Breeding and mass scale rearing of clownfish Amphiprion percula: feeding and rearing in brackishwater

Breeding and mass scale larval rearing of clownfish Amphiprion percula is very limited in brackishwater. We designed an indoor program of A. percula culture in brackishwater with a salinity of 24±1, during which the impacts of feed type, water temperature, and light intensity, on the efficiency of its reproduction, were revealed. The fish were accommodated along with sea anemones in fibre glass tanks to determine the influence of brooder diet on breeding efficiency. Higher reproductive efficiency [number of eggs laid （276±22.3 eggs）] was observed when fish were fed live Acetes sp. rather than clam （204±16.4 eggs）, trash fish （155±12 eggs） and formulated feed （110±10 eggs）. The spawning rate was increased during September and October （water temperature, 28.74±0.55℃） on average of 2.4 spawning per month; and low spawning rate was in January （water temperature, 24.55±0.45℃） on average of I spawning per month. Among three light intensities （100, 500, and 900 1x） set to evaluate larval survival rate, larvae showed the highest survival rate （65.5%） at 900 lx. The breeding method specifically in brackishwater developed in the present study is a new approach, will help the people from the regions of estuary and backwater to enhance their livelihood and it will lead to reduce the exploitation from the wild habitat.

An evaluation of the engineering suitability of extensive brackishwater ponds in Barru, South Sulawesi Province, Indonesia

In brackishwater aquaculture, pond engineering is essential to meet the cultured species’ bio-physical requirements and potentially minimizing social and environmental impacts. This study evaluated the suitability of pond engineering designs and pond, dyke, and canal construction at family-run, extensive brackishwater aquaculture farms in Barru regency of South Sulawesi, Indonesia. Soil properties, topography, hydrological data, field surveys, and high resolution (0.6 m) Quickbird imagery were used to assess the suitability of local pond engineering designs and the efficiency of canals. The study shows that in 752 of the evaluated pond units (430 ha), about 70% of pond beds were not constructed at the optimal pond elevation. Basic engineering requirements for pond layout and dyke and canal designs were not addressed in more than 70% of the pond units. Cease-to-flow conditions commonly occur due to the sedimentation of canals. Flows are also attenuated due to collapsed dykes. Farmers disregarded soil limitations and the impacts of tidal conditions and wave regimes. It is unlikely that shrimp and fish production in the region can increase without significant improvements in pond engineering. The problems identified by the study are not unique to Barru;they also occur in other extensive aquaculture areas in Indonesia and the region. Increased awareness of the need for improved pond engineering techniques is urgently needed to safeguard the economic and environmental sustainability of Indonesia’s valuable aquaculture industry.

Recent advances in flat sheet mixed matrix membrane modified by Mg-based layered double hydroxides(LDHs)for salt and organic compound separations

Magnesium(Mg)is a widely used and attractive metal,known for its unique physical and chemical properties,and it has been employed in the manufacture of many practical materials.Layered Double Hydroxides(LDHs),particularly Mg-based LDHs,rank among the most prevalent two-dimensional materials utilized in separation processes,which include adsorption,extraction,and membrane technology.The high popularity of Mg-based LDHs in separation applications can be attributed to their properties,such as excellent hydrophilicity,high surface area,ion exchangeability,and adjustable interlayer space.Currently,polymer membranes play a pivotal role in semi-industrial and industrial separation processes.Consequently,the development of polymer membranes and the mitigation of their limitations have emerged as compelling topics for researchers.Several methods exist to enhance the separation performance and anti-fouling properties of polymer membranes.Among these,incorporating additives into the membrane polymer matrix stands out as a cost-effective,straightforward,readily available,and efficient approach.The use of Mg-based LDHs,either in combination with other materials or as a standalone additive in the polymer membrane matrix,represents a promising strategy to bolster the separation and anti-fouling efficacy of flat sheet mixed matrix polymer membranes.This review highlights Mg-based LDHs as high-potential additives designed to refine flat sheet mixed matrix polymer membranes for applications in wastewater treatment and brackish water desalination.