Israeli Journal of Aquaculture - Bamidgeh

Use of Red and Blue Light-Emitting Diodes (LED) and Fluorescent Lamps to Grow Microalgae in a Photobioreactor

Caner Koc; Gary A. Anderson; Anil Kommareddy — Tue, 01 Jan 2013 00:00:00 GMT

High oil content microalgae are a source for biofuel production. They can be produced in open ponds or closed photobioreactors. To efficiently grow such microalgae, illumination for photosynthesis, CO2 consumption, and the pH and nutrient content of the growth medium must be monitored and precisely controlled. In a closed photobioreactor, illumination is the most critical parameter because it is the most expensive factor of algae production and must be operated 24 h per day. In this research, Chlorella kessleri (UTEX 398) microalgae were grown in photobioreactors. All parameters were identical, except the source and intensity of the illumination. The light sources included red light-emitting diodes (LED), blue LED, and fluorescent lights. Growth of the microalgae was observed for seven days and the effects of the three illumination sources on cell count, cell weight, and cell size were determined. In the first experiment, in which the current of all three light sources was the same, red LED produced the highest number of cells with the highest weight while blue LED light produced the largest cells. In the second experiment, in which the light intensity was the same for all three light sources, the highest weight was again achieved with the red LED. Thus, we suggest that most advantageous production system may be to use a red light initially to produce the desired cell concentration, then switch to a blue light to increase cell size.

Effects of Intensive and Semi-Intensive Rearing on Growth, Survival, and V-Shaped (Lordotic) Skeletal Deformities in Juvenile Gilthead Sea Bream (Sparus aurata)

Erkan Can — Tue, 01 Jan 2013 00:00:00 GMT

Intensive production can reduce production costs and improve efficiency of larvae culture. This study compared the effects of intensive and semi-intensive production on growth, survival, and V-shaped skeletal deformities in juvenile gilthead sea bream (Sparus aurata). At the end of the 50-day study, survival was 68.01±0.8%, mean weight was 1.32±0.03 g, and lordosis was 32% among juveniles raised in the intensive system. Survival and mean weight were significantly higher, 92.06±1.1% and 1.61±0.02 g, respectively, among juveniles raised in the semi-intensive system, and none had lordosis (p<0.05). Results suggest that semi-intensive systems are more advantageous than intensive for rearing sea bream juveniles.

Improved Resistance to Vibrio parahaemolyticus in Black Tiger Shrimp Penaeus monodon Treated with Streptococcus phocae PI80 and Bacillus subtilis

V. Pattukumar; P. Kanmani; R. Satish kumar; N. Yuvaraj; A. Paari; V. Arul — Tue, 01 Jan 2013 00:00:00 GMT

The aim of the study was to establish the immune response induced by Streptococcus phocae PI80, Bacillus subtilis, and commercial probiotics (Uni-Ecosense, EcoForce, Uni-Hatch) in the shrimp, Penaeus monodon. Total hemocyte count, phenoloxidase activity, nitroblue tetrazolium (NBT) reductase assay, phagocytic activity, and disease resistance was evaluated for 30 days. Total hemocyte count, phenoloxidase activity, NBT reductase assay, and phagocytic activity significantly increased in juveniles and adults treated with S. phocae PI80, a mixture of S. phocae PI80 and B. subtilis, or a commercial probiotic, but there were no significant differences in live weight of shrimps treated with probiotics or the control. Treatment with S. phocae PI80 plus B. subtilis enhanced survival of shrimps challenged with Vibrio parahaemolyticus. Our study demonstrates that administration of S. phocae PI80+B. subtilis at 4.6 х 108 CFU/ml water induced immune modulation, enhanced immune ability, and increased resistance to V. parahaemolyticus in juvenile and adult black tiger shrimp.

