Population Dynamics and Fishery of Ribbonfish (Trichiurus lepturus) of Saurastra Coast

Ribbonfish fishery in Saurastra coast of Gujarat is majorly supported by Trichiurus lepturus. It is exploited by trawls and gillnets throughout the year with peak during September to December. The highest length of T. lepturus was found to be 125 cm with a mean length of 76.47 cm. The asymptotic length, growth coefficient, and age at zero length were 131.25 cm, 0.13 and -0.0777 years. The performance index was 3.35. Recruitment pattern was trimodal with peak during May to July. The smallest length of recruitment was 27 cm. The total, natural and fishing mortality was 0.44, 0.13 and 0.31. The exploitation ratio and rate of exploitation was 0.30 and 0.105. The annual total stock, biomass and MSY was 1,91,935 t, 1,55,277 t and 34,161 t, respectively. The yield and yield per recruit at present fishing effort was 23,682.5 t and 65.13 g. The study revealed that currently the ribbonfish at Saurastra coast of Gujarat is underexploited. The fishing pressure has to be increased by 120% from the present condition to get maximum yield and biomass

Seasonal variations in the length-weight relationship and relative condition factor of Bombay duck, Harpadon nehereus (Hamilton, 1822) (Aulopiformes : Synodontidae) inhabiting the marine area of the west coast of India

Harpadon nehereus (Hamilton, 1822), commercially known as Bombay duck and is locally named as 'Bumla' or 'Bombil' along the western coast of India. The area between northern geographical coordinates of 18° and 22° N represents intermittent fishery resources with discontinuous distribution, and the majority of the resources are caught by the 'dol net'. The present study revealed information on 1523 specimens of Bombay duck, which were used for the analysis of lengthweight relationship (LWR), and condition factor (K) collected from various fishing villages of west coast of India during September 2014 to November 2016. The results indicated that females bear longer and heavier body sizes than males. The analysis of LWR shows exponent 'b' values of 3.03 for males indicating isometric growth and female (3.10) establish growth as positive allometric (b > 3). A significant dissimilarity is observed in 'b' values among the seasons for Bombay duck (P < 0.05). The ‘b’ value was highest during summer (3.37), followed by winter (3.22), autumn (3.20), and monsoon season showed the lowest value, i.e., 2.95, indicating higher growth during the summer season in terms of weight. The Kn value observed in the present investigation was 1.02 ± 0.21. Information from the field for this species is rare, and the outcomes of the present study will help the administration in conservation of H. nehereus fishery in its natural range

Trainings under AINP Mariculture

Vizhinjam Research Centre organized a training on Recent Advances in Mariculture for five days from 9th to 13th January 2017. Fisheries officers deputed from the Department of Fisheries, Government of Kerala and a few selected progressive farmers participated in this training besides selected scientists working for cage farmin

Observations on selected biological aspects of the spadenose shark (Scoliodon laticaudus Müller & Henle, 1838), landed along Saurashtra coast

Spadenose shark, Scoliodon laticaudus (Family: Carcharhinide) locally known as “sandhi” is a common species inhabiting near shallow coastal waters along the Saurashtra coast. It is exploited by trawls and gillnets throughout the year in fair abundance. The dietary components of the species were studied and expressed as percentage of numerical composition (CN), percentage of gravimetric composition (CW) and percentage of frequency of occurrence (F). The major food item in the stomachs of the species was determined using an Index of relative importance (IRI). Food and feeding analyses confirmed the carnivorous feeding behavior of this species and the food mostly comprised fishes, shrimps and squids. There was no evidence of cannibalism. Overall sex ratio was 1.18 that showed the predominance of females over males. As there is limited information about the biological aspects of this species from Saurashtra coast, the results of the present investigation may play a vital role in the management of the resource as well as for the efficient exploitation of this species

Rare occurrence of the bramble shark Echinorhinus brucus (Bonnaterre, 1788) along the Veraval coast

A spiny shark or bramble shark Echinorhinus brucus (Bonnaterre, 1788) was caught in trawl operated near Pakistan border off Veraval coast (Fig. 1). E. brucus is exclusively marine, inhabiting deep waters. It is also called sluggish bottom shark, sometimes occurring in shallow waters, especially on the continental and insular shelves and upper slopes upto 900 m depth

गुजरात के सागर तट की समुद्री शैवाल विविधता

गुजरात के सागर तट की समुद्री शैवाल विविधत

Capture based aquaculture of spiny lobster in sea cages: A new livelihood opportunity for the 'sidi' adivasi tribal people in Gujarat, India

Gujarat is one of the most important maritime states of the country having the longest coast line of about 1,640 km and a very broad continental shelf. The state has been bestowed with highly productive and diversifi ed ecosystems and considered as one of the leading marine fi sh producing states of India, with fi sheries providing livelihoods for more than 400,000 people directly and indirectly. However, over the last few years the marine fi sh production of the state has been relatively static at around half a million tonnes and has been showing signs of being fully exploited. However, as the state has a wide continental self it also has significant potential for mariculture. Owing to the economic importance and availability of seeds of spiny lobster, an open sea cage culture demonstration of Panulirus polyphagus was carried out involving Sidi tribes as a major stakeholder

Expansion of the open sea cage farming programme for 'Sidi' tribals of Gujarat

For the third consecutive year, the ‘Sidi’ tribals have launched open sea cages in the farm site established off Somnath coast at Veraval, Gujarat

Nursery rearing trials of Silver pompano in inland low-saline waters

Demonstration of Silver pompano (Trachinotus blochii) farming in shrimp ponds along Gujarat coast by CMFRI attracted much attention from the local famers and entrepreneurs

Integration of seaweed Kappaphycus alvarezii in open sea cages - a source of additional income

Seaweed resources exploited from coastal waters of Gujarat are inadequate to meet the growing demand from the seaweed based industries. Hence, there is a need to cultivate commercially important seaweeds to augment the supply of raw materials to the existing industries