Present piece of work encompasses various morphometric parameters viz size, sexual maturity, allometric growth and length weight relationship of a fresh water crab M. masoniana from Gho-manhasan stream of Jammu region (J&K). Specimens were collected monthly for a period of two years (January 2012 to December 2013). A total of 592 crabs were obtained, 282 being males and 310 females. The maximum carapace width in female was 6.0 cm with abdominal width of 4.5 cm. Males exhibited maximum carapace width of 6.3 cm and chela length of 5.7 cm and chela depth of 3.5 cm . The mean body weight in males varied from a minimum of 16.674 g to a maximum of 90.186 g. Whereas in females, body weight ranged between 18,770 g being minimum & 64,850 g being maximum. Based on the relationship of carapace width (CW) with abdominal width (ABDW) and mean body weight (MBDwt) in females and relationship of carapace width (CW) with Chela length (CHL), Chela depth (CHD) and mean body weight (MBDwt) in males, the size of sexual maturity and allometric growth were assessed during the study period.