Vegetable Products as Dietary Pigment Sources for Juvenile Goldfish, Carassius auratus

Kutty Juskar Jebaraja; V. Sivakumar; K.P. Kumaraguru vasagam — Tue, 01 Jan 2013 00:00:00 GMT

Amaranthus leaf meal, moringa leaf meal, and red chili powder were chemically analyzed and evaluated as carotenoid sources in diets for juvenile goldfish, Carassius auratus. The fish readily accepted all test diets, indicating good palatability of the tested ingredients. In a 56-day growth trial, all growth performance indicators except survival significantly varied (p<0.05) between dietary treatments. The highest weight gain (1.19 g) was achieved by fish fed the diet containing krill meal (positive control diet), but this weight gain did not significantly differ from that of fish fed the diet containing red chili powder. Total carotenoids were significantly highest (p<0.05) in fish fed the diet containing red chili powder (2.07 μg/g) and very low in fish fed the diet containing no pigment supplement (negative control). Growth, skin coloration, and total carotenoids in the tissue were satisfactory in fish fed the diets containing amaranthus or moringa leaf meal.

Effect of Marine Red Yeast Rhodosporidium paludigenum on Antioxidant-Related Gene Expression in Litopenaeus vannamei

Shi-Ping Yang; Zao-He Wu; Ji-Chang Jian — Tue, 01 Jan 2013 00:00:00 GMT

The effects of orally-administered dry and live marine red yeast Rhodosporidium paludigenum on antioxidant-related gene expression in the hepatopancreas and hemocytes of Litopenaeus vannamei were investigated by RT-PCR. In the hepatopancreas of L. vannamei fed dry yeast, manganese superoxidate dismutase (SODMn) and catalase (CAT) were enhanced while glutathione peroxidase (GPx) and ferritin remained at the same levels as in the control group. In the hepatopancreas of L. vannamei fed live yeast, SODMn and ferritin were higher than in the control. In hemocytes of L. vannamei fed dry yeast, SODMn was lower, ferritin was similar, and CAT and GPx fluctuated, in comparison to the control. In hemocytes of L. vannamei fed live yeast, SODMn was lower, ferritin was higher, and CAT and GPx tended to be lower than in the control group. Results suggest that consumption of the marine red yeast, R. paludigenum, can stimulate antioxidant gene expression in the hepatopancreas of shrimp.

Impact of Potential Food Sources on the Life Table of the Cladoceran, Moina macrocopa

Tue, 01 Jan 2013 00:00:00 GMT

The zooplankton Moina macrocopa was cultured with three kinds of emulsified lipid media (Selco®, squid oil, canola oil) and two kinds of fish wastes (fish pellets and fish feces) to determine the impact of these food sources on its population dynamics. All diets were provided at five levels: 0.0625, 0.125, 0.25, 0.5, and 1.0 g/l. For all diets, life history parameters showed the highest values at the lowest concentrations, i.e., <0.125 g/l. Overall demographic performance was better in M. macrocopa fed the emulsified liquid diets than M. macrocopa raised in the control treatment (dechlorinated water; no diet) but not as good as in M. macrocopa fed the fish wastes. Fish feces was excellent for propagating M. macrocopa. In conclusion, using fish wastes to cultivate M. macrocopa could be an inexpensive and sustainable cultivation approach.

Enhancement of Growth Performance and Pigmentation in Red Oreochromis mossambicus Associated with Dietary Intake of Astaxanthin, Paprika, or Capsicum

Sevdan Yilmaz; Sebahattin Ergun; Nergiz Soytas — Tue, 01 Jan 2013 00:00:00 GMT

Diets for tilapia, Oreochromis mossambicus, were supplemented with astaxanthin, paprika, or capsicum to determine their effects on growth performance and pigmentation. Seven isonitrogenous (37% crude protein) and isoenergetic (18 kJ/g) diets were formulated to contain 40 or 60 mg carotenoid per kg diet. Triplicate groups of 210 fish were stocked in 21-l plastic boxes and fed one of the three experimental diets or the control diet for 45 days. Significantly better final weight, weight gain, specific growth rate, and food conversion ratio were obtained with the diets containing 40 or 60 mg/kg paprika than with control diet (p<0.05). In general, the carotenoid-supplemented diets significantly increased the values of redness (a*), yellowness (b*), and chroma (C*), and decreased the values of lightness (L*) and hue (Hoab) on the tail, body, and head areas (p<0.05). Results show that paprika or capsicum oleoresin can be used as an alternative natural carotenoid source in O. mossambicus diets to ensure good pigmentation, better growth, and feed utilization.

