The article provides the landing details of the Periscope Shrimp, Atypopenaeus stenodactylus in different landing centers at Bombay coast during the period 1983-1984.  It also deals with some biological aspects of the species

Aravindakshan, M

Karbhari, J P

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MARINE FISHERIES INFORMATION SERVICE (fc,..-'—. fc .:....I ^ No. 83 MAY 1988 SOME ASPECTS ON THE FISHERY AND BIOLOGY OF PERISCOPE SHRIMP FROM BOMBAY WATERS* Introduction The Periscope shrimp Atypopenaeus stenodactylus Stimpson constitutes a fishery at Versova by 'dol' net. The annual average landing was reported to be 105 tonnes at this centre constituting about 3.3% of total 'dol' net landings of prawns at this centre (Kunju, 1967, Proc. Symp. Cruit., 4: 1382-97). The fishery is seasonal lasting from November to May. A compa-rative study of fishery of this little known species is given for the years 1983 and 1984 at Versova and Sassoon Dock. The area of operation for A. stenodactylus at Sas-soon Dock is off Murud-Harnai coasts of Maharashtra. The operational depth may range from 27 to 70 m. The landings at Versova were estimated for 'dol' landings considering each boat net combination as a fishing unit. At Sassoon Dock only mechanised country craft trawlers that brought medium sized pena-eids such as Metapenaeopsis stridulans during March-May were considered for study and estimation of the landings of periscope shrimps. The monthwise lan-dings by 'dol' net at Versova are given in Table 1. * Prepared by M. Aravindakshan and J. P. Karbhari, Bombay Research Centre of CMFRI, Bombay. The percentage of this species in total prawn Ian dings by 'dol' at Versova was estimated at 3.5 and 2.8 respectively for 1983 and 1984. The considerable decline in the magnitude of catches at Versova during 1984 may be attributed to the general decline in catches of prawns. Table 1. Monthwise landings of Periscope shrimp by 'dol' net at Versova during 1983-'84 Month January February March April May June July August September October November December Total Catch 1983 21,500 11,500 21,000 21,500 31,500 — — • — — — 48,500 51,290 2,06,790 ' (kg) 1984 2,005 3,015 4,015 3,010 2,010 — — — — — 2,000 2,427 18,482 21 The landings by trawlers at Sassoon Dock are given in Table 2. Table 2. Landings of Periscope shrimp by trawlers at Sassoon Dock. Months Catch (kg.) 1983 1984 March April May 4,415 3,315 2,274 4,210 3,118 3,577 Total 10,004 10,905 The quantity landed at Sassoon Dock was much less than that landed at Vcrsova. This might be due to the escaping of juveniles through the large meshes of the net (3 cm) as compared to that of 'dol ' nets (1 cm) and also due to the different depth ranges where the nets were operated. At Sassoon Dock the landings constituted 1.5% of total prawn landings. Variations were noticed with regard to size range and sex ratio at each centre. The total length was found to range from 22-38 mm at Versova with a sex ratio of 1:3 with female dominance (Table 3). In trawler landings at Sassoon Dock, females were always dominant. A size range of 40-65 mm was noticed for the specimens from trawler catches at Sassoon Dock. Table 3. Month-wise sex ratio of A. stenodactylus at Versova and Sassoon Dock Place Month 1983 1984 Male Female .Male Female Versova 5 ) >> 3> 9* 99 J » 9> 99 > 5 99 99 Sassoon Dock 9> >» January February March April May June July August September October November December March April May 48 50 43 50 60 — — — — — 50 48 30 20 22 52 50 57 50 40 — — — — — 50 52 70 80 78 46 50 42 50 48 .— — — — — 48 52 22 15 18 54 50 58 50 52 — — — — — 52 48 78 85 82 O JAN 83 FEB MAR APR 40 201 0 MAY NOV DEC ZOtnm 30 40 50 40 mm Fig. 1. Lengtli frequency distribution of Atypopenaem stenoda-ctylus Stimpson at Versova (Dol net). 'Dor catch The dominant mode at 25 mm was noticed in November and December 1983. During the other months the main mode remained at 28 mm for 'dol ' net at Versova. In 1984 the dominant mode was at 35 mm for January, November and December. During other months.chief mode was at 33 mm with slight progression in March and April when the mode stood at 38 m.m (Fig. 1). Trawler catch In 1983 the mode at 56 mm had dominated in March which more or less continued upto April. It shifted to 60 mm in May. During 1984 dominant mode at 58 mm was found to continue in April and May (Fig. 2). Of the 620 specimens of size range 22-65 mm analysed crustacean appendages, sand grains and debris constituted the major food items. 50 to 10 A, 1985 y* \ MARCH ^ , - . * " " • ^ ^ - ^ y^ I9M w>m. ^^""^^ « i» eSinm 40IMI4S Fig. 2. Length frequency distribution of Atypopenaeus stenoda ctylus Stimpson at Sassoon Dock (Trawl net). 22 The crustacean appendages were mainly of copepods and decapod crustaceans. This formed about 75% of the food injested. Sand grains and debris constituted 20% and foraminifera 5% of the total stomach contents. The specimens found in 'dol' nets were immature. Mature females were rarely noticed. In trawler landings which were mostly females, the percentage of mature specimens was as high as 80%. This indi-cated that the species spawned during these months. The sudden appearance of this species in November in 'dol' catches at Versova suggests their shoreward movement from deeper waters where spawning takes place. This species being small, does not attract a ready market in fresh conditions. The 'dol' catches are sun-dried whereas trawl net landings are sold along with medium sized penaeids. 

Some aspects on the fishery and biology of Periscope Shrimp from Bombay waters

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Some aspects on the fishery and biology of Periscope Shrimp from Bombay waters

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