D. Allen Davis

Suitability studies of inland well waters for Litopenaeus vannamei culture

The inland farming of penaeid shrimp in low-salinity waters is now de facto in many regions of the world, yet there is little information pertaining to the suitability of waters with various ionic compositions for shrimp culture. In the present study, short-term (48 h) survival of Pacific white shrimp, Litopenaeus vannamei postlarvae (PL), and long-term (4 weeks) growth and survival of juvenile L. vannamei in various inland saline ground waters were evaluated. A correlation between survival and growth of PLs and the ionic composition of the waters was performed. Short-term bioassays were conducted on 10-, 15- and 20-day-old postlarvae using waters from various wells. Salinitywasdecreasedatarateof4ppth 1 usingfreshwaterfrom24pptuntilasalinityof2pptabove the target salinity was reached. Water in the containers was then slowly exchanged with water from inland saline wells. Survival of the PLs was evaluated 48 h after the start of acclimation. In the second study, four replicates of 15 juveniles were placed in 144-l square tanks containing various saline well watersfromwestAlabama.Growthandsurvivalwereevaluatedafter4weeks.Theionicmakeupofthe various inland well waters from Alabama, Florida, Mississippi and Texas was analyzed to characterize each source. Survival of PL10 shrimp in some of the waters was similar to survival in the low-salinity reconstituted seawater control andwas significantly differentfrom the control in other waters. Survival of PL15 was greater than survival of PL10 but similar to PL20. Some waters were unsuitable for shrimp culture at all PL stages tested. Survival and growth of the juveniles paralleled results of the short-term bioassays. Shrimp survived and grew well in waters in which more than 90% of the postlarvae acclimated andsurvivedin.Juvenile survivalandgrowth wereintermediate andlowin watersinwhich PL acclimation was intermediate and low, respectively. Survival appears to be positively correlated with ions such as K, Mg and SO4 and negatively correlated with a high concentration of iron. D 2003 Elsevier Science B.V. All rights reserved.

Replacement of fish meal in practical diets for the Pacific white shrimp, Litopenaeus vannamei.

Abstract The use of a co-extruded soybean poultry by-product meal (CEPM) and flashed dried poultry by-product meal (FD-PBM) was evaluated as replacements for fish meal in a practical diet formulated to contain 32% crude protein and 8% lipid. Each meal was substituted for menhaden fish meal on an iso-nitrogenous basis and offered to juvenile Litopenaeus vannamei (mean initial wt.±S.D., 0.37±0.015 g) over a 6-week period. Inclusion levels ranged from 0 (30 g fish meal /100 g diet) to 80% replacement (6 g fish meal/100 g diet). Replacement of fish meal with CEPM resulted in equivalent values for final weight, percent weight gain and feed efficiency (FE) and a significant increase in protein conversion efficiency (PCE). Similarly, replacement of 40%, 60%, and 80% of the fish-meal protein in the basal diet with FD-PBM resulted in a significant increase in weight gain and FE. Although not significant, there was also a general increase in PCE when FD-PBM was included in the diet. Under the reported conditions, survival, FE, and PCE values were either improved or were not significantly influenced by the replacement of menhaden fish meal with either CEPM or FD-PBM. Hence, these products can be used to reduce the fish-meal content of practical diets from 30 to 6 g/100 g dry wt.

Partial Replacement of Fish Meal with Meat-and-Bone Meal, Flash-Dried Poultry By-Product Meal, and Enzyme-Digested Poultry By-Product Meal in Practical Diets for Juvenile Red Drum

Abstract To reduce long-term dependence upon fishery resources, we evaluated selected terrestrial by-products as alternatives to fish meal for rearing juvenile (mean weight, 2.3 ± 0.1 g) red drum Sciaenops ocellatus. Over a 6-week feeding trial, 10 test diets (basal diet and 9 test diets) were formulated on an isonitrogenous (44% gross protein) basis. The primary protein sources in the basal diet were fish meal and soybean meal, which were incorporated at 30 and 24.8 g/100 g of diet, respectively. Replacement of fish meal in the test diets ranged from 16.6% to 66.7%. Low ash meat-and-bone meal (MBM), flash-dried poultry by-product meal (PBM), and enzyme-digested poultry by-product meal (EPM) were used to replace the fish meal. All four MBM diets produced significantly lower weight gain compared with fish maintained on the basal diet. Feed efficiency (FE) and protein conversion efficiency (PCE) were similar for the 16.6% MBM diet and the basal diet, but higher levels of MBM produced significantly lower FE ...

