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Research Article
May 02, 2015
Fish Species Composition, Distribution and Abundance in Shadegan Wetland
Composition, distribution and abundance of fish species was carried out from April 2012 to Mars 2013 in the Shadegan wetland. Samples were collected from five stations; Mahshar, Rogbe, Khorosy, Salmane and Ateish in this local in Khuzestan provinces (Iran). A total of 3312 fish individuals comprising 26 species from 6 families were sampled throughout the entire study period. The most abundant species was Carasobarbus luteus (Cyprinidae) comprising 28.20% of the total fish caught. The mean CPUE (catch per unit effort) for all species was 29 nu/day and maximum and minimum CPUE values were 47.60 ± 11.61 nu /day (spring) and 18.40 ± 5.94 nu /day (winter), respectively. Maximum and minimum Shannon-Weinner values were 2.21 (spring) and 2 (autumn), respectively. The Shannon-Weinner value differ significantly between different station (P<0.05) and Margalef’s, Evenness, Simpson’s index didn’t differ significantly between different station (P>0.05). A comparison of value salinity is significant between different station (P<0.05) and other parameters is no significant different station (P<0.05). The Wetland Fish Index (WFI) calculated for the entire wetland using total abundance was 2.99. The WFI should prove to be an effective tool to aid in the management and protection of important fish habitat in Shadegan wetlands.
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Research Article
Apr 25, 2015
Sprostoniella teria Sp. Nov. (Monogenea: Capsalidae Baird, 1853: Trochopodinae) Parasite of Platax ... teira, from Iraqi Marine Water, Arab Gulf
During the investigation of five species of Platax teira where collecting from Arabian Gulf. One parasite was detected Sprostoniella sp. Capsalidae Baird, 1853 from gill filaments. Results give an indication that the parasite are consider as new species in Iraqi marine and Platax teira fishes as anew host in words and new geographical distribution.
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Research Article
Apr 01, 2015
Biological Phosphorus Harvesting for Multiple Uses: A New Scientific Vision
In this study method of harnessing biological Phosphorus (P), an important food and nutritional element for animals and nutrient for vegetation plants, making non dispensable use of water and linking aquatic and terrestrial ecosystems, are dealt with. The methods were devised for biological phosphorus harvesting from the birds feeding on the aquatic ecosystems, secondary consumers such as insects, flees, mosquitoes and fish fingerlings. The study substantiated availability potential of the P by using long time (about 75 year before) published academically accepted data. The measures developed for the harvesting of the biological phosphorous are fact based, feasible and sure to successfully work for the purpose intended for. Although, the quantum of collection will be small, but the material requirement for the useful purposes is also very small. Thus, this study presented a new scientific vision for the scientific development of global concern with regard to phosphorus, its multiple industrial uses and possibility of augmenting supply of source material. The study further broadens utility of terrestrial and terrestrial cum aquatic systems of ongoing fisheries and different birds’ rearing farms viz poultry, duck and aquatic bird rearing and harnessing their droppings in this domain. There is scope for up-scaling of this research for further exploration of Iodine (I), another important nutrient derived from sea and ocean ecosystem and customization in the local domain.
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Research Article
Mar 28, 2015
Biochemical and PCR Assay for Detection of Pathogenic Bacteria at Shrimp and Shrimp Farms in Bangla ... desh
The study was conducted to detect faecal coliforms and pathogenic bacteria in shrimp and shrimp farms. Although coliforms are widely distributed in the environment, but only a small percentage are pathogenic to humans. The presence of pathogenic bacteria in shrimp causes several waterborne infections in humans that are worldwide concerning issues. In order to better determination of the health risks that are associated with the exposure to pathogenic bacteria, a multiplex PCR system was used for the rapid detection of pathogenic Aeromonas sp., Clostradium sp., Listeria sp., Salmonella sp., Shigella sp., Vibrio sp. and Staphylococcus sp. in the water, sediment and shrimp. The target genes were chosen for this investigation included: Aer gene for Aeromonas sp., hilA gene for Salmonella sp., virA gene for Vibrio sp., Sec gene for Staphylococcus aureus, neurotoxin gene type A, B, E, F for Clostridium botulinum, internalin gene for Listera sp. andipaH gene for Shigella sp. Seven pairs of specific primers were used to amplify internal fragments of these genes by PCR to generate PCR products that could be analyzed and confirmed with relative ease by gel electrophoresis. The presence of Aeromona and Vibrio sp. were found in the water, sediment as well as in the shrimp that were dominant among other bacteria species. On the other hand, Salmonella and Clostridium group was found in the sediment of one sample but there is no evidence of Listeria, Staphylococcus and Shigella group in the farms. All of the samples contained relatively large number (1100 to ≥2400 cfu/g) of coliform bacteria. The unhygienic condition and polluted water source could be the major reasons for the occurrence of these types of pathogenic bacteria in the shrimp farms in this area. The result revealed that the PCRbased rapid detection system described in this study is a powerful method for routine monitoring and risk assessment of water quality in the shrimp farms and could be an effective tool for disease studies in our shrimp sector.
