Studies on the age and growth of Labeo calbasu (Hamilton) with an exploitation pattern from the Ganga River system, Uttar Pradesh (India)

Samples were collected to study the age and growth of Labeo calbasu (Hamilton) from the river Ghaghra (Guptarghat centre, Faizabad). The scales of L. calbasu have been used for age and growth studies in present paper. Study of the marginal rings on the scales of L. calbasu indicates their annual nature. The fish attained growth in 1st 18.7 cm, 2nd 27.8 cm, 3rd 35.7 cm, 4th 41.8 cm, 5th 46.9 cm, 6th 54.9 cm and 7th 57.4 cm years of the life. The growth rate was observed 18.7, 9.1, 7.9, 6.7, 5.1, 8.0 and 2.5 cm for 1st to 7th age classes respectively. The age groups 1+ to 4+ constituted 91.17% of the total exploited population and 8.83% of remaining age groups (5+ to 7+). The maximum exploited population was observed in 2+ age group with 33.68%. Overall exploitation pattern was systematic and a good indicator for heavy recruitment.

Preliminary observations on the lunar and tidal influences on the catches of seer by gill nets

The paper deals with the lunar and tidal influences on the catches of seer by gill nets. The landings during full moon and new moon nights, during low and high tides and during different quarters of the lunar month for three fishing seasons are discussed.

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.

Dol net fishery off Nawabunder (Gujarat)

Extimated catch of 6,484.9; 3,505.6 and 4,797.7 t of fishes were landed at Nawabunder in 'dol.' net during 1976-77, 1977-78 and 1978-1979 respectively. There has been an increasing trend in effort and decline in catch and catch rate. The catch rate came down from 174.8 kg in 1976-77 to 84 kg in 1978-79. The detailed studies on the catch composition revealed that the Bombay duck formed about 68.6-77% of the total catch. The other important constituents being Coilia dussumieri 1.5-9.2%, ribbon fish 3.0-6.5%, non-penaeid prawn, namely, Acetus indicus, Nematopalaemon tenuipes and Hippolysmata ensirostris together formed about 6.1-13.7% and penaied prawns 1.5-3.1% of the total dol net landings. In addition, quality fishes such as ghol, warn, pomfret and catfishes were also landed in considerable quantities. The landings of ghol are on the increase from 4.9 t in 1976-77 to 59 t in 1978-79. Large number of juveniles of economically important fishes namely, Harpodon nehereus, Pampus argenteus, Trichiurus lepturus and Ilisha filigera have been observed in the catch particularly during February-May. The destructive nature of the gear has been commented along with the suggestions for regulation of the fishery.

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.

The effect of various protein levels on the growth and survival rates of Penaeus monodon Fabricius

Postlarvae of tiger prawns, P. monodon , were fed with various protein levels of 0; 30; 40 and 50%, fish meal and rice bran were combined and pelletized for 16 wks. Prawns used had an average mean length of 1.2 mm and an average mean weight of 5.5 mg. Nitrite, ammonia, dissolved oxygen content, temperature and pH were monitored. After one month of feeding, growth increments of postlarvae fed with 30% protein diet were significantly different from those given 0; 40 and 50%. Survival rate of the group fed 40% protein was higher (81.7%) but was not significantly different from those fed 30% (68.0%). The highest feed efficiency was obtained from the 30% protein pellets (4.6). At the end of 16 weeks, growth increment of 40% protein level was significantly different from the 30% and 50% protein levels, but the survival rate was not signficantly different from the 30% protein level. Feed conversion for the 40% protein diet was 2.8.

The effect of various protein levels on the growth and survival rates of Penaeus monodon Fabricius

Postlarvae of tiger prawns, P. monodon, were fed with various protein levels of 0; 30; 40 and 50%, fish meal and rice bran were combined and pelletized for 16 wks. Prawns used had an average mean length of 1.2 mm and an average mean weight of 5.5 mg. Nitrite, ammonia, dissolved oxygen content, temperature and pH were monitored. After one month of feeding, growth increments of postlarvae fed with 30% protein diet were significantly different from those given 0; 40 and 50%. Survival rate of the group fed 40% protein was higher (81.7%) but was not significantly different from those fed 30% (68.0%). The highest feed efficiency was obtained from the 30% protein pellets (4.6). At the end of 16 weeks, growth increment of 40% protein level was significantly different from the 30% and 50% protein levels, but the survival rate was not significantly different from the 30% protein level. Feed conversion for the 40% protein diet was 2.8.

