Journal of Fisheries (University of Rajshahi)
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Length-weight relationship, condition factor and gonado-somatic index of Labeo calbasu (Hamilton, 1822)
Get PDFAn attempt was made to study dynamics of length-weight relationship (LWR), relative condition factor (Kn) and gonado-somatic index (GSI) of Labeo calbasu from the wetlands of South 24 Parganas district of West Bengal, India. A total of 275 fish specimens (130 to 430 mm) were examined over nine months from December 2006 to August 2007. Specimens were categorized into two groups based on the size at first maturity of 260 mm. The LWR was recorded W = 0.007269 L3.181 for Group A (<260 mm) and W = 0.007367 L3.031 for Group B (≥260 mm). The individuals exhibited isometric growth. The monthly mean Kn values varied from 0.924 to 1.141 with an average value of 1.059. The mean monthly values of GSI varied from 0.544 to 3.301 for male and 0.560 to 9.649 for female. There was significant variation (P < 0.05) in the mean values of GSI in different months between sexes
A flume test of a model net with varying wing-end widths to characterize the performance of shrimp trawl in Kotabaru, Indonesia
Get PDFShrimp trawl net is the prominent fishing gear that beneficially supports shrimp industries in Kotabaru, Indonesia. However, concurrently local fishermen have no idea how trawl works under towing condition. For this reason, a flume test of a 1/8 scale model net with varying wing-end widths was undertaken. The flow speeds of model were 48, 56, 64, 72, and 80 cm s–1. Meanwhile wing tips distance was set at 46–66% of head-rope length. At a towing speed of 64 cm s–1 (2-knot in full scale), the net height was 12 cm, the projective area of net mouth was 9.16×102 cm2, water filtering volume was 58.44×103 cm3 s–1 and total net resistance was 6.34×102 g. The ratios of net height to net circumference ranged of 0.04–0.08. The net height was 5.5% of net circumference and getting lower at higher towing speeds. The exponent value of 1.40 was smaller than the suggested value (2.0) indicating the shape of net body should be refined by inserting triangle nets between the side net and baiting. Moreover, the length of nets should be afforded to the lacing lines to increase the height of net opening by better distributing the towing forces
New estimates and complications in the assessment of female functional maturity for the European lobster (Homarus gammarus) on the Yorkshire Coast (UK)
Get PDFNew estimates of female Homarus gammarus functional maturity were developed from targeted offshore and quayside based industry surveys in the Yorkshire Coast fishery. Offshore surveys also provided the first stock specific quantification of pre-recruit contributions. A contrast in results identified a new complication in estimating functional maturity attributed to ‘soft’ animal exploitation which is reviewed and assessed
Morphometric and meristic comparison of local and Thai Anabas testudineus
Get PDFLocal and Thai climbing perch, Anabas testudineus are locally known as koi in Bangladesh. These two are important natural and cultured fish. This study was carried out the comparative investigations on morphometric and meristic of local and Thai A. testudineus. Both the varieties were collected from different fish markets in and around Savar. The morphometric characteristics were higher in Thai koi than local and among them; total length, standard length (SL), length of 1st and 2nd dorsal fin bases, length of 1st and 2nd anal fin bases, abdominal regional length were found different. Proportion of SL and head length (HL), HL and snout length, SL and caudal peduncle length were different between the two varieties. Among the meristic characteristics; number of dorsal spines, dorsal fin rays, anal spines, scale on upper lateral line were found difference between local and Thai koi. The body spots and the colour at pelvic fin region were also different. The present study suggested that local and Thai koi are morphometrically and meristically different in many aspects
Distribution and abundance of cichlids in the New Calabar River, Nigeria
Get PDFThis study was conducted to study the distribution, abundance and diversity of the cichlids in the New Calabar River, Nigeria. A total of 1073 cichlids belonging to ten species and seven genera (Coptodon guineensis, C. zillii, C. dageti, Pelmatolapia mariae, Hemichromis fasciatus, Pelvicachromis taeniatus, Chomidotilapia guntheri, Tylochromis sudanensis, Sarotherodon galilaeus and S. melanotheron) were collected from three sampling stations between February and July, 2017. The most abundant species, in terms of number, was C. guineensis comprising 33.3% of all the number of species recorded followed by C. zillii (19%) and S. galilaeus (16.7%) while in terms of weight the dominant cichlids were C. guineensi (38.4%), C. zillii (19.6%) and S. melanotheron (12.9%). Five species, C. guineensis, S. melanotheron, S. galilaeus, C. dageti and C. zillii were recorded throughout the months of study. The Shannon-Weaver diversity index was found the highest (1.5) at Station 1 and the lowest (0.93) at Station 3 while Pielou’s evenness index was the highest (0.77) at Station 1
Production and economics of carp polyculture in ponds stocked with wild and hatchery produced seeds
