An analysis of biological characteristics of Macrobrachium rosenbergii (de Man) in relation to pond production and marketing in Thailand

Data on production and marketing of giant freshwater prawn were collected over a 7-month grow-out period through collaboration with a medium-sized commercial prawn farm in central Thailand. Juvenile prawns with an average weight of 4.2 g were stocked at a density of 6 prawns/m2 in three 0.5-ha earthen ponds. Average growth rate determined during the first 3 months of the grow-out period was 0.4 g/prawn per day; prawns of marketable size were harvested selectively during the remaining 4 months of the rearing period, resulting in a total accumulated yield of 1.3 tonnes/ha with an average prawn weight of 32 g and 60% survival. As different sexes and sizes of prawns were sold at different prices, the harvests were customarily sorted into several categories: large, medium, and small males, long-clawed males, soft shells, females with eggs, females without eggs, and terminal males. The total weight and number of prawns recorded for each of these categories showed that the female to male ratios were 1.6:1 and 4:1 by weight and number, respectively while the ratio of short to long-clawed males was 3:1 by weight and 4:1 by number. Four percent of the marketable population was termed "soft shells" and 64% of the females bore eggs. The ratio of head weight to tail weight of marketable prawns varied substantially among the different categories: 1.0:1 for females, 2.5:1 for long-clawed males, and 1.6:1 for short-clawed males. Females predominated in the first and second 1.5-month harvest periods while males predominated in the final 1.5 months of the harvest. The economic yield of prawn culture was not only determined by the biomass, but also by the population structure of the various biological categories and the harvest season.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27065/1/0000055.pd

Effects of ochratoxin A and deoxynivalenol on growth performance and immuno-physiological parameters in black tiger shrimp (Penaeus monodon)

Ochratoxin A (OTA) and deoxynivalenol (DON), naturally occurring contaminants of animal feed, have been implicated in several mycotoxicoses in farm livestock but there is little information on their toxicity in aquatic invertebrates. Therefore, in the present study an 8-week feeding trial was conducted on black tiger shrimp (Penaeus monodon) to assess the effects of OTA and DON on growth performance, haemolymph parameters and histopathology of shrimp. Results showed that feed supplemented with DON caused no effect on growth or survival rate of the shrimp. However, shrimps fed DON feed diet with 1,000 ppb showed significantly higher growth performance. No significant difference in total haemocyte counts (THC) was found in shrimp fed mycotoxins-supplemented feed. Feeding high level of OTA (1,000 ppb) caused a decrease in phenoloxidase (PO) activity. Although no histopathological change was observed, decrease in serum alkaline phosphatase (ALP), serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) levels in shrimp fed OTA or DON indicated that mycotoxin may impair the functioning of hepatopancreatic cells. Since no adverse effect occurred with the highest levels of OTA and DON (1,000 and 2,000 ppb, respectively) on haemolymph parameters and no residue was detected at the completion of the 8-week feeding period, it can be concluded that shrimp feeds occasionally contaminated with OTA or DON have no negative impact on the shrimp culture industry

Nutritional requirements of commercially important shrimps in the tropics

The culture of tropical shrimps has gained greater economic importance particularly among Southeast Asian countries. As shrimp fanning moves from low-input, low-technology operation to the intensive and even highly intensive scales of operation, farmers are increasingly seeking ways to achieve more efficient means of production. Feed takes up the major portion of the cost of production. It also has a significant effect on the health of cultured species. Therefore, nutritional adequacy and cost-effectiveness of feeds are critical to the growth of the aquaculture industry. This paper discusses the nutritional requirements for growth as well as for health of some commercially important shrimp species in the tropics with emphasis on P. monodon

The use of chemicals in aquafeed

Various chemicals and additives used in fish and shrimp feeds may have impacts on animal health, product quality and the environment. This paper reviews the use and effects of vitamins (vitamins C and E), essential fatty acids, carotenoids, immunostimulants, hormones and attractants added to feeds for cultured fish and shellfish

Effects of thiamine, pyridoxine, pantothen acid, and riboflavin on growth performance, feed efficiency, and body composition of seabass, lates calcarifer (Bloch)

