Assessment of Carapace Dimensions, Condition Factor and Sex Ratio of Portunus pelagicus (Linnaeus, 1758), Along the Mangaluru Coast, Karnataka, India
N.M. Anjum
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
S.R. Somashekara
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
K. U. Sheethal
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
U.A. Suryawanshi
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
H. N. Anjanayappa
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
S. T. Shelke
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
P.A. Telvekar
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
J. G. K. Pathan *
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
*Author to whom correspondence should be addressed.
Abstract
The research examined the correlations between width-weight and length-width relationships in Portunus pelagicus along the Mangaluru coast in Karnataka, India. A total of 607 specimens were collected fortnightly from the Mangaluru fish landing centre from January to December 2022, of which 327 were males and 280 were females. The relationship between weight and carapace width for both sexes was determined as y = 2.8661x - 1.0413, with an R-squared value of 0.7252. Conversely, the relationship between carapace length and weight for both sexes yielded the equation y = 2.9571x - 0.1628, with an R-squared value of 0.7449. By using the Chi-square analyses, the male and female ratio was compared. The sex ratio of P. pelagicus was found to be 1:0.88 (Male: Female), showing no significant deviation from the anticipated ratio of 1:1. The condition factor varied between 0.9933 to 1.0427 for males and 1.0047 to 1.0658 for females, exhibiting a range in physiological status across the sexes.
Keywords: Blue swimming crab, Portunus pelagicus, mangaluru coast, sex ratio, condition factor