ELECTRONICAL LARVICULTURE NEWSLETTER ISSUE 213
1 February 2005
- THE RELATION BETWEEN AGE AT FIRST MATURITY AND GROWTH IN ATLANTIC HALIBUT (HIPPOGLOSSUS
HIPPOGLOSSUS) REARED AT FOUR DIFFERENT LIGHT REGIMES
- DETERIORATION PATTERNS IN DIAPAUSING EGG BANKS OF BRACHIONUS (MÜLLER, 1786) ROTIFER
SPECIES
- FLAVOBACTERIUM PSYCHROPHILUM IN RAINBOW TROUT, ONCORHYNCHUS MYKISS (WALBAUM), HATCHERIES:
STUDIES ON BROODSTOCK, EGGS, FRY AND ENVIRONMENT L.
- MICROBIAL COMMUNITY DYNAMICS IN A LARVAL AQUACULTURE SYSTEM OF THE TROPICAL ROCK LOBSTER,
PANULIRUS ORNATUS
- EFFECTS OF TEMPERATURE AND FOOD DENSITY ON THE SURVIVAL AND GROWTH OF EARLY STAGE
PHYLLOSOMA OF THE WESTERN ROCK LOBSTER, PANULIRUS CYGNUS
- COMPLETE LARVAL DEVELOPMENT OF THE SEA URCHIN LYTECHINUS VARIEGATUS FED AN ARTIFICIAL
FEED
- INDUCED OVULATION AND SPAWNING OF POND RAISED AFRICAN GIANT CATFISH, HETEROBRANCHUS
BIDORSALIS BY EXOGENOUS HORMONES
- CRYOPRESERVATION OF SPERM OF THE PACIFIC OYSTER (CRASSOSTREA GIGAS): DEVELOPMENT OF A
PRACTICAL METHOD FOR COMMERCIAL SPAT PRODUCTION
- LIPID AND FATTY ACID COMPOSITION OF PRE- AND POST-SPAWNING BLACKLIP (HALIOTIS RUBRA) AND
GREENLIP (HALIOTIS LAEVIGATA) ABALONE CONDITIONED AT TWO TEMPERATURES ON A FORMULATED FEED
- FECUNDITY OF THE JAPANESE CRAYFISH, CAMBAROIDES JAPONICUS: OVARY FORMATION, EGG NUMBER AND
EGG SIZE
- EFFECT OF DIETARY LIPIDS ON FATTY ACID COMPOSITION AND METABOLISM IN JUVENILE GREEN SEA
URCHINS (STRONGYLOCENTROTUS DROEBACHIENSIS)
- AMINO ACID COMPOSITION OF EARLY STAGES OF CEPHALOPODS AND EFFECT OF AMINO ACID DIETARY
TREATMENTS ON OCTOPUS VULGARIS PARALARVAE
- DEVELOPMENT, GROWTH AND SURVIVAL OF THE LARVAE OF QUEEN CONCH STROMBUS GIGAS UNDER
LABORATORY CONDITIONS
- EFFECT OF VITAMIN C DERIVATIVES ON THE PERFORMANCE OF LARVAL KURUMA SHRIMP, MARSUPENAEUS
JAPONICUS
- THE INFLUENCE OF DIETARY LIPID INCLUSION AND DAILY RATION ON GROWTH AND SMOLTIFICATION IN
1+ ATLANTIC SALMON (SALMO SALAR) PARR
- DIETARY VITAMIN E REQUIREMENT OF MRIGAL, CIRRHINUS MRIGALA FRY
- EXPRESSION AND LOCALIZATION OF SOME RETINOID RECEPTORS DURING EUROPEAN SEA BASS
(DICENTRARCHUS LABRAX) LARVAE DEVELOPMENT d
- EFFECTS OF DIETARY VITAMINS C AND E ON ALTERNATIVE COMPLEMENT ACTIVITY, HEMATOLOGY, TISSUE
COMPOSITION, VITAMIN CONCENTRATIONS AND RESPONSE TO HEAT STRESS IN JUVENILE GOLDEN SHINER (NOTEMIGONUS
CRYSOLEUCAS)
- DOES DIETARY N-3 HIGHLY UNSATURATED FATTY ACIDS LEVEL INFLUENCE THE EUROPEAN SEA BASS
(DICENTRACHUS LABRAX) CAPACITY TO ADAPT TO A HIGH TEMPERATURE?
- ESTIMATED AMINO ACID REQUIREMENTS DURING EARLY ONTOGENY IN FISH WITH DIFFERENT LIFE
STYLES: GILTHEAD SEABREAM (SPARUS AURATA) AND SENEGALESE SOLE (SOLEA SENEGALENSIS)
- ASSESSMENT OF WATER TURBIDITY FOR EVALUATION OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) EGG
QUALITY
- REPRODUCTIVE EVALUATION OF TRIPLOID YELLOWTAIL FLOUNDER, LIMANDA FERRUGINEA (STORER)
- EFFECTS OF CRYOPROTECTANT TOXICITY ON THE EMBRYOS AND LARVAE OF PACIFIC WHITE SHRIMP
LITOPENAEUS VANNAMEI
- GROWTH, SURVIVAL AND MANDIBLE DEVELOPMENT IN THE LARVAE OF THE SHORTFIN SILVERSIDE
CHIROSTOMA HUMBOLDTIANUM (VALENCIENNES) (ATHERINIFORMES: ATHERINOPSIDAE) UNDER LABORATORY CONDITIONS
- ONTOGENIC DEVELOPMENT OF THE SPINE AND SPINAL DEFORMITIES IN LARVAL BARRAMUNDI (LATES
CALCARIFER) CULTURE
- ELIMINATION OF ADHESIVENESS IN THE EGGS OF SHISHAMO SMELT SPIRINCHUS LANCEOLATUS USING
KAOLIN TREATMENT TO ACHIEVE HIGH HATCHING RATE IN AN ENVIRONMENT WITH A HIGH IRON CONCENTRATION
- A REVIEW OF THE CULTURE POTENTIAL OF SOLEA SOLEA AND S. SENEGALENSIS
- STOCK ENHANCEMENT AS A FISHERIES MANAGEMENT TOOL
- HABITAT DIVERSITY AND ADAPTATION TO ENVIRONMENTAL STRESS IN ENCYSTED EMBRYOS OF THE
CRUSTACEAN ARTEMIA
THE RELATION BETWEEN AGE AT FIRST MATURITY AND GROWTH IN ATLANTIC HALIBUT (HIPPOGLOSSUS HIPPOGLOSSUS)
REARED AT FOUR DIFFERENT LIGHT REGIMES
Albert K. Imsland, Thor M. Jonassen-2005
Aquaculture Research,
36(1): 1-7
Abstract: The effect of extended photoperiods on growth and age at first maturity was
investigated in 166 (79 females and 87 males) individually tagged Atlantic halibut. The halibut were reared at
11°C on four different light regimes from 10 February to 6 July 1996: simulated natural photoperiod, (LDN),
continuous light (LD24:0), constant 8 h light and 16 h darkness (LD8:16) and LD8:16 switched to continuous
light on 4 May 1996 (LD8:16 24:0). From 6 July 1996 to 9 February 1998 the LD24:0 and LD8:16 24:0 were reared
together under continuous light and the LDN and LD8:16 together under natural photoperiod. Juveniles subjected
to continuous light exhibited faster growth than those experiencing a natural photoperiod or a constant short
day. Moreover, the results suggest an overall growth enhancing effect of continuous light in females, but not
in males. No females matured during the trial, but the proportion of mature males differed between the
photoperiod groups, with significantly fewer males maturing in groups reared at continuous light. Independent
of photoperiod regime and maturation status, females were significantly bigger than males from 14 April 1997
onwards. Immature males were bigger than maturing males from 23 March 1996 onwards. As continuous light reduced
maturation at age 2+ in males, this could be used to reduce precocious maturation in males.
