A note on morphometric and length-weight relationship of Upeneus moluccensis (Bleeker) off Veraval coast

Upeneus moluccensis were collected from the catches of bottom fish trawl of "M. V. Saraswati" off Veraval coast in the area lat. 20 degree 26 N and long. 70 degree 35 E. The fish were analysed for length-weight relationship and morphometric characters. The fishes were found to vary from 116 to 161 mm in length and 20.0 to 50.0 g in weight. The exponent value and correlation coefficient for length-weight relationship was found to be 2.73 and 0.991 respectively.

Pawn [i.e. prawn] fishery in Gujarat location of new prawn grounds off Veraval

Details about the three departmental vessels, Gulf shrimp, Indian Salmon and Silver Pomfret and gear in the exploratory fishing off Veraval coast are reported. Potential prawn fishing grounds have been located by their operation in section 20-70, 21-69 and 22-69 in the cruises conducted in October, 1962. Observation regarding suitability of gear and composition of catch are given. The possibility of better prawn grounds occurring in areas deeper than the present grounds is indicated.

A few observations on the biology of Tachysurus thalassinus Ruppell from Veraval (Gujarat)

The length-weight relationship of T. thalassinus differed in the sexes and, therefore separate equations were obtained; for males log W = -5.1728 4- 3.0495 log L; and for females log W = -5.7456 + 3.2798 log L. The spawning period of this species appears to be restricted to a short period from October to November. Fecundity has been found to range from 33 to 55 mature eggs in specimens of the size range 421-564mm. The sex ratio of males to females was 1.8:1. T. thalassinus is a bottom carnivore, crustaceans ranking first in food followed by fishes, mollusc and polychaetes.

On the results of preliminary fishing trials with shark long lines in Veraval waters

Experimental fishing operations with shark long lines were conducted in the sea off Veraval with a view to studying their efficiency and gathering information on the available resources of sharks to be used for planning the future gear investigations. The trials were undertaken in 1967, employing departmental fishing vessel "Fishtech No. IV" (10.9 m O.L. and 48 H.P. engine). A total of 5525 hooks were employed and 242 sharks weighing 8629 kg were landed. Data on composition of catch, weight of fishes landed, effectiveness of various baits in capture of different species of sharks and effectiveness of gear including its catch efficiency in this area were compiled. Bait preference was also observed in certain species of sharks caught. Chirocentrus dorab proved to be the cheapest and most effective bait in capture of all the three varieties of sharks landed.

Some observations on the performance of 10.5 m mid-water trawl operated off Veraval

The communication presents the results of fishing trials conducted off Veraval with a 10.5 m four-seam unequal paneled mid-water trawl with vertically curved otter boards. The design and structural details of net and otter boards are described in detail. Particulars such as the fish caught during experimentation, horizontal spread of the net as well as towing resistance offered in action are also incorporated.

Some aspects of the biology of Otolithes cuvieri (Trewavas) and Johnius glaucus (Day) from Veraval

The length-weight relationship in O. cuvieri and J. glaucus can be described by the equations log W=-5.27997+3.13225 log L and log W=-4.93431+3.02556 log L respectively. The length at first maturity in O. cuvieri is estimated as 256 mm and in J. glaucus as 180 mm. Empty stomachs occurred in high percentage in both the species. A study on composition of food items revealed that O. cuvieri feeds on a variety of organisms while J. glaucus a selective feeder.

On the biology of Tachysurus caelatus (Valenciennes) from Veraval

The length-weight relationship of males and females of Tachysurus caelatus can be described by the equation log W = -5.6659 + 3.2685 log L and log W = -4.7648 + 2.9104 log L, respectively. A sex ratio of 1.37 males : 1.00 females was observed. Fecundity in the fish measuring 385 to 402 mm ranges between 44 and 55 ova. It is a demersal carnivorous feeder, feeding chiefly on crustaceans, fish, molluscs and polychaetes.