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Research Article
Mar 28, 2015
Studies on the Mangrove Macro Faunal Diversity and Assessment among Different Sites in Port Blair B ... ay, South Andaman Islands
The mangrove intertidal zone is characterised by plenty floral and faunal diversity. The mangroves provide important habitat for a wide range of species like diverse communities of benthic organisms and function as nursery habitats for different types of crab, prawn and fish species and support offshore fish populations and fisheries. To assess the occurrence, spatial distribution and species composition of macro fauna in a mangrove area, core samples were taken along with transect in Portblair bay, South Andaman Islands. Three sites were taken; each study area was divided into three zones viz. Proximal, middle and distal zones, which were analyzed according to the floral composition. The highest value was observed at Barmanallah (2061 no.m-2), followed by Carbyn’s Cove (1710 no.m-2) and the lowest value was noticed at Manjery (882 no.m-2). Terebralia palustris, Cerithidea sp., Periopthalmus sp., Uca sp., Balanus sp. and Polychaetes were dominated in order. Some locations were found to support a high diversity of organisms across habitats, while other locations had high densities of a few species only
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Research Article
Mar 27, 2015
Effect of Testosterone-induced Sex Reversal on the Sex Ratio, Growth Enhancement and Survival of Ni ... le Tilapia (Oreochromis niloticus) Fed Coppens and Farm Produced Feed in a Semi Flow-through Culture System
The study aimed at determining the effect of testosterone-induced sex reversal on the sex ratio, growth enhancement and survival of Nile tilapia, Oreochromis niloticus fed two feed type (coppens and farm produced feed of 56% and 25% crude protein respectively) and reared intensively under controlled conditions in a semi flowthrough culture system in twelve fibre glass tanks. The present study also examine the effectiveness of water flowthrough culture system in controlling unwanted reproduction during culture of mixed sex O. niloticus. The experiment was designed as 4 treatments × 24 weeks factorial replicated thrice. The fry was treated with a steroid hormone, 17α-methyltestosterone and cultured for a period of 21 days to reverse the sex to male fishes. After completion of the trial period of 21 days, nursing of the experimental fry (mixed sex and sex reversed) was continued for further 24 weeks with the two feed type. The results of the study showed that the highest sex occurrence of 95% and 90% males was recorded in the sex reversed fishes fed Coppens (Treatment II) and Farm Produced Feed (Treatment IV) respectively. Survival rate was 100% among all the treatments. Treatment II had the highest/best mean body weight gain (19.97 g), daily weight gain (0.12 g) and highest final weight (50.11 g). The study clearly indicated that the inclusion of the steroid hormone, 17α-methyltestosterone in the diets significantly altered the sex ratio towards male and enhanced the growth performance and survival rate in the sex reversed group in Treatments II and IV (P<0.05) irrespective of the feed type and thus recommended for tilapia culture. In spite of the overall best performance recorded in 56% CP of the commercial diet (Coppens) fed the tilapias in Treatments I and II, which is outside the recommended levels for the growth of tilapia, a significant growth rate (P<0.05) was also observed in the tilapias fed Farm Produced Feed with 25% CP content and is also recommended. The inability of O. niloticus to reproduce during the 24 weeks of the culture period in this study is an indication that the semi flow-through culture system using fibre glass tanks is a successful reproduction control method for O. niloticus and thus should be adopted in the aquaculture industries
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Research Article
Feb 28, 2015
Mass Propagation of Danio aequippinatus, an Ornamental Fish of North Eastern India
North eastern region (NER) of India harbours 266 species of fishes out of which 196 have potential ornamental value. The present paper incorporates the technique of mass propagation of indigenous ornamental fish species with Danio aequipinnatus as the test species. For successful mass propagation of D. aequipinnatus, selection of brood stock, food and feeding schedule and breeding set-up are important criteria. Maintenance of physic- chemical parameters of the breeding tank is important in the survival of the breeders. Best fertilization rate are obtained with 3:2 male to female ratio.