(Akvaplan-niva,
Iceland Office, Akralind 4, 201 Kópavogur, Iceland; e-mail of A.Imsland:
albert.imsland@akvaplan.niva.no)
DETERIORATION PATTERNS IN DIAPAUSING EGG BANKS OF BRACHIONUS (MÜLLER, 1786) ROTIFER SPECIES
Eduardo M. García-Roger, María José Carmona, Manuel Serra-2005
Journal of
Experimental Marine Biology and Ecology, 314 (2): 149-161
Abstract:
Rotifers are cyclical parthenogens
that produce sexual diapausing eggs at some stage in their life cycle. These eggs are encysted embryos that
remain viable for extended periods in lake and pond sediments, thus acting as an egg bank with many ecological
and evolutionary consequences. Despite its importance to rotifer evolution, there are no studies on resting egg
deterioration and associated processes in natural environments. In this study, more than 4000 diapausing eggs
of species from the Brachionus plicatilis complex, which includes several closely related cryptic species, were
collected from different sediment depths in 15 ponds in eastern Spain and were classified according to three
features thought to be related to their viability: shell integrity, embryo size, and embryo colour. A positive
association was found between embryo size and hatching success in those eggs having an intact shell. Diapausing
eggs that showed good shell integrity and no more than a 25% reduction of multinuclear embryo maximum size were
classified as healthy and 98.9% hatched. Darkening of diapausing egg embryo was an indicator of viability loss.
A decreasing frequency of healthy-looking diapausing eggs was observed with increasing sediment depth, although
some exceptions were found.
(Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de
València, A.O. 22085, València 46071, Spain; email of E. García: eduardo.garcia@uv.es)
FLAVOBACTERIUM PSYCHROPHILUM IN RAINBOW TROUT, ONCORHYNCHUS MYKISS (WALBAUM), HATCHERIES: STUDIES ON
BROODSTOCK, EGGS, FRY AND ENVIRONMENT L.
Madsen, J. D. Møller, I. Dalsgaard-2005
Journal of Fish
Diseases, 28 (1): 39-48
Abstract:
The occurrence of Flavobacterium psychrophilum at four rainbow trout
hatcheries was investigated to provide more knowledge about the reservoirs and transmission of this bacterium.
Broodstock were sampled at stripping (including both unfertilized and fertilized eggs), and the offspring were
then sampled at the eyed egg and fry stages. Water and surface samples (e.g. hatchery trays) were also sampled.
Flavobacterium psychrophilum was found in ovarian fluid and milt, indicating that broodstock may serve as a
reservoir and are latent carriers of the pathogen. Flavobacterium psychrophilum was not found on or inside
eggs, but further egg studies will be necessary to elucidate the possibility of vertical transmission of the
pathogen. Flavobacterium psychrophilum was isolated from water samples, but only from water that had been in
close contact with farmed rainbow trout or eggs. Flavobacterium psychrophilum isolates were characterized and
compared with well-characterized strains, using degradation of elastin, serotype and ribotype profiles.
Different ribotypes of F. psychrophilum were found between hatcheries, but a common ribotype A was found at all
four hatcheries. Different ribotypes were found in broodstock without clinical disease, whereas only a few
ribotypes (mostly ribotype A) were found in diseased fry. The same ribotype A was found in broodstock, in water
samples from hatchery trays and in fry, which suggests the possibility of transmission of F. psychrophilum
between broodstock and offspring.
(Fish Disease Laboratory, Danish Institute for Fisheries Research,
Stigbøjlen 4, DK-1870 Frederiksberg C, Denmark; email of Lone Madsen: lm@dfu.min.dk)
MICROBIAL COMMUNITY DYNAMICS IN A LARVAL AQUACULTURE SYSTEM OF THE TROPICAL ROCK LOBSTER, PANULIRUS
ORNATUS
David G. Bourne, Neil Young, Nicole Webster, Matthew Payne, Matthew Salmon, Sabine Demel Mike
Hall-2005
Aquaculture 242 (1-4): 31-51
Abstract:
Commercial scale rearing of the tropical rock
lobster (Panulirus ornatus) has been unsuccessful to date, with attempts characterised by periodic mass
mortalities of early stage hatchery-reared larvae. Here, we investigate the microbiological and
histopathological factors affecting early stage phyllosomas. Histopathology identified microbial infestation of
phyllosomas, including proliferation of bacteria in the hepatopancreas and heavy external fouling of appendages
and cuticle with filamentous bacteria and sessile protozoa. Scanning electron microscopy confirmed fouling by
filamentous bacteria of at least two morphological types and also fouling by rod-shaped bacteria, indicative of
a diverse epibiont community. Culture- and molecular-based microbial community analysis was performed on the
water column, tank biofilm and whole phyllosomas of standard larval-rearing environments. No correlation
between bacterial numbers (measured as colony-forming units [CFU] mL-1) and phyllosoma mortalities was
established. Culture-based studies using selective media indicated that Vibrionaceae-related organisms were a
dominant part of the microbial community and Vibrio parahaemolyticus was the most commonly isolated organism
from each environment investigated. Limited microbial phylogenetic diversity was observed for culture-based
studies when compared against molecular-based denaturing gradient gel electrophoresis (DGGE) results. DGGE
profiles of water, biofilm and phyllosoma environments differed, indicative of unique microbial niches
sustaining different microbial populations. These microbial populations appeared dynamic since DGGE profiles
changed within each environment over the course of the experiment. Few Vibrio-affiliated sequences were
retrieved from DGGE profiles highlighting differences between the two methods for assessing microbial diversity
within the larval-rearing system.
(Australian Institute of Marine Science, PMB No. 3, Townsville MC QLD
4810, Australia; email of D. Bourne: d.bourne@aims.gov.au)
EFFECTS OF TEMPERATURE AND FOOD DENSITY ON THE SURVIVAL AND GROWTH OF EARLY STAGE PHYLLOSOMA OF THE
WESTERN ROCK LOBSTER, PANULIRUS CYGNUS
Grant C. Liddy, Bruce F. Phillips, Greg B.
Maguire-2005
Aquaculture, 242 (1-4): 207-215
Abstract:
Stages I, II and III phyllosoma larvae of the
western rock lobster, Panulirus cygnus, were reared at all combinations of three temperatures (19, 22 or 25
°C) and three Artemia densities (1, 5 or 10 ml-1). The survival of larvae within each stage at these
combinations did not significantly differ. Increases in temperature significantly reduced the intermoult period
for all stages tested. Stages I and II larvae reared at 19 °C were significantly larger after moulting than
larvae reared at the higher temperatures; however, this was not found with stage III larvae. Increases in food
density had little effect on the intermoult period or postmoult size at any stage. Feeding above 1 Artemia ml-1
made no difference to the intermoult period or postmoult size, suggesting that =1 Artemia ml-1 is the minimum
for optimum growth. Rearing larvae at 25 °C significantly reduced the intermoult period; however, it also
reduced the postmoult size of stages I and II larvae, indicating that a compromise between rapid development
and larval growth is needed when determining an optimum rearing temperature. A temperature of 22 °C is
recommended.
(Aquatic Science Research Unit, Division of Resources and Environment, Curtin University of
Technology, G.P.O. Box U1987, Perth, W.A. 6845, Australia; email of G. C. Liddy: gcliddy@hotmail.com )
COMPLETE LARVAL DEVELOPMENT OF THE SEA URCHIN LYTECHINUS VARIEGATUS FED AN ARTIFICIAL FEED
Sophie B.
