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Research Article
Oct 24, 2015
Procedure for Maturation and Spawning of Imported shrimp Litopenaeus vannamei in Commercial Hatcher ... y, South East Coast of India
The reproductive performance of the broodstock was assessed at each stage of the maturation and spawning process. Measures of maturation rate, spawning rate, fecundity, hatch rate and nauplii production rate were obtained. The reproductive performance was found for the imported Specific Pathogen Free (SPF) broodstock from Shrimp Improvement system (SIS), Florida, USA. The no.of spawning, eggs quantity, fertility, hatching rate and nauplii production were lowest in 1st to 3rd spawning when females were 7 months old and increased from 4th spawning rate onwards. As the size of females increased from 30 g to 52 g the mean number of eggs per spawning increased from 150,000 to 442,000. Although female body weight was increasingly larger through the study period and the larger females would be expected to produce more eggs per spawning and hatching. The hatching rate was increased from 3rd spawning onwards. The nauplii production rate (NPR), which is a function of egg production and hatching rate, showed a significant increasing from 48% to 96%. In 10th spawning all the activities were increased. This information can be used to select broodstock for hatchery production.
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Research Article
Oct 24, 2015
Survey on Phytoplankton Biomass and Water Parameters in the Habitats of Invasive Tigers Shrimps (Pe ... naeus Monodon) in Nigeria
Penaeus monodon is an invasive species found in the coastal waters of Nigeria. Although widely exploited with significant economic importance, investigation into its adaptation and potential ecological impact in the newly found environment is poorly known. This survey provides baseline information on the phytoplankton community and physico-chemical parameters in ten selected stations from five states where they are exploited in Nigeria. These include: Ibeno (Akwa Ibom State), Bonny (Rivers State), Kaa (Rivers State), Brass (Bayelsa State), Aiyetoro (Ondo State), Makoko (Lagos state), Folu (Lagos state), Apapa (Lagos state), Tin Can Island (Lagos state) and Tarkwa Bay (Lagos state). Total of 147 species of phytoplankton from six classes were recorded during the survey with diatoms being the most prevalent (70.4%), green algae (20.4%), Blue-green algae (5.6%), Chrysophyceae (1.9%). Water parameters recorded temperature (range: 27.33 ± 1.53°C-29.00 ± 1.00°C), pH (7.39 ± 0.08-8.13 ± 0.14), dissolved oxygen (5.40 ± 3.22 mgL1-8.00 ± 1.44 mgL-1), Conductivity (11.22 ± 10.03 µS/cm-39.33 ± 5.87 µS/cm) and salinity (11.02 ± 15.56% -25.98 ± 2.02%). Lowest values for phosphate, nitrate-nitrogen and sulphate were 0.11 ± 0.07mgL1 , 0.10 ± 0.07 mgL-1 and 523.67 ± 880.21 mgL-1 respectively. Generally, ecological factors in their newly found environment are similar to their native range. However, negative impact as an invasive species most be checked.
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Research Article
Aug 26, 2015
Controlling Chaos in a Food Chain Model through Threshold Harvesting
In this paper, we propose a new harvesting strategy namely the harvesting for controlling chaotic population in a food chain model. In particular, we have taken the three species Hastings and Powell food chain model for demonstration. We have shown threshold harvesting strategy can be effectively employed to obtain a steady or cyclic behaviour from chaotic fish population by varying either the frequency of harvesting or the amount of harvesting of fish population. Numerical simulation results are presented to show the effectiveness of the scheme. We obtain steady state; limit cycle, period-2 and period-4 behaviour from chaotic Hastings and Powell model. This threshold harvesting strategy will be very useful for species conservation and fishery management.
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Research Article
Jul 28, 2015
Fishing Methods and their Implications for a Sustainable Environment
Commercial fishes found in Nigeria have been discovered over several thousand years ago. They are found in the Nigeria water ways such as, stream, lakes, rivers lagoon and even the sea. Notably among the fishes are the Cat fish (Scaly and non-scaly etc.). It has been established that protein from foods of animals origin is dangerously lacking in the diets of Nigerians and most Africans Idodo-Umeh (2003).The supply of meat from games and various domestic animals are not enough to meet the protein demand of the growing population in most African countries (Federal Department of Fisheries, 2003).The importance of fish protein in Nigeria cannot be over emphasized since more than 40% of the animal protein consumed by an average Nigeria comes from fish. Thus the total demand for fish in Nigeria is expected to increase since the population is increasing.
