Open Access Original Research Article

Response of Macrobenthic Invertebrate to Organic Carbon and Particle Size in Lagos Lagoon, Nigeria

O. A. Olapoju, C. A. Edokpayi

Asian Journal of Fisheries and Aquatic Research, Page 1-13
DOI: 10.9734/ajfar/2018/v2i126111

Macrobenthic fauna communities are important constituents of soft bottom marine ecosystems which inhabit the bottom environments playing a key factor in controlling structure and functioning of the aquatic environment. Lagos lagoon is the most exposed lagoon to anthropogenic influence in Nigeria coastal lagoon system. Bimonthly sampling was carried out in the Lagos lagoon from September 2014 - July 2016 for water and sediment in twenty – four stations to examine response condition of benthic communities to measures of water quality and sediment quality in Lagos lagoon in order to understand the benthic condition of the aquatic environment. A range of 9 – 91% for sand, 7 – 25% for silt, 0 – 73% for clay while a range of 0 – 4.77 was observed for TOC. The Diversity (H,) richness (d) and evenness (j) were positively correlated with the silt sediment particle size and. Kruskal-Wallis test showed that there was significant difference (p<0.05) between species richness and diversity at all sampling stations. Analysis of variance (ANOVA) showed no significant difference (p>0.05) in mean percentage particle sizes and TOC recorded at the stations but was significant (p<0.05) between TOC and macrobenthic invertebrates. The overall low diversity of macrobenthic fauna observed was attributed to anthropogenic activities majorly industrial dredging and local sand mining which altered the sediment characteristics of the aquatic ecosystem. Assessments of human induced stressors in the lagoon provided information useful for strict regulations and environmental policies to help prevent the aquatic environment from continuous deterioration hence, causing more loss of biodiversity.  Responses of macrobenthic invertebrates to measured variables showed that there are high abundance and diversity of ecological groups of sensitive species majorly distributed around the slightly disturbed zones of the study area. In summary, variables examined in this study showed that the total organic content does not have a depleting effect on the abundance of macrobenthic invertebrates because the values are within permissible limits but the particle size characteristics present in this study showed good environmental indicator for evaluating macrobenthic invertebrate responses to stress pattern in water bodies along the coastal areas surrounded by various human activities.

Open Access Original Research Article

Assemblage, Abundance and Diversity of Fish Species in River Dhaleshwari, Bangladesh

Mehady Islam, Rumana Yasmin

Asian Journal of Fisheries and Aquatic Research, Page 1-28
DOI: 10.9734/ajfar/2018/v2i126112

Biodiversity in realism is a measure of the adherents of species that characterize a biological community and thought to be one of the extremely imperative aspects of community establishment and structure. The study regarding the fish biodiversity is very much needed as it is directly related to the fisheries resource structure and also contributes significantly towards resource richness. Therefore the present study was performed to evaluate the concurrent fish species composition, abundance and some major fish biodiversity indices of the River Dhaleshwari of Bangladesh. The study area was about 564.20 ha and 20 kilometers long along the main stream of the river Dhaleshwari. The starting point was the Tulshikhali bridge, Keranigonj and the end point was Balur char, Munshigonj. The geographical locations of the sampling stations were between 90̊ 17ʹ E to 90̊ 25ʹ E and 23º 40´ N to 23º 37´ N. The study was conducted between August’2015 and October’2016.The fish species diversity showed spatial variation among the sampling stations. The biodiversity appraisal validates Shannon index (0.122-0.634) with highest value in Balur char and lowest in Pathor ghata; Simpson’s index (0.325-0.893) with utmost valuation for the Pathor ghata and lowermost for Balur char; Pielou’s evenness index (0.117-0.588) with maximum value for the Balur char and least for Pathor ghata; Margaleff index (4.793-7.438) with uppermost value for the Balur char and minimum in Tulshikhali; topmost abundance of fish was recorded from Tulshikhali and least for Balur char and maximum number of unique species was recorded for Tulshikhali and minimum from Balur char. Moreover, the current study correspondingly has ascertained the pragmatism and efficacy of biodiversity assessment to scrutinize and epitomize fisheries resources for better management of the river Dhaleshwari. Effective management approach should be applied for precisely maintaining the fish habitat health and ecological condition intact before it’s too late.

Open Access Original Research Article

Artificial Reproduction of Zebrafish Dania rerio under Controlled Laboratory Condition

Kemal Dede, Şehriban Çek Yalniz

Asian Journal of Fisheries and Aquatic Research, Page 1-8
DOI: 10.9734/ajfar/2018/v2i126115

The objective of this study was to describe a standard universally accepted artificial culture protocol for zebrafish. Also, developmental stages of embryogenesis were also described. Because Zebrafish are considered as a model organism and are widely used in biomedical research to study human genes and human diseases. Despite this, the artificial reproduction of zebrafish is poorly described, and there is not any standard universally accepted artificial culture protocol. To satisfy the scientist working in the biomedical area, a standard culture method of zebrafish under controlled laboratory conditions must be developed.