George, John M. Lawrence, Addison L. Lawrence-2005
Aquaculture, 242 (1-4): 217-228
Abstract:
Complete
development of sea-urchin larvae fed an artificial feed has been carried out for the first time. Naturally
spawned gametes were obtained from adult Lytechinus variegatus fed an artificial feed in the laboratory for 9
months. Larvae from these adults, cultured in artificial seawater and fed microencapsulated capsules, reached
the rudiment stage between 9 and 12 days, the usual time required. Larvae produced by artificial spawning and
cultured in natural seawater and fed microencapsulated capsules or phytoplankton (Dunaliella tertiolecta) had
similar chronology of development and sizes of newly metamorphosed juveniles. The larvae fed capsules were
significantly smaller than those fed D. tertiolecta. Larval survival was 72±6% for those fed capsules
and 85±4% for those fed D. tertiolecta. Artificial feed for larvae eliminates the necessity of culturing
phytoplankton and provides the potential of establishing nutritional requirements of larvae and of
standardizing and manipulating the diet. This has application in mass aquaculture of sea urchins as well as
using larvae as models in developmental studies.
(Department of Biology, Georgia Southern University,
Statesboro, GA 30460, USA)
INDUCED OVULATION AND SPAWNING OF POND RAISED AFRICAN GIANT CATFISH, HETEROBRANCHUS BIDORSALIS BY
EXOGENOUS HORMONES
O.T. Adebayo, O.A. Fagbenro-2005
Aquaculture, 242 (1-4):
229-236
Abstract:
Artificial spawning was induced in female African giant catfish, Heterobranchus
bidorsalis by single intramuscular hormone injections of carp pituitary suspensions (CPS) at 4 mg/kg body
weight (bw), 1.5 ml of homoplastic pituitary suspension (HPS) per fish or human chorionic gonadotropin (HCG) at
2000 IU/kg bw, over 3 months of rainy season (June to August) in Nigeria. At ambient temperature (27±1
°C), ovulation occurred within 14-18 h post injection. Egg hydration gave 16-20% increase in egg diameter.
Hatching rates were high (>84%) and similar for all hormone-treated fish (P>0.05). The percentage normal
larvae hatched ranged from 81.6% to 86%. They were reared in 500-l circular tanks and fed initially on
zooplankton, followed by brine shrimp nauplii and finally weaned onto commercial fish fry diet. During the
larval rearing trials for 30 days, survival rates >82% were achieved. Although the four hormones tested were
effective inducers, the use of HPS would save operational costs in fish hatchery management in African
countries.
(Department of Fisheries and Wildlife, Federal University of Technology, P.M.B 704, Akure,
Nigeria)
CRYOPRESERVATION OF SPERM OF THE PACIFIC OYSTER (CRASSOSTREA GIGAS): DEVELOPMENT OF A PRACTICAL METHOD FOR
COMMERCIAL SPAT PRODUCTION
Serean L. Adams, John F. Smith, Rodney D. Roberts, Achim R. Janke, Heinrich F.
Kaspar, H. Robin Tervit, P. Anne Pugh, Steven C. Webb, Nick G. King-2005
Aquaculture, 242 (1-4):
271-282
Abstract:
This paper describes a simple method for cryopreserving sperm of the Pacific oyster
(Crassostrea gigas Thunberg) in quantities suitable for commercial spat production. Experiments to refine the
cryoprotectant mixtures demonstrated the key role of trehalose. Trehalose alone (at 0.45 M final concentration)
was an effective cryoprotectant. The addition of 2.5-15% dimethyl sulphoxide (DMSO) in combination with 0.45 M
trehalose gave only modest improvement in fertility over trehalose alone (p=0.056). There was no significant
difference in fertility among DMSO concentrations (p=0.611). Seawater (SW) without cryoprotectant gave very
poor results, but yielded some fertilization at very high sperm concentrations (7±1% at 107 sperm mL-1,
21±2% at 3.2×107 sperm mL-1, mean±S.E., n=3). The fertility of unfrozen sperm was 30- to
100-fold higher than that of sperm cryopreserved with DMSO and/or trehalose. For sperm cryopreserved in 4.5-mL
cryovials, two simplified freezing methods gave fertilization rates equivalent to sperm cryopreserved by
controlled rate freezing (p=0.386). These methods involved securing the cryovials to aluminium canes and then
either placing them into a bath of methanol chilled with dry ice, or holding them on a floating rack 3 cm above
liquid nitrogen. A third technique of plunging the cryovials directly into liquid nitrogen gave reduced and
variable fertility relative to the methanol/dry ice bath method (p=0.032). The commercial applicability of the
protocols was demonstrated on a batch of 30 million eggs. Fertilization with cryopreserved sperm yielded 81%
fertilization, and larval rearing by normal commercial practises yielded 3.7 million settled spat, which was
comparable to the 2.5 million spat from a parallel batch fertilized with unfrozen sperm.
(Department of
Marine Science, University of Otago, P. O. Box 56, Dunedin, New Zealand; email of Rodney Roberts:
rodney.roberts@cawthron.org.nz)
LIPID AND FATTY ACID COMPOSITION OF PRE- AND POST-SPAWNING BLACKLIP (HALIOTIS RUBRA) AND GREENLIP
(HALIOTIS LAEVIGATA) ABALONE CONDITIONED AT TWO TEMPERATURES ON A FORMULATED FEED
Mark A. Grubert, Graeme
A. Dunstan, Arthur J. Ritar-2005
Aquaculture, 242 (1-4): 297-311
Abstract:
Wild-caught blacklip
(Haliotis rubra) and greenlip (Haliotis laevigata) abalone fed a formulated feed were held from spent to gravid
condition at 14 or 18 °C. Half the gravid animals were induced to spawn (using heated UV-irradiated
seawater) and the remainder left untreated. All animals were then killed and samples of foot, digestive gland
(DG) and gonad analyzed for lipid and fatty acid (FA) composition, as was the feed. The feed contained 5%
lipid, of which the major FA were 18:2n-6 (27%), 18:1n-9 (20%) and 16:0 (16%). The lipid content of each tissue
was similar for both species, ranging from 4-6%, 8-9%, 14-15%, and 30-32% in the foot, testis, DG and ovary,
respectively. Each tissue had a different FA signature, with the foot, testis and ovary characterized by
elevated levels of 20:4n-6 (arachidonic acid-ARA), 20:5n-3 (eicosapentaenoic acid-EPA) and 18:2n-6 (linoleic
acid-LA), respectively. The proportions of LA and EPA in the DG were intermediate between those of the testis
and ovary. There was no change in the lipid or fatty acid composition of blacklip or greenlip tissues in
response to the two culture temperatures. Likewise, these compositions did not appear to differ between tissues
from spent and gravid individuals. Tissue FA profiles from abalone fed a formulated feed are compared to those
from macroalgal feeding trials to determine if the formulated feed can be further improved.
(Marine
Research Laboratories, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Nubeena Crescent,
Taroona, Tasmania 7053, Australia; email of Mark Grubert: mark.grubert@rmit.edu.au)
FECUNDITY OF THE JAPANESE CRAYFISH, CAMBAROIDES JAPONICUS: OVARY FORMATION, EGG NUMBER AND EGG SIZE
Kazuyoshi Nakata, Seiji Goshima-2005
Aquaculture, 242(1-4): 335-343
Abstract:
Ovary formation,
egg number and egg size was studied to examine the fecundity of the Japanese crayfish Cambaroides japonicus.
From histological observations of ovaries, the ovarian eggs of C. japonicus developed as asynchronous oocytes.
Many well-grown oocytes were in the ovary after spawning, as well as before spawning. The smallest carapace
length of ovigerous females was 15.2 mm. The pleopodal egg number ranged from 22 to 75 and significantly
increased with female body size. Both egg diameters (2.13-2.50 mm) and weights (0.009-0.017 g) also
significantly increased as the female body size increased, but were variable even for the same size crayfish.
We conclude that larger females should be used for seed production of C. japonicus because of its high
fecundity and large eggs. Mature females spawn only once a year in natural habitats, but multiple spawning can
be artificially induced within 1 year because of well-grown oocytes that remain in the ovary after spawning.
Thus, we recommend that an effective technique for artificial induction of multiple spawning be developed from
our results.
