Laboratory of Aquaculture & Artemia Reference Center

EFFECT OF CRYOPROTECTANTS, EQUILIBRATION PERIODS AND FREEZING RATES ON CRYOPRESERVATION OF SPERMATOZOA OF MAHSEER, TOR KHUDREE (SYKES) AND T. PUTITORA (HAMILTON)
Ravindragouda Patil, Wazir Singh Lakra-2005
Aquaculture Research 36 (15): 1465-1472
Abstract :

A study was conducted to standardize a protocol for cryopreservation of spermatozoa of the endangered mahseer, Tor khudree (Sykes) and T. putitora (Hamilton). The suitability of the cryoprotectants, dimethyl sulphoxide (DMSO) and glycerol, and the combination of the two were tested. Four equilibration periods and four freezing rates were also tested for their standardization. A combination of 9% DMSO and 11% glycerol gave significantly higher mean percentage of hatching in both T. khudree (45.59±1.86%) (control 71.08±0.59%) and T. putitora (45.00±1.25%) (control 73.48±1.19%) among the eight different treatments. Among the four different equilibration periods tested, the equilibration period of 30 min1 yielded the highest mean hatching percentage in T. khudree (39.46±1.94%) (control 71.70±0.61%) and T. putitora (38.28±1.06%) (control 73.11±0.82%). Freezing straws at a height of 8 cm above LN2 surface for 10 min1 gave higher hatching percentages for both T. khudree (41.75±1.72%) (control 73.99±1.17%) and T. putitora (41.34±2.04%) (control 72.48±1.51%). The study reports the superior performance of the combination of DMSO and glycerol for the first time.

(Division of Fish Genetics and Biotechnology, Central Institute of Fisheries Education, Deemed University, Mumbai, India; email of W. Singh Lakra: lakraws@hotmail.com)

INCREASE IN MILT PRODUCTION BY HORMONAL TREATMENT IN THE PEJERREY FISH ODONTESTHES BONARIENSIS (VALENCIENNES 1835)
Leandro A Miranda, Maria C Cassará, Gustavo M Somoza-2005
Aquaculture Research 36 (15): 1473-1479
Abstract :

In spite of interest in the cultivation of the pejerrey fish Odontesthes bonariensis (Cuvier & Valenciennes 1835), there are few studies on subjects required to advance this activity. One of the problems is the synchronization of female and male maturation to provide eggs and sperm for larval production. The low volume of expressible milt, either in wild or culture fish, is a major problem. The aim of this work was to study the effectiveness of the administration of different hormones on sperm production in pejerrey. Milt production was enhanced by the injection of human chorionic gonadotropin (hCG) (16.7-fold increase, 625 IU kg1), carp pituitary extracts (13.5-fold increase, 30 mg kg1), salmon pituitary extracts (12.8-fold increase, 30 mg kg1), salmon-type gonadotropin-releasing hormone analogue (GnRH) (16.7-fold increase, 10 µg kg1) and mammalian-type GnRH analogue (10.8-fold increase, 20 µg kg1). Sperm concentration, motility and the fertilization rate were not statistically different compared with control groups. It was also demonstrated that sperm could be obtained off-season. Taken together, hCG is recommended to stimulate pejerrey spermiation because it is effective in low doses is inexpensive and is widely available.

(Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas/Instituto Tecnológico de Chascomús (CONICET-UNSAM), Camino de Circunvalación Laguna, Km 6. CC 164, (B7130IWA), Chascomús, Provincia de Buenos Aires, Argentina; email of L. Miranda: lmiranda@intech.gov.ar)

EFFECT OF DIFFERENT METHODS FOR THE INDUCTION OF SPERMIATION ON SEMEN QUALITY IN EUROPEAN EEL
Juan F. Asturiano, Luz Pérez, Daniel L. Garzón, David S. Peñaranda, Francisco Marco-Jiménez, Silvia Martínez-Llorens, Ana Tomás, Miguel Jover-2005
Aquaculture Research 36 (15): 1480 -1487
Abstract :

