Larval development of a mangrove crab (Perisesarma bidens De Haan) (Crustacea: Brachyura: Sesarminae)

Larval development of Perisesarma bidens (De Haan) was investigated in laboratory conditions. Morphology of all larval stages and 1st crab stage was described and illustrated in detail, and compared with other species of sesarmid crabs. The zoeae morphological features of P. bidens are almost similar to other species of Sesarma in lacking a pair of lateral spines on carapace.

Development of low-cost feed for culture of giant freshwater prawn (Macrobrachium rosenbergii de Man) in ponds

An experiment was conducted for 105 days in 12 earthen mini ponds of each 30m² size. Five different experimental diets containing 32% protein were formulated and prepared using fishmeal, shrimp meal, soybean meal, mustard oil cake, sesame meal, wheat bran and rice bran. A commercial shrimp diet (SABINCO starter-III) was assigned to treatment six and considered as the control. Prawns were stocked at the rate of 2.5 fry/m² and feed twice daily at the rate of 10% at the beginning and reduced to 8% for the last two months. The results of the experiment showed that prawn fed diets 1, 2, and 6 (control) showed significantly (P<0.05) highest weight gain among the dietary groups, while prawn fed diet 5 showed significantly lowest weight gain. The FCR values of diets ranged between 3.06 to 4.85. Prawns fed diet 1 and 6 showed significantly higher SGR, survival (%) and production among the dietary groups. The survival (%) of the prawns ranged between 46.6 to 66.6% and the production ranged between 304.5 to 563.3 kg/ha/105 days. The result of the study showed that diet containing 30% fishmeal, 5% shrimp meal, 5% soybean meal, 10% mustard oil cake, 10% sesame meal, 20% wheat bran, 18% rice bran, 1% oyster shell and 1% vitamin premix may be recommended for monoculture of M. rosenbergii.

The Development of Ceylon's fisheries (a symposium)

In July, 1964, it was decided that a Government Fisheries Corporation be set up. At the request of the Directors-designate of this Corporation a series of lectures on the development of Ceylon's fisheries was organised by the Fisheries Research Station, all except two being delivered at a seminar on 15th September, 1964. The speakers were asked to prepare and submit their texts and these are presented in the sequence in which the talks themselves were delivered: 1. Ceylon's fisheries: past and future (A.C.J. Weerekoon) 2. Fisheries by-products (C.St.E. Gunesekara) 3. The role of technology in fisheries development in Ceylon (N.N. De Silva) 4. Seaweeds (M. Durairatnam) 5. Coastal fisheries (T.P. Goonewardente) 6. The trawler fishery (A.S. Mendis) 7. A review of Japan's tuna long-line fishery in the Indian Ocean (K. Sivasubramaniam) 8. Off shore and deep sea fishery for larger scombroids in the Indian Ocean (K. Sivasubramaniam) 9. The development of fresh water fisheries in Ceylon (H.H.A. Indrasena) 10. Brackish-water fish farming in Ceylon (T.G. Pillai) 11. The role of inland waters in relation to the development of Ceylon's fisheries and a note on the pearl oyster fishery (C.H. Fernando) 12. The mechanization of the inshore fisheries and the relationship to fisheries development in Ceylon (E. Kvaran)

Effects of salinity and temperature on the larval development of a sesarmid crab Neosarmatium trispinosum Davie (Crustacea: Brachyura: Sesarmidae) from mangrove swamp in Okinawa Island, Japan

The larval development of the semiterrestrial sesarmid mangrove crab Neosarmarium trispinosum was studied under laboratory conditions at salinities 0-35%o and constant temperatures of 20-30°C. The larval development consists of five zoeal stages and a megalopa. Larvae survived to the first crab stage at salinities between 15 and 35%o with different percentages. At 0, 5 and 10%o, the larvae died within 12-18 hours without moulting to subsequent stages. The highest survival rate was recorded at 20-25%o and 25-30°C with shortest development duration to the first crab stage ranging from 24-28 days. At the highest salinity (35%o), survival rate was gradually decreased with increasing development duration. There were significant differences (Pdevelopment period among the tested salinities. Results of this study suggest that the larvae of N. trispinosum develop in estuarine water and recruit to the mangrove swamp at the megalopa stage, where they spend the rest of their lives.