Effects of Stocking Density on Growth, Nonspecific Immune Response, and Antioxidant Status in African Catfish (Clarias gariepinus)

Xiaomei Wang; Wei Dai; Min Xu; Baoping Pan; Xiaoqin Li; Yitong Chen — Tue, 01 Jan 2013 00:00:00 GMT

African catfish were stocked at densities of 35, 65, 95, and 125 kg/m3 for 60 days. The effects of the stocking density on growth, non-specific immune response, and antioxidant status were investigated on days 30 and 60. Serum cortisol levels were assayed on day 60. Increased stocking density led to decreased growth. Most non-specific immune indices (total number of leukocytes, differential leukocyte count in percent, respiratory burst activity, C3 and C4 complements, spleen and head kidney mass indices) were unaffected by the stocking density (p>0.05). There were significant differences between the 35 and 125 kg/m3 treatments in lysozyme activity on day 60 (p<0.05) but no significant effects of stocking density on malondialdehyde (MDA) level on either day 30 or day 60 (p>0.05). On day 30, only glutathione peroxidase (GSH-Px) activity was stimulated by increased stocking density while, on day 60, increased stocking density resulted in increased glutathione (GSH), GSH-Px activity, and superoxide dismutase (SOD) activity. The serum cortisol level on day 60 was unaffected by stocking density (p>0.05). Findings suggest that high physiological welfare standards were maintained in African catfish reared in high stocking densities.

Diseases of Mariculture Finfish Species: A Review

K.Saravanan; S. Ezhil Nilavan; S. Arun Sudhagar; V. Naveenchandru — Tue, 01 Jan 2013 00:00:00 GMT

Mariculture has been steadily growing over the last few decades. To satisfy the increasing demand of local and export markets for fish and to control overexploitation of marine fish species, many countries are expanding mariculture activities. Disease is one of the most limiting factors in mariculture. Intensification of mariculture favors pathogens, which increase disease outbreaks. Diseases are broadly classified into infectious and noninfectious diseases. Infectious diseases are further divided into four groups based on the nature of the pathogen: viral, bacterial, parasitic, or fungal. Noninfectious diseases are divided into neoplastic diseases, genetic and environmentally induced diseases, and nutritional deficiency diseases. This paper provides detailed information regarding prevalent diseases of maricultured finfish species.

Hematological Changes in Common Carp (Cyprinus carpio) and Rainbow Trout (Oncorhynchus mykiss), Infected with Saprolegnia spp.

Raghvendra Singh; N.N. Pandey; Monika Gupta — Tue, 01 Jan 2013 00:00:00 GMT

The present study was conducted to investigate the physiological impairment in common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) infected with Saprolegnia spp. The following hematological parameters were studied: total erythrocyte count (TEC), total leukocyte count (TLC), hemoglobin (Hb), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). Except TLC, which significantly increased in the infected fish, all parameters decreased in response to infection. Decreases in Hb, TEC, and Hct were significant, indicating that saprolegniosis causes anemia and immunosuppression.

