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Invasive fish species pose several threats to aquatic biodiversity and health, necessitating a good understanding of their biology and ecology. This study aims to understand the biology of invasive fish species collected from a Langat River tributary, Selangor, focusing on their growth, reproduction, and feeding habits. Fish and water samples were collected between March and August 2022. A total of 171 specimens were recorded, including 71, 55, and 45 individuals of Pterygoplichthys disjunctivus, P. pardalis, and Oreochromis sp. The b values for length-weight relationships of P. disjunctivus, P. pardalis, and Oreochromis sp. were 2.79, 2.92, and 2.89, respectively. The mean condition factor for Oreochromis sp. was significantly (p < 0.05) higher than that of the other two species. There were no significant differences between the observed and expected number of males and females for all three species. The females had higher mean gonadosomatic index values compared to males. The mean fecundity for P. disjunctivus, P. pardalis, and Oreochromis sp. were 973 ± 596, 10562 ± 830, and 1052 ± 1068, respectively. The most important stomach contents of the three species were detritus, mineral particles, and diatoms, with a higher proportion of mineral particles found in the diets of P. disjunctivus and P. pardalis. The information on growth patterns, reproductive strategies, and dietary preferences provides valuable insights for controlling their invasion of local rivers. [ABSTRACT FROM AUTHOR]

Fish is a key component of Nigeria's protein supply, making up about 40% of the nation's protein intake and considerably aiding in the achievement of the second Sustainable Development Goal of feeding the expanding population. Despite its importance, Nigeria's fish production and supply cannot keep up with demand. While total fish output has increased from 1,073,059 tonnes in 2014 to 1,169,000 tonnes in 2018 and is expected to reach 1,275,000 tonnes by 2030, there is a great supply gap. Fish production not only affects food security but also the national economy and employment. Notwithstanding, the fisheries sub-sector suffers several difficulties, such as poor management, a deficient fisheries policy, overfishing, diminishing catch, and a lack of technical know-how among fish growers and fishermen. Thus, exploring untapped aquaculture potential and managing small-scale fisheries effectively are necessary to close the gap between the demand for and supply of fish. The fish output situation can be improved by enforcing fisheries policy and regulations, increasing investments in ethical fisheries and aquaculture, and providing sufficient training for fish farmers and fisherfolk. To reduce waste associated with the limited number of fish now produced, post-harvest losses must also be addressed. By solving these issues and putting in place the necessary actions, Nigeria can increase its fish production, strengthen its food security, and accomplish the sustainable development goals in its evolving blue economy. [ABSTRACT FROM AUTHOR]

Streptococcus agalactiae and Streptococcus iniae are the two main pathogens causing streptococcosis in fish. This study compares the clinicopathological changes in red hybrid tilapia experimentally infected with S. agalactiae or S. iniae. A total of 180 tilapias were divided into six groups. Groups 1A, 2A, and 3A were inoculated intraperitoneally with sterile phosphate-buffered saline, S. agalactiae, and S. iniae. Fish of Groups 1A, 2A, and 3A were then immediately allowed to cohabitate with fish of Groups 1B, 2B, and 3B, respectively. All fish were observed at 6-hr intervals for 120 hr before surviving fish were euthanized. The spleen, liver, and brain samples were collected for bacterial isolation and histopathology. Clinical signs were developed at 72 hr in Groups 2A and 3A and 96 hr in Groups 2B and 3B. Group 2A showed the highest clinical score (P<0.05). Significantly (P<0.05), more cohabitating fish (Groups 2B) were infected by S. agalactiae compared to S. iniae (Group 3B) at 55.0±0.0 and 43.70±1.25%, respectively. The mortality rate was significantly (P<0.05) higher for Groups 2A and 2B than other groups. The gross lesions were significantly (P<0.05) more common in fish of Group 2A. Histopathologically, encephalitis was observed in fish infected with S. iniae of Groups 3A and 3B, while meningoencephalitis was observed in fish infected with S. agalactiae of Groups 2A and 2B. The findings suggest that S. agalactiae is more pathogenic than S. iniae, producing slightly different histopathological lesions in the brain. [ABSTRACT FROM AUTHOR]

Fishmeal is widely accepted as a protein source in fish feed formulation, making it a highly demanded ingredient, and this has probably contributed to its increased cost. Cheaper protein sources of plant and animal origin have been tested as potential replacements for fishmeal to reduce feed costs in fish production and guarantee a suitable nutrient supply for adequate growth. Therefore, this review assessed the effect of replacing fishmeal in the diet of African catfish, Clarias gariepinus based on empirical findings. Using a systematic literature review protocol, an extensive search of five databases resulted in the final inclusion of 32 articles for appraisal and meta-analysis. Fishmeal replacements were at levels ranging from 7–100%, while fish survival rate and feed conversion ratio recorded non-significant effects of fishmeal replacement (p > 0.05). However, final weight, weight gain, specific growth rate, and protein efficiency ratio revealed a significant effect of fishmeal replacement (p < 0.05) in the diet of African catfish. Our overall analyses suggest that feed ingredients such as microalgae and insects/ worms are potentially perfect replacements for fishmeal. [ABSTRACT FROM AUTHOR]

Invasive introduced fish species are well known for their deleterious impacts on aquatic biodiversity and environment. This study provides the first report on the occurrence of introduced Amazon sailfin catfish, Pterygoplichthys pardalis from the Gombak basin, Selangor, Malaysia, where the suckermouth catfish, Hypostomus plecostomus and vermiculated sailfin catfish, Pterygoplichthys disjunctivus had been previously reported. Besides, selected morphometric and meristic measurements between P. pardalis and P. disjunctivus from the Pusu River, Gombak basin were compared. Moreover, we also described two body patterns of the P. pardalis collected from the river. The body pattern which does not fit entirely with the known characteristics of P. pardalis or P. disjunctivus is suspected to be a result of hybridization between both species, but deeper study should be conducted to confirm this claim. [ABSTRACT FROM AUTHOR]

This study aim to provide an updated checklist of fish species inhabiting Tembeling and Pahang rivers, Pahang, Malaysia. A total of 4,834 fish belonging to 10 orders, 64 genera, 25 families and 82 species were collected from both connected rivers. Cyprinidae present the highest number of fish species registered herein, followed by Bagridae, Pangasiidae and Siluridae. The most common fish species were Cyclocheilichthys apogon, followed by Barbonymus schwanefeldii, Hypsi­barbus wetmorei, Amblyrhynchichthys truncatus and Pun­ti­oplites proctozysron. A total of nine introduced fish and four endangered fish species were also recorded from this study. This checklist adds knowledge on the fishes inhabiting both rivers, which could be useful for the planning of fisheries activities and fish conservation of the rivers in the near future. [ABSTRACT FROM AUTHOR]