bluuebunny/crossref_metadata_2025 huggingface dataset:
DEVELOPMENT OF ARTIFICIAL DIETS FOR THE LOBSTER, HOMARUS AMERICANUS
Authors: Conklin Douglas E. , Devers Kathryn , Bordner Clark
Published: August 2010

A series of artificial diets was evaluated in terms of growth, survival, and normalized biomass during three‐month growth studies utilizing juvenile lobsters. The effects of both texture and the addition of specific nutrients were examined.

An increase in normalized biomass resulted from the addition of water soluble vitamins and minerals as well as with the addition of shrimp meal. The effect of shrimp meal in the diet could not be duplicated by the addition of chitin or glucosamine. A number of jell‐textured diets produced better growth rates than similar hard pelletized diets but animals on the soft diets suffered a high percentage of mortalities by the end of the experiment. These results are discussed in comparison with those of other investigators using lobsters as test animals.
INVESTIGATION OF METHODS TO SHORTEN THE INTERMOLT PERIOD IN A CRAWFISH1
Authors: Huner Jay V. , Avault James W.
Published: August 2010

Subadult crawfish, Procambarus clarkii (Girard) (50–70 mm total length, the preferred bait size), were injected with ecdysial hormones and subjected to bilateral eyestalk removal to examine methods for shortening the intermolt period. Ecdysterone injection (3 μg/g) and bilateral eyestalk removal, 4 days postmolt, were both effective. Ecdysterone injection (3 μg/g) 1 day postmolt, and Molting Formulation No. 14injection (20 μl/individual), 4 days postmolt, were not effective. Bilateral eyestalk removal was a better method for producing soft shell crawfish than ecdysterone injection because the crawfish molted successfully whereas most of the crawfish injected with ecdysterone (4 days postmolt) died during molt.
THE POTENTIAL FOR EYESTALK ABLATION AS A TECHNIQUE FOR ACCELERATING GROWTH OF LOBSTERS, (Homarus americanus) FOR COMMERCIAL CULTURE
Authors: Castell J. D. , Covey J. F. , Aiken D. E. , Waddy S. L.
Published: August 2010

An experiment with 201 “canner” lobsters (6.3–8.1 cm carapace length) was undertaken to determine whether eyestalk ablation could be used to accelerate growth rate and thus increase market value of small commercially caught lobsters. The experiment was designed to test the effect of ablation on molting, and to compare mass culture with individual containers, growth at 15°C with that at ambient temperature (0–10°C average about 3°C), growth and survival of females with that of males and to compare the effects of two formulated diets.

Eyestalk ablation greatly accelerated the molting and also increased the weight gain of lobsters which molted. Survival of ablated lobsters was good, with cannibalism of molting lobsters in the mass rearing tanks being the main cause of death. The molting rate for both ablated and control lobsters was greater at 15°C than at ambient temperatures. The percent weight gain tended to be greater for males than females. Slight differences in weight gain were also observed between dietary treatments. Both test diets contained rock crab, cooked lobster bodies from a cannery, sea urchin and mussels with gelatin and agar as binders, one diet was supplemented with fish oil, vitamins and fish meal.

Flavor panel testing indicated no significant difference between control, ablated or freshly caught wild lobsters in either taste or texture.
REPRODUCTION IN CAPTIVITY AND GROWTH OF Penaeus monodon, FABRICIUS IN POLYNESIA
Authors: Aquacop
Published: August 2010

To develop shrimp farming in French Polynesia where no indigenous commercial species of penaeid prawn exists, the first step is to select the right species according to the following criteria: maturation and spawning in captivity, mass production of post‐larvae, fast growth at semi‐intensive density, acceptability of artificial diet, disease resistance and hardiness.

This paper presents the results on P. monodon, Fabricius, the largest Indo‐Pacific species. Experiments have been conducted in the “Centre Océanologique du Pacifique” in Tahiti Island where the environmental conditions are: water temperature range 25–29 C, salinity 35 ppt, pH 8.2.

Beginning with 9 females and 4 males from Fiji and New‐Caledonia, kept in sand bottom 12 m3tanks, F1 generation was obtained in November 1975 and F2 generation in August 1976. Maturation is induced after one eye ablation by pinching the eyestalk. From May to July, 6 females from 45 to 130 g gave 18 spawnings which totalized 3.3 times 106eggs, thus proving it is possible to sustain a commercial operation from captive reared animals. Mass mortalities which occurred during the larval rearing are now under control by use of antifungicides und antibiotics.

Protein and energy requirements were studied by means of purified and artificial diets. It has been found that a 40% protein content and 3.3 kcal/g diet gives the best growth performance. An artificial dry pellet has been developed and 25 g mean weight animals have been harvested after 7 months in earth rearing ponds at a density of 10 ind/m2.