The present study was conducted at the Aquaria Research unit of Marine Sciences and Technology Faculty of Iskenderun Technical University, Iskenderun Turkey, from March 2018 to October 2018.

Spawn traps and gravels are not used for spawning of broodstock. Female and male broodstock were selected from our previously cultured stock, based on their swollen abdomens. Mean body lengths for female and male were 3.34±0.40, 2.97±0.3 cm and the mean weights were 0.38±0.14, 0.25±0.27 g, respectively. First eggs were squeezed from the ovaries then milt was taken from the testes onto the eggs. Fertilisation was done artificially by the dry method. The eggs hatch within 4-5 days at 28±1°C. The mean diameter of eggs and fecundity were measured using a micrometre attached to a microscope. During the experimental studies, the water quality parameters were also maintained at optimum.

In the present study, temperature and pH were maintained at 28±1°C, and 7.28 respectively and which were the best for reproduction of zebrafish. Fecundity differed widely between individuals, and the number of eggs ranged from 7 to 110. The average diameter of the eggs ranged from 405± 0,001 to 570 ± 0,001 µm. Mainly seven developmental stages of embryogenesis were described; the zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching stages.

The results of the present study suggest that with the right artificial culture conditions and proper manual stripping, the required number of eggs and embryos for biomedical research can be easily obtained.

Open Access Original Research Article

GIS-Based Modelling of Water Quality in Different Hilsha Spawning Grounds and Sanctuaries of Bangladesh

Rumana Yasmin, Mehady Islam

Asian Journal of Fisheries and Aquatic Research, Page 1-11
DOI: 10.9734/ajfar/2018/v2i126116

The current study was performed to monitor in situ condition and spatio-temporal modelling of the present status of water quality parameters of different spawning grounds and sanctuaries of Hilsha. The study was conducted in nine sites in lower Padma River (Maowa) to lower Meghna River (Bhola, Patuakhali) from 1 August 2015 to 31 January 2016. This study demonstrates surface water temperature, salinity, conductivity and transparency were ranged from 19.00-33.00°C, 0.10-2.90 ppt, 125.60-4720.00 µS/cm and 6.60-74.00 cm respectively. The values of pH, DO, free CO2, total alkalinity, total hardness and free NH3 were varied from 6.00-9.50, 4.50-11.60 mg/L, 3.46-24.00 mg/L, 33.00-172.50 mg/L, 34.20-1291.00 mg/L and 0.20-1.40 mg/L respectively. Moreover, water quality model reveals that the present status of some water quality parameters (free CO2, free NH3, transparency) deviated from optimum condition suitable for the normal physiological process and spawning of Hilsha.

Open Access Original Research Article

Reproductive Performances of African Catfish Clarias gariepinus according to the Type of Hormones and Substrates in Recycled Water in Southern Cameroon

Claudine Tekounegning Tiogué, Delphin Alfred Eva Ambela, Paulin Nana, Minette Eyango Tomedi –Tabi

Asian Journal of Fisheries and Aquatic Research, Page 1-10
DOI: 10.9734/ajfar/2018/v2i126119

Aims: Improve production of Clarias gariepinus fry through the use of local materials.

Place and Duration of the Study: From 1st April to 09th May 2016 at the Akak Essatolo Fish Farm in Ebolowa, South Region Cameroon.

Study Design: 10 broodstock of C. gariepinus, were used for the artificial reproduction. Pituitary extract and Ovaprim hormones were used to induce oocytes maturation on females. Eggs were obtained by the abdominal pressure of the female. Wicks (or Local raffia fibbers (Raphia regalis)) and mesh frame were used as incubators of fertilised eggs. 12 experimental batches each consisting of 50 g of fertilised eggs were spread in triplicates on both types of incubators previously arranged in closed-circuit tanks.

Methodology: Fertilized eggs were enumerated by direct observation. At the end of the hatching (D0) and of vitelline resorption (D3), larvae of each experimental lot were counted.

Results: Similar (P = .05) absolute and relative fecundities used were recorded in all treatments. Female eggs induced with pituitary extracts and incubated on raffia fibbers recorded lower (P ˂.05) fertilisation and hatching rates. All other treatments were comparable (P = .05) for these parameters. Deformed larvae rates were comparable (P = .05) for all treatments. Survival rates at the end of yolk sac resorption (J3) were higher (> 70%) in all treatment. However, treatment with Ovaprim and wick showed a survival rate (71.1%) significantly (P ˂ .05) lower than the other treatments (> 80); which have otherwise remained comparable (P = .05).

Conclusion: The superiority of ovaprim at the beginning of reproduction is offset by the poor survival rate, which is better with the pituitary gland. It is therefore concluded that the use of the synthetic hormone is not economical for optimal production of C. gariepinus fry. In the same way a mastery of the use of the raffia fibres will improve the cost-effectiveness and consequently will decrease the production costs.