Cephalopod fishery at Kakinada along the east coast of India: Resource characteristics and stock assessment of Loligo duvauceli ·

At Kakinada along the east coast of India, cephalopods were exploited by trawls. Fishery occurred round the year with peak during August-October. Peak abundance and fishery of cuttlefishes coincides with this period, whereas for squids it is during March-May. Cephalopod production continued to increase initially with fishing effort, until 1995, but declined thereafter despite increased fishing effort and expansion of fishing to deeper waters. Fishery, growth, mortality, recruitment pattern and exploitation rates of Loligo duvauceli were studied. Nearly 97% of their catch was by zero year groups. They attain sexual maturity and spawn during the first year itself. Spawning occurred round the year with peak during December-February. Exploitation rate of the species is large, 0.741 compared to Emax (0.44). This indicated that their stock is under heavy fishing pressure and subjected to over-exploitation. Stock also exhibited declining trend over the years during 1995-'99. These necessitate immediate attention to avoid coHapse of the stock and fishery.

Polychaetous annelids (order Sabellida) from the Karachi coast, Pakistan

Fifteen species of polychaete worms, belonging to order Sabellida, are described from the Karachi coast. Of these 10 are new records for Pakistan: Hydroides albiceps (Grube, 1870), H. exaltatus (Marenzellar, 1885), Protula sp. Spirobranchus tetraceros (Schmarda, 1861), Vermiliopsis infundibulum glandigera group, Demonax sp. and Bispira cf tricyclia (Schmarda, 1861).

Fishery, population characteristics and stock assessment of cuttlefishes, Sepia aculeata and Sepia pharaonis at Kakinada along the east coast of India

Cuttlefishes were exploited exclusively by trawls along the coast. Growth, recruitment, mortality and exploitation rates of Sepia aculeata and Sepia pharaonis were studied. Fishery of the former was supported mainly by zero year and the latter by zero and one + age groups. Both attain sexual maturity during the first year itself and spawn during August-March with peak during November-December. Natural mortality of S.aculeata was 2.22, fishing mortality 2.34 and total mortality 4.56. It was 1.69, 1.97 and 3.66 respectively for S.pharaonis. Exploitation rate was 0.52 and Emax 0.72 for S.aculeata and it was 0.54 and 0.76 respectively for S.pharaonis. Their mortality and exploitation rates indicated that stock remains under-exploited and have considerable scope for improving the production. However, both stock and catch exhibited wide annual fluctuation with declining trend during the period. These necessitated immediate attention including measures to minimise juvenile exploitation for improving stock and fishery.

A check list of opisthobranch snails of the Karachi coast

The check list deals with 44 species of opisthobranchs belonging to Cephalaspidea (12 species), Anaspidea (4 species), Sacoglossa (4 species), Notaspidea, (2 species) and Nudibranchia (21 species), collected from Pakistan coast of northern Arabian Sea.

A new record of Excirolana Orientalis (Dana, 1853), a cirolanid genus and species (Isopoda, Flabellifera) from the Pakistan coast

Excirolana orienta/is (Dana, 1853) belonging to the Cirolanidae, hitherto unknown from Pakistan, is collected from the rocky intertidal region of Manora Island, Karachi coast The specimens are fully described and illustrated. A list of the known species of the genus Excirolana is also provided since the genus is also first time reported from here.

On the comparative fishing experiments with a four-seam and a two-seam trawls on the east coast

Fishing experiments were undertaken to study the relative utility of a newly designed four seam type net on a conventional two seam net at the centre along the East Coast in both inshore and deeper zones (up to 100m.) and the results indicated that the new four seam net has given higher catch rate of 6 to 8% more with higher catch rate of fish supposed to belong to off bottom region. Further this gear found more selective in obtaining Lactarius, which is one of the good variety of fish from trawlers, in both quantity as well as in quality. In terms of horizontal spread this new net gave less on comparison with the conventional two seam net, thereby showed corresponding increase in vertical spread; but warp tension remained more or less same in both the gear. Both gear have worked equally well in majority of depth ranges experimented with optimum spread. Finally the results indicated that the new net can work well from the present trawlers along the coast.