Get PDFLack of quality carp seeds is one of the major problems for fish production in Bangladesh. This experiment was conducted during July to December 2013 to study the production and economics of carp polyculture using wild and hatchery produced seeds in ponds in Faridpur district, Bangladesh. Seeds of native major carps (NMCs) (Catla catla, Labeo rohita and Cirrhinus mrigala) and non-native carps (NNCs) (Hypophthalmichthys molitrix, Ctenophryngodon idella, Aristichthys nobilis and Cyprinus carpio) from four different sources were tested in feed and fertilizer based polyculture ponds under controlled mesocosm trials with four treatments (T1–T4), each with four replications. Combination, weight and density of the stocked species were same for all the treatments. Water quality parameters were monitored monthly and mean values were found within suitable range for fish farming. Mean final weight, weight gain, specific growth rate and yield of L. rohita, C. catla and C. mrigala were found significantly (P < 0.05) higher with treatment T1, T3 and T2 respectively. Treatments T1-T3 varied more significantly (P < 0.05) than treatment T4 for total fish yield and cost benefit ratio. Polyculture of wild sourced NMCs and hatchery produced NNCs were found more profitable than aquaculture of hatchery produced NMCs and NNCs
Inclusion of cricket (Gryllus bimaculatus) meal in African catfish (Clarias gariepinus) feed influences disease resistance
Get PDFIn our present study, we observed the effect of cricket meal (CM) on disease resistance of African catfish. Fish were fed diets containing 350 g kg–1 and 400 g kg–1 of CM and 350 g kg–1 of fishmeal as control. The fish were divided into triplicates treatments of ten fish per replicate, weighed 22.5±0.6 g and fed with experimental diets for 40 days before being challenged against Aeromonas hydrophila. Relative percentage of survival (RPS) was recorded over 12 days post-challenge. White blood cell count, total protein, globulin and lysozyme showed significantly increasing levels in those fed with cricket meal diet compared to the control group. Mortalities at 12-day post-challenge significantly decreased to 30% (RPS: 66.7%) and 27% (RPS: 70%) for 35% and 40% CM respectively compared to 90% mortality in control group. Intestines and liver tissues of infected fish were dissected for pathogenic confirmation. The intestines of control diet showed the highest bacterial load (58.2×107 cfu g–1) compared to CM diets. The current study indicates that dietary CM could enhance the innate immune system and disease resistance of African catfish
Freshwater fishes of Orissa, India
Get PDFVaried freshwater resources of Orissa blessed with diverse fish fauna. In total, 186 species of fishes belonging to 11 orders, 33 families and 96 genera were recorded from various freshwater bodies of Orissa. Cypriniformes was the most dominant order and Cyprinidae was diverse family. The trophic level of fishes of Orissa ranged from 2.0 to 4.5 containing 62.41% of carnivorous species. Fishery status revealed existence of 120 species worth for capture fishery, 101 species worth for ornamental fishery, 37 species worth for culture fishery and 25 species worth for sport fishery. Threat status comprises of one Critically Endangered species, five Endangered species, three Vulnerable species and remaining 177 species were Not Threatened. The findings of present communication may serve as baseline information for planning, conservation and management of fish and fisheries resources of Orissa
Pond fish culture and socio-economic status of fish farmers in Parbatipur upazila of Dinajpur district, Bangladesh
Get PDFThis study investigates the socio-economic conditions of the fish farmers and aquaculture status in Parbatipur of Dinajpur district during May to October 2016. Majority of the fish farmers belonged to the age group of 31 to 40 years (44.3%) and represented by 68.6% Muslims. Among them 40% had secondary level of education and most of the families were nuclear (64.3%). Farmers were involved in fish culture as their primary (24%) and secondary occupation (53%). Over 80% of the farmers had electricity facilities and 41% of them received health services from the village doctors. Only 9% of the fish farmers received formal training on fish culture. The average aquaculture pond size was 0.18 ha, where 84% ponds were perennial. The average stocking density was 23208 fingerlings ha–1 whereas organic fertilizer, urea and TSP were applied at 8665.4 kg ha–1 yr–1, 210.1 kg ha–1 yr–1 and 133.5 kg ha–1 yr–1 respectively. Pre and post stocking liming doses were 205.7 kg ha–1 yr–1 and 138.4 kg ha–1 yr–1 respectively. Necessary training facilities with institutional supports, credit facilities and extension services could play an important role in improving the fish production
Impacts of water regulation on Tenualosa ilisha in the Narmada Estuary, Gujarat, India
Get PDFHilsa is a highly prestigious fish for esteemed delicious taste, high market demand and price. It forms an important fishery of funnel-shaped 72 km long Narmada Estuary. Rapid decline in hilsa catch has been recorded in the Narmada Estuary over last few decades. Hilsa catch was recorded 5180 ton in 2006–07 that reduced to only 419 ton in 2014–15. Pre-impoundment of dam showed that T. ilisha contributed to the tune of 977.1 to 3727 ton from 1974–75 to 1982–83 and the highest catch of hilsa was 15319 ton during 1993–94. Sardar Sarovar Dam started functional in the year 1994 which has impacted natural water flow of the river and resulted in a reduction of freshwater availability in the estuary; the development of sand bars at the mouth of the estuary also reduced the tidal ingress into the system; low depth, loss of breeding, nursery and feeding grounds, over fishing may be the most important factors affecting hilsa fishery in Narmada estuary. Catching of juvenile hilsa during winter by ‘Golava’ net (small meshed bag net) also led to a rapid decline in hilsa catch