Laboratory of Marine Biodiversity, Graduate School of Fisheries Sciences, Hokkaido University,
Hakodate, Hokkaido 041-8611, Japan; email of K. Nakata: nakata@fish.hokudai.ac.jp)
EFFECT OF DIETARY LIPIDS ON FATTY ACID COMPOSITION AND METABOLISM IN JUVENILE GREEN SEA URCHINS
(STRONGYLOCENTROTUS DROEBACHIENSIS)
John D. Castell, Eddy J. Kennedy, Shawn M. C. Robinson, G. Jay Parsons,
Tammy J. Blair, Enrique Gonzalez-Duran-2005
Aquaculture, 242 (1-4): 417-435
Abstract:
Relatively
little is known of the nutritional requirements of sea urchins, especially at the juvenile stages. One of the
costly restrictions on feed formulation for marine fish species is the requirement for fish oils to supply the
essential n-3 highly unsaturated fatty acids (HUFA). This study investigated the effects of different dietary
lipid sources on the fatty acid composition and metabolism of juvenile green sea urchins (Strongylocentrotus
droebachiensis). Kelp (Laminaria longicruris) served as a reference diet. Experimental diets contained 5% of:
corn oil (high in 18:2n-6), linseed oil (high in 18:3n-3), menhaden oil (high in n-3 HUFAs 20:5n-3 and
22:6n-3), or 1:1 mixtures of corn oil and linseed oil, or corn oil and menhaden oil or linseed oil and menhaden
oil. Unlike marine fish, the sea urchins exhibited ample ability for elongation and desaturation of shorter
chain (18 carbon) polyunsaturated fatty acids (PUFA) to longer chain (20 carbon) n-3 and n-6 HUFA. Thus 18:2n-6
from corn oil in the diet resulted in high levels of 20:4n-6 in the sea urchin and similarly 18:3n-3 in the
diet resulted in high levels of 20:5n-3. Even when fed kelp or diets with menhaden oil, the sea urchins did not
incorporate high levels of 22:6n-3 into their lipids. In addition to the effects of dietary lipid sources on
fatty acid composition of the lipids of total soft tissues of sea urchin, there were great differences in fatty
acid composition among different tissues and among lipid classes of these tissues. For example, the test
(shell) and associated tissue membranes, which are in constant contact with the seawater, incorporated much
higher proportions of 20:4n-6 than the gonad or gut tissues. This may reflect an important role of 20:4n-6 in
ion transport and osmoregulation. The sea urchins also synthesized a number of 20 and 22 carbon
non-methylene-interrupted dienes (NMID) and the concentration of the major NMID was directly related to the
tissue levels of 18:2n-6 and inversely proportional to the dietary and tissue levels of n-3 PUFA and HUFA. The
significance of these and other interesting aspects of fatty acid metabolism in sea urchins are
discussed.
(Department of Fisheries and Oceans, Biological Station, 531 Brandy Cove Rd., St. Andrews, NB,
Canada E5B 2L9; email of J. Castell: castellj@mar.dfo-mpo.gc.ca)
AMINO ACID COMPOSITION OF EARLY STAGES OF CEPHALOPODS AND EFFECT OF AMINO ACID DIETARY TREATMENTS ON
OCTOPUS VULGARIS PARALARVAE
R. Villanueva, J. Riba, C. Ruíz-Capillas, A. V. González, M.
Baeta-2005
Aquaculture, 242 (1-4): 455-478
Abstract:
During the present study, we aimed to provide a
first look at the amino acid composition of the early stages of cephalopods and follow possible effects of
certain dietary treatments. Amino acid profiles of cuttlefish Sepia officinalis, squid Loligo vulgaris and
octopus, Octopus vulgaris hatchlings and wild juveniles of L. vulgaris and O. vulgaris were analysed.
Cephalopod hatchlings showed high fractions of non-protein nitrogen (NPN), from 25% to 38% of the dry weight.
Lysine, leucine and arginine represented half of the total content of essential amino acids (EAA), and
glutamate and aspartate represented also nearly half of the non-essential amino acids (NEAA). In O. vulgaris, a
general tendency for a decrease in the level of EAA from mature ovary and eggs to hatchlings was observed.
Hatchlings after 4 days of fasting lost 28% of their dry weight and the level of EAA and NEAA decreased in both
the total content and free forms. Free proline after 2 days of fasting and free tyrosine at 4 days of fasting
were not detected. Comparison of the total EAA profiles of preys showed few differences between enriched
Artemia nauplii and hatching crab zoeae (Pagurus prideaux and Maja squinado). The enriched Artemia nauplii EAA
profiles showed no differences with the EAA profiles of O. vulgaris paralarvae during first 10 days of culture,
except for histidine. Present results confirm the positive capacity for amino acid uptake from seawater by
early stages of cephalopods. In the three species analysed, radiolabelled phenylalanine was incorporated in
inverse relation to body size. After 10 days of culture, O. vulgaris paralarvae showed a tendency to increase
the levels of total and free amino acids in the groups receiving a daily amino acids solution. At 20 days of
age, the O. vulgaris cultures that received the amino acids solution had survivals that on average were three
times that of the control group. However, the supposed beneficial effects of the amino acids solution remained
unclear, as the dry weight of these paralarvae was equal or lower to that of paralarvae from the control group.
In wild O. vulgaris juveniles, the percentage of protein and total amino acids increased with the dry weight of
the individuals. These juvenile biochemical changes were associated with strong morphometric changes in body
proportions after settlement with the development of the muscular, protein-rich arm crown.
(Institut de
Ciències del Mar (CSIC), Passeig Marítim 37-49, E-08003, Barcelona, Spain; email of R.
Villanueva: roger@icm.csic.es)
DEVELOPMENT, GROWTH AND SURVIVAL OF THE LARVAE OF QUEEN CONCH STROMBUS GIGAS UNDER LABORATORY CONDITIONS
Nancy Brito-Manzano, Dalila Aldana Aranda-2005
Aquaculture, 242 (1-4): 479-487
Abstract:
The
development, growth and survival of Strombus gigas (Linné, 1758) larvae were studied over a period of 30
days in laboratory culture. The fertilized egg masses used for the larval culture experiment were collected in
Alacran's Reef from March to September. Experiments were conducted at 29±1 °C. Veligers were reared
at 200 larvae l-1 in 4-l containers. Larvae were fed with the algae Tetraselmis suecica at 1000 cells ml-1. At
hatching for the egg masses from March to May and September, the larvae showed two velar lobes and 1.5 shell
whorls; the larvae hatching from June to August showed two velar lobes and two shell whorls. The larvae reached
metamorphosis between 25 and 29 days. The results obtained in the development show that the larvae of March,
May, April and September have slower development than the larvae of June, July and August. The shell length at
hatching was 290-300 µm, with an average of 300±6.17 µm (n=630 larvae). Larvae hatching at
March were measured to be 290±3.94 µm, and the larvae for June measured 300±8.31 µm.
Average larval growth for March was 22.33 µm day-1; for the larvae from July, average larval growth was
30.00 µm day-1.The shell length obtained at metamorphosis was between 867 and 902 µm, with an
average of 883±1.23 µm. The survival at settlement varied from 20% to 38%, with an average of
30±5.18%. The highest survival was found in June and July with 38±6.30%, whilst the percentage of
survival for larvae of March and September was significantly lower, with an average of 22±7.22% and
20±7.02%, respectively.
(CINVESTAV IPN Unidad Mérida, Km 6 antigua carretera a Progreso, C.P.