Five hormonal treatments with human chorionic gonadotropin (hCG) were tested for the induction of maturation and spermiation in male farmed eels. The main aim was to optimize previously used hormonal treatments to achieve shorter induction treatments, longer spermiation periods and/or higher sperm quality. Fish treated for just 3 weeks (treatment E) or until the onset of spermiation (treatment C) showed the worst results, while the treatment consisting of weekly administration of 1.5 IU hCG g1 fish (treatment A) induced the highest percentage of spermiating males, the highest number of sperm samples and sperm volumes and densities similar to the rest of the treatments (B: half hormone dosage, or D: biweekly administration). Evaluation of the sperm quality was performed by computer-assisted sperm analysis (CASA), considering the percentage of total motile spermatozoa, the percentage of fast and medium-velocity spermatozoa, as well as different motility parameters. Sperm samples from A-D groups showed between 44% and 54% motile spermatozoa, and between 10% and 15% fast spermatozoa, while samples from E-treated males showed 0% motile cells. No significant differences were found in the spermatozoa straight line velocity (VSL), curvilinear velocity (VCL) or the angular velocity (VAP), neither spermatozoa beating cross frequency (BCF) between A–D groups.

(Grupo de Investigación en Recursos Acuícolas, Departamento de Ciencia Animal, Universidad Politécnica de Valencia, Camino de Vera s/n 46022, Valencia, Spain; email of J. Asturiano: jfastu@dca.upv.es)

EGG QUALITY DETERMINANTS IN COD (GADUS MORHUA L.): EGG PERFORMANCE AND LIPIDS IN EGGS FROM FARMED AND WILD BROODSTOCK
Guillaume Salze, Douglas R Tocher, William J Roy, Derek A Robertson-2005
Aquaculture Research 36 (15): 1488-1499
Abstract :

Lipids and essential fatty acids, particularly the highly unsaturated fatty acids, 20:5n-3 (eicosapentaenoic acid; EPA), 22:6n-3 (docosahexaenoic acid; DHA) and 20:4n-6 (arachidonic acid, AA) have been shown to be crucial determinants of marine fish reproduction directly affecting fecundity, egg quality, hatching success, larval malformation and pigmentation. In Atlantic cod (Gadus morhua L.) culture, eggs from farmed broodstock can have much lower fertilization and hatching rates than eggs from wild broodstock. The present study aimed to test the hypothesis that potential quality and performance differences between eggs from different cod broodstock would be reflected in differences in lipid and fatty acid composition. Thus eggs were obtained from three broodstock, farmed, wild/fed and wild/unfed, and lipid content, lipid class composition, fatty acid composition and pigment content were determined and related to performance parameters including fertilization rate, symmetry of cell division and survival to hatching. Eggs from farmed broodstock showed significantly lower fertilization rates, cell symmetry and survival to hatching rates than eggs from wild broodstock. There were no differences in total lipid content or the proportions of the major lipid classes between eggs from the different broodstock. However, eggs from farmed broodstock were characterized by having significantly lower levels of some quantitatively minor phospholipid classes, particularly phosphatidylinositol. There were no differences between eggs from farmed and wild broodstock in the proportions of saturated, monounsaturated and total polyunsaturated fatty acids. The DHA content was also similar. However, eggs from farmed broodstock had significantly lower levels of AA, and consequently significantly higher EPA/AA ratios than eggs from wild broodstock. Total pigment and astaxanthin levels were significantly higher in eggs from wild broodstock. Therefore, the levels of AA and phosphatidylinositol, the predominant AA-containing lipid class, and egg pigment content were positively related to egg quality or performance parameters such as fertilization and hatching success rates, and cell symmetry.

(Institute of Aquaculture, University of Stirling, Stirling FK9 4LA,, UK; email of D. Tocher: d.r.tocher@stir.ac.uk)

CELL GROWTH, EFFECT OF FILTRATE AND NUTRITIVE VALUE OF THE TROPICAL PRASINOPHYTE TETRASELMIS TETRATHELE (BUTCHER) AT DIFFERENT PHASES OF CULTURE
Milagros R de la Peña, Cesar T Villegas-2005
Aquaculture Research 36 (15): 1500-1508
Abstract :