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Research Article
Jul 28, 2015
Spatial and Temporal Variability of Phytoplankton Assemblages and Physico-Chemical Characterization ... in Three Similar Dams
The present preliminary study was undertaken from April to September 2013 in order to assess the limnological factors and phytoplankton communities in three dams, having depth of 6 m and area of 10 ± 2 Hectares, at Node Khanduz (Dam 1), Seyed Abad (Dam 2) and Marzban (Dam 3) in Azad Shahr, Gorgan, Iran. During the study period, a total number of 8 families and 28 genera were identified from all sampling sites. Of these 28 genera, 6 genera were belonging to family Bacillariophyceae, 5 genera were from Cyanophyceae, 2 genera from Charophycea, 2 genera from Chrysophyceae, 2 genera from Euglenophyceae, 8 genera from Chlorophyceae, 2 genera from Dinophyceae and 1 genus was belonging to Xanthophyceae. It was concluded that all the dams were having very well balanced phytoplankton communities yet changes in individuals’ composition and numbers were significantly varying among the three studied dams. Further studies focusing on other factors such as presence of heavy metals in the dams and of lengthy periods are recommended.
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Research Article
Jul 28, 2015
A Model Strategic Framework for Prioritization and Development of Inland Water Bodies under Fisheri ... es and Aquaculture
The present article summarizes the available management options and strategies for development of fisheries & aquaculture in inland water bodies. Each section focuses on the key issues or parameters that are crucial from fisheries and/or aquaculture point of view.
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Research Article
Jul 16, 2015
Ornamental Fishery in Rio Negro (Amazon region), Brazil: Combining Social, Economic and Fishery Ana ... lyses
The cardinal tetra is the number one export species in the ornamental fish trade industry in Brazil, accounting for 70% of the total amount of Brazilian fish exports [1]. The cardinal tetra inhabits the middle and upper Negro River, and its trade corresponds to 60% of the economy of the Barcelos municipality. However, fishery data have yet to be collected to better evaluate the effects of this artisanal fishery on fish populations. The present work presents data obtained from field collection interviews and a sample fishery. The data correspond to the quantity of fish caught per collection region, how many people were involved in the activity, the number of nets used, and the catch volume. Data from fisherman interviews and the type of fishing were compared for corroboration of the findings and to assist in calculating the number of fish extracted from the collecting areas during different times of the year. Altogether, these data were used to determine whether ornamental fisheries are sustainable. The present study shows that a fisheries observatory program is viable for the ornamental fish market and can be combined to increase sales, which emphasizes the preservation and wellbeing of the local communities that are active in this trade, as accomplished by the “fair trade coffee market”. We hope this idea can be pursued further by local authorities, and with better data, the preservation of the aquatic fauna can be prioritized because aquatic fauna preservation increases sales.
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Research Article
Jul 12, 2015
Utilization of Treated Duckweed Meal (Lemna pausicostata) as Plant Protein Supplement in African Mu ... d Catfish (Clarias gariepinus) Juvenile Diets
The utilization of treated duckweed (Lemna pauciscostata) as soybean supplement in the diet of African mud catfish (Clarias gariepinus) was carried out for 6 weeks (42 days). Freshly harvested duckweed was given varying treatments (raw, soaked in potash (maize cob as solution), sundried and blanched (at 100°C)) were included at 50% inclusion level. The experimental set up was in triplicate. The result showed highest mean weight gain in the diet 1 (Control diet) and followed by the diet 5 (blanched diet) while diet 2 (raw duckweed) gave the lowest mean weight gain. The food conversion ratio, specific growth rate and protein efficiency ratio followed the same pattern. There was no significant difference between the net profit value of control diet (601.1) and the blanched diet (592.66) (p>0.05) and the blanched diet gave the best benefit cost ratio (BCF). Apart from been viable supplement for soybean meal in the diet of Clarias gariepinus, blanching of duckweed gave better performance than other treatments.
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Research Article
Jun 25, 2015
A Short Review on Infectious Viruses in Cultural Shrimps (Penaeidae Family)
A major constraint limiting the shrimp production is diseases. Shrimp aquaculture is an important industry in many countries especially Southeast Asia and Iran. In cultured pond, the shrimp may be infected with several pathogens such as several viruses. There are at least six lethal viruses affecting penaeid shrimps production in the world especially Southeast Asia and Thailand. However, known viral pathogen in shrimp is about 20. They have been identified from 1970. Incidence of infection in artificial condition is more than nature. The 6 viruses are very important and they cause serious problem for shrimp cultivation and economic losses. They are consisting of HPV, IHHNV, MBV, TSV, WSSV and YHV. Two of them are highly pathogenic and lethal in shrimp such as WSSV and TSV. Shrimp aquaculture is a successful activity. Despite this success, annual production decreased in the latter because of widespread epidemics (epizootics) caused by new viral pathogens. Molecular diagnostic methods such as PCR are tools to detection viral diseases in shrimp in many parts of the world. Pathological methods and electron microscopy are good tools to detection viral disease especially at the first outbreak. Sanitary methods are the best way to control and prevention of viral diseases.
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Research Article
Jun 18, 2015
Polysaccharides in Aquatic Disease Management
Aquaculture is one of fast growing food producing sector in the world. Diseases and out breaks are painstaking as the major problem for this industry. Traditional approaches to control diseases in aquaculture comprise the use of antibiotics and chemical disinfectants, but they are no longer recommended due to the emergence of resistant strains of pathogens and accumulation of residues in the environment and non-target organisms. Although, vaccination is an effective means of disease prevention in fish, it could be expensive, time-consuming and stressful to the fishes. In this context, immunostimulant is a naturally occurring compound that modulates the immune system by increasing the host’s resistance against the diseases that in most circumstances are caused by pathogens, and are widely used in aquaculture. Nowadays using polysaccharides as immunostimulant for controlling aquatic diseases gained great attention due to its less toxic, eco-friendly nature and bioactivity. This review article discussed several marine polysaccharides and their role in controlling the diseases in both fin and shell fish species.