97310, Mérida Yucatán, Mexico; email of D. Adana Aranda: daldana@mda.cinvestav.mx)
EFFECT OF VITAMIN C DERIVATIVES ON THE PERFORMANCE OF LARVAL KURUMA SHRIMP, MARSUPENAEUS JAPONICUS
Yin
Yin Moe, Shunsuke Koshio, Shin-ichi Teshima, Manabu Ishikawa, Yusuke Matsunaga, Arthur Panganiban,
Jr.-2005
Aquaculture, 242 (1-4): 501-512
Abstract:
This study was conducted to determine the effect of
two vitamin C (Ascorbic acid, AsA) sources; L-ascorbyl-2-monophosphate-Mg (AMP-Mg) and
L-ascorbyl-2-monophosphate-Na/Ca (AMP-Na/Ca), on larval kuruma shrimp performance, i.e., percentage survival
(%S), developmental stage (DS), the number of larvae metamorphosed to the postlarval stage (%PL), body weight
(BW), total body length (TL), tolerance against formalin stress (LT50), and whole body ascorbic acid
concentration in shrimp (WBAA). Seven different levels of two vitamin C sources, 0, 23, 223, 695, 1034, 1819,
and 2240 mg/kg diet for AMP-Mg and 0, 48, 198, 614, 1134, 1817, and 2494 mg/kg diet for AMP-Na/Ca were
incorporated in kappa-carrageenan microbound diets (MBD), and each MBD was fed to five replicate groups of the
larvae from zoea1 stage up to postlarva1 stage for 11 days. There were no differences between AMP-Mg and
AMP-Na/Ca on %S, DS, BW, and TL under the similar AsA level. However, significant differences were found in %S,
DS, %PL, and BW among the groups fed diets containing the different levels of AsA supplementation in both
AMP-Mg and AMP-Na/Ca groups (P<0.05). Whole body AsA concentration increased with increased dietary AsA
level. Shrimp fed the higher AsA diet survived longer than those fed AsA-free or lower AsA diets in both groups
when exposed to the formalin stress. The optimum dietary AsA level for kuruma shrimp larvae were 71 and 43 mg
AsA/kg diet when AMP-Mg and AMP-Na/Ca were used, respectively, based on the broken-line analysis. The minimum
AsA concentration in shrimp whole body with 22 µg/g wet weight might be required to produce the
high-quality postlarvae which could tolerate a stressful condition.
(Science of Marine Resources, The
United Graduate School of Agricultural Science, Kagoshima University, 1-21-24, Korimoto, Kagoshima 890-0065,
Japan; email of S. Koshio: koshio@fish.kagoshima-u.ac.jp)
THE INFLUENCE OF DIETARY LIPID INCLUSION AND DAILY RATION ON GROWTH AND SMOLTIFICATION IN 1+ ATLANTIC
SALMON (SALMO SALAR) PARR
I.K. Berrill, M.J.R. Porter, N.R. Bromage-2005
Aquaculture, 242 (1-4):
513-528
Abstract:
The effects of diet regime on growth and smoltification in 1+ Atlantic salmon parr were
studied. Two groups of approximately 400 salmon parr in triplicate were fed diets containing either 25% or
12.5% lipid from first feeding. Two further treatments were fed, either the 25% or 12.5% lipid diet for 98
days, after which they were fed the alternate diet. In a second experiment, three groups of 550 parr in
duplicate were fed at full, two-thirds or one-third of the manufacturers' recommended ration from first
feeding. All groups were maintained on their respective diet regimes until smoltification, approximately 1 year
after first feeding. In experiment 1, lipid level had a significant effect on whole body lipid content.
However, growth and the incidence of smoltification were not affected by dietary lipid inclusion, with the
upper modal group (UMG) fish from each treatment achieving a similar smolt status (in terms of condition factor
[CF] and Na+, K+ ATPase) at seawater transfer. In experiment 2, growth and the incidence of smolt
transformation increased with ration. Full and two-thirds ration fish maintained similar body lipid contents
throughout the experiment, with that of the one-third ration fish lower only during the early development,
indicating that growth was controlled by the maintenance of a distinct lipid level.
It is concluded that
ration and not dietary lipid inclusion has a significant effect on growth and the decision to undergo
smoltification in salmon parr.
(Institute of Aquaculture, University of Stirling, Scotland, FK9 4LA, UK;
email of I. Berrill: i.k.berrill@bangor.ac.uk)
DIETARY VITAMIN E REQUIREMENT OF MRIGAL, CIRRHINUS MRIGALA FRY
B.N. Paul, S. Sarkar, S.N. Mohanty-2005
Aquaculture, 242 (1-4): 529-536
Abstract:
A 12-week feeding trial was conducted using a flow-though
system to determine the dietary requirement of vitamin E for mrigal fry in relation to growth performance,
carcass composition and erythrocyte fragility. Five semi purified diets containing 19, 66, 120, 165 and 216 mg
vitamin E (DL-a-tocopheryl acetate)/kg diet were fed to triplicate groups of fish (initial weight
0.68±0.01 g/fish). Significant higher weight gain, specific growth rate, protein efficiency ratio and
lower feed conversion ratio were observed in fish fed 120 mg vitamin E/kg diet than the other diets. Addition
of vitamin E to the basal diet did not significantly affect whole body protein, crude fat, ash and moisture.
However, the addition of vitamin E in basal diet significantly increased the deposition of vitamin E in the
fish up to 216 mg/kg vitamin E. With the increasing level of vitamin E, erythrocyte fragility values was
reduced. The erythrocyte fragility was maximum in fish fed 19 mg/kg vitamin E. Based on the broken-line
analysis, the dietary vitamin E requirement was 99 mg/kg dry diet based on maximum weight gain.
(Fish and
Shellfish Nutrition Division, Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar-751 002,
Orissa, India; email of B.N. Paul: bnp63@rediffmail.com)
EXPRESSION AND LOCALIZATION OF SOME RETINOID RECEPTORS DURING EUROPEAN SEA BASS (DICENTRARCHUS LABRAX)
LARVAE DEVELOPMENT
Laure Villeneuve, Enric Gisbert, Chantal L. Cahu, Marie-Madeleine Le Gall Jose L.
Zambonino-Infante-2005
Aquaculture, 242 (1-4): 537-551
Abstract:
In the present study, we report the
characterization in European sea bass of the partial cDNA sequences of three nuclear receptors, retinoic acid
receptor (RAR)a, RAR?, retinoid X receptor (RXR)a, involved in retinoid pathways. These pathways participate to
vertebrates morphogenesis processes and may be responsible for the appearance of skeletal malformations. The
predicted polypeptide encoded by each cDNA sequence contains the ligand-binding domain (LBD) characteristic of
nuclear hormone receptors, and the RXRa cDNA sequence also includes a partial zinc finger domain corresponding
to the DNA-binding domain (DBD) of this receptor. The relative expression levels of the three receptors were
determined by real-time polymerase chain reaction (RT-PCR) in European sea bass larvae. Between 10 and 42 days
posthatch (dph), the expression of RARa and RAR? increased 7.3- and 35.6-fold, respectively, while RXRa
expression was down-regulated with a factor of 35.4. The same trend was observed between 10 and 21 dph but was
not statistically different. Using RNA/RNA hybridizations, RARa antisense probes were revealed in jaws at 5
dph, and, at 37 dph, they were detected in jaws, vertebra, liver, muscle, pectoral fins, brain, neural tissues,
eyes, and branchial arches. At 37 dph, RAR? expression was found in the cartilage, eyes, and operculum, while
the presence of RXRa mRNA was localised in the exocrine pancreas, liver, thyroid, kidney, heart, jaws, and
teeth. These results suggested that RARa and RAR? were used for European sea bass development. RAR? would play
a key role in the morphogenesis of the cephalic region, while RXRa would be essential during the early stages
of development in European sea bass larvae when an intense process of differentiation occurred.