A local algal isolate Tetraselmis tetrathele was studied to determine the suitable levels of three growth factors (nutrient medium, light intensity and photoperiod) for mass culture. Significantly higher population cell count (141.92 × 104) were found in 4-day-old cultures (exponential phase) enriched with Conwy medium and exposed continuously to 93.31–103.5 µmole photon m2 s1 light intensity compared with two other media (F, SEAFDEC/AQD) under the same light conditions. Cultures exposed to higher levels of photosynthetic photon flux density and continuous photoperiod had a significantly higher cell count regardless of nutrient media used. The chemical composition of T. tetrathele varied as the culture aged. Significantly higher crude protein (49.6%) and crude ash (15.9%) were found in cultures harvested at exponential than at stationary phase of growth. In contrast, significantly higher carbohydrate (55.2%) was noted as the culture aged. There was an increase in the percentage of saturated, monoenoic and n-3 highly unsaturated fatty acids at the stationary phase of growth. Addition of filtrate from various phases of growth and from 10-day-old cultures at various concentrations stimulated cell growth of T. tetrathele. This study identified the optimum growth conditions for mass culture of T. tetrathele and demonstrated its change in the chemical composition as the culture aged.

(Southeast Asian Fisheries Development Center, Aquaculture Department (SEAFDEC/AQD), 5021 Tigbauan, Iloilo, Philippines; email of M. R. de la Peña: miladp@aqd.seafdec.org.ph)

IMPACT OF BACTERIA ON SHORT-TERM STORAGE OF SALMONID EGGS
Michael Holcomb, Joseph G. Cloud, Rolf L. Ingermann-2005
Aquaculture Research 36 (15): 1555- 1561
Abstract :

Unfertilized eggs of steelhead, Oncorhynchus mykiss (Walbaum 1792), were stored at a low temperature (0°C) with antibiotics (penicillin and streptomycin) for up to 22 days and fertility assessed. Unfertilized eggs of chinook salmon, Oncorhynchus tshawytscha (Walbaum 1792), were stored at a low temperature (0°C) either with or without antibiotics for up to 24 days and fertility assessed. There were no significant decreases in fertility under these conditions. Steelhead eggs were maintained at 4°C for up to 15 days with or without added bacteria and with or without gentamicin. Gentamicin inhibited bacterial growth during storage at 4°C and its use resulted in a less pronounced decline in fertility with storage. These results suggest that low temperatures and antibiotics play an important role in extending the period over which salmonid eggs can be successfully stored.

(Department of Biological Sciences & Center for Reproductive Biology, University of Idaho, Moscow, ID 83844-3051, USA; email of R. L. Ingermann: rolfi@uidaho.edu)

DESIGN AND SYNTHESIS OF 14C-LABELLED PROTEINS AS TOOLS FOR PROTEIN DIGESTION STUDIES IN FISH LARVAE
S.C. Hovde, M.C. Vidal, I. Opstad, A.J. Raae-2005
Aquaculture Nutrition 11 (6): 395- 401
Abstract :

In order to study the protein digestive capability in early stages of fish larvae, a method was developed to produce adequate amounts of pure, well-defined, high-quality, specifically 14C-labelled proteins. The proteins that were chosen were integral parts of the abundant cytoskeleton protein spectrin. The proteins were engineered by molecular biology technology to allow the specific incorporation of 14C-labelled leucine. The purified monodisperse proteins could be concentrated to more than 10 mg mL1 without precipitation. These proteins were parts of the same 'mother protein' with similar amino acid compositions and sequences but different molecular weights. This made them suitable to study the influence of the molecular sizes of the proteins on digestion in fish larvae.

(Institute of Marine Research, Storebø, Norway; email of Arnt J. Raae: arnt.raae@mbi.uib.no)

EFFECTS OF VARYING DIETARY FATTY ACID PROFILE ON GROWTH PERFORMANCE, FATTY ACID, BODY AND TISSUE COMPOSITION OF JUVENILE PIKE PERCH (SANDER LUCIOPERCA)
C. Schulz, U. Knaus, M. Wirth, B. Rennert-2005
Aquaculture Nutrition 11 (6): 403-413
Abstract :

