Open Access Original Research Article

Assessment of Livelihood Vulnerability of Fisherfolks in Coastal and Freshwater Fishing Communities of Ilaje in Ondo State

Siyanbola A. Omitoyin, Adeniyi P. Ogungbure, Kemisola D. Osakuade

Asian Journal of Fisheries and Aquatic Research, Page 1-14
DOI: 10.9734/ajfar/2021/v11i230197

The study assessed the livelihood vulnerability of fisherfolks in both coastal and freshwater fishing communities of Ilaje Local Government area of Ondo state, Nigeria. Structured questionnaires were used to collect information from 200 fisherfolks from both communities. Data were analyzed using the descriptive statistics, Livelihood Vulnerability Index data were aggregated using a composite index and differential vulnerabilities were compared. The results showed that majority of the fisherfolks from freshwater and coastal communities were below 46 years old, respondents from the freshwater communities were 95% male, 5% females while all (100%) respondents in the coastal communities were male with majority assenting to fishing as their primary occupation. The freshwater communities showed greater vulnerability on the socio-demographic profile (SDP) index than coastal communities (SDP freshwater 0.49;SDPcoastal communities 0.34). Freshwater also showed greater vulnerability on the livelihood strategies component (0.45) than coastal communities (0.40). The social networks indicators were the same for the two communities. The overall health vulnerability score for freshwater communities (0.46) was higher than that for coastal communities (0.44).  Also, the overall food vulnerability score for freshwater households (0.23) was greater than that of coastal community households (0.22). Freshwater households had a lower vulnerability score (0.03) for the water component than coastal communities (0.17). Based on the incidents of flooding, droughts, storms and erosion, households in the coastal communities (0.50) were more vulnerable to natural disasters than those in the freshwater communities (0.41). Overall, coastal communities had a higher Livelihood Vulnerability Index (LVI) than freshwater (0.357 versus 0.356).This logical approach may be used to monitor vulnerability, programs and resources to assist fisherfolks. Also, there should be enlightenment on how to mitigate the factors enhancing climate change while good infrastructure and aids be given to those who suffer losses due to climate change impacts.

Open Access Original Research Article

Efficacy of Probiotics and Bioflocs on the Production Performance of Tiger Shrimp Penaeus monodon and Pacific White Shrimp Litopenaeus vannamei during Polyculture Operation

K. Sirisha, Y. Aparna, M. Srinivasulu Reddy

Asian Journal of Fisheries and Aquatic Research, Page 15-28
DOI: 10.9734/ajfar/2021/v11i230198

Shrimp culture has been developed during the last three decades and the production of farmed shrimp reached its peak. However, the shrimp production was decreased all over the World including in Asian Countries because of the mass mortality due to the outbreak of several diseases predominantly White Spot Syndrome Virus (WSSV) which caused extensive economic damage to the shrimp culture industry. Various Polyculture technologies of shrimp with shellfish, finfish or seaweeds have been implemented to reduce economic damages by mass mortality of shrimp. The present study was conducted with Tiger shrimp Penaeus monodon and Pacific white shrimp Litopenaeus vannamei through Polyculture operation to determine optimum stocking ratios for induction of best performance and highest production rates. Initially, the experiments were conducted with different ratios and combinations of stocking densities 1:1, 2:1 and 1:2 ratios of Penaeus monodon and Litopenaeus vannamei with control group feed with commercial feed, the other group certain Probiotic bacteria such as Bacillus licheniformis and Lactobacillus rhamnosus added in feed, the third group both the Probiotic bacteria and the addition of external Carbon source from sugarcane molasses in the form of Bioflocs for 100 days. To ascertain further interaction of ratios influence, 20:10, 20:12, 20:15 ratios of stocking and Monoculture experiments were conducted. In both the experiments the Survival rate, Final body weights, Weight Gain, Feed conversion ratio, Specific growth rates, Average daily growth rates, Protein efficiency ratio, and Productivity rates were significantly different (P<0.05) in all the different treatments both for P. monodon and L. vannamei. From the results obtained 20:10 ratio of P. monodon and L. vannamei was considered as the best ratio of stocking, which yielded the highest production rates in all the Control, Probiotic added and both Probiotic & Biofloc added groups. The results obtained in the present study clearly demonstrate that the rearing of taxonomically similar species with optimum stocking ratios seems to improve the efficiency of shrimp farming and substantially increasing the production rates. So, this polyculture of P. monodon and L. vannamei can be considered as an alternative approach towards the establishment of sustainable shrimp farming activity which will yield good economic returns.