Nibbling Frequency of Carps in Periphyton-Based Aquaculture Systems with and without Supplemental Feed

Rai, Sunila; Yi, Yang — Sun, 01 Jan 2012 00:00:00 GMT

The nibbling frequency of five carp species (rohu Labeo rohita, mrigal Cirrhinus mrigala, catla Catla catla, common carp Cyprinus carpio, silver carp Hypophthalmichthys molitrix) on bamboo lateral sticks (kanchi) colonized by periphyton was examined in fed and unfed systems. There were three treatments: (a) no carp and no supplemental feed (control), (b) carp without supplemental feeding (unfed treatment), and (c) carp with supplemental feeding (fed treatment). For 12 h (07:30-19:30) during six days, nibbling behavior was observed in real time via a digital video camera and recorded on a camcorder for later viewing. Rohu, catla, and common carp nibbled on the kanchi, while mrigal and silver carp did not. In rohu and catla, the nibbling frequency was significantly higher in the unfed treatment than in the fed treatment (p<0.05); supplemental feeding reduced nibbling frequency by 81% and 91%, respectively. Hence, in periphyton-based aquaculture systems, there is no need for a high density of substrates in ponds that receive supplemental feed. Alternatively, the amount of supplied feed can be reduced to force these species to consume more periphyton.

Effects of Dietary Fish Oil Substitution with Palm Oil on Growth, Survival, and Muscle Proximate Composition of Cirrhinus mrigala (Hamilton, 1822)

Sun, 01 Jan 2012 00:00:00 GMT

A 60-day growth experiment was carried out to evaluate the effect of replacing dietary cod liver oil with palm oil on the growth, survival, and muscle proximate composition of the Indian major carp, Cirrhinus mrigala. Five diets were fed to triplicate groups of 20 advanced C. mrigala fry (2.16±0.01 g): 100% cod liver+0% palm (control), 25% palm+75% cod liver, 50% palm+50% cod liver, 75% palm+25% cod liver, and 100% palm+0% cod liver. At the end of the experiment, mean weight gain, average daily growth, specific growth rate, feed conversion efficiency, feed conversion ratio, and percentage survival were assessed. Growth performance and survival were not compromised when fish oil was substituted with palm oil up to 25%. However, beyond this level, growth was significantly retarded (p<0.01). There were no significant (p>0.01) differences in feed efficiency or muscle proximate composition. Results confirm the feasibility of substituting up to 25% dietary fish oil by palm oil in diets for C. mrigala advanced fry without negatively affecting growth or feed utilization efficiency.

Effect of Stocking Density on Growth and Survival of Sub-Adult Tench (Tinca tinca Linnaeus 1758)

Pantazis, Panagiotis A. — Sun, 01 Jan 2012 00:00:00 GMT

Three hundred and fifty-nine (359) sub-adult tench were allocated to twelve tanks to investigate the effect of stocking density on survival and growth. The experimental population consisted of two weight groups (small = 11.27-11.36 g and large = 15.38-15.44 g) and two initial stocking densities (1.4 kg/m3 and 2.5 kg/m3). The experiment lasted seven months (217 days). The total lack of deformities in the caudal peduncle in all groups and the low incidence of mortality indicate that sub-adult tench cultured in a water recirculation system perform well when stocked at a relatively high stocking density (2.5 kg/m3) and fed 1.0% of their body weight per day. By the end of the experiment, the weight of the best-performing groups increased 83-90% and confirmed the hypothesis that high densities favor the growth and survival of sub-adult tench reared in artificial tanks in a water recirculation system.

An Improved Method of DNA Extraction from the Shell of the Pacific Oyster, Crassostrea gigas

Zhang, Guofan; Wang, Xiaotong; Song, Xiaorui; Li, Li — Sun, 01 Jan 2012 00:00:00 GMT

We earlier developed a method to extract DNA from in vivo-sampled mantle tissue of the bivalve Pacific oyster (Crassostrea gigas) for molecular marker-assisted selection (MAS) in breeding. However, mortality was too high when using this method. In the current study, a more efficient and safer method of extracting DNA from the oyster shell was developed, based on the improved phenol-chloroform DNA extraction method. Both nuclear DNA and mitochondrial DNA were successfully extracted from the oyster shell, and mortality was 0%. These results illustrate the safety of extracting DNA from the bivalve shell. In addition, because DNA is a cellular component, the results provide molecular evidence that cells are likely involved in shell formation.

