Oxygen is a vital parameter in aquaculture activities. The decrease of dissolved oxygen levels in aquaculture media should be highly observed, since very low dissolved oxygen conditions (hypoxia) could negatively affect to the growth and survival of fish. Therefore, research on the condition of hypoxia is very important to be studied. This study was conducted in January-February 2013 at the Laboratorium of Fish Reproductive Physiology, Pukyong National University, South Korea to measure oxygen consumption in tilapia Oreochromis niloticus (total length: 14.2 ± 1.4 cm, weight: 31.3 ± 2.0 g) under normal conditions (normoxia) and hypoxia. Measurement was conducted using respirometer (dimension: 20 × 17,5 × 10 cm; volume: 3,5 L) every 10 minutes during four hours of observation. Experiment was conducted with three replications. The results showed that oxygen consumption of tilapia fingerlings in hypoxia conditions (12.09 ± 3.20 mg O2/kg/h) was lower than normoxia (35.67 ± 4.19 mg O2/kg/h) (P<0.01). Continuous hypoxic conditions could negatively affect fish movements, which could ultimately lead to mortality when dissolved oxygen levels are very low. Meanwhile, the results on determination of critical oxygen levels for tilapia showed a dissolved oxygen range of 1.9 ± 0.5 mg/L
Increased fisheries products have raised by-products that are discarded due to low economic value. In addition, marine by-products are still rich in protein and nutritional value that have biological activities and give benefits to human health. Meanwhile, there is raised pressure for sustainability practices in marine industries to reduce waste and minimize the detrimental effect on the environment. Thus, valorization by-products through bioactive peptide mining are crucial. This review focus on various ways to obtain bioactive peptides from marine by-products through protein hydrolysis, for instance chemical hydrolysis (acid and based), biochemical hydrolysis (autolysis and enzymatic hydrolysis), microbial fermentation, and subcritical water hydrolysis. Nevertheless, these processes have benefits and drawbacks which need to be considered. This review also addresses various biological activities that are favorable in pharmaceutical industries, including antioxidant, antihypertensive, anticancer, anti-obesity, and other beneficial bioactivities. In addition, some potential marine resources of Indonesia for the marine biopeptide from their by-product or undesired marine commodities would be addressed as well.
An unusual new species of the alpheid shrimp genus Salmoneus Holthuis, 1955 is described from Sekotong Bay, southwestern Lombok, Indonesia. The holotype and single known specimen of Salmoneus yoyo sp. nov. was collected with a suction pump from a burrow of unknown host, on a seagrass flat partly exposed at low tide. The new species presents three characters on the chelipeds that are unique within Salmoneus: a conspicuous, mesially curved, hook-like process on the distomesial margin of the merus, a row of blunt teeth on the ventromesial margin of the merus, and a series of blunt teeth on the ventromesial margin of the propodus. Salmoneus yoyo sp. nov. also has a characteristic colour pattern consisting of bright red chromatophores occupying most of the carapace surface, except for the frontal and post-frontal areas.
Several rare or uncommon, mostly infaunal decapod crustaceans are reported from intertidal and shallow subtidal habitats of Lombok, Indonesia. The alpheid shrimps Alpheus angustilineatus Nomura & Anker, 2005, Athanas shawnsmithi Anker, 2011, Jengalpheops rufus Anker & Dworschak, 2007, Salmoneus alpheophilus Anker & Marin, 2006, Salmoneus colinorum De Grave, 2004, and the laomediid mud-shrimp Naushonia carinata Dworschak, Marin & Anker, 2006, are reported for the first time since their original descriptions and represent new records for the marine fauna of Indonesia. The alpheid shrimps Alpheus macellarius Chace, 1988, Alpheus platyunguiculatus (Banner, 1953), Athanas japonicus Kubo, 1936, Athanas polymorphus Kemp, 1915, Leptalpheus denticulatus Anker & Marin, 2009, Richalpheus palmeri Anker & Jeng, 2006, Salmoneus gracilipes Miya, 1972, Salmoneus tricristatus Banner, 1959 and the laomediid mudshrimps Laomedia astacina De Haan, 1841 and Naushonia lactoalbida Berggren, 1992 are new records for Indonesian waters. The remaining alpheid shrimps, namely Alpheopsis yaldwyni Banner & Banner, 1973, Alpheus savuensis De Man, 1908, Automate anacanthopus De Man, 1910, Automate dolichognatha De Man, 1888, Salmoneus serratidigitus (Coutière, 1896), and the strahlaxiid mud-shrimp Neaxius glyptocercus (von Martens, 1869), all previously known from Indonesia, are recorded for the first time from Lombok. Colour photographs are provided for all species reported, some shown in colour for the first time.
<strong>Determination of Calcium Concentration in Formulated Feed for Early Zoea Crab Scylla paramamosain.</strong> Calcification process of the new shell during postmoulting of crab fries needs calcium from food and water in the environment. However, the digestive enzymes in the early phase of zoea have not functioned perfectly yet, so the artificial feed given in the ration of crab fries may be less digestable. Therefore, in this study Enzyplex (commercial enzyme) was added to the formulated feed for rearing of crab fries (zoea at early phase). The purpose of this study was to determine the effect of calcium addition into the formulated feed on the growth and survival of mud crab Scylla paramamosain Zoea. The study was conducted in August 2015 for 3 days. Zoea were kept in ecoplast containers with a stocking density of 50 ind / L. Calcium-D Kalzana was added as much as 0 mg/g (A), 50 mg/g (B), 100 mg/g (C), 150 mg/g (D ), and 200 mg/g (E) per batter (34.50 g) of formulated feed, with 9 replications for each treatment. All ecoplast containers were placed in a waterbath at 30°C. The results show that the addition of calcium at a dose of 50 mg/g can successfully support the growth of Zoea I into Zoea II (66%) with the highest survival rate (7.6 ± 4.98%). The size of cephalothorax (597.69 ± 65.81 m), abdomen ( 1135.39 ± 126.47 m), and telson (409.23 ± 61.80 m) are shown to be larger than the other four treatments.<br /><br />
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