(Unité Mixte de Nutrition des Poissons IFREMER-INRA, IFREMER, 29280 Plouzané, France; email
of L. Villeneuve: lvillene@ifremer.fr)
EFFECTS OF DIETARY VITAMINS C AND E ON ALTERNATIVE COMPLEMENT ACTIVITY, HEMATOLOGY, TISSUE COMPOSITION,
VITAMIN CONCENTRATIONS AND RESPONSE TO HEAT STRESS IN JUVENILE GOLDEN SHINER (NOTEMIGONUS
CRYSOLEUCAS)
Ruguang Chen, Rebecca Lochmann, Andrew Goodwin, Kesavannair Praveen, Konrad Dabrowski,
Kyeong-Jun Lee-2005
Aquaculture, 242 (1-4): 553-569
Abstract:
The objective of this study was to
characterize the response of golden shiner fed one of eight purified diets with either 0 or 38 mg a-tocopherol
(a-T) kg-1 and one of four levels of ascorbic acid (AA) (23, 43, 98, or 222 mg kg-1 diet) in a 2×4
factorial design. Growth, survival, signs of vitamin E deficiency, and immune and stress responses were
monitored in groups of 30 golden shiners (mean average initial weight=0.79 g) fed the diets to apparent
satiation twice daily in triplicate aquaria for 14-19 weeks. The average individual weight gain was not
affected by dietary a-T concentrations at 14 weeks, but the survival of fish fed the a-T-unsupplemented diets
was lower than that of fish fed the a-T-supplemented diets. After 10 weeks, fish fed the a-T-unsupplemented
diets began to show vitamin-E-deficiency signs such as increased prevalence of fish with darkened skin. After
17 weeks the deficient fish had lower a-T concentrations in viscera, lower whole-body crude protein, total
lipid, dry matter, hematocrit, hemoglobin, lymphocyte (%), alternative complement activity (ACH50), and
survival after exposure to stressful water temperatures (36-37 °C) than those fed the a-T-supplemented
diets. A sparing effect of vitamin E on vitamin C was evident. Elevated dietary vitamin C reduced the incidence
and severity of vitamin E deficiency signs in a dose-dependent manner. The interactive effect of vitamins C and
E on ACH50 activity and percentage of thrombocytes was also significant. Regardless of vitamin E levels,
different vitamin C levels did not influence the a-T concentration in viscera and other interactions between
vitamins C and E were not evident.
(School of Agriculture, Fisheries, and Human Sciences, University of
Arkansas at Pine Bluff, Pine Bluff, AR 71601, USA; email of R. Lochmann: rlochmann@uaex.edu)
DOES DIETARY N-3 HIGHLY UNSATURATED FATTY ACIDS LEVEL INFLUENCE THE EUROPEAN SEA BASS (DICENTRACHUS
LABRAX) CAPACITY TO ADAPT TO A HIGH TEMPERATURE?
J. Person-Le Ruyet, A. Skalli, B. Dulau, N. Le Bayon, H.
Le Delliou, J.H. Robin-2005
Aquaculture, 242 (1-4): 571-588
Abstract:
Triplicate groups of European
sea bass juveniles (60 g) were fed for 84 days two experimental diets containing either vegetable or marine oil
(0.4 and 2.2% n-3 highly unsaturated fatty acid [n-3 HUFA] dry matter in LD and HD, respectively) and held at
22 or 29 °C (LD-22, LD-29, HD-22 and HD-29 groups). Significant differences in mass gain between the two
diets and temperatures were observed from day 28 onwards, and on day 84, weight was 18% higher in the HD-29
group than in the LD-22 group (the highest and lowest values, respectively). Over the 84-day period, SGR was
significantly affected both by temperatures and diets (P=6×10-4 and 2×10-4 respectively), averaging
1.01 and 1.07 in the HD-22 and HD-29 groups compared to 0.92 and 1.0 in the LD-22 and LD-29 groups. Differences
in growth rate between the experimental conditions were mainly explained by differences in feed intake (FI). FI
was more affected by temperature than by diets (in fish fed HD, it was 1.7% day-1 at 29 °C and 1.4% day-1
at 22 °C, and 1.7% day-1 and 1.3% day-1, respectively, with LD). Feed conversion ratio (FCR) was
significantly affected by temperature and diets; days 0-84 FCR was on HD and LD 1.6 and 1.7 at 29 °C and
1.4-1.5 at 22 °C. Considering growth and feeding parameters, no interaction between dietary concentration
in n-3 HUFA and temperatures were observed. In acclimated fish, MO2 on routine metabolism was the highest at
HD-29 (396 mg O2 kg-1 h-1) as it was dependent on FI. There was no major difference in fish whole body
composition, and protein retention was more affected by temperature than by diets. Diets and temperature
affected polar lipid fatty acid content, without interaction; n-3 HUFAs were lower at 29 °C than at 22
°C. Fatty acids of total and neutral lipids (NL) were mainly affected by dietary fatty acids, while some
low but significant influences of temperature were observed. Interactions between the two studied factors
concerned particularly n-3 HUFAs content, lower at 29 than at 22 °C only in fish fed vegetable oil (LD).
This study demonstrated that in high-quality sea bass juveniles, a 3-month deficiency in dietary n-3 HUFA did
not drastically impair fish capacity to adapt to a high temperature, 29 °C.
(Unité mixte
Nutrition, Aquaculture, Génomique Inra-Ifremer-Bordeaux I, Laboratoire Adaptation Reproduction Nutrition
des Poissons, Ifremer, Centre de Brest, BP 70, 29280 Plouzané, France; email of J. Person-Le Ruyet:
Jeannine.Person@ifremer.fr)
ESTIMATED AMINO ACID REQUIREMENTS DURING EARLY ONTOGENY IN FISH WITH DIFFERENT LIFE STYLES: GILTHEAD
SEABREAM (SPARUS AURATA) AND SENEGALESE SOLE (SOLEA SENEGALENSIS)
Cláudia Aragão, Luis E.C.
Conceição, Hans-Jørgen Fyhn, Maria Teresa Dinis-2005
Aquaculture, 242 (1-4):
589-605
Abstract:
Little is known about the amino acid (AA) requirements of larval fish and their
possible ontogenetic changes. This paper aims to contribute to the study of these requirements in two common
cultured species in Southern Europe: gilthead seabream (Sparus aurata) and Senegalese sole (Solea
senegalensis). Moreover, it is intended to identify possible dietary AA imbalances occurring in normal hatchery
conditions for both species. Fish larvae were reared following standard procedures and the normal feeding
schemes used in hatcheries, which includes the use of live prey for several weeks. The experiments were
finished once the fish were adapted to a dry feed. Samples were collected at different points for dry weight,
total protein, and AA analysis. The A/E ratios [each indispensable AA content×(total indispensable AA
content including cysteine and tyrosine)-1×1000] of fish and food were compared to identify possible
dietary AA imbalances. The AA profile of both fish species changed during ontogeny, but was more stable during
seabream than Senegalese sole development. This is probably linked to the marked metamorphosis observed in
sole. These changes in fish larval AA profile suggest that the AA requirements change during seabream and
Senegalese sole ontogenesis. Several dietary AA deficiencies were found during the ontogenetic development of
both species. These deficiencies result from ontogenetic changes in the fish AA profile, but also from
differences in the AA composition of the different food items. These results suggest that both the live food
(rotifers and Artemia at different developmental stages) and the dry feed used in the rearing of gilthead
seabream and Senegalese sole does not have an AA profile that entirely meets the requirements for the early
stages of these species.
(CCMAR, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal;
email of C. Aragaõ: caragao@ualg.pt)
ASSESSMENT OF WATER TURBIDITY FOR EVALUATION OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) EGG QUALITY
Mariola
Wojtczak, Rados aw Kowalski, Stefan Dobosz, Krzysztof Goryczko, Henryk Ku minski, Jan Glogowski, Andrzej
Ciereszko-2005
Aquaculture, 242 (1-4): 617-624
Abstract:
Upon contact with water, two types of rainbow
trout ova can be distinguished: ova causing turbid water and ova that do not cause such an effect. The
objective of this study was to evaluate the quality of eggs in relation to their ability to cause water
turbidity. The biochemical characteristics of ovarian fluid were also determined. When water was used as the
fertilization medium, a clear difference in fertilization rate was observed between both types of ova. The
percentage of eyed embryos for eggs causing turbid water (15.7±3.0%) was significantly lower than eggs
causing non-turbid water (67.2±9.6%). No differences were found when salt solutions were used as the
fertilization medium. Protein and lipid concentrations of ovarian fluid collected from eggs causing turbid
water were significantly higher than in samples collected from eggs that did not cause turbid water. Our
results indicate that the turbidity of water was caused by the coagulation of water with egg contents. In our
opinion, performing turbidity tests might be critical for successful fertilization when water is used as the
fertilization medium. In such instances, ova causing turbid water must be discarded. The test for turbidity
should provide valuable data concerning initial quality of eggs.