Open Access Original Research Article

Morphometric Relationships in the Blue Swimming Crabs, (Portunus pelagicus) (Linnaeus, 1758) from the Palk Bay, Sri Lanka

S. S. K. Haputhantri, S. J. W. W. M. M. P. Weerasekera, K. H. K. Bandaranayake

Asian Journal of Fisheries and Aquatic Research, Page 29-38
DOI: 10.9734/ajfar/2021/v11i230199

The blue swimming crab (Portunus pelagicus) has become the focus of an important export-oriented fishery in Sri Lanka for a decade. The Palk Bay in the Northern coastal waters of Sri Lanka is one of the best-known fishing grounds for blue swimming crabs in Sri Lanka. This study was undertaken with the aim of establishing some morphometric relationships for P. pelagicus in the Palk Bay.

Biological sampling was conducted for five consecutive days per month from November 2014 - October 2015 in the Northern landing sites in the Jaffna District where the catch of Palk Bay blue swimming crab fishery was landed. P. pelagicus specimens were also randomly collected for laboratory analysis. The morphometric measurements of the specimens for the following parameters were undertaken: CW - carapace width with the spine, CWW - carapace width without spine, MW – mouth width, TL - total length, LCPL - left chelar propodus length, LMOV - left movable part Length, RMOV - right movable part length, LCPH - left chelar propodus height, RCPH - right chelar propodus height, ABW - abdominal width, ABL - abdominal length and BW - body weight. The least squared method was used to obtain the Length-Length (L-L) and Length-Weight (L-W) relationships.

Of the 65 L-L relationships obtained for P. pelagicus from the study, 34 relationships were correlated (r2>0.5). The estimated relationships between BW and CW for males and females were BW=0.0001 CW 3.01 (r2 =0.84) and BW= 0.0001 CW 2.90 (r2 =0.86), respectively.

Positive allometric growth was observed for male P. pelagicus, whereas a negative allometric growth was observed for female P. pelagicus. Most of the morphometric relationships of P. pelagicus obtained in this study were not isometric.

Open Access Original Research Article

Comparison of Length and Weight Characteristics of O. niloticus and O. aureus from Garmat Ali River, Iraq

Abdul-Razak M. Mohamed, Ayat N. Salman

Asian Journal of Fisheries and Aquatic Research, Page 39-51
DOI: 10.9734/ajfar/2021/v11i230200

Cichlid species invaded the Iraqi waters in the mid-2000s and are now dominant fish species. The present study was carried out to investigate the age and growth of two cichlid species, Oreochromis niloticus and O. aureus in Garmat Ali River, Iraq from October 2019 to September 2020. A total of 2707 specimens of O. niloticus ranging from 7.0 to 25.5 cm and 1664 of O. aureus varying from 7.0 to 26.3 cm were examined which were captured by various fishing gears. The length-frequency distributions revealed that fish lengths (13.0-18.0 cm) formed 64.1% of the total catch of O. niloticus and 67.2% of O. aureus. The length-weight relationships were W=0.012*L3.109 for O. niloticusand W=0.015*L3.075 for O. aureus, and both species indicated positive allometric growth. The highest values of the relative condition factor were obtained during spring and the values decrease when length of two species increase. Seven age groups were determined for O. niloticus: 9.9, 12.9, 15.6, 17.9, 19.4, 20.4 and 22.2 cm, and for O. aureus: 9.3, 12.5, 15.2, 18.0, 19.4, 21.3 and 22.2 cm. The theoretical maximum length (L∞) was 29.2 cm for O. niloticus and 28.6 cmfor O. aureus. These results can assist in fisheries management and conservation of the fish species in Iraqi waters.

Open Access Original Research Article

Effect of Spirulina Flour on Changes of Color Intensity in Angelfish (Pterophyllum scalare) Strain Three Color

Walim Lili, Achmad Rizal, Roffi Grandiosa Herman, Rachmat Mahadika Ramadhan

Asian Journal of Fisheries and Aquatic Research, Page 52-58
DOI: 10.9734/ajfar/2021/v11i230201

Ornamental fish is a fishery commodity that has promising business opportunities. Ornamental fish will have a high selling value if they have bright and brilliant colors. The advantage of ornamental fish is in the intensity of the color on its body. This study aims to analyze the levels of Spirulina added in feed which can increase the color intensity of the Angelfish juvenille. The method used was an experimental method Completely Randomized Design, consisting of five treatments and four replications. The parameter observed was an increase in color on the head of the fish and analyzed using Kruskal-Wallis.The results showed that giving 3% spirulina flour in commercial feed could provide the best color improvement for angelfish with an increase in color value by 3, and if discontinued addition of spirulina flour can reduce the brightness level of the angelfish.