Journal of Aquatic Sciences

Morphometric characterization of Nile, Thai and Hawaiian Red Tilapia.

M. Ohwerhi, — 2024-12-19

The study examined morphometric characterization and phenotypic variations of Nile Red Tilapia (Oreochromis niloticus), Thai Red Tilapia (Oreochromis niloticus x Oreochromis mossambicus) and Hawaiian Red Tilapia (Oreochromis mossambicus × Oreochromis urolepis hornorum). A total of 90
samples of each of the test fish were collected from private farms in Nigeria. They were taken to the Wet Laboratory of Department of Fisheries and Aquaculture of Delta State University, Abraka Nigeria. A total of 14 body parts were measured by one person using buss truss protocols. The measured parts were subjected to discriminate analysis on SPSS version 23 and on Past software version 10.1. The countries or origin of the fish species were the independent variables while the measured body parts remained the dependent variables. Results inferred that, examined fish had close ancestor. However, the total length, standard length, body length and maximum mouth length could be used to discriminate this fish into their base population. Similarly, strong loadings on the canonical discriminate function were observed in the first and second functions indicating that the differences shown by the total length, standard length, body length and maximum mouth length are noticeable on close examination of the fish.

The crisis of freshwater biodiversity: impacts, challenges and conservation strategies.

M. T. Ojubolamo, — 2024-12-19

The study reviewed the economic, social, and cultural importance of freshwater biodiversity, as well as the increasing threats it faces due to human activities. Freshwater ecosystems, valued at over $4 trillion annually, are declining faster than most other ecosystems, highlighting the urgent need for effective conservation measures. The analysis revealed significant gaps in current efforts and emphasized the necessity for more integrated and robust management strategies. To mitigate biodiversity loss and preserve the vital services provided by freshwater ecosystems, the study calls for a concerted global effort to strengthen conservation initiatives, incorporate biodiversity considerations into policy frameworks, and involve stakeholders in sustainable management practices. This review highlights the critical need for immediate action to ensure the long-term sustainability of freshwater biodiversity and its essential ecosystem services. Comprehensive conservation strategies are required to address these challenges, focusing on mitigating current threats, restoring degraded habitats, and preventing further damage. By implementing these approaches, the resilience and functionality of freshwater ecosystems would be protected, ensuring their continuous support to diverse species and provision of essential services for future generations. The review further underscores the importance of coordinated global efforts to protect and conserve freshwater biodiversity, stressing its vital role in maintaining ecological balance and promoting human well-being.

Length-weight relationships and condition factors of Sarotherodon melanotheron, Chrysichthys nigrodigitatus and Periophthalmus koelreuteri from tropical creek, southwestern Nigeria.

B. E. Emmanuel, — 2024-12-19

The length-weight relationships and condition factor of Sarotherodon melanotheron, Chrysichthys nigrodigitatus and Periophthalmus koelreuteri inhabiting Abule-Eledu Creek, Lagos Lagoon were studied. Fish samples were collected using a gill nets which were set in the evening between the hours of 4pm to 6pm and retrieved the following morning between the hours of 6.00am to 9.00am. Fish collection was carried out from February to July, 2021. Length and weight data collected were analyzed with Microsoft excel to estimate relationship in body parameters. Results revealed that, mean b value for S. melanotheron was 2.7835. The value of 2.5894 was recorded for P. koelreuteri while 1.2681 was obtained in C. nigrodigitatus. This indicated that all the fish collected at the lagoon exhibited negative allometric growth, i.e. fish became slim as they increased in length. The results further revealed high correlation for S. melanotheron (R² = 0.9811 at p = 0.05) and P. koelreuteri (R² = 0.9174 at p = 0.05). This high correlation proved a strong relationship between the standard lengths and body weights of these fish species. However, a reverse performance was observed for C. nigrodigitatus (R² = 0.3894 at p = 0.05). Fish condition factor showed that S. melanotheron had values ranging from 0.001 to 0.094 with a mean of 0.04±0.02. Mean condition factor for P. koelreuteri was 1.97±1.28 while C. nigrodigitatus recorded 0.99±0.17. Based on these results, it could be concluded that both P. koelreuteri and C. nigrodigitatus (K ≥ 1.00) were in good condition of well-being. Thus, the present study revealed that these species were healthy despite that Lagos Lagoon receives wastewater from different anthropogenic sources. Thus, the study area is conducive for the development and sustenance of fisheries resources.