Development of low cost feed using local ingredients for culture of freshwater prawn, Macrobrachium rosenbergii in ponds

Two experiments were conducted to formulate and evaluate test diets using locally available ingredients to find out suitable diets for mono and polyculture of Macrobrachium rosenbergii in ponds. The first experiment was conducted from 1 July 2003 to 29 September 2003 in 12 experimental ponds each measuring 30 square meters behind the Fisheries Faculty Building, BAU campus, Mymensingh. Three experimental diets containing 30% protein were formulated using fish meal, meat and bone meal, mustard oilcake, sesame meal and rice bran and assigned to treatments 1, 2 and 3, respectively. A special shrimp feed (Starter-II) from Saudi-Bangla Fish Feed Ltd. was assigned to treatment 4 (Control). Each treatment had three replications. Juveniles of M. rosenbergii (2.90±0.81g) were stocked at the rate of 4/square meter. Prawns were fed three times daily at the rate of 15% of their body weight at the beginning, which was gradually reduced to 10% and 5% for the last two months. There was no significant (P>0.05) difference between the weight gains of prawns fed diets 1 and 4 (control), but they were significantly (P<0.05) higher than those of diets 2 and 3. The FCR values of diets ranged between 2.61 to 3.36 with diets 1 and 4 showing significantly (P<0.05) lower FCR values. The survival rate of prawns ranged between 68 to 78% with prawns fed diets 1 and 4 showing significantly higher survival rate. The production of prawn ranged from 921 to 1,428 kg/ha/90 days and diet 1 gave the highest production. Treatment 1 gave the highest net profit ofTk. 161,980/ha/90 days. The second experiment was conducted from December, 2003 to April, 2004 to see the growth of over wintered M. rosenbergii juveniles in polyculture with indigenous major carps (catla and rohu) in ponds using formulated diets. Three isoenergetic experimental diets formulated using fish meal, meat and bone meal, mustard oil cake, rice bran, wheat bran and molasses, and a shrimp feed 'Golda special feed' from Saudi-Bangla Fish Feed Ltd. were assigned to treatments 1, 2, 3 and 4 (control), respectively, each treatment had two replications. Eight experimental ponds each measuring 80 square meters in the Field Laboratory Complex of the Faculty of Fisheries, BAU campus, Mymensingh were used. The mean initial weights of M. rosenbergii, catla and rohu were 1.60±0.01, 30.0±0.09 and 25.0±0.08 g, respectively. A total of 160 fish and prawn (20,000/ha) were stocked in each pond at the ratio of 2:1:1 (prawn: catla: rohu). Fish were fed at the rate of 3-5% of their body weight. Prawns fed diet 1, 2 and 4 showed higher weight gains compared to diet 3. The weight gain of catla was significantly higher in T1 while in case of rohu was higher in T1 and T4, respectively. There were no significant differences (P>0.05) in the survival rate of fish as obtained from different treatments. The overall total fish production ranged from 2196 to 2679 kg/ha/5 months. The highest production and the highest profit (Tk. 56,531/ha/5 months) was obtained from T1 and the lowest (Tk. 24,932/ha/5 months) from T4.

Utilization of trash fish for human consumption. 3: Studies on the development of fish pickle from Nemipterus japonicus

A method for the preparation of fish pickles from a lean variety of fish namely pink perch (Nemipterus japonicus) is described. Dipping the fish in 10% sodium chloride solution containing 6% acetic acid before pickling, was found desirable for retaining the meaty texture of the product. The product has no fish smell or flavour and has a shelf life of more than six months at ambient temperatures and scored very well in organoleptic tests.

