Penaeus indicus H. Milne Edwards, 1837: resumo das conclusões dos cruzeiros de pesca exploratória entre 1979 e 1983 no banco de Sofala em Moçambique

From 1979 to 1983, several surveys were carried out with research and fishing vessels at Sofala Bank in Mozambique. Their main objective was the assessment of shallow water prawn stocks, as this resource is of great economic importance for the country. A summary of the conclusions of these surveys regarding the species Penaeus indicus is presented. During the rainy season the species occurs closer to the shore than during the dry season. Estimates of biomass are very variable. The spawning peak seems to occur at the beginning of the rainy season (September-October). The spawning areas are located very close to the shore in the northern part of Sofala Bank and South of 17 degree 10'S in the 15-25 m depth interval.

Bioconversion efficiency and growth in the white shrimp Penaeus indicus (Milne Edwards), fed with decomposed mangrove leaves

Food conversion efficiency and growth in the white shrimp Penaeus indicus fed with decomposed mangrove leaves of Avicennia marina and A. officinalis were monitored under laboratory conditions. It was observed that test animals fed with the decomposed leaves of A. marina had higher assimilation efficiency (87.96%), gross growth efficiency (10.82%), net growth efficiency (12.3%) and relative growth rate (0.0603 g/day) than those fed with A. officinalis. The relatively higher growth registered in the animals fed with decomposed leaves of A. marina was attributed to its high calorific and protein content.

Chemoreception studies in relation to feeding responses in the marine shrimps H. Milne Edwards (Penaeus indicus) and Miers (Metapenaeus dobsonii)

A study of chemoreception in relation to feeding and other factors involved showed that feeding behavior in shrimps can be triggered by chemical stimuli. However, Penaeus indicus and Metapenaeus dobsoni differ significantly in their chemotactic response to different stimuli.

Some aspects of association and development of Lytocestus indicus Moghe in catfish Clarias batrachus (Lin.)

Some aspects of association and development of the caryophyllid cestode Lytocestus indicus Moghe, 1925 infecting the catfish Clarias batrachus (Linn.) from the Kailla Beel of Mymensingh, Bangladesh were studied. About 33.14% of Clarias batrachus were infected with a mean intensity of 3.75, mean density 1.25. The infection was not found throughout the year. Two seasonal occurrence of this cestode were observed, one in April-May and the other in August-September. However, maturation period of the worm coincided with the maturation of the host. The worm was found attached to the wall of the intestine of the host. At the site of attachment tissue layers were compressed due to mechanical injuries. Prevalence and mean intensity of infection increased with length groups. No variation in infection was significantly observed in different sexes of the host examined.

Dietary cholesterol requirement of larvae and postlarvae of the prawn Penaeus indicus (H. Milne Edwards)

Two sets of experiments were conducted to determine the dietary cholesterol requirement of larvae and postlarvae 1-10 of Penaeus indicus. Seven approximately isocaloric and isonitrogenous purified experimental diets were tried with graded levels of cholesterol ranging from 0 to 4%. The control feed for larvae and postlarvae 1-10 were phytoplankton and compounded feed NPCL-17, developed by CMFRI, Cochin respectively. Result of these experiments indicates that cholesterol is an essential nutrient in the diet of larvae and postlarvae 1-10. Survival and growth of larvae and postlarvae 1-10 were greatly affected by cholesterol deficiency in the diet. The optimal cholesterol requirement for larvae appeared to be 0.5% of the diet, while it was higher for postlarvae where inclusion of cholesterol at a level of 2% in the diet gave higher growth.

Penaeus indicus H. Milne Edwards, 1837: a summary of the conclusions from the fishing exploratory surveys between 1979 and 1837 at Sofala Bank, Mozambique

From 1979 to 1983, several surveys were carried out with research and fishing vessels at Sofala Bank in Mozambique. Their main objective was the assessment of shallow water prawn stocks, as this resource is of great economic importance for the country. A summary of the conclusions of these surveys regarding the species Penaeus indicus is presented. During the rainy season the species occurs closer to the shore than during the dry season. Estimates of biomass are very variable. The spawning peak seems to occur at the beginning of the rainy season (September-October). The spawning areas are located very close to the shore in the northern part of Sofala Bank and South of 17 degree 10'S in the 15-25 m depth interval.