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Research Article
Feb 28, 2015
Quantitative Analyses of Parasite Load in the Cardinal Tetra (Paracherodon axelrodii), along the Pe ... riod of Capture and Storage
Fish disease reduces productivity and quality of fish raised in fish farms all over the world and impacts the economic activity of exporting firms, leading also to credibility loss. The current paper is the result of examinations performed on two nature born batches received from the Barcelos region at the installations of a tropical fish exported. A total of 100 fish out of 1000 were removed and inspected for parasites, the remaining 900 fish were kept for a month at the company’s facility where they were fed and treated for parasites. After this month, an additional 100 fish were inspected for ectoparasites. For most ectoparasites species, treatment reduced the quantity of the infection vector proving the effectiveness of the treatment used.
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Research Article
Feb 01, 2015
A Review of Epigenetic Imprints in Aquatic Animals
Epigenetics is one of the most rapidly expanding fields in biology. On a molecular level, covalent modifications of cytosine bases and histones, and changes in the positioning of nucleosomes are commonly regarded as the driving epigenetic mechanisms. They are fundamental to the regulation of many cellular processes, including gene and microRNA expression, DNA protein interactions, suppression of transposable element mobility, cellular differentiation, embryogenesis, X-chromosome inactivation and genomic/ imprinting. Genomic imprinting is an epigenetic genemarking phenomenon that occurs in the germ line, leads to parental-origin-specific expression of a small subset of genes in mammals and oviparus. The epigenetic imprints regarding the parental origin are established during male and female gametogenesis, passed to the zygote through fertilization, Maintained throughout development and adult life, and erased in primordial germ cells before the new imprints are set.
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Research Article
Feb 01, 2015
Isotopic Differences between the Left and Right Side Otoliths of Flatfish Indicating Growth rather ... than Environment
This paper reports a new result for the isotopic differences between the left and right sagittal otoliths of Pacific halibut Hippoglossus stenolepis, a flatfish with both eyes on the right side. Using microsampling techniques we were able to collect subsamples from the nucleus and the 5th and 8th annulus from 63 pairs of halibut otoliths. Isotopic analyses of δ13C and d18O showed that there was a significant difference between the left and right side otoliths from the nucleus in both Washington Coast and Puget Sound samples; but no significant difference from the 5th and 8th annuli of the same otoliths. These results were difficult to be explained as the differences in environmental parameters between ocean and estuary, but the mass accumulation from growth bias that was caused by gravitational force. The management implications on the results are clear: when using the nucleus of flatfish samples on stock structure investigations, one should consider the possible isotopic differences between the left and right side otoliths. However, when using the same samples for adult population, one may choose otoliths from either sides.
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Research Article
Jan 30, 2015
Influence of Stocking Density on Growth and Survival of Post Fry of the African Mud Catfish, Claria ... s gariepinus
The effect of stocking density on growth and survival of post fry of the African mud catfish, Clarias gariepinus, was investigated. C. gariepinus post fry were stocked at the rate of 5, 10, 15, 20, and 25 post fry/litre of water. The post fry were fed to satiation four times daily with crumbles of a commercial catfish feed. The survival, mean total length, mean body weight, condition factor, specific growth rate and performance index were found to be density dependent. Survival rate ranged from 29.7 ± 7.4 to 56.6 ± 33.3%, while specific growth rate was between 0.00143 ± 0.0014 to 0.00702 ± 0.0044. Optimum growth and survival rates were recorded at stocking densities of 5, 10, 15 post fry/litre of water. However, the determined optimum stocking density for rearing of C. gariepinus post fry in tanks is 15 post fry/litre of water. It is concluded that increased density impacts on growth and survival of the fish, a consequence of increased activity (frequent surfacing, feeding and swimming) and aggressiveness.
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Research Article
Jan 21, 2015
Research of Ascocotyle (Phagicola) longa in Heat Treated Fillets of Mullet (Mugil platanus)
Seafood can present many biological hazards, such as zoonotic parasites. Among these, Ascocotyle (Phagicola) longa trematode is generally found in mullets (Mugil platanus) and is the most common parasite involved in heterophyiosis outbreaks. This research aimed to detect viable metacercariae of Ascocotyle (Phagicola) longa after heating muscle of mullets. The method used was sedimentation followed by microscopy observation. It was found 100% (16/16) of inactivated metacercariae in the analyzed samples. This is the first study involving samples of mullets ready to eat sold directly to consumer. We conclude, consumers must be alerted to the risk of infection by raw mullet eating and proper heating or cooking kills this trematode.