(Institute of Animal Reproduction and Food
Research, Polish Academy of Sciences, 10-747, Olsztyn, Tuwima 10, Poland; email of A. Ciereszko:
acieresz@pan.olsztyn.pl)
REPRODUCTIVE EVALUATION OF TRIPLOID YELLOWTAIL FLOUNDER, LIMANDA FERRUGINEA (STORER)
Anthony J.
Manning, Margaret P. M. Burton, Laurence W. Crim-2005
Aquaculture, 242 (1-4): 625-640
Abstract:
The
reproductive effects of induced triploidy were assessed in 3-year-old yellowtail flounder. Diploids of this
small flatfish show a propensity for early sexual maturation in culture. Triploidy was effective in reducing
gonadal development in yellowtail flounder, but permitted physiological maturation in both sexes. Triploid
males sampled during the regular spawning period in captivity had small testes and variable plasma androgen
levels (n=7; age, 34 months). A limited production of spermatozoa and evidence of spermatogenetic dysfunction
were noted histologically. Spermatozoa from triploids exhibited poor or no motility and further demonstrated
reduced fertility in fertilization trials with eggs from diploid females. Most larvae resulting from
fertilization trials were abnormal and nonviable; however, some triploid males produced a few larvae of normal
appearance which may indicate long-term viability. Females sampled at 37 and 40 months of age had small ovaries
with varying numbers of oocytes, previtellogenic to vitellogenic, that were developing amid oogonial tissue
(oog). Evidence of prior summer ovulatory activity was found in 2 of the 17 females. A high proportion of the
remaining 3-year-old females had vitellogenic oocytes and was likely to become fully mature by 4 years of age.
Plasma estradiol-17 (E2) levels were low in triploid females despite the fact that ovarian tissue from pubertal
triploids can demonstrate a strong steroidogenic response to gonadotropic stimulation in vitro. The production
of triploids will help to reduce the energetic costs of reproduction in the yellowtail flounder.
(Ocean
Sciences Centre, Memorial University of Newfoundland, Marine Lab Road, St. John's, NL, Canada A1C 5S7; email of
A. Manning: amanning@munalum.ca)
EFFECTS OF CRYOPROTECTANT TOXICITY ON THE EMBRYOS AND LARVAE OF PACIFIC WHITE SHRIMP LITOPENAEUS VANNAMEI
Qiaoxiang Dong, Junda Lin, Changjiang Huang-2005
Aquaculture, 242 (1-4): 655-670
Abstract:
We
tested the toxicity of four cryoprotectants (methanol, ethylene glycol, propylene glycol and dimethyl sulfoxide
(DMSO) on embryos and larvae of the Pacific white shrimp Litopenaeus vannamei. The developmental stages tested
include prenauplius embryos, nauplius I (N1), nauplius III (N3), nauplius V (N5), protozoea I (Z1) and
protozoea III (Z3). The animals were exposed to three concentrations of each cryoprotectant for 5, 10, 15, 20,
25, 30 and 60 min. We found that ethylene glycol was the least toxic cryoprotectant. Concentration of 30% v/v
was well tolerated by Z1 larvae for 20 min, yielding 83±7% revival. Methanol was less toxic than
propylene glycol and DMSO, while the later two showed similar toxicity. Except for the Z3 stage, larvae of
later developmental stages had higher tolerance to high concentrations and long exposure time than did larvae
of early stages. Prenauplius embryo is the most sensitive stage to the cryoprotectants tested. Toxicity of
cryoprotectant was also concentration and exposure time dependent. Five min duration showed an overall
viability of 86±4%, while 1-h exposure was fatal to embryos and larvae when concentration was above 10%
v/v. Our study provides critical baseline data for attempts to cryopreserve embryos and larvae of the penaeid
shrimps.
(Department of Biological Sciences, Florida Institute of Technology, Melbourne, Florida 32901,
USA; email of Qiaoxiang Dong: qdong@agctr.lsu.edu)
GROWTH, SURVIVAL AND MANDIBLE DEVELOPMENT IN THE LARVAE OF THE SHORTFIN SILVERSIDE CHIROSTOMA
HUMBOLDTIANUM (VALENCIENNES) (ATHERINIFORMES: ATHERINOPSIDAE) UNDER LABORATORY CONDITIONS
Gerardo
Figueroa-Lucero, Omar Meza-González, M. Cecilia Hernández-Rubio, Irene de los A. Barriga-Sosa,
Antonio Rodríguez-Canto, José L. Arredondo-Figueroa-2005
Aquaculture, 242 (1-4):
689-696
Abstract:
Chirostoma humboldtianum is an endemic silverside fish of the central part of Mexico
and is a key species of potential use for aquaculture. Since food is a determining factor for fish culture
particularly during the first weeks of development when the highest mortality occurs due mainly to constraints
in morphology and physiology. In this study, we evaluated growth, survival and mandible development in the
larvae of the shortfin silverside fed with three species of rotifers, Brachionus rubens (T1), B. calyciflorus
(T2) and B. plicatilis (T3) from the beginning of exogenous feeding up to the fourth week of development. In
addition, mouth size was examined during the first 17 days of feeding and correlated to the size of food
particles. The treatment with B. rubens (T1) showed the highest gain in weight and notochordal length.
Significant differences were not observed in relation to the other two treatments (T2 and T3, ANOVA,
p<0.05). Survival was >80% in all treatments. The weight/length ratio was negative allometric throughout
the study in all the cases. A linear relationship was observed between mouth size and notochordal length as
well as between the width and length of the mandible. From the results, we conclude that the ingestion of the
food depends on the structures associated to the buccal apparatus.
(Laboratorio de Hidrobiología
Experimental, Departamento de Zoología, Escuela Nacional de Ciencias Biológicas, Instituto
Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Santo Tomás, México,
D. F. C. P. 11340, Mexico; emai of G.Figueroa-Lucero: gerardfig@yahoo.com.mx)
ONTOGENIC DEVELOPMENT OF THE SPINE AND SPINAL DEFORMITIES IN LARVAL BARRAMUNDI (LATES CALCARIFER) CULTURE
M.R. Fraser, T.A. Anderson, R. de Nys-2005
Aquaculture, 242 (1-4): 697-711
Abstract:
Morphological
deformities are a significant problem preventing barramundi (Lates calcarifer) aquaculture from achieving
optimal production. This study describes the osteological development of the vertebral column and the types and
occurrence of spinal deformities during the larval development of L. calcarifer between 2 and 38 days after
hatch (DAH). The first structures to appear as cartilage in the development of the spine are the anterior
neural spines, anterior haemal spines and pre-caudal centra which are laid down as cartilage in larvae at 2.7
mm or 6 to 8 DAH. Initial cartilage formation of the pre-caudal centra is characterised by a centrally ventrad
U-shaped development. Ossification of the spine begins with the neural and haemal spines at 3.3 to 3.6 mm or 8
to 10 DAH proceeded by ossification of the centra at 3.0 to 4.1 mm or 6 to 12 DAH. The process of ossification
is complete by 6.0 mm or 14 DAH. Three types of spinal deformities were recorded in larvae with the most common
being slight malformations of the centra. One case of lordotic/scoliotic/kyphotic (LSK) syndrome and one gross
vertebral malformation were also documented. The first spinal deformities were observed at 20 DAH. The
frequency of deformities increased to a maximum of 7.7% of sampled fish at the completion of the study at 38
DAH. The deformities were recorded 6 days after ossification of the spine (20 DAH) implying dysfunctions in
bone metabolism.
