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Aquaponics is known to be a smart way of producing fish and crops simultaneously; however, there is a paucity of information about the extents of this system's efficiency over other conventional methods of food production. Thus, this study was designed to evaluate the performance of a catfish–pumpkin aquaponics system in comparison with recirculatory and static aquaculture systems (for fish performance), as well as irrigated and nonirrigated systems (for pumpkin performance). Results obtained showed that the production of fish in the aquaponics system was 29% and 75% more efficient than recirculatory and static aquaculture systems, respectively. The survival of the fish was also significantly improved probably due to better water quality in the aquaponics system. With respect to pumpkin production, yield in the aquaponics system was about five times the performance in irrigated land and eleven times those in nonirrigated land. This study gives definitive evidence to support the efficiency of the aquaponics system over other conventional food production methods.

This study investigated the use of electric-shock in inducing triploidy in African catfish Clarias gariepinus. To achieve this, three voltages (9, 12, 21 V) were applied for different durations (3, 5, 10 min). the shock was initiated approximately three minutes after fertilization followed by incubation in ambient temperature. After incubation, hatchability and survival rates were determined while ploidy status of the treatment fishes was confirmed in one-month-old fingerlings using the exclusive triploid range of the erythrocyte major axis previously reported for the same species (11.9-14.9 μm) and by cytogenetic analysis of the chromosome. The results showed triploidy were achieved in 10 to 85% of the treatment groups. A consistent trend of decrease in hatchability and an increase in triploidy rate was observed with increased electroporation voltages and shock durations. The mean erythrocyte major axis length of triploid progenies (3n = 84) was observed to be between 11.3-14.6 μm and was higher than the range of 7.0-10.5 μm recorded for diploid progenies (2n = 56). It was concluded that electric shock can be used to induce triploidy in African catfish C. gariepinus.

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This study determined the density and diversity of water and terrestrial dependent avian species in man-made Putrajaya wetlands, Peninsular Malaysia using the distant point count techniques. A total sum of 36,544 bird’s individuals (25water bird and 75 terrestrial bird species) was identified from November 2016 to July 2018. The overall bird’s density is 1.17 ± 0.04 birds’ ha−1 at 95.00% confidence limit. The terrestrial bird species (TBS) had a higher density (1.35 ± 0.04 birds’ ha−1), while the water bird species (WBS) had a lower density (0.98 ± 0.16 birds’ ha−1). For WBS, Nycticorax nycticorax and Casmero diusalbus recorded the highest (5.31 ± 3.27 birds’ ha1) and least (0.13 ± 0.15 birds’ ha−1) densities respectively. Also, Columba livia and Arachnothera flavigaster recorded the highest (7.15 ± 1.77 birds’ ha−1) and least (0.07±0.02 birds’ ha−1) densities respectively in TBS. The TBS had higher Shannon– Wiener species diversity index (N1 = 5.67), Margalef’s species richness index (R1 = 15.06) and Pielou’s J species evenness index (E = 1.29) in contrast to the WBS (N1 = 3.71; R1 = 4.58 and E = 1.18). The study revealed the potentials of the man-made Putrajaya wetlands to harbour diverse avian species. This implied the needs to conserve this enclave in order to increase the population, perpetuity and sustainability of the avian species.