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Research Article
Dec 24, 2014
Length–Weight Relationships of Twelve Fishes from the River Padma near Rajshahi City, Bangladesh
The objective of this study was to evaluate the length-weight relationships (LWRs) of freshwater fish species, which serves as a baseline for comparison to other relatively altered tropical Bangladeshi rivers. The LWRs of 12 species belonging to four classes, seven families and 11 genera (Gagata youssoufi, Cirrhinus reba, Clupisoma garua, Ompok bimaculatus, Pangasius pangsius, Securicula gora, Ailia coila, Chanda nama, Parambassis ranga, Botia lohachata, Rhinomugil corsula and Labeo boga) captured from the River Padma near Rajshahi City, Bangladesh, were studied. The allometric coefficient (b) of the LWRs indicated positive allometric growth in P. pangsius, A. coila, C. reba, B. lohachata and C. nama (b>3.00), but negative allometric growth in G. youssoufi, C. garua, O. bimaculatus, S. gora, P. ranga, R. corsula and (b<3.00). The results would be useful for sustainable management and conservation of the limited stocks in the Padma River ecosystem.
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Research Article
Dec 10, 2014
A CYP19 Based Sex Determination and Monosex Production in Aquaculture Species Oreochromis niloticus ... L. and a Cyprinid Cyprinus carpio L.
The efficacy and effect of tamoxifen and letrozole on sex reversal in common carp and Nile tilapia was studied using free swimming fry of Cyprinus carpio and tilapia Oreochromis niloticus. Treatment of letrozole in the dose of 100 mg kg-1 feed brought about 79.39 ± 1.09% masculinisation in C. carpio and 87.91 ± 1.39% masculinisation in O. niloticus, while larger dose (200 mg kg-1 feed) produced 98.47 ± 1.34% male C. carpio and 99.65 ± 0.72% male O. niloticus. In the control group, there was 48.28% male and 50.78% female C. carpio while 46.38% male and 53.616% female O. niloticus. Letrozole significantly increased serum testosterone (T) level suppressing 17β-estradiol (E2 ) production and the androgenizing action was more potent when compared with tamoxifen treatment. The histological examination of letrozoletreated C. carpio and O. niloticus revealed increased number of irregularly spread spermatids and there was hardly any difference in control testes and letrozole treated gonads. The results showed potent and complete action of letrozole (Cyp19) on sex reversal for monosex male fish production delineating its commercial application in aquaculture
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Research Article
Nov 23, 2014
Induced Breeding of Grass Carp (Ctenopharyngodon idella) and Silver Carp (Hypophthalmichthys molitr ... ix) Using Ovatide as Synthetic Hormone at National Fish Seed Farm (Nfsf) Manasbal, Kashmir, J&K
In the present study economically important and fast growing food fishes grass carp (Ctenopharyngodon idella) and silver carp (Hypophthalmichthys molitrix) were successfully spawned with Ovatide (combination of GnRH analogue with dopamine antagonist pimozide) in Kashmir. The preparations were administered by an intramuscular injection of single dose of 0.7 and 0.8-0.9 ml/kg body weight for female grass carp and silver carp and a single dose of 0.35 and 0.4-0.45 ml/kg body wt. body wt. for male fishes respectively. After dosing, the fishes were immediately carried to breeding pools in the Chinese Hatchery. After 14-16 hours of dosing spawning took place. After 10-12 hours of spawning, twitching movement started. Hatching occurred after 20-30 hours of fertilization at 24-26°C. Fecundity of grass carp and silver carp were recorded as 70000- 80000 and 1-1.10 lac eggs/kg body wt. of fish respectively. The fertilization percentage of grass carp and silver carp were recorded as 80.03% and 78.12% respectively. The hatching percentage of grass carp and silver carp were recorded as 70.10% and 69.71% respectively. And the fry survival percentage of grass carp and silver carp were recorded as 15. 21% and 14.56% respectively. The source of water was Manasbal Lake that favored most of the water quality parameters for spawning, hatching and survival of fry than ground water.