Studies on the occurrence of enteric bacteria in the estuarine waters along the Mangalore coast

Occurrence of enteric bacteria in water, sediment and shellfishes of Mulki, Pavanje, Gurpur and Netravathi estuaries of the Mangalore coast is reported. 70 water samples, 71 sediment samples and 37 shellfish samples were analysed in 18 months. Total bacterial load in sediment and shellfishes was found to be more than that in water samples. The total bacterial load was not very high. However, enterococci, particularly coliforms in sediments, water and shellfishes were found to be quite high, indicative of faecal pollution. The incidence of Salmonella spp. was recorded in all the estuaries except the Mulki estuary.

The fecundity of the false trevally, Lactarius lactarius (Bloch and Schneider) along the Karwar coast

A clear knowledge of the reproductive potential or fecundity of a fish is quite an essential pre-requisite for the proper management and conservation of the resources. The fecundity studies are also undertaken to determine the index of diversity dependent factor affecting the population size (Simpson, 1951). Qasim & Qayyam (1963) have detailed the various pathways by which an understanding of fecundity could be used for fishery biological work. The ability of egg production varies within the individual limits such as length, somatic weight, gonadal weight, volume of fish etc.

On the occurrence of mature penaeid prawn Penaeus merguensis in a shallow solar salt works reservoir along the Okhamandal Coast of Gulf of Kutch and its spawning in laboratory

Penaeus merguensis is so far reported to attain complete maturity and spawn in the sea or deep culture ponds only. Mature specimens of stage III to V collected from a shallow reservoir of solar saltworks were studied and spawned in laboratory. A comparison of spawning of spawner from sea and reservoir is also reported.

Stock assessment of the demersal offshore fishery resources off the Karnataka coast

The total biomass of the demersal stocks in the depth range of 30-200m between 12°401 and 15°N latitudes in the Indian Exclusive Economic Zone is estimated to be a:round 1,23,000 metric tons (t). There is scope for doubling the present catch of about 40,000 t from demersal resources by extending exploitation to 50-200m depth zone. About 78% of this increase is expected to come from four species, namely, Nemipterus japonicus, Priacanthus macracanthus, Saurida tumbil and Arius spp.

Quality of cured fish from the Maharashtra coast

Chemical, bacteriological and organoleptic characteristics of sun dried/dry salted fish collected from five major centres of coastal Maharastra [sic] are reported. Wide variations are seen in the quality of the different samples. In dry salted products, moisture ranged from 16.17 to 46.58%; salt from 5.18 to 22.75%; acid insoluble ash from 1.0 to 6.8%. In sun dried samples moisture varied from 16.15 to 39.51% and acid insoluble ash from 0.42 to 2.82%. The sun dried samples, though no salt was used in the process, showed fairly good amount of salt.

Quality of cured fish on the west coast: comparative study with the IS specifications

Moisture and salt content in cured fish products from various centres on the west coast of India are compared. The moisture contents varied in samples from different centres, whereas the salt content remained more or less uniform. The deviations from the Indian standard specification were highly significant in both cases. The high mean moisture values and low salt values with respect to accepted standards are indicative of the improper drying and poor salting.

Ecosystem characterisation of Indian coast with special focus on the west coast

CSIR-National Institute of Oceanography (CSIR-NIO), Goa, India in collaboration with CSIRO, Australia organised a 2 day national experts workshop to: pool information between fisheries and oceanography experts; verify a draft ecosystem characterisation for the east coast of India; and develop a draft ecosystem characterisation for the west coast of India.