Quality assessment of traditional, rotary and solar tunnel dried small indigenous fish species products

Studies on the quality assessments of three traditional, rotary and solar tunnel dried SIS products were conducted. Organoleptic quality of traditional dried SIS products available in the markets was poor compared to those produced in rotary and solar tunnel dryer. Reconstitution of samples were in the range of 54.26% to 75.24%, 69.37% to 83.73% and 55.08% to 80.24% when soaked at 80°C for traditional, rotary and solar tunnel dried products, respectively. The percentage of reconstitution increased with the increase of soaking time and the uptake of water was maximum after 60 min of soaking. The moisture contents of traditional, rotary and solar tunnel dried products were in the range of 26.02% to 27.33%, 16.23% to 22.84% and 13.71% to 19.30%, respectively. The protein contents were in the range of 60.78% to 72.59%, 62.17% to 76.27% and 61.11% to 76.00%, respectively; lipid contents were in the range of 12.26% to 22.60%, 14.00% to 24.71% and 13.92% to 22.39%, respectively and ash contents in the range of 15.11% to 16.59%, 8.32% to 13.51% and 8.71% to 16.45%, respectively on dry matter basis. The TVB-N content of rotary and solar tunnel dried products was low compared to traditional one ranging from 10.64 to 17.52 mg/100g and 14.34 to 15.68 mg/100g, respectively whereas the TVB-N content of traditional samples was in the range of 15.46 to 20.36 mg/100g. The bacterial load of traditional, rotary and solar tunnel dried products were in the range of 1.43x10 super(8) CFU/g to 2.89 x10 super(80 CFU/g, 1.91x10 super(8) CFU/g to 2.84x10 super(8) CFU/g and 1.95x10 super(8) CFU/g to 2.59x10 super(8) CFU/g, respectively. The results of the study indicated that dried fish products from rotary dryer and solar tunnel dryer were found to be of better quality in nutritional and food quality aspects than those of traditional dried products.

Organoleptic, biochemical and bacteriological aspects of the low cost tunnel dried fish products

Studies were conducted on the organoleptic, biochemical and bacteriological aspects of three dried fish products produced from two different model of low cost solar tunnel dryer. The overall quality of the products obtained from both dryers was excellent. Sixty minutes soaking showed the maximum water reconstitution of the products with values between 66.82 to 75.28% and 71.98 to 78.09% in dryer 1 & 2 respectively. The highest reconstitution was obtained from Silver Jew fish (75.28-78.09%) and lowest from Bombay duck (66.86-71.98%) from both dryers. The average moisture, protein, lipid and ash content of the dried products were 11.8-15.0%, 57.32-68.49%, 6.08-8.62% and 12.25-14.88% respectively in fish in dryer 1 and dryer 2. The TVB-N values were in the range of 24.3 to 30.9 in dryer 1 and 22.1 to 28.2 mg/100 g samples in dryer 2. The highest values were obtained from Bombay duck and lowest value in Silver Jew fish in both dryers. The peroxide values varied from 14.1 to 16.9% in dryer 1 and 13.3 to 16.4% in dryer 2. The highest peroxide value was obtained from Ribbon fish and lowest from Silver Jew fish. Total bacterial load varied in the range of 6.6x10⁴— 8.6x10⁴ CFU/g in dryer 1 and 2.54x10⁴ to 4.9x10⁴ CFU/g in dryer 2. The highest value was obtained from Ribbon fish and lowest from Silver Jew fish.

Determination of some dominant genetic characteristics and morpho-meristic features for selection of rainbow trout (Oncorhynchus mykiss) broodstocks

In this study, Iranian and French male and female Oncorhynchus mykiss broodstocks were divided into two groups 50 and 24 respectively in Research center of genetic and breeding of coldwater fishes, Yasouj, Iran and the genetic structure of them was investigated using 6 microsatellite markers. Then 19 morphometric and 5 meristic of broodstock were measured and compared in two populations. Along with broodstock maturation, fertilization 1:1(female:male) were randomly assigned and occurred in 25 of 12 Iranian and French treatment respectively. Reproductive parameters were recorded for the whole family. Average number of observed alleles in Iranian and French stocks was 6.68 and 6.83, respectively. Average number of effective alleles in Iranian and French stocks was 3.13 and 3.45 respectively. Fixation index Fst was calculated based on allelic frequency between two stocks was 0.058 with significant difference between 2 stocks. Morphometric analysis showed significant difference between two stocks in 8 characteristics. Meristic characters was without significant difference in broodstock groups. Eyed percentage for french broodstock calculated zero and deleted. Fertilization rate (100-0), the eyed percentage (98- 0), The hatch rate (98-0), the average fecundity 4114.708, the average eggs size 4.88 mm, Survival in the first three months 19-73% calculated for Iranian broodstocks. Considering the quality of eggs and larvae at different stages and selection between the different family and the within family remained 10 treatments and are kept as future broodstocks. The relationship between fecundity - egg size, fecundity - weight , fecundity - length, egg size- weight was performed using regression. The results showed that Fecundity was influenced more by weight and productive length. The research is beginning to ID the broodstock in our country.