Phytobiotic enhances growth, gut health and immunity of GIFT challenged with consortium of bacteria.

U. D. Enyidi, — 2024-12-19

The culture of genetically improved farm tilapia (GIFT) has been successfully introduced in Nigeria. Study on the growth and immune responses of this fish to local feeds is important. Moreover, the use of imported feed and growth promoters is not cost effective prompting search for alternatives. This study evaluated how phytogenic feed can possibly enhance growth and immune responses of this fish. Six novel aqua-feed were produced using oyster mushroom (MU) and turmeric (TU) in the following ratio (MU:TU): Feed 1, 148:0g, Feed 2, 104:44g, Feed 3 84:64g, Feed 4 , 64:84g, Feed 5 44:104g and Feed 6 60:148g respectively. GIFT tilapia of average weight 2.4g, were stocked at 10 fish per three replicate treatment feed aquaria, and fed for 60 days. After the feeding experiment 4 fishes were selected from the replicates and left for further 10 days before being challenged with consortia of bacteria. The fish treated with Feed 3 had the best specific growth rate (SGR) of 2.43±0.22% day-1, the best food conversion ratio (FCR) of 0.87±0.09 and the highest final weight of 103.00±0.08g. The best protein conversion and efficiency ratios and survival rates were also recorded in this treatment group. The group treated with Feed 1 was next to Feed 3 in performances. Those on Feed 6 had the lowest final weight 84g. Gut histological analysis showed photomicrograph of broad healthy mucosal fold size villi of about 300µm in length, and 70 µm in width, with densely populated enteroendocrine cells, paneth cells, and goblet cell. The best survival rates were recorded in fish treated with lower turmeric inclusions in feed. The results showed that Feed 3 could be adopted in the production of GIFT tilapia in terms of growth and inert immunity.

Evaluation of chemical qualities of smoked freshwater fishes vended in major market, New Bussa, Nigeria.

K. M. Adelakun, — 2024-12-19

This study evaluated the biosafety of smoked freshwater fish sold in major market of New Bussa, Niger State, Nigeria. Three smoked fish samples: Labeo senegalensis (African carps), Citharinus citharus (Moonfish) and Alestes baromoze (Silverside fish) were procured from Monday market, New Bussa. Fish samples were collected weekly for ten weeks, filleted and processed for further analyses. Proximate analysis of filleted samples was carried out following standard procedure. Fish fillets were further processed and analyzed for eight (8) heavy metal: iron (Fe), copper (Cu), cadmium (Cd), chromium (Cr), nickel (Ni), zinc (Zn), lead (Pb) and cobalt (Co) concentrations using the atomic absorption spectrophotometer. The results showed that there were significant variations in nutrient compositions across the fish samples: A. baromoze had the highest protein content of 55.17±0.90%, crude fibre of 0.03±0.01%, crude fat of 8.90±0.18% as well as 4.10±0.10% of ash which was not significantly (p>0.05) different from 3.95±0.37 recorded in L. senegalensis. The results also showed that there were significant (p<0.05) variations in metal concentrations in the muscle tissue. Fe was the most accumulated of all metals. The level recorded in L. senegalensis (308.11±31.19 mg/kg) was significantly (p<0.05) higher than the least value of 61.99±10.31 mg/kg obtained in C. citharus. This high Fe level recorded in L. senegalensis exceeded the maximum permissible limits of 100 mg/kg recommended by FEPA/WHO. Pb concentration ranged from 0.74±0.29 mg/kg in L. senegalensis to 0.18±0.07 mg/kg in A. baromoze. Chromium was not detected in C. citharus and A. baromoze all through the sampling period. Based on the observations in this study, L. senegalensis accumulated Fe above permissible limit. Hence, it is advisable that biological safety is regularly monitored in fish sold in the study area so that human health will not be at risk.