Pike perch (Sander lucioperca) has been identified as specie destined to diverse European inland aquaculture, but knowledge on the nutritional requirements is weak. Therefore, we investigated the effect of varying dietary fatty acid (FA) profile by partial replacement of fish oil (FO) with vegetable oils on growth, FA and body composition of juvenile pike perch. An extruded basal diet containing 59 g kg1 crude lipids (FO) was added with 60 g kg1 FO, 60 g kg1 linseed oil (LO) or 60 g kg1 soybean oil (SO). The resulting dietary FA composition differed mainly in the triglyceride fraction and was characterized by highest amounts of linolenic acid (18:3 n-3) in the LO diet and linoleic acid in the SO diet. Diet enriched with FO contained highest contents of highly unsaturated FA 20:5 n-3 (eicosapentaenic acid) and 22:6 n-3 (docosahexaenic acid). Pike perch were held in a recirculation system and each feeding group (in triplicate) was fed with experimental diets at a daily rate of 35 g kg1 of biomass for 57 days by automatic feeders. Weight gain and specific growth rate of experimental feeding groups ranged between 18.47 and 19.58 g and 1.37–1.45% day1 and was not affected by the dietary composition indicating that FO can be replaced by vegetable oils without negative impact on growth performance. In contrast to the whole body and muscle composition, liver tissue was affected by the varying diets. Liver tissues of fish fed diets enriched with vegetable oils showed significantly increased lipid contents of 162 (LO) and 147 (SO) g kg1 and indicate decreased lipid utilization compared with fish fed FO diet (liver lipid content 112 g kg1). Nevertheless, hepatosomatic index of pike perch was not influenced by dietary lipid composition. The FA profile of pike perch was generally determined by the dietary FAs.

(Institute of Animal Science, Faculty of Agriculture and Horticulture, Humboldt-Universität zu Berlin, Philippstr. 13, House 9, 10115 Berlin, Germany; email of Carsten Schulz: carsten.schulz@agrar.hu-berlin.de)

WATER IMMERSION TIME REDUCES THE PREFERENCE OF JUVENILE TROPICAL SPINY LOBSTER PANULIRUS ORNATUS FOR PELLETED DRY FEEDS AND FRESH MUSSEL
K.C. Williams, D.M. Smith, S.J. Irvin, M.C. Barclay, S.J. Tabrett-2005
Aquaculture Nutrition 11 (6): 415-426
Abstract:

Development of a pelleted dry feed as an alternative to feeding fresh fishery by-catch is an environmental priority for tropical spiny lobster aquaculture. Earlier studies have shown the lobster's acceptance of pelleted dry feed diminishes rapidly after immersion in water. In this work, we quantified the rate at which dry matter, total protein, soluble protein and individual and total free amino acids were lost from pieces of green-lipped mussel Perna canaliculus, a commercially-extruded Penaeus japonicus (kuruma) shrimp feed (KSF) and four laboratory-made, fishmeal-based, pelleted feeds upon immersion for up to 7.5 h. The laboratory-made feeds contained homogenates of either green-lipped mussel, polychaete (Marphysa sanguinea), prawn (Metapenaeus bennettae) or squid (Sepioteuthis spp.). After being immersed in water for 0, 2.5 or 5 h, these same feeds were offered as a paired choice with KSF in two preference feeding studies with juvenile Panulirus ornatus lobsters. The loobster's preference for fresh mussel always exceeded that of KSF, irrespective of immersion time. Regression of the proportional intake of test feeds against the relative leach rate of KSF identified soluble protein, glycine and taurine as the principal leachate components having the highest positive correlations with the lobster's feeding preference.

(CSIRO Division of Marine Research, PO Box 120, Cleveland, Qld. 4163, Australia; email of Kevin Williams: kevin.williams@csiro.au)

EFFECT OF VARIOUS LEVELS OF LIPID EXCHANGED WITH DEXTRIN AT DIFFERENT PROTEIN LEVEL IN DIET ON GROWTH AND BODY COMPOSITION OF JUVENILE FLOUNDER PARALICHTHYS OLIVACEUS
S.-M. Lee, K.-D. Kim-2005
Aquaculture Nutrition 11 (6): 435-442
Abstract:

