The tropical Lake Rawa Pening, designated by presidential decree as one of Indonesia's national priority lakes, is crucial to the region's biodiversity and ecosystem services. This study analysed the biodiversity of fish species in the lake using Illumina paired-end sequencing, yielding 125,374 reads. The analysis identified 34 taxa across 11 orders and 16 families, with high similarity between sampling sites (0.91–1.00). Order Cypriniformes dominated the fish community, representing 41.80 % of average reads. Conversely, Order Clupeiformes had the lowest total reads count at 0.11 %. Significant presence was also observed for Order Cichliformes (19.90 %) and Order Anabantiformes (19.18 %). At the species level, Channa micropeltes was the most dominant species (11.07 %), followed by Osteochilus vittatus (10.70 %), Amphilophus labiatus (9.63 %), and Ctenopharyngodon idella (8.94 %). Native species accounted for 54.7 % of the total reads, while introduced species comprised 43.3 %, including invasive (31.7 %) and non-invasive species (11.6 %). The high presence and dominance of invasive species underscore the need for targeted conservation and management efforts. It is recommended that biodiversity monitoring be promptly initiated in other nationally prioritised lakes, as biodiversity is crucial for ecosystem health and resilience.
The fisheries sector in Malaysia is important for food security and the national economy. However, fish populations in Malaysian waters, especially the capture fisheries, are gradually declining due to overexploitation, climate change, poor water quality, and habitat destruction. As a result, aquaculture has emerged as an important solution to address the depletion of fish stocks in Malaysia. Aquaculture not only reduces the pressure on wild fish populations, but it also contributes to economic growth and sustainability. This review offers an overview of the current state of aquaculture in Malaysia, noting existing strengths in areas such as wastewater management policies, zonation for aquaculture activities, established practices, and successful research projects. Despite these foundations, the industry faces numerous challenges including a lack of biosecurity measures, spatial constraints, resource dependency, and technological lag. In response, this review highlights the concerted efforts needed to address these challenges, with a focus on implementing robust aquaculture biosecurity, improving aquafeed management, and promoting further research and development. This review also aims to guide the path toward sustainable aquaculture practices, emphasising the critical aspects of assimilative capacity and research and technological advancement. The adoption of these innovative practices and technologies presents a clear pathway for Malaysia to enhance the efficiency and long-term sustainability of its aquaculture sector.
This study applies a systematic literature review of 53 scientific articles on technical efficiency (TE) analysis in fisheries, focusing on determinants of efficiency, especially subsidies. Stochastic frontier analysis (SFA) was applied in ¾ of the papers, with data envelopment analysis (DEA) in the remainder. Only five articles discuss subsidies as determinants of TE. Owner/crew characteristics and vessel/gear characteristics were the most investigated determinant of efficiency in the literature. The experience of the former increased TE, while the latter showed diverging results, and subsidies increased efficiency. The paper discusses problems surrounding analysis of subsidies in TE analysis, and underlines use of newer models such as the robust and conditional DEA framework, accounting for the presence of outliers and allowing control for the influence of external factors potentially affecting the production process. Moreover, the findings indicate that studies of the subsidy -efficiency nexus lack analysis of TE over time. This is important since the subsidies, especially in open access fisheries, could lead to fish stock depletion, thereby diminishing TE over time. Subsidies could compensate for the reduction in TE, but in the long run, they also enable t he continued depletion of stocks. Thus, unless subsidies rise more significantly than the adverse effects of overfishing on an open access fishery, TE may be expected to decrease over time. Future studies should focus on the relationship between type of subsidy and TE to help policymakers choose the most appropriate subsidy. This since governments often intervene heavily to support fisheries livelihoods, potentially distorting market signals and causing overexploitation.
The guppy Poecilia reticulata (Peters, 1859), native to South America, is now an established invasive species in the ecologically sensitive Western Ghats biodiversity hotspot in India, yet its invasion biology in the region remains poorly understood. This study examines the dietary habits of invasive guppy populations in the Bonacaud Forest Range of the Peppara Wildlife Sanctuary, southern Western Ghats, India. A total of 130 individuals (38 males, 92 females; 10–37.6 mm in total length) were analysed. Their diet was dominated by midge fly larvae (34.18 %) and algae (32.15 %), followed by miscellaneous items including fibres, sand, and mud (11.95 %). Insect remains (Hemiptera, Coleoptera) accounted for 9.09 % of the diet, with smaller contributions from detritus (5.94 %), zooplankton (2.49 %), nereid larvae (2.03 %), fish remains (1.74 %), and arachnids (0.43 %). Frequency-of-occurrence analysis similarly identified Chironomidae larvae (27.53 %) and algae (25.87 %) as the most common food items. Feeding intensity assessments indicated that none of the fish had empty stomachs; most showed moderate (29 %) or good (28 %) fullness, with additional full (15 %), poor (17 %), and gorged (11 %) conditions. Larger individuals exhibited greater consumption, supported by gastrosomatic index values. Microplastics - primarily polyamide (PA) and polyethylene (PE) fibres - were detected in the gut, with a mean abundance of 1.03 ± 0.42 items per fish, and scanning electron microscopy confirmed evidence of microplastic degradation. These findings underscore the need for further research to evaluate the ecological impacts of invasive guppy populations on freshwater biodiversity in the Western Ghats across spatial and temporal scales.
Given the abundance and cost-effectiveness of catching sandbar sharks (Carcharhinus plumbeus), their muscle protein may serve as a valuable alternative protein source, particularly for the elderly, while also promoting the sustainable utilisation of marine resources. Food-processing protease is an effective tool to improve the texture and taste of food, enhancing intake in elderly people. The utilisation of sandbar shark muscle as a functional food ingredient was investigated through protease hydrolysis and the identification of angiotensin-converting enzyme (ACE) inhibitory peptides. Among various protease treatments, Papain W-40, Protin SD-AC10F, and Thermoase PC10F hydrolysis exhibited stronger inhibition. By comparing protease reaction times and IC50 values, we determined the optimal condition to be Thermoase PC10F for 12 h, which yielded the highest ACE inhibitory activity with minimal bitterness. Fractionation of the hydrolysate revealed multiple potential active peptides, with the most potent fraction containing an active peptide identified as Ala-Phe. The synthesised Ala-Phe exhibited an IC50 of 93.8 μg.mL⁻¹ and demonstrated a non-competitive inhibition mechanism against ACE. This study highlights the potential of sandbar shark muscle hydrolysates as a novel functional food ingredient with antihypertensive properties.