A review on the use of Lagenaria breviflorus as potential feed additive in diet of African catfish, Clarias gariepinus.

O. Adagha, — 2024-12-19

The African catfish (Clarias gariepinus) is a crucial species in African aquaculture due to its adaptability and resilience in diverse environments. Feeding innovations are essential in enhancing growth performance and sustainability in fish farming, with feed constituting up to 70% of production costs. Recently, plantbased feed additives like Christmas melon (Lagenaria breviflorus) have gained attention for their potential benefits, offering a natural, affordable alternative to artificial additives. The present review revealed that Christmas melon is rich in bioactive compounds, including vitamins, antioxidants, and fiber, which can support immune function, improve feed conversion ratio and promote fish health by boosting immune system and reducing oxidative stress. According to recent studies, using Christmas melon as a feed
supplement in the diets of C. gariepinus has produced encouraging results. Moreover, Christmas melon has been reported to possess antimicrobial properties, which could further support the health and welfare of fish in aquaculture systems. Thus, the plant could be used in aquaculture as a sustainable and environmentally friendly substitute for artificial additives in fish feed formulation. This review revealed effects of Christmas melon supplementation on growth performances, nutrient utilization, and health indicators in C. gariepinus, highlighting its promise in advancing sustainable aquaculture in Nigeria.

Food and feeding habits of African bony tongue, Heterotis niloticus from Urhie Lake, Igbide, Delta State, Nigeria.

A. A. Nwabueze, — 2024-12-19

For efficient management in fish farming there is need for proper nutrition strategies, which can only be achieved by understanding the food and feeding habits of the fish to be cultured in their natural habitat. The study was conducted to investigate the food and feeding habits of Heterotis niloticus in Urhie Lake. Fish samples were collected from fishermen at the landing sites, the major fishing methods employed by the fishermen were cast and set netting. A total of 20 specimens (13 males and 7 females) of H. niloticus were collected examined to ascertain the food and feeding habits using frequency of occurrence, numerical and point methods. The stomach contents of the samples were studied by visual examination. Results revealed that the specimens had standard length ranging from 30.7cm to 54.7cm in males and 32.6cm to 43.6cm in females. Fish body weights varied from 230.0g to 1950g in males and between 400.0g and 740g in females. The condition factor ranged from 0.79-1.29 for males and 0.89-1.25 for females. Results of stomach contents showed that the fish fed mostly on macrophytes accounting for 43.16% followed by phytoplankton (27.89%). Other food items observed were sand (16.32%) and unidentified mass, likely detritus (12.63%). Hence H. niloticus from Urhie Lake is considered to be herbivorous in nature.

Impacts of turmeric (Curcuma longa) on growth and survival of Heterobranchus longifilis.

U. Sambo, — 2024-12-19

Globally, there has been an upsurge on derivable benefits of the use of turmeric, Curcuma longa to promote welfare of fish. The study evaluated impacts of turmeric on growth and survival of Heterobranchus longifilis. Four diets were produced containing dietary turmeric in the proportions of 0%, 1%, 3% and 5% representing Feeds 1 to 4 respectively. A total of 276 H. longifilis fingerlings (mean initial weight ranging between 27.24 and 31.04g) were stocked at 23 fish per replicate and fed for 56 days. After the feeding trial, growth performances and survival rates were determined using standard procedure. Results showed that fish treated with 1% C. longa exhibited the best (p<0.05) weight gain (106.4±12.99g). This was followed by those treated with 3% C. longa having mean weight gain of 98.9±4.82g. Fish in the control group (0% turmeric) recorded the least mean weight gain of 97.9±6.49g). The best specific growth rate (2.20±0.19%/day) and feed conversion ratio (1.29±0.0) were also recorded in fish fed with 1% inclusion level of C. longa. These results revealed that growth variables increased with decrease in inclusion level of C. longa in the fish diet. Similarly trend was observed in the protein contents of fish muscle. The percentage survival of fish was generally high among the treatments containing inclusion levels of C. longa when compared with the control group. The study demonstrated that incorporating C. longa at 1% level in H. longifilis diets could enhance growth rates and optimize survival. This highlights the potential of turmeric as a valuable dietary additive in aquaculture.