Assessment of pelagic primary and secondary production in Sefidrud River estuary

Sefid-Rood River Estuary (SRE) is the most important riverine ecosystem in the south Caspian Sea along the Iranian coast lines. The aim of this study was to examine spatial and temporal variability in Phytoplankton and Zooplankton abundance and diversity in SRE. Variability of Chlorophyll a and inorganic nutrient concentration were determined during a year (November 2004– October 2005) in five sampling stations. Primary and secondry production were determined during a year. Total chlorophyll a concentration during the investigation ranged between zero to 22.8 μgl-1 and the highest levels were consistently recorded during summer and the lowest during winter with a annual mean concentration 4.48 μgl-1. Nutrient concentration was seasonally related to river flow with annual mean concentration: NO2 0.05±0.2 mgl-1, NO3 1.13±0.57 mgl-1, NH4 0.51±0.66 mgl-1, total phosphate 0.13±0.1mgl-1 and SiO2 5.68±1.91 mgl-1. Bacillariophytes, Cyanophytes, Chlorophytes, Pyrophytes and Euglenophytes were the dominant phytoplankton groups in this shallow and turbid estuary. The diversity and abundance of phytoplankton had a seasonal pattern while Diatomas and Chrysophytes were dominant throughout the year but Cyanophytes observed only during the summer. Zooplankton community structure was dominated by copepods which 68% of the total zooplankton. In the winter and summer seasons two increased in the number of zooplankton community and usually toward the sea had occurred. Zooplankton also showed a significant spatial and temporal variation. The high turbidity and temperature prime characteristics of SRE seem to be determining factors acting directly on phytoplankton and zooplankton temporal variability and nutrient fluctuations. Everywhere in this estuary nutrients appeared to be in excess of algal requirement and did not influence a phytoplankton and zooplankton composition. Also there was a positive correlation between chlorophyll a and temperature and a negative one with DIN and TP. Primary production determined in this estuary by dark and light butter method and G.P.P. 38.27±34.12 mgcm-2h-1 and N,PP 201.6±289.9 mgcm-2d-1. secondry production determined 15/128 mgc/m3/year. Everywhere in this estuary nutrients appeared to be in excess to algal requirement and did not influence in Chl. a and primary production. The most important factor influence on Chl. a was water temperature.

The genetic diversity of Acipenser stellatus populations in the Caspian Sea was studied using microsatellite technique

A total of 361 caudal fin samples were collected from adult A. stellatus specimens caught in the north Caspian Sea, including specimens from Kazakhstan (Ural River), Russia (Volga River), Azerbaijan (Kura River), specimens caught in the south Caspian Sea including specimens from Fishery Zone 1 (from Astara to Anzali), Fishery Zone 2 (from Anzali to Ramsar), Fishery Zone 3 (from Nowshahr to Babolsar), Fishery Zone 4 (from Miyankaleh to Gomishan) as well as from specimens caught in Turkmenistan (all specimens were collected during the sturgeon stock assessment survey). About 2 g of fin tissue was removed from each caudal fin sample, stored in 96% ethyl alcohol and transferred to the genetic laboratory of the International Sturgeon Research Institute. Genomic DNA was extracted using phenol-chloroform method. The quality and quantity of DNA was assessed using 1% Agarose gel electrophoresis and Polymerase Chain Reaction (PCR) was conducted on the target DNA using 15 paired microsatellite primer. PCR products were electrophoresed on polyacrylamide gels (6%) that were stained using silver nitrate. Electrophoretic patterns and DNA bands were analyzed with BioCapt software. Allele count and frequency, genetic diversity, expected heterozygosity and observed heterozygosity allele number, and the effective allele number, genetic similarity and genetic distance, FST and RST were calculated. The Hardy Wienberg Equilibrium based on X2 and Analysis of Molecular Variance (AMOVA) at 10% confidence level was calculated using the Gene Alex software. Dendrogram for genetic distances and identities were calculated using TFPGA program for any level of the hierarchy. It is evident from the results obtained that the 15 paired primers studied, polymorphism was observed in 10 pairs in 12 loci, while one locus did not produce DNA bands. Mean allele number was 13.6. Mean observed and expected heterozygosity was 0.86 and 0.642, respectively. It was also seen that specimens from all regions were not in Hardy Wienberg Equilibrium in most of the loci (P≤0.001). Highest Fst (0.063) was observed when comparing specimens from Fishery Zone 2 and Fishery Zone 4 (Nm=3.7) and lowest FST (0.028) was observed when comparing specimens from the Volga River and those from the Ural River (8.7). Significant differences (P<0.01) were observed between RST recorded in the specimens studied. Highest genetic distance (0.604) and lowest genetic resemblance (0.547) were observed between specimens from Fishery zones 2 and 4. Lowest genetic distance (0.311) and highest genetic resemblance (0.733) was observed between specimens from Turkmenistan and specimens from Fishery zone 1. Based on the genetic dendrogeram tree derived by applying UPGMA algorithm, A. stellatus specimens from Fishery zone 2 or in other words specimens from the Sepidrud River belong to one cluster which divides into two clusters, one of which includes specimens from Fishery zones 1, 3 and 4 and specimens from Turkmenistan while the other cluster includes specimens from Ural, Volga and Kura Rivers. It is thus evident that the main population of this species belongs to the Sepidrud River. Results obtained from the present study show that at least eight different populations of A. stellatus are found in the north and south Caspian Sea, four of which are known populations including the Ural River population, the Volga River population, the Kura River population and the Sepidrud River populations. The four other populations identified belonging to Fishery zones 1, 3, and 4 and to Turkmenistan are most probably late or early spawners of the spring run and autumn run of each of the major rivers mentioned. Specific markers were also identified for each of the populations identified. The Ural River population can be identified using primers Spl-68, 54b and Spl-104, 163 170, 173, the Volga River population can be identified using primers LS-54b and Spl-104, 170, 173 113a and similarly the population from the Kura River can be identified using primers LS-34, 54b and Spl-163, 173 and that from the Sepidrud River can be identified using primers LS-19, 34, 54b and Spl-105, 113b. This study gives evidence of the presence of different populations of this species and calls for serious measures to be taken to protect the genetic stocks of these populations. Considering that the population of A. stellatus in Fishery zone 2 is an independent population of the Sepidrud River in the Gilan Province, the catch of these fishes in the region needs to be controlled and regulated in order to restore the declining stocks of this species.