Escala macroscópica de maturaçāo e ciclo sexual das espécies Penaeus indicus H. Milne Edward e Metapenaeus monoceros (Fabricius)

The macroscopic scale used for determination of sexual maturity in shrimps was tested against objective parameters namely the gonad-somatic index and the size of oocytes. The two main species caught in Mozambique, Penaeus indicus and Metapenaeus monoceros, were the object of the work. In order to reduce the subjectivity in the macroscopic exam, a table with the colours representative of each stage is presented. Since this study was conducted over a period of 13 consecutive months and there were observations from previous years, the sexual cycle of the two species is also presented, as well as an estimate of the size at first maturity.

Population dynamics of Penaeus indicus at Sofala Bank, Mozambique: a preliminary study

Length-based methods are used to estimate growth and mortalities of Penaeus indicus at Sofala Bank in Mozambique. This Penaeid shrimp is one of the most important species in the fishery as it constitutes 45% of the catches and has a great influence in their trend. First estimates of growth parameters for this species in Mozambique are presented and a comparison of the derived mortalities with the previous estimates is made.

Recolha de camarões reprodutores vivos da espécie Fenneropenaeus indicus da pesca de arrasto semi-industrial na Baía de Maputo

The collection of wild breeders of the Indian white prawn Fenneropenaeus indicus from two semi-industrial trawlers fishing in Maputo Bay is assessed for the period between August and November 1993. The daily mean catch (12-21 prawns dayˉ¹) increased until October but monthly yields were not significantly different (P>0.05). The monthly mean mortality ranged between 8% and 20% and was similar for males and females. More than 70% of the catch comprised small (grade B1: 20-39 g) and medium size (grade B2: 40-59 g) prawns. While males were exclusively of grade B1 (99%), the females were predominantly of grades B2 and B3 (60-80 g). The collection of larger breeders (grade B4: >80 g) was low and represented only 1% of total catches and a maximum of 3% of females. The net profit of breeders collection increased with size (grade) of prawns, and represented a maximum yield of 114% for grade B3. The added value of live prawns exceeded 450% of the cost to the fisherman, but decreased with size of breeders. It is considered that the semi-industrial trawling fishery operating in Maputo Bay has potential for supplying wild breeders of the Indian white prawn for aquaculture. This activity can also contribute to value adding of part of the catch traditionally destined for human consumption.

Preliminary study on the rearing of Chilka prawn ('Kantala') Penaeus indicus H. Milne-Edwards in the brackish water ponds at Keshpur (Orissa)

Results of experimental rearing of Penaeus indicus without supplemental feeding in unfertilized brackish water ponds in fore-shore of Chilka lake are presented in this paper. Higher rate of survival was recorded where advanced juveniles were stocked and lower rate of survival was recorded where early juveniles were stocked. The average growth rate recorded from the rearing experiments was higher than the average growth rate of Penaeus indicus recorded from the adjoining Chilka Lake which indicates the promising future of prawn farming in and around the lake. Analysis of gut contents revealed that Penaeus indicus could efficiently utilise algal and higher plant matter present in the ponds. No noticeable differences in daily growth rates were noticed between early and advanced juveniles in rearing experiments.

Succession of bacterial genera during iced storage of three species of tropical prawns, Penaeus indicus, Matapenaeus dobsoni and M. affinis

The native bacterial flora of ocean fresh tropical prawns, Penaeus indicus, Metapenaeus dobsoni and M. affinis was more or less similar, mainly consisting of Pseudomonas, Acinetobacter, Moraxella and Arthrobacter. A definite succession of bacterial genera during iced storage was observed in these prawns. As the day of ice storage increased, the proportion of Acinetobacter and Moraxella also increased considerably and constituted 70-78% of the flora at the time of spoilage. Spoilage by Pseudomonas was very not significant in prawns under iced storage.

Spoilage bacteria of Penaeus indicus

Bacteria isolated from raw (untreated and unprocessed) prawn (Penaeus indicus) stored at 28±2°C, 4°C and-18°C were tested for spoilage potential, namely, production of protease, lipase, amylase, reduction of trimethylamineoxide (TMAO) to trimethylamine (TMA), production of off odours from flesh broth and halo zone around the colony grown on flesh agar. About 63 % of the total isolates tested were potential spoilers. Members of Vibrio, Pseudomonas and Acinetobacter were found to be dominant potential spoilers at all temperatures.