Among 6 penaeid species under experiment in Tahiti, P. monodon is the most promising for the South Pacific tropical area.
POPULATION STRUCTURE OF MALAYSIAN PRAWNS, Macrobrachium rosenbergii (DE MAN), REARED IN EARTHEN PONDS IN SOUTH CAROLINA, 1974–19761
Authors: Smith T. I. J. , Sandifer P. A. , Smith M. H.
Published: August 2010

Population structures of Malaysian prawns, Macrobrachium rosenbergii, reared in earthen ponds in South Carolina are presented and various pond management strategies discussed. Sex ratios were generally biased toward females and overall, the total biomass of females was 20.6% greater than the total biomass of males. Mean sizes of males and females at harvest were usually similar (within one gram); however, their respective population structures showed distinct and characteristic differences. In general, females exhibited unimodal approximately normal distributions over a relatively narrow size range whereas the male populations exhibited markedly skewed, bi‐ or multimodal distributions over a comparatively broad size range.

The size distributions of prawns produced in the 15 grow‐out studies were influenced by prawn size at stocking, stocking density, and duration of grow‐out (4 to 6 months). Of these, initial prawn size was clearly the most important factor controlling size distribution. Stocking juveniles resulted in shifting the prawn biomass at harvest into the larger size classes and the lower the stocking density or longer the rearing period, the more pronounced was this shift in biomass distribution. In contrast, regardless of density (8.4–20.1 m‐2) and grow‐out time (137–181 days), the stocking of postlarvae resulted in 46 to 96% of the harvested biomass being contained in the small (<15.0 g), less valuable size category.

Although stocking juveniles results in a more valued crop, the cost of producing these juveniles may offset much of this economic gain. Our data suggest that an alternative stocking strategy which consists of stocking a mixture of postlarvae and juveniles may in fact result in a greater net return. Pilot‐scale demonstrations coupled with economic analyses are needed to test this pond stocking strategy.
MOLTING AND MORTALITY IN Macrobrachium rosenbergii
Authors: Peebles B.
Published: August 2010

Mortality estimates for M. rosenbergii, grown from postlarvae to adult, range from 20 to nearly 50%. My observations indicated that certain types of mortality, previously reported as cannibalism by some authors, followed a characteristic pattern and were related to molt state. In order to explore the relationship between mortality and molt state, a method of fragmenting M. rosenbergii's molt cycle was used, in a 4 by 3 factorial experiment where the relationship of molt state and relative size to injury and mortality was tested. The results indicated that prawns of equal size were susceptible to behaviorally related deaths at 2 points in the molt cycle, late premolt and early postmolt. The importance of this finding to aquaculture and behavioral research on crustaceans is discussed.
EFFECTS OF WATER‐BORNE MIREX ON THE SURVIVAL AND PRODUCTION OF Macrobrachium rosenbergii (DE MAN)1
Authors: Summer S. E. , Eversole A. G.
Published: August 2010

Post‐larval Macrobrachium rosenbergii (11–30 nun total length) were exposed to mirex in water for 24 and 96 hours under static laboratory conditions. A LC50 value of 104 μg/liter was determined by probit analysis for prawns exposed for 24 hours, transferred to uncontaminated water, and observed for 72 hours. Prawns exposed for 96 hours at lower concentrations (100, 10, 1, and 0.1 μg/liter) had higher survival with the greatest mortality occurring at 100 μg/liter.

One hundred prawns were individually exposed to 100, 10, 1, and 0.1 μg/liter for 96 hours, transferred to uncontaminated water and observed for an additional 24 days. No significant difference was found in number of molts, percent gain in length and weight, feeding or activity among concentrations (including control). However, those prawns exposed to the highest concentration molted fewer times. Also, a greater number of molt failures were observed with treatment animals, most occurring during the exposure period. The molt interval increased linearly with mirex concentration. Prawns in the control had significantly (P<0.05) shorter molt intervals than prawns exposed to 10 and 100 pg/liter. Consequently a loss in potential production (wet weight) over 28 days would be expected and the calculated percent gain in the control was 1.70 and 2.24 times that of the 10 and 100 μg/liter treatments.
THE FEASIBILITY OF FARMING MACROBRACHIUM IN DOMINICA, WEST INDIES
Authors: New M. B. , Sanders S. , Brown R. L. , Cole R. C.
Published: August 2010

The technical feasibility of freshwater prawn framing in the Windward Island of Dominica is reviewed in the light of environmental, topographic, economic and marketing conditions. Although environmental conditions are good for the culture of Macrobrachium spp. in Dominica, the nature of the terrain precludes the construction of large farms. However, small farms supplied with stock from a government hatchery should be economically viable. Despite the need to import at least part of the feedstuff requirement, freshwater prawn farming would have a favorable effect on balance of payments due to the export market available in the neighboring French Departments of Martinique and Guadeloupe.
GROWTH IN TANK‐REARED POPULATIONS OF THE MALAYSIAN PRAWN, Macrobrachium rosenbergii (DE MAN)
Authors: Mancebo V. J.
Published: August 2010