Seabass (Lates calcarifer) of initial average weight 0.45-0.47 gm. were experimentally reared in 200 1.glass aquaria fitted with a closed recirculating system. The experiment comprised 6 treatments with 3 replications each. Six diet formulae were used; 1) minced fish; 2) minced fish supplemented with complete vitamins and minerals; 3),4),5) and 6) same as that of formula 2 but deficient in thiamine, pyridoxine, pantothenic acid and riboflavin, respectively. After rearing for 6 weeks ,results appeared the fish in treatment 1 (minced fish alone) had developed the deficiency symptoms, and revealed the lowest value of growth. A study of recovery proved that fish fed basal diet incorporated with complete vitamin showed better growth and other parameters i.e. feeding rate, FCR and body composition than the other group (as given minced fish alone). Fish in treatment 2-6 gave an insignificant different on average body weight among them, but showed some anomali after rearing for 8 weeks i.e. fish in treatments 3 (thiamine deficiency) and 5 (pantothenic acid deficiency) 1M.S. (Fisheries) 2M.S. (Marine Zoology) Ph.D. (Aquatic Biology), Dept.of Aquatic Science,Fac of Natural Resources Prince of Songkla Univer., THAILAND, 90110.Prince of Songkhla Universit

Overview on the use of plant protein in aquaculture feed

Fish meal (FM) is the best and main protein source for fish and shrimp feed because of the favorable amino acid profile, highly unsaturated fatty acids, palatability and absence of antinutritional factors. Aquaculture production has increased (about 8-9% a year) and is expected to increase further at the same rate to meet the demand for increase world population and health concern. In this connection, more aquafeed is required. Aquafeed rely much on fish meal (FM) and fish oil (FO) for the supply of major essential nutrients (essential amino acids, essential fatty acids, mineral and attractant). Therefore, more FM is required. However, world fish meal production has been relatively static in the last 15 years and is unlikely to increase further, coupled with public pressure on sustainable feed (fish in fish out ratio or fish meal independent ratio). Thus, levels of FM use in fish feed will have to be reduced and replaced by alternative protein sources for a sustainable increase in aquaculture production. Therefore, the identification and development of alternative feed ingredients that can replace FM is recognized as an international research priority. Consequently, several international integrated projects have been established in Europe, USA and Australia to reduce fish meal and fish oil in fish feeds. A European integrated project involving 14 countries, 32 partners with 4 major programs has been established to develop feeds from sustainable alternatives to fish meal and fish oil to produce safe, healthy seafood; assess the health benefits of fish farmed on the new diets; assess the safety of fish farmed on the new diets; assess perceptions regarding farmed fish and to devise a framework to communicate the risk and benefit of consuming farmed fish to the public and other stake holders. The strategic goal of this project is to tailor aquaculture feeds to produce high-quality fish with significantly reduced use of fish meal (FM) and fish oil (FO)

Water soluble vitamins essential for the growth of Clarias

Meeting: Asian Finfish Nutrition Workshop, 23-26 Aug. 1983, Singapore, SGIn IDL-724

Dietary exposure to melamine and cyanuric acid induced growth reduction, oxidative stress and pathological changes of hepatopancreas in Pacific white shrimp

Abstract This study examined the effects of dietary melamine (MEL) and cyanuric acid (CYA) singly and in combination on growth, nutrient utilization, immunological responses, oxidative stress, and histological changes in Pacific white shrimp. Seven experimental isonitrogenous (35%) and isolipidic (8%) diets were formulated, namely diet 1 (a control diet without MEL and CYA); diets 2–5 (with MEL and CYA at 2.5 + 2.5, 5 + 5, 7.5 + 7.5 and 10 + 10 g kg−1 diet); diet 6 (with only MEL at 10 g kg−1 diet) and diet 7 (with CYA alone at 10 g kg−1 diet). The shrimp with initial body weight 2.37 ± 0.02 g were fed with these diets for 10 weeks. The results indicate that all the diets with MEL and CYA singly or in combination had adverse effects on growth and nutrient utilization relative to the control diet (p < 0.05). Total protease and trypsin activities were significantly lowered by all diets containing MEL (p < 0.05). Haemolymph parameters, including total hemocyte count, phenoloxidase (PO) activity, respiratory burst, and lysozyme activity, were significantly decreased (p < 0.05) in shrimp receiving MEL alone (10 g kg−1 diet) and at high combination dosages (10 + 10 g kg−1 diet). Moreover, MEL and CYA induced oxidative stress, damaged hepatopancreas, decreased antioxidant responses, increased lipid peroxidation, and caused abnormality of hepatocytes

Mali Boonyaratpalin

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