A 3 × 3 factorial experiment was conducted to determine proper levels of dietary protein, lipid and dextrin for juvenile flounder. Nine experimental diets were formulated to contain three protein levels (410, 460 and 510 g kg1) and three lipid levels (60, 130 and 190 g kg1) with corresponding dextrin levels (250, 150 and 50 g kg1). Triplicate groups of fish (8.9 ± 0.4 g) were hand-fed the diets to apparent satiation for 7 weeks in flow-through system. Specific growth rate was the highest in fish fed the 510 g kg1 protein diet with 60 g kg1 lipid, and was not significantly different from that of fish fed 460 g kg1 protein diet with 60 g kg1 lipid. Feed efficiency ratio tended to increase as dietary protein level increased. The feed efficiency ratio of fish fed the 510 g kg1 protein diets with 60–190 g kg1 lipid levels was not significantly different from that of fish fed 460 g kg1 protein diet with 60 g kg1 lipid. Daily feed intake tended to decrease with increasing dietary lipid level at each protein level. Daily protein intake increased with increasing dietary protein level at 60 g kg1 lipid level. Hepatosomatic index and visceralsomatic index increased with increasing dietary lipid level at each protein level. The lipid contents of liver, viscera and whole body, and concentrations of plasma total cholesterol and triglyceride increased with increasing dietary lipid levels; however, no significant difference was observed in the contents of dorsal muscle lipid. The results of this study suggest that the diet containing 460–510 g kg1 protein with low lipid level (60 g kg1) is optimal for growth and efficient feed utilization of juvenile flounder.

(Faculty of Marine Bioscience and Technology, Kangnung National University, Gangneung 210–702, South Korea; email of Sang-Min Lee: smlee@kangnung.ac.kr)

FREE- AND PEPTIDE-BASED DIETARY ARGININE SUPPLEMENTATION FOR THE SOUTH AMERICAN FISH PACU (PIARACTUS MESOPOTAMICUS)
M.B. Tesser, B.F. Terjesen, Y. Zhang, M.C. Portella, K. Dabrowski-2005
Aquaculture Nutrition 11 (6): 443-453
Abstract:

Arginine was hypothesized to be a model compound in the present study on molecular forms of indispensable amino acid (IAA) dietary supplementation. Juvenile South American pacu (Piaractus mesopotamicus) were fed diets containing arginine in a protein base (casein-wheat gluten or casein-gelatin), or the casein-wheat gluten base supplemented with dipeptide or free arginine at two levels (5 and 10 g kg1). Growth and protein efficiency ratios were significantly affected by diets, but not by arginine molecular form. Three free dispensable amino acids (DAA) and four IAA in plasma were affected by diet, but plasma arginine concentrations did not differ. Plasma urea concentrations, being very low in the pacu, and hepatic arginase activities, were not affected by diet (P = 0.10–0.11), but together with plasma ornithine, mirrored the growth data. Molecular form of arginine supplementation, free or dipeptide, significantly changed several free IAA (Phe, Leu, Ile, His) and urea, with a higher mean plasma concentration in dipeptide fed fish. The dietary treatments, or molecular form of the arginine supplementation, did not change proximate composition, except that calcium levels decreased with higher dietary arginine supplementation level. The present study indicates that dipeptides can provide IAA to pacu, and that arginine supplemented in this form is utilized as efficiently as in free form.

(School of Natural Resources, The Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 43210, USA; email of K. Dabrowski: dabrowski.1@osu.edu)

DAILY FOOD INTAKES AND OPTIMAL FOOD CONCENTRATIONS FOR RED KING CRAB (PARALITHODES CAMTSCHATICUS) LARVAE FED ARTEMIA NAUPLII UNDER LABORATORY CONDITIONS
Anna B. Epelbaum, Nikolina P. Kovatcheva-2005
Aquaculture Nutrition 11 (6): 455-461
Abstract:

Daily food intakes, optimal feeding regimes and food concentrations for laboratory reared Paralithodes camtschaticus (Tilesius, 1815) larvae were investigated. Artemia nauplii hatched at standard conditions were used as food. Daily food intakes of zoeae I–IV at 7–8 °C comprised 11.3, 22.4, 33.2, and 41.8 nauplii individuals (ind)1 day1, respectively, taking into account that wet weight of Artemia nauplii used for the experiments constituted 0.026 mg, dry weight 0.0042 mg. Optimal initial Artemia nauplii concentrations for feeding zoeae I–IV was determined as 400–600, 600–800, 800–1000 and 1000–1200 nauplii L1 respectively. Recommendations on using Artemia nauplii as food for red king crab larvae were outlined on the basis of experimental results. Growth, development and survival rates of zoeae I–IV reared in recycling water system at 7–8 °C and fed Artemia nauplii according to these recommendations were described.