Sperm Characteristics of Wild European Flounder (Platichthys flesus luscus)

Sahin, Temel; Günes, Erdinç; Aydin, Ilhan; Kurtoglu, Ilker Zeki — Sun, 01 Jan 2012 00:00:00 GMT

The spermatologic characteristics of European flounder (Platichthys flesus luscus) were determined. Flounder were collected during the spawning season and sperm of eight males was extracted by abdominal massage. Body weight and total length of the flounder were measured, volume, motility, duration of motility, spermatocrit, density, and pH of the sperm were determined, and correlations between the spermatologic characteristics and weight and length were investigated. Mean values were 0.7±0.16 ml for sperm volume, 87.5±3.66% for motility, 22.0±1.49 min for duration of motility, 94.0±1.22% for spermatocrit, 2.7±0.16 × 109/ml for density, and 6.9±0.05 for pH. Body length and sperm volume had positive correlations with body weight (p<0.01), but the correlation between length and sperm volume was negative (p<0.01). Likewise, the correlations between spermatocrit and total length, sperm volume, and density were negative (p<0.05).

Pigmentary and Zootechnical Responses of Juvenile Litopenaeus vannamei (Boone, 1931) Maintained on Diets Supplemented with Xanthophylls of Marigold Tagetes erecta Flowers

Sun, 01 Jan 2012 00:00:00 GMT

Practical diets supplemented with 75 or 150 ppm xanthophylls (75% zeaxanthin, 15% lutein) industrially extracted from marigold (Tagetes erecta L.) flowers increased the astaxanthin and total carotenoid concentrations in juvenile Litopenaeus vannamei, compared to shrimp fed a practical control diet. Our results paralleled or exceeded those obtained with a diet containing 75 ppm supplementary synthetic astaxanthin. The post-feeding astaxanthin concentration accounted for more than 84% of the total carotenoid concentration in shrimp fed either diet, while beta-carotene, zeaxanthin, lutein, and other non-identifiable carotenoids comprised a minority of the total concentration. That this was seen in both the tail exoskeleton and abdominal muscle indicates that L. vannamei can metabolize precursor xanthophylls to produce astaxanthin. In most cases, more than 60% of the astaxanthin was esterified. In general, survival improved in shrimps fed the supplemented diets compared to those fed the control diet. There were no differences in growth.

Stress Survival in Larvae of Florida Pompano (Trachinotus carolinus) Fed Enriched Rotifers (Brachionus plicatilis) and Nauplii of the Calanoid Copepod (Pseudodiaptomus pelagicus)

Cassiano, Eric J.; Ohs, Cortney L.; DiMaggio, Matthew A. — Sun, 01 Jan 2012 00:00:00 GMT

The Florida pompano, Trachinotus carolinus, is a highly prized marine fish whose larviculture includes the feeding of live rotifers and brine shrimp nauplii. In a previous study, growth and survival of pompano larvae fed nauplii of the calanoid copepod, Pseudodiaptomus pelagicus, were compared to those of larvae fed enriched rotifers, Brachionus plicatilis. There were advantages to including the copepod in the larvae diet. The current study examines the stress tolerance of such larvae. Two trials were conducted: for seven (trial 1) and nine (trial 2) days post-hatch. Larvae were fed diets that included enriched rotifers and/or P. pelagicus nauplii and subjected to varying durations of air exposure (‘sieve stress’). Larvae fed copepods exhibited significantly greater stress tolerance than larvae fed only enriched rotifers. In trial 1, stress tolerance increased as the number of days on which copepods were fed increased. It is possible that stress tolerance improved because of a better nutritional profile of the copepod nauplii.