Protein requirement for maintenance and maximum weight gain for the Pacific white shrimp, Litopenaeus vannamei

The dietary crude protein requirement of penaeid shrimp is an important nutritional consideration because protein is often the major limiting nutrient for growth. In most cases, research has focused on total dietary protein levels rather than a daily requirement for protein. This research utilized three practical diets containing 16%, 32%, and 48% protein and various daily rations to estimate daily requirements for protein. In the first series of studies, four 28-day feeding trials were conducted to determine the maintenance requirement for protein (protein required to maintain body functions with all other nutrients provided in adequate amounts) by juvenile and subadult shrimp. Shrimp were offered practical diets containing 16% or 32% crude protein. In order to estimate the maintenance requirement, weight gain was regressed against daily protein ration. Juvenile shrimp were found to have maintenance protein requirements in the range of 1.8-3.8 g dietary protein/kg body weight per day (g DP/(kg BWd)), and subadult shrimp were found to have maintenance protein requirements in the range of 1.5-2.1 g DP/(kg BWd). Four additional 28-day feeding trials were conducted to determine the protein requirement for maximum growth by juvenile and subadult shrimp. These studies, utilized three practical diets containing 16%, 32%, and 48% dietary protein. On an isonitrogenous basis, the 16% protein diet produced significantly lower weight gain, feed efficiency (FE), and protein conversion efficiency values, than the 32% protein diet for both the juvenile and subadult shrimp. The 48% protein diet produced significantly lower weight gain in the juvenile shrimp, but there was no significant effect in the subadult shrimp. Feed efficiency values were higher for shrimp fed the 48% protein diet as compared to those offered the 32% protein diet. Broken line analysis was conducted on the growth responses for each diet and each size of shrimp, in order to determine the protein requirement for maximum growth. Protein requirement for maximum growth of juvenile shrimp was found to be 46.4 g DP/(kg BWd) when fed the 32% protein diet and 43.4 g DP/(kg BWd) when fed the 48% protein diet. Subadult shrimp exhibited a maximum protein requirement of 23.5 g DP/(kg BWd) when fed a 32% protein diet and 20.5 g DP/(kg BWd) when fed a 48% protein diet. In summary, FE increased as the protein concentration of the diet increased, and decreased as feeding rates (offered feed/day) increased. Weight gain reflected daily protein intake. Based on these results, a wide range of dietary protein levels could be used to produce maximum weight gain of juvenile and subadult shrimp. Due to a restriction of feed intake and consequently protein intake, low protein diets did not support maximum weight gain.

The effects of dietary protein level on growth, feed efficiency and survival of juvenile Florida pompano (Trachinotus carolinus)

Florida pompano is considered a suitable candidate for mariculture due to its ready adaptation to culture systems, acceptance of formulated feeds, and rapid growth rates. Little information on the nutritional requirements or growth rates under controlled conditions have been reported. A seven week feeding experiment was conducted with juvenile fish (mean wt. 4.5 g) to evaluate the effect of dietary protein level on growth, feed intake, feed utilization and survival. Four practical diets were formulated to be isoenergetic and to contain increasing levels of protein (30, 35, 40 or 45% crude protein). Although total feed intake was not significantly different among treatments, feed intake expressed as amount consumed per unit of body weight was significantly different among treatments. Fish fed the highest protein diet had lower percentage daily feed consumption values than did fish fed the lowest protein diet. Growth and feed efficiency ratios increased with dietary protein level and were highest for fish fed the diet containing 45% protein. The results obtained in the present study indicate that juvenile Florida pompano required a minimum of 45% protein for maximum growth and feed efficiency ratio when fish meal and soybean meal are the primary sources of protein.

Dietary mineral requirements of fish and marine crustaceans

Abstract Information concerning mineral nutrition of fish and marine crustaceans is rather limited compared to that available for terrestrial animals; however, significant advances have been made in recent years. This article summarizes pertinent information about mineral nutrition of fish and marine crustaceans, including classification and general functions of the minerals; dietary essentiality and/or quantitative requirements; bioavailability and dietary interactions; and general recommendations for dietary supplementation. Dietary requirements for approximately ten minerals (calcium, copper, iodine, iron, magnesium, manganese, phosphorus, potassium, selenium, and zinc) have been identified for fish, and seven minerals (calcium, copper, phosphorus, potassium, magnesium, selenium, and zinc) have been recommended for inclusion in penaeid shrimp and lobster feeds. Based on current literature, it is clear that when evaluating the dietary essentiality of a mineral, not only growth must be evaluated, but als...

Evaluation of growout diets with varying protein and energy levels for red drum (Sciaenops ocellatus)

The augmentation of nutrient retention and subsequent reduction of effluent waste generated by aquaculture production facilities are important factors in lowering production costs while simultaneously minimizing pollution and environmental impact resulting from intensive growout culture. Consequently, the present study was designed to evaluate the influence of dietary protein and energy levels on growth and nutrient utilization of the red drum in the initial stages of growout culture. Four practical diets were formulated to contain 44, 40, 36, and 32% protein with practical energy:protein (E:P) ratios. Additionally, the E:P ratio of the 44% protein diet was increased and the E:P ratio of the 32% protein diet was reduced. Each diet was fed to juvenile red drum (mean initial weight 50 g) to apparent satiation in triplicate tanks containing 670 l of seawater at 35‰, 28.8±1.4°C for 13 weeks. Significant differences (P<0.05) in final weights, protein consumption, feed efficiency (FE), protein conversion efficiency (PCE) and intraperitoneal fat ratios (IPFR) were observed due to the dietary treatments. Weight gain and FE generally increased with protein and energy content of the diet. Increasing the lipid content of the 44% protein diet resulted in significantly higher FE values but also doubled the amount of fat deposited in the peritoneal cavity. Reduction of digestible energy from 335 to 279 kcal/100 g diet in the 32% protein diet did not significantly influence body composition or feed consumption. Based on regression analyses of feed consumption data, consumption rates appear to be primarily influenced by the weight of the fish and not the energy content of the diet. Consequently, reduced growth rates of fish offered the low protein feeds appear to be due to reduced protein intake and not imbalances in E:P ratios. These data indicate that red drum reared in seawater require at least 44% dietary protein (dry weight basis) for maximum growth and FE.