Post‐larval Malaysian prawns(Macrobrachium rosenbergii) were stocked in cylindrical tanks at densities ranging from 33 to 115 prawns/ m2 (3.0 to 10.7 prawns/ft2). Mean weight and survival measurements were taken at 2‐month intervals for a total grow‐out cycle of 6 months. The results show that populations of postlarvae (mean weight .016 g to .060g) grow to an approximate mean weight of 18 g within the 6‐month cycle. Mortality averaged 0.33%/day for the first 4 months and increased to 0.50%/day during the last 2 months of grow‐out.
A DISCUSSION OF POSSIBLE SOURCES OF INBREEDING IN HATCHERY STOCK AND ASSOCIATED PROBLEMS
Authors: Newkirk G. F.
Published: August 2010

It is necessary to establish breeding programs for the species used in aquaculture. However, until such programs have been established and start producing superior strains, these species will be under widespread, intensive culture. Unless the propagation of these species is done properly it could lead to inbreeding of hatchery stock which will make selection in future generations futile and may in fact produce a deterioration in performance. Some of the ways inbreeding can occur in routine hatchery procedure and ways of avoiding them are discussed.
COMPONENTS OF GROWTH RATE VARIATION AMONG LABORATORY CULTURED LOBSTERS (Homarus)
Authors: Hedgecock D. , Nelson K.
Published: August 2010

Laboratory‐reared juvenile lobsters (Homarus americanus) vary considerably in growth rate. Up to 30% of this variation appears to be heritable, but culture system, family by system interaction, and density differences within and between systems also contribute substantial growth rate variance. Results from split‐plot analyses of growth variance among 8 families of full‐sib juveniles grown for 90 days on live, adult brine shrimp at 3 temperatures (14°C ambient, 18°C, and 21°C; 2 replications) are in complete agreement with previous findings. Family, and by implication genotype, is a significant component of growth rate variance. Environment, however, plays an even more significant role. Density of lobsters in a system at the time of stocking new families affects growth of the younger juveniles adversely. Temperature produces expected fixed effects on growth rate with no evidence of statistical interaction between family and temperature. Replication over similar, but independent, experimental grow‐out systems reveals added growth variance apparently due to uncontrolled culture system variables. Significant culture system x genotype interactions are also observed.

Maternal influences and environmental effects arising from separate rearing of families until stage IV are confounded in the family differences observed in our growth studies. Two preliminary observations bearing on this problem show no evidence for a strong influence of larval history on juvenile growth.

Implications from this study are (1) that selective breeding for faster growth of lobsters would probably be successful although genotype x environment interactions might make the breeding program more complex and costly; (2) that important, possibly density‐dependent, environmental factors have not been identified or controlled in studies of lobster growth; and therefore (3) that much more research is needed to verify the biological validity of current concepts of high density, commercial Lobster aquaculture.
THE USE OF INTERPOPULATION HYBRIDIZATION IN DEVELOPMENT OF COHO SALMON STOCKS FOR AQUACULTURE
Authors: Hershberger W. K.
Published: August 2010

Three separate and apparently genetically distinct coho salmon (Oncorhynchus kisutch) stocks managed and reared by the Washington Department of Fisheries were crossed in a 3 times 3 factorial design. Data on early life history traits, such as mortality, time to 50% and 100% hatch, growth rate, and food conversion efficiency were taken for each of the nine possible crosses. Statistical analyses of the data demonstrated few significant differences among the crosses for traits expressed prior to the free feeding stage. After the fish started actively feeding, significant differences were found in growth rate and food conversion efficiency. These results could be explained in some instances by “hybrid vigor” and in other instances by the genes contained in one population. The data indicate that judicious use of in‐terpopulation crosses could provide significant gains in the early rearing of coho salmon for aquaculture.
EFFECTS OF DIETS ON THE FATTY ACID COMPOSITION OF JUVENILE ATLANTIC SILVERSIDES (Menidia menidia)
Authors: Schauer P. S. , Simpson K. L.
Published: August 2010

Juvenile Atlantic silversides (Menidia menidia) were cultured for 24 days on a live 3‐day‐old brine shrimp nauplii (Artemia salina) diet as well as the following artificial diets: a Conklin modified lobster diet, a Tunison laboratory modified diet (pellet and flake forms), and a Meyers closed formula flake prawn diet. A combination diet of brine shrimp nauplii and the Meyers prawn diet was also evaluated. The total lipid level and fatty acid profile of the diets and cultured fish were compared to those of the wild fish. Growth and survival were used as indicators of the overall performance of the various diets.