Effects of Total Replacement of Fishmeal with Spirulina Powder and Soybean Meal on Juvenile Rainbow Trout (Oncorhynchus mykiss Walbaum)

Sun, 01 Jan 2012 00:00:00 GMT

Juvenile rainbow trout (Oncorhynchus mykiss) were fed diets in which fishmeal was totally replaced by mixtures of Spirulina powder and soybean meal. Three experimental diets were formulated with 75% Spirulina and 25% soybean meal, 50% Spirulina and 50% soybean meal, and 25% Spirulina and 75% soybean meal. A commercial diet and a diet with 100% fishmeal served as controls. Diets were fed to triplicate groups of 10 juveniles with an initial weight of 6.8±0.4 g for 50 days. At the end of the experiment, growth performance, oxygen consumption, nitrogen and phosphorus excretion, protein digestibility, and serum protein content and lysozyme activity were evaluated. Data were analyzed by one-way ANOVA. Growth performance was not significantly affected by the experimental diets, but values tended to be lower as the level of dietary soybean meal increased. Among the experimental diets, the 75% Spirulina/25% soybean diet produced the best growth performance. Further, in fish fed this diet, the apparent coefficient of digestibility of protein was higher than 98% (as with all diets), oxygen consumption was lower and lysozyme activity was higher than in fish fed other replacement diets, and dissolved phosphorus and phosphorus in feces were similar or lower than in the controls. The present research shows the possibility of using mixtures of Spirulina powder and soybean meal as total substitutes of fishmeal in diets for juvenile rainbow trout.

Effect of Dietary Supplementation of Achyranthes aspera Seed on the Immune System of Labeo rohita Fry

Chakrabarti, R.; Srivastava, P. Kumar — Sun, 01 Jan 2012 00:00:00 GMT

Labeo rohita (rohu) fry (0.547±0.01 g) were fed one of four diets containing 0 (control), 0.1, 0.5, or 1.0% Achyranthes aspera seed. After 30 days, the fry were immunized with chicken red blood cells (c-RBC). Blood samples were collected 7, 14, and 21 days after immunization. Significantly (p<0.05) higher average weight (2.565±0.02 g) and SGR were were obtained in fry fed the 1.0% diet compared to others. The increase in average weight was directly related to the increasing dose of seed. FCR was significantly (p<0.05) lower in fry fed the 1.0% diet while total serum protein, albumin, and globulin were higher in treated groups than in the unsupplemented control. The antigen-specific antibody titer level was significantly (p<0.05) lower in rohu fed the control diet than in rohu fed the supplemented diets. Titer levels were 32-128, 128-256, 256-1024, and 256-1024 in the 0, 0.1, 0.5, and 1.0% diets, respectively. Serum glutamic oxaloacetic transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), and alkaline phosphatase (ALP) were significantly (p<0.05) higher in rohu fed the control diet than in rohu fed the supplemented diets while myeloperoxidas was lower in the former. Among the treated groups, myeloperoxidase was significantly (p<0.05) higher in rohu fed the 1.0% diet (1.561-2.558, ? 450 nm) than in those fed other diets. The present study documents the immunostimulatory properties of A. aspera seed and finds that a dose of 1.0% might be suitable for rohu fry.

Low Mercury Levels in Lake Kinneret Fish

Sun, 01 Jan 2012 00:00:00 GMT

Human exposure to the neurotoxin, methylmercury (MeHg), occurs primarily through the consumption of contaminated fish that are present even in pristine freshwater ecosystems. Lake Kinneret is the sole freshwater lake in Israel and supports an important commercial fishery. We examined total mercury (THg; often equivalent to MeHg in fish muscle tissue) for nine fish species in Lake Kinneret. Concentrations were low for all fish species, 6-409 ng/g, and below 500 ng/g MeHg, the level generally considered safe for human consumption. Of particular relevance are the very low levels of THg (<60 ng/g) in Galilee St. Peter’s fish (Sarotherodon galilaeus) and lavnun (Acanthobrama terrascantae), the most commercially important species in Lake Kinneret. Biomagnification was apparent among trophic guilds, with THg concentrations increasing from primary to secondary to tertiary consumers. This study suggests that consumption of commercial species, especially primary consumers, will result in low MeHg exposure to humans.