(Crustacean Reproduction Laboratory, Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), 17, V. Krasnoselskaya str., Moscow 107140, Russia; email of A. Epelbaum: anna_epelbaum@hotmail.com, epelbaum@vniro.ru)

REVIEW: ROLE OF NITRIC OXIDE IN LARVAL AND JUVENILE FISH
F.B. Eddy-2005
Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology 142 (2): 221-230
Abstract:

Fish are known to express the three isoforms of nitric oxide synthase (NOS), the constitutive forms endothelial or eNOS, neuronal or nNOS and the inducible form iNOS. Most studies in fish have focussed on possible roles for NO in cardiovascular physiology although there has been recent attention on the role of nNOS in embryonic development. However compared to mammalian studies there have been relatively few studies on effects of nitric oxide (NO) on fish. Studies on heart and blood vessel preparations from various fish species appear to show results specific to the species or to the particular preparation. Possible roles of NO in the in vivo biology of adult fish or larval fish have received little attention. This article reviews effects of nitric oxide on cardiovascular physiology in fish with special emphasis on larval fish. It introduces some experimental work on possible signaling pathways in larval fish and introduces the possibility that NO could be an important environmental influence for some aquatic organisms. In higher vertebrates LPS (lipopolysaccharide) is known to activate the cytokine signaling system and stimulate increased expression of iNOS and increased production of NO, but this remains less investigated in fish. The effects of LPS on cardiovascular and osmoregulatory physiology of larval and juvenile salmonids are discussed and a possible role of NO in stress-induced drinking is suggested.

(Biological Sciences Institute, Faculty of Life Sciences, University of Dundee DD1 4HN, UK; email of F.B. Eddy: F.B.Eddy@dundee.ac.uk)

REVIEW: NITRIC OXIDE IN MARINE INVERTEBRATES: A COMPARATIVE PERSPECTIVE
Anna Palumbo-2005
Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology 142 (2): 241-248
Abstract:

Since the discovery of the biological effects of nitric oxide (NO) more than two decades ago, NO has been identified as an important physiological modulator and a messenger molecule in mammals. Parallel to these studies, evidence that has accumulated in recent years has revealed that the NO signalling pathway is spread throughout the entire phylogenetic scale, being increasingly found in lower organisms, ranging from Chordata to Mollusca. The present review attempts to provide a survey of current knowledge of the genesis and possible roles of NO and the related signalling pathway in marine invertebrates, with special emphasis on Sepia, a choice dictated by the increasing appreciation of cephalopods as most valuable model systems for studies of NO biology and the present expectation for new exciting insights into as yet little explored segments of NO biology.

(Stazione Zoologica A. Dohrn, Villa comunale 80121 Napoli, Italy; email of A. Palumbo: palumbo@szn.it)

PASSIVE TRANSFER OF MATERNAL ANTIBODIES AND THEIR EXISTENCE IN EGGS, LARVAE AND FRY OF INDIAN MAJOR CARP, LABEO ROHITA (HAM.)
P. Swain, S. Dash, J. Bal, P. Routray, P.K. Sahoo, S.K. Sahoo, S. Saurabh, S.D. Gupta, P.K. Meher-2005
Fish & Shellfish Immunology 20 (4): 519-527
Abstract:

Lack of immune competence in the early stages of life leads to severe mortality in larval stages of different fish species including Indian major carp (IMC). Investigation through indirect enzyme linked immunosorbent assay (ELISA) and agglutination test revealed a significant increase in specific serum antibody response in the brood fish of Indian major carp, Labeo rohita (Ham.) following immunisation with a virulent Aeromonas hydrophila bacterin 1 month prior to breeding, which was transferred to larvae through the egg. No significant differences (P > 0.05) in mean antibody levels in larvae at the 1st and 2nd weeks post-hatch was recorded while a slight rise in antibody level was observed in 3-week-old fry, perhaps due to exposure to A. hydrophila present in the aquatic environment. Immunised brood fish serum, egg and larval extracts in non-reducing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and subsequent western blot analysis revealed an antibody molecule of approximate molecular weight 210 kDa. On challenge with virulent A. hydrophila, a significant reduction in mortality was recorded in immunised larvae and fry (58.0, 43.75 and 37.14% in the 1st, 2nd and 3rd week, respectively) relative to control fish (87.0, 79.0 and 76.4% in 1st, 2nd and 3rd week, respectively). The present study indicated the role of maternally derived antibody in protection of hatchlings of Indian major carp against specific pathogens.

