Trawl Selectivity on  Johnius dussumieri (Cuvier, 1830) along Gujarat, Northwest Coast of India

Madhu V.R.; Panda S.K.; Meenakumari B.

doi:10.56093/ft.v50i2.29152

Authors

Madhu V.R. Central Institute of Fisheries Technology, P.O. Matsyapuri, Cochin - 682 029
Panda S.K. Central Institute of Fisheries Technology, P.O. Matsyapuri, Cochin - 682 029
Meenakumari B. Division of Fisheries, Krishi Anusandhan Bhawan - II, New Delhi - 110 012

https://doi.org/10.56093/ft.v50i2.29152

Keywords:

Trawl codend selectivity, diamond mesh, Johnius dussumieri, length at first maturity, optimum mesh size

Abstract

The codend selectivity of Johnius dussumieri, an important resource targeted by trawlers along Gujarat coast was studied. Covered codend method was used to derive the selection parameters of J. dussumieri using a 40 mm diamond mesh codend. Stacked haul method was used to derive the selection parameters which were utilized for deriving the selectivity estimates. The data on the escapement through experimental codend collected from 6 hauls were used for the analysis. The length at 50% retention (L50)Â±SE of the species was derived as 7.55 Â±0.12 cm. The selection range was worked out as 3.41 Â±0.18 cm, selection factor as 0.19 and the selection ratio as 0.45. Considering the length at first maturity to be 122 mm, the optimum mesh size required in the codend (diamond mesh) for conser- vation of this species was found to be 64.2 mm.