Morphometric study of horseshoe crab (Tachypleus gigas and Carcinoscorpius rotundicauda) from Balok, Pahang

Abstract

This study was conducted at Balok, Pahang. Sampling was done during full moon and new moon in May to September 2010. The samples of horseshoe crab (Tachypleus gigas and Carcinoscorpius rotundicauda) were collected at the beach and mangrove area for morphometry measurement. Existence area of horseshoe crab was important for distribution record. Ten variables of morphometry (millimeter) including body weight have been taken during sampling. The total of 115 individual of two horseshoe crab species were collected from the sampling sites. There are 92 individual of T gigas consists of 33 males and 59 females, while 15 males and 8 females from total 23 individual of C. rotundicauda. Weight ranges (g) of horseshoe crab are 180 - 420 gram for male and 290 - 1200 gram for female T gigas, while 100 - 260 gram for male and 260 - 340 gram for female C. rotundicauda. In addition, range of length for male and female T gigas are 244- 378 mm and 230- 516 mm, whereas 269 - 337 mm and 299390

mm for male and female C. rotundicauda. Ratios of male to female tells the comparative body size which is for T. gigas species, the male size is nearly 72% of the female while for C. rotundicauda, male size is nearly 83% of female. In every aspect, it shows that female of T gigas and C. rotundicauda are bigger and heavier than male of both species.