Report of the training workshop on the application of Ecopath with Ecosim to BOBLME, Phuket, Thailand, 8-12 September, 2014

The workshop's objective was to provide information to improve a regional Ecopath with Ecoism (EwE) model.The workshop described the basis and principles underlying the software, encompassing the basics of Ecopath to Ecospace, economics and management strategy evaluation.

The role of satellite lakes in conservation of fish species diversity in the Lake Kyoga basin

Lakes Victoria and Kyoga had, a diverse fish fauna, which was important as food for local population and valuable in scientific studies. Over the past twenty years, the diversity of fish in these lakes had declined due to over-exploitation, introduction of new fish species including the piscivorous Nile perch and degradation of fish habitat. Studies of satellite lakes in the Victoria and Kyoga lake basins suggested that some of these lakes harboured species which had been lost from the main lakes. In order to better understand the extent, to which these satellite lakes may serve as refugia, a faunal survey was undertaken to determine the distribution and nature of the taxa found. Seven satellite lakes and the eastern end of the main Lake Kyoga adjacent to these minor lakes were surveyed over a two-year period for fish species diversity. A total of 68 fish species were recorded of which 41 were haplochromines. Almost all the native non cichlids which occurred in the main lakes (Victoria and Kyoga) before the Nile perch upsurge recorded. Lakes Nawampasa, Gigati, Kawi, Agu and Nyaguo had the highest fish species and trophic diversity. The trophic diversity of haplochromines (based on Shannon Weaver Index) was highest in Lake Nawampasa (1.28), followed by Gigati (1.25), Kawi (1.18), Agu (0.8), Lemwa (0.81), Nyaguo (0.35) and was lowest in the main Lake Kyoga. Potential threats to these lakes were from collectors of ornamental fish species, especially the haplochromines, the spread of the predatory Nile perch and the water hyacinth, which are already in Lake Kyoga, and the destruction of macrophytes through harvesting of papyrus and reclamation for agriculture. The human population around these lakes harvested the fishes for food but the levels of exploitation were still low because the lakes were adjacent to main Lake Kyoga, the major supply of fish. Ornamental fish dealers were encouraged to start captive breeding of the fish for export to reduce pressure on the lakes and demonstrations for breeding were set up at FIRI in Jinja. Meetings and seminars were held with some of the communities living around the lakes sampled and the importance of fish species found in these lakes and the dangers of destructive practices discussed. Representatives of all taxa of fish caught from the lakes were preserved, catalogued and stored in the FIRI Museum. Results from this survey support the motion that these satellite lakes are important refugia for endemic diversity. Based on survey, we recommend that SaIne of these lakes like Nawampasa, Gigati, Kawi, Agu and Nyaguo could be designated as conservation areas of species threatened in the main lakes. One of the factors that seem to have prevented the spread of Nile perch into Kyoga Minor lakes seems to have been the presence of extensive swamps around these lakes and the low oxygen levels that exist in these habitats. Clearing of swamps and vegetation that separate Kyoga minor lakes from the main lake should be avoided to prevent Nile perch from spreading into these lakes.