(Aquatic Animal Health Division, Central Institute of Freshwater Aquaculture, Kausalyaganga-751002, Bhubaneswar, Orissa, India; email of P. Swain: pswainy2k@yahoo.co.in)

INFLUENCE OF HIGH-M ALGINATE ON THE GROWTH AND SURVIVAL OF ATLANTIC COD (GADUS MORHUA L.) AND SPOTTED WOLFFISH (ANARHICHAS MINOR OLAFSEN) FRY
Dag Vollstad, Jarl Bøgwald, Olav Gåserød, Roy A. Dalmo-2005
Fish & Shellfish Immunology 20 (4) 548-561
Abstract:

Atlantic cod and spotted wolffish fry were fed high-M alginate containing feed for 59 and 55 days, respectively. During this period the fry showed a higher specific growth rate compared to controls. Uptake and distribution of alginate was studied by inclusion of the 125I-labelled molecule in the feed. The stomach and intestine contained the highest amount while the kidney, liver and spleen contained some, indicating that the alginate was taken up by the gut and transported to internal organs. Cod fry fed 0.06% and 0.1% high-M alginate showed a death rate of 51.4% and 53.3%, respectively. The lowest mortality, 48.1%, was found in fry fed 0.01% high-M alginate. Controls showed a mortality rate of 49.0%. Differences were, however, not statistically significant. Challenge of the immunostimulated fry (fed 0.02% and 0.06% alginate for 62 days) with atypical Aeromonas salmonicida bacteria resulted in accumulated mortalities of 56% and 49%, respectively, 47 days after infection. The group that received 0.06% alginate for a shorter period (47 days) and then control feed until challenged, and the group that received alginate by bath reached a cumulative mortality of 59% and 60%, respectively. Lowest mortality (44%) was seen in the control group. Numerous microabscesses were found in both immunostimulated and control fish in secondary lamellae of the gills, haematopoietic tissues of the kidneys, the submucosa and mucosa of the intestine, the spleen, the liver and the myocardium of the heart.

(Department of Marine Biotechnology, Norwegian College of Fishery Science, University of Tromsø, N-9037 Tromsø, Norway; email of Jarl Bøgwald: jarlb@nfh.uit.no)

CARP (CYPRINUS CARPIO L.) INNATE IMMUNE FACTORS ARE PRESENT BEFORE HATCHING
Heidi B.T. Huttenhuis, Cláudia P.O. Grou, Anja J. Taverne-Thiele, Nico Taverne and Jan H.W.M. Rombout-2005
Fish & Shellfish Immunology 20 (4): 586-596
Abstract:

Expression of the innate immune factors, complement factor 3 (C3), a2-macroglobulin (a2M), serum amyloid A (SAA) and a complement factor 1 r/s – mannose binding lectin associated serine protease-like molecule (C1/MASP2), was determined with Real Time Quantitative-PCR in carp (Cyprinus carpio L.) ontogeny around hatching. Furthermore, the expression of C3 mRNA and the presence of C3 protein were studied in carp embryos and larvae using In Situ Hybridisation, Western Blotting and Immunohistochemistry. C3, a2M, SAA and C1/MASP2 mRNA were produced by embryos from 12 h post-fertilisation, which is relatively long before hatching (2 days post-fertilisation (dpf)), indicating either involvement of these factors in development itself or more probably a preparation of the immune system for the post-hatching period. In addition, maternal mRNA of the aforementioned innate immune factors and maternal C3- and immunoglobulin protein was present in unfertilised eggs. Furthermore, C3 mRNA production was situated in the yolk syncytial layer in embryos from 24 h post-fertilisation to 5 dpf, followed by the liver in larvae, providing a new sequence of C3 production in teleost development.

(Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, Marijkeweg 40, 6709 PG Wageningen, The Netherlands; email of H. Huttenhuis: heidi.huttenhuis@wur.nl)

ELECTRONICAL LARVICULTURE NEWSLETTER ISSUE 232 15 November 2005

ELECTRONICAL LARVICULTURE NEWSLETTER ISSUE 232
15 November 2005