Survival, growth and production of Penaeus monodon and P. indicus at different density combinations with milkfish

Penaeus monodon and P. indicus juveniles were stocked and reared for about 3 months in earthen ponds at different density combinations with Chanos chanos. The presence of either Penaeus species at any density ratio did not affect significantly the C. chanos survival. Survival rates of the penaeids indicated that intraspecific and interspecific competition occurred and were reduced with the reduction in stocking rate. It is concluded that further studies on higher density ratios and feeding and economic consideration would be of help to the development of this kind of fishpond management system.

Survival, maturation, fecundity and hatching rates of unablated and ablated Penaeus indicus H.M. Edwards from brackishwater ponds

Penaeus indicus harvested after three months of rearing in brackishwater ponds and averaging 6.9 g for females and 5.6 g for males were stocked in two 12 cu m flowthrough ferrocement tanks at 240 females and 200 males per tank. The females were ablated on one eyestalk in one tank and remained unablated in the other tank; all males were unablated. Ablated females spawned up to 7 times per female; unablated females spawned up to only 3 times during the two month duration of the experiment. Ablated females produced a total number of 17.5 x 10⁶ eggs, 6.6 x 10⁶ nauplii, and an average of 23,480 eggs/spawning and 37.8% hatching rate from a total of 757 spawnings. Unablated females produced a total of 2.0 x 10⁶ eggs, 1.1 x 10⁶ nauplii, and an average of 26.990 eggs/spawning and 53.9% hatching rate from a total of 74 spawnings. Survival of ablated females was 53.5% compared to 69.4% for unablated females; males in both tanks averaged more than 90% survival.

Genetic diversity of Bartail flathead (Platycephalus indicus (Linnaeus,1758)) using AFLP markers in Persian Gulf

Platycephalus indicus is a large benthic fish that inhabits temperate and tropical coastal waters of the Indo-West Pacific and found on sand or mud bottom in vary shallow area of estuary and near shore to depth of 25m. This species is dominant species of platycephalidae family, in Khuzestan, Bushehr and Hormozgan provinces and mainly is captured by bottom trawl, gillnet and moshta in Hormozgan. This study was designed to evaluate population variation and differentiation of bartail flathead (Platycephalus indicus (Linnaeus, 1785))in the Iranian waters of Persian Gulf using the morphometric and meristic characters and by AFLP marker. . A total 180 fish specimens were collected by gill net from six station(khor mosa, bahrekan, shif, motaf, charak and bandar abbas) that was 30 individual related to every station in Iranian shores of Persian Gulf . 28 morphometric factors and 11meristic specialties were measured and morphometric factors was standardized with Beacham formula. Univariate analysis of variance (One-way ANOVA) revealed significant differences with varying degrees between the means for 21 standardized morphometric measurements and 6 meristic counts that showed high significant differences between the six stations sampling. Discriminate function analysis (DFA) or the overall random assignment of individuals into their original groups was for morphometric and meristic characters was 47.9% and 53.9% respectively. The data were subjected to a principle component analysis (PCA) which grouped in eight and four factors for morphometric and meristic charactersrespectively.. Genetic diversity of six populations of bartail flathead (Platycephalus indicus) was investigated using amplified fragment length polymorphism (AFLP). A total of 118 reproducible bands amplified with ten AFLP primer combinations were obtained from 42 fishes that were collected from six different locations in the northern of Persian Gulf. The percentage of polymorphic bands was 57.06%. Average of Nei’s genetic diversity was 0.200±0.008, and Average of Shannon’s index was 0.300±0.011. The results of AMOVA analysis indicated that 66% of the genetic variation contained within populations and 34% occurred among populations and gene flow was 0.6454.The estimated level of population differentiation asmeasured by average Fst value across all loci was 0.327. Plotting discriminant functions 1 and 2 and UPGMA dendrograms based on Euclidian distance and genetic distance also showed at least five separate populations of bartail flathead in the northern Persian Gulf.