Genetic diversity of Saccostrea cucullata population in the northern coast in Persian Gulf and Oman Sea

Genetic diversity of Saccostrea cucullata in the northern coast lines of the Persian Gulf and the Sea of Oman were determined using DNA extraction and RAPD - PCR. A total of 300 samples were collected from 6 station along the coastline. Two out of six primers showed positive results namely GCG - ATC - CCC - A (Primer 1) and GTC - CAC - ACG - C (Primer 5) which were in accordance with morphometric analysis. The number of bands in the two above - mentioned primers in Khor - Tang and Chabahar station (Province of Sistan and Balouchestan) was significantly different from the number of produced bands in Dayer and Bushehr station (Province of Bushehr) as well as Gheshm and Bandar - Lengeh station (Province of Hormozgan). The cluster analisys was used to confirm the above variations. The results showed that the oyster population can be divided into two separate clusters. The first cluster included Bushehr Dayer Gheshm and Bandar - Lengeh species. The second cluster included Khor - Tang and Chabahar species. The analysis also showed that the first cluster can be divided into two Sub — cluster. Bushehr and Dayer belong to one Sub - cluster whereas Gheshm and Bandar - Lengeh form the other Sub — cluster. The formation of different vluster can be related to Physico - Chemical properties of water and climatic variations in different habitats along the Persion Gulf and the Sea of Oman. Key words: Molecular genetics, Population, RAND, PCR' Saccostrea cucullata

Study biological characteristics related with development and reproduction in Barbus capito on the southern coast of the Caspian Sea, Gilan Province

In the present research, a total of 207 pieces of fish from 25 sampling stations in Gilan Province coasts in the years 2001-2002 were biologically studied in terms of their growth and development, reproduction and feeding. The average length and weight of the fishes are increased, as they get older. The highest index of length and weight growth is observed in the years 1 to 2. As the age increases, gradient of length and weight growth diagrams decrease. In studying the relation between length and weight, it was observed that proportionate to the total length, the weight is increased progressively. The fatness coefficient index in the initial years of life and prior to maturity is higher than the post maturity period. As the age increases, the decrease of this index is observable. The fatness coefficient index rate is directly related to index of fullness. The highest Gonadosomatic Index is seen in the months of June and July, i.e. at the times of spawning; and the lowest index rate is observed in the months of November and December. The appropriate temperature for reproduction of these species is from 18 to 22 degree centigrade. The Gonadosomatic Index is higher in spring and summer seasons as compared with autumn and winter. Besides, as the fishes become aged, the amount of the said index increases in a manner that the gradient of it in the years to maturity is less than the maturity time and thereafter. Sexual maturity stages in different months are directly related to Gonadosomatic index, and increase as the age increases. The sexual ratio of male fishes to the female fishes in terms of number is plus one prior to maturity; about one at the time of maturity and minus after maturity. In general the frequency of male fishes as compared with female fishes in all group ages is approximately two times. The fecundity mean, and the diameter and the rate of eggs will substantially increase, as the Gonadosomatic index rises. The maturity age in the male fishes is 3 to 4 years and in female fishes is 4 to 5 years. The spawning of this species in rivers occurs repeatedly and in different time intervals, and do not take place once (Asyncronous). The Gastrosomatic index is directly related to index of fullness and will decrease, as the age increases. The index of fullness is relatively the months of April and May. The underlying reason is the need of the fishes to energy for reproduction. As the spawning time commences, the index of fullness moves down and the downward direction continues. After spa g mg and reduction of the volume of energy in the body, the index of fullness rises, and it will be substantially high until the beginning of fall. In fall and winter as it gets cold, the index of fullness moves downward and the body fat deposits are used. A correlation is shown between the changes in vacuity index and fullness indices. This means that as the fullness index rises, the vacuity index decreases, and vice versa. The Hepatosomatic index prior to the reproduction is at the highest amount and after spawning is at the lowest. No correlation is observed between the fullness and Hepatosomatic indices. In other words reproduction is an inherent and instinct originated matter; and its cycle goes on, alternately and in an orderly manner, upon completion of germinal cells, even when it coincides with reduction or stoppage of somatic cell growth. The rising trend of Hepatosomatic starts in August and will continue until the next July. The volume of fat around digestive tract is severely reduced in early spring and this trend will reach its apex in summer season. In the cold seasons, i.e. the fall and winter, the accumulation of fat around digestive tract increases. Consequently, a meaningful and inverse relation is observed between index of fullness, also the progress of sexual maturity stages and the volume of fat.