height was differently (p<0.05). Eight forms of D. faba were found in all stations in difference proportion, the largest size of them were found at Bang Ruea Nak Beach in August. This can be suggested that the variation on some environmental factors in station and each time periods, especially the particle size and organic content may be influence to the morphological variation of D. faba.