A report on a survey with the r/v "Ernst Haeckel" in July-August 1980: shallow-water shrimp and by-catch, oceanography

A survey of the Sofala Bank (Mozambique) was conducted to: estimate the abundance of shallow-water shrimp in the area between 16 degree 20'S and 20 degree 20'S, from 5 to 100 meters; estimate the shallow-water shrimp species composition and distribution pattern of main species. Collect biological data of the main species, Penaeus indicus and Metapenaeus monoceros; study the shrimp by-catch, species composition and biological data collection of the most abundant species of commercial value; and collect environmental data to clarify the shelf circulation on the Sofala Bank and the main oceanic features in the regions 15 degree S to 18 degree S and south of 22 degree S.

Trade of live brooders of the black tiger shrimp, Penaeus Monodon Fabricius 1978, at Visakhapatnam, Andhra Pradesh

The demand for brooders of Penaeus monodon by the hatcheries, which are solely dependant on wild brooders for their seed production, has resulted in a vigorous fishery and trade for this species, especially along the Visakhapatnam coast. More than three hundred brooders are brought in per day for trading during the peak landing season from December to March every year. The price of gravid brooders has been declining over the years but on an average is about Rs. 30,000 per brooder. The total length of male brooders ranged from 190 to 246 mm during the three years under study and for females it varied between 210 and 330 mm. A specialized methodology for transportation, storage and trade of P. monodon brooders has been evolved over the years at Visakhapatnam Fishing Harbour. Concentrated exploitation of brooders from the wild and presence of pathogens in them makes a strong case for development of specific pathogen free brooders and conservation of wild stock.

Effect of copper, cadmium and Cu.Cd mixture on amino acid content in the poslarvae of penaeid shrimp, Penaeus monodon and P. penicillatus

This study document effects of short-term (96h) sublethal levels of copper, cadmium and their mixture on the amino acid composition of postlarvae of the penaeid shrimp, P.monodon and P.penicillatus . All experimental conditions were kept constant, temperature between 25-27•C and salinity 21-22 ppt. The estimated LD50 for Cu was 200 ug/L, for Cd 177.5 ug/L and for Cu.Cd mixture 250ug/L. In P. penicillatus at the same concentration of each metal, there was significant reduction in amino acid content, which was 8.01% higher than the control. Almost similar reduction in some amino acids was observed in P.monodon. At the maximum concentration of 400 ug/L, cadmium caused higher reduction in amino acid composition than did copper. Thus, amino acid composition may be regarded as a sensitive biochemical indicator of Cu and Cd toxicity because of the effect of these metals on protein synthesis, a signal of physiological stress in marine organisms subjected to heavy metal pollution.

The potential of mixed culture of freshwater giant prawn Macrobrachium rosenbergii de Man and tiger shrimp Penaeus monodon Fab. at Khulna region, Bangladesh

The freshwater giant prawn (golda), Macrobrachium rosenbergii and tiger shrimp (bagda), Penaeus monodon were stocked together with or without fin fishes at different stocking rates in semi-saline waters at Khulna region and their growth, survival, yield and costreturn analysis were made. Survival rate of golda and bagda ranged from 23.0 to 36.8% and 8.2 to 24%, respectively. The both species were significantly affected by their own stocking density. The average final weight of golda and bagda ranged from 62.4 to 73.3 g and 32.0 to 66.4 g. The bivariate analysis of average final weight of both golda and bagda revealed that golda positively and bagda negatively influenced by the total stocking density. However, the results of the individual sizes of both golda and bagda showed an increase in the proportions of smaller animals and a decrease in the proportion of larger ones with increasing stocking rates. The harvesting weights of all animals in the experimental ghers were in marketable sizes although their prices varied with the individual size. The total production comprised of both golda and bagda ranged from 514.6 to 952.8 kg ha·1, over a culture period of 10 months. Return on investment ranged from 51.0 to 125.7%.

Effect of farm made feeds on polyculture of shrimp (Penaeus monodon) and three brackishwater finfish species

A study was conducted to evaluate the effects of feed made from locally available ingredients on polyculture of shrimp and three brackishwater finfish species. Hatchery produced post-larvae (PL) of shrimp Penaeus monodon (0.005g) were stocked at the rate of 15,000 PLs/ha. Brackishwater finfish species Liza parsia, Mugil cephalus and Rhinomugil corsula of 0.63-1.4lg collected from local rivers were stocked at the rate 8,000, 1,000 and 2,000/ha, respectively in four treatments. Shrimp and finfishes were fed four different experimental diets composed of fish meal, mustard oil cake, rice bran, oyster shell power and vitamin premixes at the rate of 3-5% estimated crop/day for 195 days. Among four treatments, P. monodon showed comparative better growth in T4 and T3. Finfish L. parsia showed its better performance in treatment T2. Species M. cephalus and R. corsula showed insignificant production. P. monodon showed better growth with diet of fish meal and mustard oil cake@ 28.84 and 33.65%, respectively in T 3 and 19.22 and 43.27%, respectively in treatment T4.

Monogenean gill parasites of Indian major carps from different fish farms of Mymensingh, Bangladesh

All together 148 fish host samples of Labeo rohira, Cirrhina mrigala, Catla catla and Labeo gonius were collected from different fish farms of Mymensingh. The gill monogeneans were then dislodged from the gill under dissecting microscope and fixed in ammonium picrate. Five species of Dactylogyrus namely, Dactylogyrus mrigali, D. chauhanus, D. yogendrai, D. labei and D. kalyanensis were recovered from sampled fishes. All the parasites were studied and redescribed, and reported for the first time from Bangladesh. The present investigation established Catla catla as a new host of D. labei.