Some aspects of the biology of Tachysurus tenuispinis Day from Veraval

The regression coefficients in length-weight relationship of males and females of Tachysurus tenuispinis differ significantly. The relative condition factor was calculated for females in relation to various lengths and months. The sex ratio in the catch varied widely in the different months. The number of eggs ranged from 72 to 89 for the fish of length 394 to 570 mm. Empty stomachs occurred in a very high percentage (63.5%) of the total stomachs examined. This is a bottom carnivorous feeder. The main food items found in the guts in order of preference were crustaceans, polychaetes, molluscs, fishes and echinoderms.

Development of trawls for medium sized trawlers for Veraval, north-west coast of India

Comparative fishing experiments with 25 m bulged belly and 25 m six seam trawls were carried out to study the relative efficiency of the gear. Bulged belly trawl was found more efficient than the other at depths below 40 m. The tension and horizontal opening were more in bulged belly and six seam trawl respectively. Bulged belly caught more of prawns and lobsters but there was no significant difference in the catch of sciaenids, cephalopods and ribbon fishes in the two nets.

On the results of bottom-drift-long-lines operated off Veraval with particular reference to selective action of baits and hooks used

Hither to comprehensive data on the various types of baits used for capture of predatory fish and selective action of different hooks for bottom-drift-long lines is conspicuous by its absence. In the present studies attempts were made to evaluate the effectiveness of three types of baits and four sizes of hooks. Significant results obtained during the course of these investigations are presented in this communication.

On the performance of otter trawls operated from a 15.4 m trawler off Veraval

Results obtained with three trawl nets namely, 13.7m four seam, 15.8m six seam and 18.3m four seam operated from a 15.4m wooden trawler, are presented. Among the three nets operated, 15.8m six seam trawl and 18.3 four seam trawl were found to be equally effective for the capture of shrimp and during the lean season 15.8m six seam trawl can be successfully operated to exploit demersal as well as semi-pelagic fish resources. The catch data were analysed using analysis of variance and Gulland's method.

Studies on the effect of colour of webbing on the efficiency of gill nets for hilsa and pomfret off Veraval

Influence of colour of webbing on the catch of gill nets for commercially important hilsa (Hilsa toli and Hilsa ilisha) and pomfret (Pampus argenteus and Parastromateus niger) has been studied in the coastal waters off Veraval. Among the colours tested yellow and white are recommended for hilsa and pomfret gear. Influence of fishing depth, surface water temperature and turbidity on catch are also discussed.

A new high opening trawl for Veraval waters

The newly developed 25m high opening trawl possesses the properties of a high rising bottom trawl and a semi-pelagic trawl. The new gear is effective for the capture of demersal and semi-pelagic fishes. The net offered more horizontal opening and less resistance with significantly high catch of ribbon fish when compared with bulged belly trawl.

On the comparative efficiency of "V" shaped and rectangular flat otter boards for trawling off Veraval, north west coast of India

V shaped all steel boards, with their inherent stability to tide over obstacles and mud, interchangeability of starboard and portside boards are found to be superior to conventional flat rectangular boards for bottom trawling. These are cheaper in construction, offer less resistance and give longer service. Comparative trials with the two types of boards showed significant difference in tension between the boards but not in catch or horizontal opening.

Performance of 25m large mesh demersal trawl off Veraval, north west coast of India

Performance of a 25m large mesh demersal trawl, with 150mm mesh size in the fore parts of the trawl was evaluated in comparison with one boat high opening trawl of the Bay of Bengal Programme (BOBP) with 360 meshes of 160mm mesh size and 25.6m head rope length. An 8.2% increase in catch was obtained by 25m large mesh demersal trawl. The gear is comparatively cheaper, lighter in construction and offered better horizontal spread with significantly lower towing resistance. Commercial suitability of the gear for efficient harvesting of demersal fish resources of the region is discussed.