Effects of dietary lipid level and source on growth and proximate composition of juvenile redclaw (Cherax quadricarinatus) reared under semi-intensive culture conditions

Abstract The influence of dietary lipid level on growth, survival, and proximate composition of juvenile redclaw crayfish was evaluated during a 12-week growth trial utilizing semi-intensive culture conditions. Four diets were formulated to be isoenergetic (17.58 kJ g −1 ) and isonitrogenous (30% crude protein). Three of the diets were designed to contain 4.2% (L4), 8.2% (L8) and 12.3% (L12) lipid in a 1:1 ratio of corn oil/fish oil. A fourth diet was formulated to contain 8.7% (LC8) lipid, with corn oil as lipid supplement. A fifth treatment (UF) was included in which the redclaw were not fed in order to estimate the contribution of primary production. Juvenile redclaw (4.08±0.2 g initial weights) were stocked at a density of 10 per tank in 15, 2.5-m 3 fiberglass tanks with three replicates per treatment. The trial was conducted in an outdoor flow-through water system. The redclaw in the unfed treatment gained 8.3 g whereas redclaw that received a prepared ration gained an average of 31.9 g. Hence, in this experiment natural productivity contributed about 26% of the weight gain of the redclaw maintained in outdoor tanks. Among the fed treatments, there were no significant differences in survival, final weight, growth, or feed utilization. The hepatosomatic index (HI) generally increased with lipid level and was influenced by the sex of the redclaw. Results indicated that in similar culture conditions, diets containing 4% lipid are sufficient for redclaw growth and survival when natural food is present.

The design, management and production of a recirculating raceway system for the production of marine shrimp

Despite continuing problems with disease outbreaks and environmental concerns over effluent pollution and land usage, world shrimp farming continues to expand. Although traditional pond production systems will continue to be the dominant driving force in aquaculture expansion, there is continued interest in alternate production systems. The use of high density, water reuse systems is one alternative to conventional pond production systems which addresses restrictions associated with environmental regulations and user conflicts of coastal land and water usage. This paper reports on techniques which have been developed for the production of marine shrimp in recirculating raceway systems and typical results which have been observed over a 6-year production period. Both bait shrimp (Penaeus setiferus) and food shrimp (P. vannamei) have been produced with final biomass loads as high as 10 kg/m3 utilizing 100–120-day and 160–175-day production cycles, respectively. Results from multi-phase growout are most promising and indicate that this may be a suitable mechanism to optimize biomass loading of the culture system. Although the economic viability of recirculating production systems for bait and food size shrimp have yet to be proven, the consistent results of production, low water usage and ease of waste management are encouraging and warrant further economic and marketing evaluations.

Influence of Dietary Lipid Sources on the Growth Performance, Immune Response and Resistance of Nile Tilapia, Oreochromis niloticus, to Streptococcus iniae Challenge

ABSTRACT This experiment was conducted to determine the effect of dietary lipid sources on growth performance, body proximate composition, hematology, immune response and resistance of Nile tilapia, Oreochromis niloticus, to Streptococcus iniae infection. Six isocaloric (3.2 kcal/g) and isonitrogenous (34% crude protein) semi-purified diets were supplemented with 7% of various sources of lipid, namely, corn oil (CO), beef tallow (BT), menhaden fish oil (FO), linseed oil (LO), and equal combinations of FO+CO+BT or LO+CO+BT. Diets were fed to tilapia in quadruplicate aquaria to apparent satiation, twice daily for 12 weeks. Fish fed the BT-diet exhibited significantly lowest weight gain, diet intake, feed and protein efficiency ratios, apparent protein utilization, and survival. Whole-body protein and ash were significantly (P < 0.05) lowest and highest, respectively, for fish fed the beef tallow-diet, but the values of these parameters did not differ among fish fed other diets. No significant differences (P > 0.05) were found among hematological values, except for fish fed the FO-diet which had abnormally high red and white blood cell counts. Serum protein concentration, lysozyme activity, and natural hemolytic complement activity were significantly (P < 0.05) reduced in fish fed the BT-diet. The values of these parameters did not differ among fish fed other diets. Post-challenge antibody titer was not influenced by dietary lipid sources. Cumulative mortality 15 days post-challenge with S. iniae was significantly lower (P < 0.05) for fish fed the BT diet compared with those fed FO or FO+CO+BT diets. No significant differences were observed in fish fed other dietary lipid sources.