A study on performances of intensification in the farming system of a shrimp farm at Cox's Bazar, Bangladesh

This study examines the harvest and mean production in relation to the stocking of P. monodon fry during the period between March 1992 and October 1994, at the farm owned by M/s Monugung Sea Food Ltd., Cox's Bazar. The analysis shows that production figures were initially up to expectation, but after harvesting 4 crops within 16 months, production sharply decreased. The unexpected high mortality of the growing stock was due to outbreak of an uncontrollabe disease (Vibriosis). Significantly higher variations in production, survival and growth were also noted among the different treatments.

Observation on some of the environmental parameters and feed quality of selected golda (Macrobrachium rosenbergii) farms in Bangladesh

A study was conducted to ascertain the existing farm water, effluent and feed quality of selected giant freshwater prawn farms from major prawn farming areas (Bagerhat Sadar, Noakhali Sadar and Mymensingh) of Bangladesh during July to November 2005. Water quality parameters such as the mean values of dissolved oxygen, alkalinity, nitrite-nitrogen, phosphate-phosphorus and ammoniacal nitrogen did not show any significantly differences among the farming areas. Whereas significant differences (p < 0.05) were observed in the mean values of temperature, secchi disc visibility, pH and chlorophyll a. However, all the water quality parameters in the farming areas were within the suitable range for prawn culture. There was no significant variation in nutrients concentration of discharged effluent among the prawn farming areas. All of the nutrients measured in effluent water were within the acceptable range and did not seem to pose a direct threat to the recipient environment. The analysed crude protein contents of commercial CP, Quality and Saudi-Bangla prawn feeds were 31.84%, 27.21% and 28.97%, respectively, whereas all analysed farm made feeds were less than 25%. The other nutrients of prawn feeds varied largely with the source of feeds and ingredients used to prepare feed. The annual yield of prawn varied from 320.4 to 512.6 kg/ha (mean 412.3 kg/ha) depending on the management system.

Distribution of drug resistant luminous bacteria in penaeid shrimp grow-out ponds

Distribution of luminous bacteria (LB) in penaeid shrimp grow-out pond water in semiintensive seawater farming system and their resistance to 15 antibacterials were investigated. Total viable counts and luminous bacterial counts in pond water ranged from 2.00xl03 to 1.35xl04/ml and l.OOxl01 to 8.00Xl02/ml, respectively. The percentage composition of LB in the total viable population increased significantly with period of culture. Five species of LB such as Vibrio fischeri, V. harveyi, V. orientalis, V. splendidus 1 and Photobacterium leiognathi were encountered. V. harveyi was the dominant species, constituting >80% of the total LB. Multiple antibiotic resistance was more common in these LB. Pond water isolates showed resistance to at least four antibacterial agents.

Factor intensity and economic returns of alternate shrimp crop and shrimp-salt farming in the coastal areas of Bangladesh

The paper examines the factor intensity and economic returns of alternate shrimp-crop and shrimp-salt farming in the coastal areas of Bangladesh. Data were collected from 30 shrimp-crop and 30 shrimp-salt farmers, 30 shrimp farmers and 30 rice farmers from three selected coastal districts of Bangladesh. Cobb-Douglas production function model was used to determine the effect of various factors on alternate shrimp-crop farming. The chosen variables were stocking of juveniles, paddy seed, labour, fertilizers, feed and farm size of respective type of farming. The results indicated that the production function exhibited increasing remrns to scale for alternate shrimp-rice, alternate shrimp-salt and year round shrimp farming while it indicated decreasing returns for year round rice farming. Economic analysis of same system of farming indicated that higher amount of input use produced higher level of yield, gross return and net return for each type of production system.

Culture feasibility of silver barb (Barbodes gonionotus Bleeker) and GIFT with shrimp (Penaeus monodon Feb.) in brackishwater pond

An experiment was conducted to understand the culture feasibility of sliver barb (Barbodes gonionotus) and GIFT (Genetically Improved Farmed Tilapia) with shrimp (Penaeus monodon). There were three different treatment (T) combinations: (T1) shrimp (10,000/ha) and silver barb (10,000/ha), (T2) shrimp (10,000/ha) and GIFT (10,000/ha), and (T3) shrimp (10,000/ha). Shrimp, after 120 days of culture, attained an average weight of 23.77g in T1, followed by T3 (23.70g). The highest average weight was recorded in T2 (24.93g). The specific growth rate (SGR) of shrimp was 6.9%, 6.94% and 6.9% for T1 T2 and T3, respectively. The SGR for the B. gonionotus and GIFT was 2.56% and 4.26%, respectively. The final weight of silver barb was 69.75g and that of GIFT was 161.83g. Survival of shrimp was higher (65.50%) in T2, followed by T3 (59.97%) and T1 (57.03%). Survival rate of silver barb (58.10%) was lower compared to that of GIFT (78.43%). Sporadic and scanty mortality of silver barb with a symptom of blind-red-protruded eye, swollen belly and body lesion was observed. Production of shrimp was higher of 284.05 kg/ha in monoculture, followed 162.47 kg/ha in concurrent culture with silver barb and 136.77 kg/ha culture with GIFT. In spite of similar stocking density of B. gonionotus and GIFT in T1 and T2, respectively, the production of GIFT was higher (1272.95 kg/ha) than that of silver barb ( 402.72kg/ha). Survival, final weight and production rates of shrimp among the treatments were found insignificant while total production of shrimp/fish was found to vary significantly (P