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Research Article
Jun 08, 2015
Use of Plant Products as Candidate Fish Meal Substitutes: An Emerging Issue in Aquaculture Producti ... ons
The search for new dietary ingredients for total or partial replacement of fish oil has assumed a growing importance and is currently the subject of advanced scientific research. Plants are recognized to be a good source of both peptides and oils for fish aquafeeds. The present paper reviews the effects played on fish growth and physiology by some plant products, highlighting also their possible detrimental effects related to the presence of anti-nutritional factors. Although complete replacement of fish meal in feeds for cultured species is still difficult, the results obtained by the current studies performed on plant products are promising and encourage further research on this issue.
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Research Article
May 30, 2015
Effect of Daucus carota and Beta vulgaris on Color of Anabus testudineus
Ornamental fish keeping is one of the most popular hobbies in the world today and rapidly gaining importance for their aesthetic value as well as trade value. The knowledge of nutritional requirement in ornamental fish species is essential to improve productive development and also for color improvement. The Climbing Perch, Anabas testudineus (Bloch) is a highly priced air breathing, freshwater food fish species which belongs to the family Anabantidae and order Perciformes. This paper deals with effect of feed; formulated from Natural plant products viz. carrot (Daucus carota) and beetroot (Beta vulgaris) on color improvement of Anabus testudineus. The feed and water environment changed the color of Ananus testudineus by 80% during the experiment. In practice, Fishery business has enormous potential to accelerate Indian Economy by earning foreign currency as well as it may also reopen a door for young entrepreneurs to do fishery business using natural plant products as feed. Also Ornamental fish feed from natural plant product will make its culture and rearing easy and less expensive and makes this business vibrant and native fishes will get the level of demand they deserve
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Research Article
May 29, 2015
Evaluation of Maggot Meal (Muscadomestica) and Single Cell Protein (Mushroom) in the Diet of Claria ... s gariepinus Fingerlings (Burchell, 1822)
The growth performance of Clarias gariepinus fingerlings (mean weight 0.9 g) fed diets of maggot meal and single cell protein supplemented diet were investigated for 56 days. Nine diet of 40% FM and 30% FM, 10%MM and 20% FM, 10%MM, 10%SCP and 10%FM, 20%MM, 10%SCP and 30%MM, 10%SCP and 40%MM and 10MM, 30% SCP and 10%FM, 10%MM, 20%SCP and 40%SCP. The result of the experiment showed that fingerlings on the diet of 30%FM and 10% MM plus dry pelleted feed (T2) has the best specific growth rate (1.22%), food conversion (2.14) indicating that feed with maggot in combination with other supplemented diet formed better balance diet for the fingerlings. Feed with 30% fish meal and 10% maggot meal is recommended by this study
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Research Article
May 29, 2015
Length-weight Relationship, Body Morphometrics, and Condition Based on Sexual Stage in the Rusty Cr ... ayfish, Orconectes rusticus Girard, 1852 (Decapoda, Cambaridae) with Emphasis on Management Implications
The Rusty crayfish, Orconectes rusticus Girard, is an invasive crayfish species found in the Midwestern United States and Canada. O. rusticus has displaced native crayfish species throughout its range. Length-weight relationship, body morphometric relationship, and condition within the species native range in south-central Indiana were studied. Growth, size relationships based on gender, sexual phase for adults and juveniles and chelae-length, width relationships was used to interpret patterns in sexual dimorphism. Carapace length (CL)–wet weight (Wwt) relationships for all genders (i.e., male, female, juvenile) and all male forms (form I and II) had positive allometric growth. Native O. rusticus were found to be larger in all measurements and heavier than the O. rusticus collected in the invasive range. Orconectes rusticus has a smaller mean carapace length and had a mean weight less than Orconectes limosus, Procambarus acutus, Procambarus fallax, and Procambarus clarkii. Orconectes rusticus shows strong sexual dimorphism patterns, but compared to other freshwater crayfish it is generally smaller. To establish populations in occupied areas O. rusticus may use a combination of competitive and aggressive behaviors. Orconectes rusticus should be managed with depletion trapping and by restoring native predatory fish populations
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Research Article
May 08, 2015
Fish Mycobateriosis: An Emerging Disease in Italy
Mycobacteriosis is a severe chronic disease that affects a wide range of species globally both in culture and wild settings and is zoonotic also. The pathology is caused by Mycobacterium. Recently in Italy this the disease is becoming emerging, in fact outbreaks of disease have been reported in both marine and freshwater fish. Therapy is rather difficult, so it is important try to prevent the disease through the development of vaccines.
