ลักษณะทางนิเวศวิทยาและชีววิทยาบางประการของเม่นทะเลชนิด Temnopleurus toreumaticus ในอ่าวปัตตานี

Abstract

The purpose of this research is to investigate the distribution pattern of brown decorate sea urchin (Temnopleurus toreumaticus), relationship of the sea urchin with environmental factors and other benthic fauna, reproductive biology, impact of the size and month factors on its feeding habit. Samples were collected by towing metal dredging net at 8 selected stations covering all area of Pattani, Pattani province during November 2018 to July 2020. Some water parameter was measured together with dredging and bottom sediment was collected at all study sites. The samples were immediately preserved in the ice box and brought back to laboratory for further analysis. It was found that the density of sea urchin in Pattani bay were 22 individuals/1,000 m2 . Water salinity, water depth, transparency, pH of soil and sand had a positive impact to the abundance of the sea urchin. Abundance of benthic species including Nephtys 2, Glycera 2, Perinereis, Clithon, Barbatiaand Lepidophthalmus showed a positive relationship with abundance of the sea urchin. It was found that polychaete was the major food component of the sea urchin (29.15%), followed by mollusc (24.69%) crustaceans (22.25%) sand (10.62%) sponge (4.88%) fish (4.83%) and plant (3.58%). The average number of food items, fullness index, vacuity index and diet breadth were 2.88±1.38, 4.56±2.40, 16.13 and 0.43, respectively. There was no significant difference on sex ratio between male and female 0.9:1.0 (P>0.05). Moreover, it was found that the size at first maturity of male and female were 33.17 millimeter and 37.08 millimeter, respectively. Result from ANOVA indicated that size of sea urchin and month of collection significantly affected the average number of food item (P<0.001) . However, the size did not affect fullness index (P>0.05). This study is considered the first effort investigated some ecological and biological aspects of this species in the world. Information gathered from this study will thus be helpful for the management of sea urchin resources and their application for future sea urchin culture.