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.

Development of trawling in India

Of the three main methods of capturing fish, namely luring, attacking and snaring, the last mentioned has hitherto proved to be relatively more effective and apparently yielded better returns. Trawling falls under this method. The trawl is an economic gear, in terms of investment and yield, even in spite of the fact that the total trawl catches come only second to that of the seines. Commercial trawling in Indian seas is of recent origin and seems to have been initially introduced for the purpose of ground resources survey.

Development of partially hydrolysed and deodourised fish flour

A process developed for preparation of partially hydrolysed and deodorised (PHD) fish flour, without solvent extraction is described. The PHD fish flour prepared from four varieties of trash fish had creamy white colour and contained 87-92% protein and 7-8% available lysine. The products had shelf life of more than a year at room temperature, and caused no grittiness when incorporated in snacks and bakery products at 10% and 7.5% level respectively. The flour prepared from Nemipterus spp. had a PER 2.32 compared to 2.68 of raw fish meat and 2.5 of standard casein.

Some further considerations in the development of an experimental design for sensory evaluation of fish quality

An experimental procedure along with a method of analysis to judge the suitability of an individual to be included in a taste panel is described. The procedure is based on comparison of the organoleptic scores assigned by the individual to pairs of fish samples whose qualities are known and a set of physical measurements of the same samples. Fisher's Exact Probability Test provides a criterion for the judgement.

Development of canned fish curry

A process for canning sardine in two different curry media is presented. One curry medium yields a product with medium pungency while the second one has a low pungency. Sardine canned in curry medium having medium pungency developed signs of internal corrosion as well as slight bitter taste at the end of 15 months storage at ambient temperature. Similar phenomenon took place in the other product only at the end of 18 months storage. Being a ready to serve product it needs no further preparation for the table.

Effect of furanace on the development of larval stages of Penaeus monodon Fabricius

Zoea 2(Z SUB-2 ) Mysis 1 (M SUB-1 ) and Postlarva 1 (P SUB-1 ) of P. monodon artificially spawned in closed-system concrete hatchery tanks were bioassayed for their tolerance to the antibiotic furanace. The setup consisted of four 20-liter capacity plastic basins previously conditioned for 15 days with freshwater in full sunlight. During the experiment, each basin was filled with 5 liters of seawater to which was added filtered Chaetoceros and Brachionus to give densities of 5 . 0-7 . 5 x 10 SUP-4 cells/ml and 10-20 individuals/ml, respectively. The following are the properties of the water used throughout the experiments: salinity, 26-32%; pH, 7 . 3-8 . 4; temperature, 25-30 degree C; dissolved oxygen, 4 . 5-8 . 4 ppm; nitrite, 0 . 36-0 . 99 ppm; and ammonia, 0 . 10-0 . 30 ppm. To each basin were added 50 healthy larvae of specific stages of P. monodon. After an initial acclimation of one hour in the medium, preweighed amounts of the antibiotic were added and thoroughly dissolved. The concentrations tested were 1 . 0, 2 . 0 and 3 . 0 ppm. One basin always served as control. After 24 hours of exposure, the surviving population in each basin was counted. The survivors were then examined thoroughly under the microscope for unusual behavior and morphological defects brought about by the exposure. To minimize wide variations in the medium as a result of feeding and other manipulations, the systems were all prepared at 9:00 a.m. each time, and the feeds on two instances, one at 5:00 p.m. and another at 5:00 a.m. Fifteen trials conducted with Z SUB-2 showed survival ranges of 68% to 98% with a mean of 77 . 6% in the controls; 32% to 94% with a mean of 65 . 7% at 1 ppm, and 0% to 56% with a mean of 36 . 5% at 2 ppm. There were no survivors at 3 ppm. Interpolation from the survival-dose curve gave a 24-hr LC SUB-50 of approximately 1 . 6 ppm.