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  Optimising tank colour for enhanced growth, survival, and carapace colouration for megalopa and instar purple mud crab (Scylla tranquebarica) 

  Thien, Fui Yin; Sanudin, Noorsyarinah; Teoh, Chui Fen ; Hamasaki, Katsuyuki ; Huervana, Joana Joy ; Biswas, Amal; Wang, Muhua; Yong, Annita Seok Kian (Elsevier, 2026-08-13)

  The influence of tank background colour on the growth and survival of the purple mud crab (Scylla tranquebarica) megalopa and instar was elucidated to refine the mud crab seed production techniques. Both megalopa and instar stages were reared in five background colours: black, white, blue, green, and red, in triplicate groups for 14 days and 8 weeks, respectively. The megalopa metamorphosed into instars 1 and 2 (C1 and C2) at the end of the megalopa experiment. Growth and survival of C1 and C2 were highest in the blue tank, as indicated by total yield (641.5 mg), overall survival rate (67.9%), and relative contribution of C2 (64.9%). The instar metamorphosed into a juvenile after 8 weeks. The juvenile total yield was comparable in all treatments, with a higher trend observed in blue and red tanks than in other treatments. The juvenile's survival rate was significantly greater in the blue tank (53.3%) than in the other treatments. The juveniles reared in the black tank exhibited significantly darker carapaces than the others. This study provides baseline data on the rearing of purple mud crab megalopae to juveniles for seed production, indicating that blue tanks are suitable for nursery-phase rearing of both stages.
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  Effects of shelter types and feeding rates on culture performance, shelter preference and feeding behaviour of spiny lobster Panulirus ornatus juveniles under laboratory conditions 

  Noran-Baylon, Roselyn ; Pacardo, Nelbert G. (Brill Academic Publishers, 2026-08-03)

  Spiny lobsters, Panulirus ornatus, are a highly valued crustacean worldwide, with strong demand and high prices making it important for fisheries and aquaculture economies. This study examined the effects of shelter types and feeding rates on rearing performance (which includes growth in weight and carapace length, survival, moulting frequency, shelter preference and feeding behaviour) in early juvenile spiny lobster, P. ornatus in two subsequent tank experiments. In experiment 1, groups of five juveniles (approx. 16 g) were reared separately in replicated tanks (200 litres) with different shelter types (bundled nets vs pipes vs no shelter as control). After 60 days, survival was higher in the bundled net treatment (73%) than in the pipe treatment (67%) and control (33%). However, survival and other rearing performance parameters did not differ significantly among shelter types (P > 0.05). In experiment 2, shelter preference among early juveniles (<1 g) were further tested in rectangular tanks (20 litres) with both shelter type (bundled nets and stacked pipes) provided. In addition, different feeding rates using fresh mussel meat were tested: FR₁₀, FR₂₀ and FR₃₀, corresponding to 10, 20 and 30% of mean body weight per day. Results showed that young lobsters strongly preferred bundled net shelters (80% occupancy) vs pipes (20%). Feeding rate significantly affected growth, with FR₃₀ resulting in the highest gain in weight and carapace length. There was a strong positive correlation between mean body weight and daily feed consumption (P = 0.001). Nocturnal feeding behaviour was validated, as lobsters significantly consumed more food at night (81%) than during the day (69%) (P = 0.001). These results confirmed the importance of providing complex shelters, like bundled nets and optimising feeding regimes (30% of body weight per day, with a higher proportion at night) for improving productivity in the nursery rearing of spiny lobsters.
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  Propagation techniques for economically important seaweeds: Current practices, challenges, and future directions 

  Faisan, Jr., Joseph (CAB International, 2026-07-31)

  The large-scale cultivation of economically important seaweeds depends on the development of reliable and efficient propagation techniques that ensure a continuous, sustainable supply of seedlings for farming. Propagation is the foundation of seaweed aquaculture, linking the availability of natural stocks to the increasing demand for raw materials across industries. The advancement of propagation methods—whether through vegetative cuttings, tissue culture, or spore-based hatchery systems—has been vital in supporting the commercial success of many seaweed species. Despite this progress, optimizing and standardizing species-specific propagation protocols remains a challenge for further growth. Differences in reproductive biology, environmental conditions, and physiological responses among species make it difficult to create unified propagation models. This chapter reviews the commercial practices and development of propagation techniques across three main seaweed groups, emphasizing their advantages and limitations. It also discusses emerging biotechnological innovations that show great potential for improving seed stock quality and advancing large-scale commercial seaweed cultivation.
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  Series: Aquaculture Extension Manual; No. 80

  On-farm aquafeed production for small-scale freshwater aquaculture 

  Aya, Frolan ; Romana-Eguia, Maria Rowena R. ; Cuvin-Aralar, Maria Lourdes (Aquaculture Department, Southeast Asian Fisheries Development Center, 2026-07)

  With the increasing demand for food fish as the primary source of dietary protein, some aquaculture practices have shifted from traditional to semi-intensive or intensive system, requiring the use of feeds for successful growth of aquaculture. Alone, feeds are considered as a costly input in aquaculture, comprising over 50 % of the total operating costs. Most, if not all farms in the country, are relying on commercial feeds which are either imported or locally produced. For many years, locally available materials have been studied for their potential as alternative protein sources or feed additives in fish feeds. Utilization of these alternative or non-conventional feed sources with little or no use as human food may provide reasonable options in feed formulation. In the Philippines, there is a potential for fish farmers to develop and utilize local feedstuff resources to manufacture their own feeds. However, limited information on nutrient requirements of fish species, available feed ingredients and their nutritional value, processing techniques, and the preparation of farm-made feeds are available to the small-scale farmers. Given the rising cost of feeds, it is important to provide small scale farm operators, the option to make their own feeds. This manual is written for fish farmers engaged in small-scale freshwater fish culture, particularly during grow-out. It intends to provide information on the components of fish feed, indigenous or locally sourced ingredients for feeds and their processing techniques, and ultimately to assist the small-scale fish farmers in using modest equipment to make farm- made feeds to feed their stocks.
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  Sustainable aquaculture practices in Cambodia 

  Somnea, Outh; Somony, Thay (Aquaculture Department, Southeast Asian Fisheries Development Center, 2026-07)

  Cambodia's aquaculture sector plays a vital role in food security, rural livelihoods, and economic development. It contributes significantly to the national GDP and supplies approximately 75% of the animal protein consumed by Cambodians. Historically reliant on wild fisheries, Cambodia has undergone rapid growth in aquaculture, with production increasing from 143,000 tonnes in 2015 to 320,280 tonnes in 2024. This expansion is driven by rising demand and strong government support under the Rectangular Strategy Phase IV. The sector includes inland aquaculture systems (pond, cage, and rice-fish) and emerging mariculture activities (sea cage and shellfish farming). Key species in inland aquaculture include Pangasius catfish, snakeheads, tilapia, and carps, while mariculture focuses on high-value species like groupers and sea bass. Despite its rapid growth, the aquaculture sector faces challenges such as high feed costs (comprising 50–70 % of production expenses), environmental degradation, limited technical knowledge, and regulatory gaps. The reliance on imported feed and pollution from intensive farming are critical concerns. However, opportunities lie in sustainable mariculture expansion, use of alternative protein sources, and investments to improve infrastructure. Strengthening research, capacity building, and policy frameworks is essential for long-term sustainability. With strategic investments and adoption of best practices, Cambodia’s aquaculture sector can improve productivity, enhance rural development, and strengthen its competitiveness in regional markets.

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