Biology and stock assessment of Tachysurus jella (Day)
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Authors
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S G Raje
Mumbai Research Centre of Central Marine Fisheries Research Institute, Mumbai - 400 001, India
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A P Dineshbabu
Mangalore Research Centre of Central Marine Fisheries Research Institute, Mangalore - 575 001, India
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THAKUR DAS
Mumbai Research Centre of Central Marine Fisheries Research Institute, Mumbai - 400 001, India
Abstract
Biological parameters such as length-composition, food and feeding, length-weight relations and growth of
Tachysurus jella
was studied using the data collected during 1987-2003. The occurrence of empty stomach was high (70%). Stomach content
analysis revealed that the fish is a carnivore feeding mainly on bottom dwelling crustaceans (Preponderance Index, PI : 97.3)
such as
Squilla
spp. (PI: 39) and crabs (PI: 35). The length-weight relationship was Log W = -5.7938 + 3.4426 Log L (r =
0.96). Estimated values of
L∞ and K were 518 mm and 0.65yr-1 respectively. It was estimated that T. jella
reaches 278 mm at
the end of one year and 377 mm in two years. The longevity was estimated to be 4 to 4 ½ years. Stock assessment of
T. jella
during 1987-1999 indicated that the stock was overexploited (E = 0.73). Higher fishing effort and sharp reduction in yield
during 2000 - 2004 confirmed that the species was under heavy fishing pressure and regulatory measures have to be imposed
to sustain and improve the fishery of this species.