(School of Marine Biology and Aquaculture, James Cook University, Townsville, QLD 4811,
Australia; email of R. de Nys: rocky.denys@jcu.edu.au)
ELIMINATION OF ADHESIVENESS IN THE EGGS OF SHISHAMO SMELT SPIRINCHUS LANCEOLATUS USING KAOLIN TREATMENT TO
ACHIEVE HIGH HATCHING RATE IN AN ENVIRONMENT WITH A HIGH IRON CONCENTRATION
Shinya Mizuno, Yoshitaka
Sasaki, Naotaka Omoto, Kazushi Imada-2005
Aquaculture, 242 (1-4): 713-726
Abstract:
Using tannic acid
treatment to eliminate egg adhesiveness results in a low hatching rate because of iron attachment to the egg
surface in an iron-enriched environment in shishamo smelt, Spirinchus lanceolatus. This is an issue affecting
hatcheries in northern Japan. Therefore, we tested kaolin as an alternative to tannic acid for the elimination
of egg adhesiveness. In a small-scale experiment, we found that treatment with kaolin at 5.0 g/L for 5 to 30
min and at 10.0 g/L for 10 s to 30 min is more effective in eliminating adhesiveness than treatment with tannic
acid. In a large-scale experiment in an environment with high iron concentration, the total iron amount on the
egg surface increased in the nontreated, tannic acid-treated and the 5.0 g/L kaolin-treated groups, where
treatment was conducted for 5 min, although the amount of iron in the tannic acid-treated group was
significantly higher than in the kaolin-treated or nontreated groups just before hatching (P<0.05). The
hatching rate of the tannic acid-treated group was significantly lower than in the kaolin-treated and the
nontreated group just before hatching (P<0.05). Furthermore, the tannic acid-treated group showed a
significantly higher mortality during hatching compared to the kaolin-treated and the nontreated groups
(P<0.05). There were no differences in starvation and seawater tolerance of the larvae among all groups.
These results suggest that a 5-min treatment with kaolin 5.0 g/L is a more suitable method of eliminating egg
adhesiveness than treatment with tannic acid in the case of egg rearing in an iron-enriched
environment.
(Hokkaido Fish Hatchery, 3-373 Kitakashiwagi, Eniwa, Hokkaido 061-1433, Japan; email of S.
Mizuno: mizunos@fishexp.pref.hokkaido.jp)
A REVIEW OF THE CULTURE POTENTIAL OF SOLEA SOLEA AND S. SENEGALENSIS
A. K. Imsland, A. Foss, L. E. C.
Conceição, M. T. Dinis, D. Delbare, E. Schram, A. Kamstra, P. Rema, P. White-2003
Reviews in
Fish Biology and Fisheries, 13(4): 379-408
Abstract:
A number of scientific studies have investigated
aspects of soles (Solea solea and S. senegalensis) ecology, population genetics and biology in their natural
environment, and the species have been extensively studied in captivity during the last decade. Studies on the
genetic population structure of sole indicate that several distinct breeding populations exist within its
distributional range in European waters. Recent studies suggest a phylogenetic relatedness of S. solea and S.
senegalensis, being found as closest sister lineages in most reconstructions. However, studies on molecular
genetics and morphological traits give diagnostic differences that consistently lead to their taxonomic
separation at the specific rank. Studies show that sole spawn readily in captivity, and the buoyant, fertilized
eggs are easily collected. Stocking density during maturation should be 1-1.5kg/m2, and temperature should be
kept above 16°C (S. senegalensis) or between 8 and 12°C (S. solea). In nature, the onset of spawning is
related to a rise in temperature occurring during spring (March-June). Salinity should be kept constant around
33-35‰ and the fish reared under simulated natural photoperiod (LDN). In other cultured flatfish species,
a change in the photoperiod is the key environmental signal used to manipulate and control maturation, but at
present time there are no published work that verifies or contradicts this for either S. senegalensis or S.
solea. Studies indicate that a mixture of inert and live food may increase the weaning success of sole fry, and
this can be further enhanced by using attractants in the dry feed. Future experiments are needed to determine
the ideal time to commence weaning and determine the minimum duration of this period. Studies on alternative
feeding strategies are also required. The effect of temperature and photoperiod on juvenile growth has not been
studied systematically in neither of the two species and the relative importance of a direct photoperiod effect
on growth in sole therefore remains to be defined.
(Akvaplan-niva, Iceland Office, Akralind 4, Iceland)
STOCK ENHANCEMENT AS A FISHERIES MANAGEMENT TOOL
Brett W. Molony, R. Lenanton, G. Jackson, J.
Norriss-2003
Reviews in Fish Biology and Fisheries, 13(4): 409-432
Abstract:
Stock enhancement has
been viewed as a positive fisheries management tool for over 100 years. However, decisions to undertake such
activities in the past have often been technology-based, i.e., driven by the ability to produce fishes, with
most stock enhancement projects having limited or no demonstrated success. The reasons for this have been due
to an inability to identify and/or control the underlying reasons why a fishery is under-performing or not
meeting management objectives. Further, stock enhancement has often been applied in isolation from other
fisheries management tools (e.g., effort control). To address these issues and consider stock enhancement in a
broader ecosystem perspective, a new approach for stock enhancement is proposed. The proposed model comprises
four major steps; a review of all information about an ecosystem/fishery/stock and the setting of clear
management targets; a comparison of all relevant fisheries management tools with the potential to meet the
management targets; the instigation of a scientifically based, pilot-scale, stock enhancement program with
clear objectives, targets, and evaluations; and a full-scale stock enhancement program if the pilot project
meets the objectives. The model uses a flow-chart that highlights a broad range of scientific and other
information, and the decisions that need to be made in relation to stock enhancement and fisheries management
in general. In this way all steps are transparent and all stakeholders (managers, scientists, extractive and
non-extractive users, and the general public) can contribute to the information collection and decision making
processes. If stock enhancement is subsequently identified as the most-appropriate tool, then the stepwise
progression will provide the best possible chance of a positive outcome for a stock enhancement project, while
minimizing risks and costs. In this way, stock enhancement may advance as a science and develop as a useful
fisheries management tool in appropriate situations.
(Department of Fisheries, West Australian Marine
Research Laboratories, WA, Australia; Oceanic Fisheries Programme, Secretariat of the Pacific Community, New
Caledonia)
HABITAT DIVERSITY AND ADAPTATION TO ENVIRONMENTAL STRESS IN ENCYSTED EMBRYOS OF THE CRUSTACEAN
ARTEMIA
Joshua A. Tanguay, Reno C. Reyes, James S. Clegg-2004
J. Biosc. 29(4):
101-113
Abstract:
Encysted embryos (cysts) of the brine shrimp, Artemia, provide excellent opportunities
for the study of biochemical and biophysical adaptation to extremes of environmental stress in animals. Among
other virtues, this organism is found in a wide variety of hypersaline habitats, ranging from deserts, to
tropics, to mountains. One adaptation implicated in the ecological success of Artemia is p26, a small heat
shock protein that previous evidence indicates plays the role of a molecular chaperone in these embryos. We add
to that evidence here. We summarize recently published work on thermal tolerance and stress protein levels in
embryos from the San Francisco Bay (SFB) of California inoculated into experimental ponds in southern Vietnam
where water temperatures are much higher. New results on the relative contents of three stress proteins (hsp70,
artemin and p26) will be presented along with data on cysts of A. tibetiana collected from the high plateau of
Tibet about 4.5 km above sea level. Unpublished results on the stress protein artemin are discussed briefly in
the context of this paper, and its potential role as an RNA chaperone. Interestingly, we show that the
substantial tolerance of A. franciscana embryos to ultraviolet (UV) light does not seem to result from
intracellular biochemistry but, rather, from their surrounding thick shell, a biophysical adaptation of
considerable importance since these embryos receive heavy doses of UV in nature.
(Section of Molecular and
Cellular Biology and the Bodega Marine Laboratory, University of California (Davis), Bodega Bay, California
94923, USA; email of J.S. Clegg: Jsclegg@ucdavis.edu)
© Copyright 2000 - Laboratory of Aquaculture & Artemia Reference Center - Ghent
University, Belgium