The greatest growth and survival was found in fish fed live brine shrimp. However, their fatty acid profile resembled their diet profile more than that of the wild fish. The combination diet produced nearly equal growth and survival compared to brine shrimp fed fish and gave a fatty acid profile more like the wild fish. Therefore, the combination diet sacrificed little overall performance but promoted a better lipid character. Although the Conklin modified lobster diet produced an acceptable survival (7851, no artificial diet promoted growth or survival which was equal to brine shrimp or the combined diet fed fish.

The use of the brine shrimp‐artificial diet combination reduced, by 50%, the number of brine shrimp cysts required for the successful culture of silversides.
AMINO ACID STUDIES WITH JUVENILE Macrobrachium rosenbergii
Authors: Stahl M. S. , Ahearn G. A.
Published: August 2010

This study reports the results of growth experiments with the freshwater prawn (Macrobrachium rosenbergii), using purified diets to establish the dietary requirements for lysine, arginine, methionine, and tryptophan. Four dietary levels of each amino acid were evaluated to determine quantitative requirements. The surprising outcome of these experiments indicated that these 4 amino acids were found dispensable for growth when omitted individually from the diets. Gut and/or tank bacteria may have supplied the prawns with amino acids in amounts sufficient for growth. These results suggest that searching for optimum amino acid levels for incorporation into cammercial diets may be less important than originally suspected. This would probably be particularly so where natural pond productivity provides prawns with many of their requirements.
SPAWNING, OOCYTE DEVELOPMENT AND LARVAE REARING OF THE FLORIDA POMPANO (Trachinotus carolinus)
Authors: Hoff F. H. , Mountain J. , Frakes T. , Halcott K.
Published: August 2010

Twenty‐five spawning attempts on the most reproductively developed fish were conducted on conditioned and unconditioned Florida pompano (Trachinotus carolinus). Human chorionic gonadotropin (HCG) was used to stimulate ovarian development. Dosage levels of .55 IU/g and .275 IU/g were usually administered 24 to 48 hours apart. Strip spawning and semi‐natural spawning were used, Spawning occurred 7 to 208 hours after initial injection depending on initial oocyte size. Optimum oocyte size (580–718 μ) produced spawning in 30–40 hours. A close correlation exists between rate of fertilization and oocyte growth during the first 16–25 hours. Fertilized eggs may shrink as much as 16% within one hour after fertilization.

Two successive batches of pompano were reared to juvenile stage in 23 days. Larvae were fed a mixed diet of natural plankton (66 μ mesh net), protozoans, rotifers (Brachionus plicatilus) and copepod nauplii (Oithona sp.). Water was initially conditioned with 40 liters of dense algae (Dunaliella sp. and Tetraselmis sp.). Water quality was controlled by partial exchanges from a 40,000‐liter biologically filtered system. Eighteen‐hour lighting was used. Larvae developed edema at 8–10 days and, combined with low aeration, reduced survival to only 300 juveniles.
CONDITIONING AND INDUCED SPAWNING OF THE RED DRUM (Sciaenops ocellata) UNDER VARIED CONDITIONS OF PHOTOPERIOD AND TEMPERATURE
Authors: Roberts D. E. , Harpster B. V. , Henderson G. E.
Published: August 2010

Vitellogenesis, culminating in spawning, was artificially induced in red drum (Sciaenops ocellata) using photoperiod and temperature as exogenous stimuli. Maturation was induced out of season during the normal refractory period of red drum found in central Florida waters. Four regimes were compared to a control. Three regimes culminated in advanced vitellogenesis and spawning. A semi‐natural regime induced spawning in 129 days, an abbreviated decelerating regime induced spawning in 83 days, and an abbreviated accelerating/decelerating regime induced spawning in 117 days. Functional maturity of females was defined by analysis of vitellogenic stage frequency and oocyte diameter frequency. Ovarian biopsies were taken by catheter at 30‐day intervals during experiment I, and 60‐day intervals during experiment II. For a 90‐day period in 1976, 4 females spawned 8.43 million eggs. For a 100‐day period in 1977, 8 females spawned 4.41 million eggs. Fertilization success was always greater than 99% and mean hatching success was 93.40% for all spawns.
MONOCULTURE AND POLYCULTURE POND STUDIES WITH POMPANO (Trachinotus carolinus) AND PENAEID SHRIMP (Penaeus aztecus, P. duorarum, AND P. setiferus) IN ALABAMA, 1975–19771
Authors: Tatum W. M. , Trimble W. C.
Published: August 2010

Studies were conducted seasonally from 1975–1977 in 0.08 ha, brackish water ponds at the Claude Peteet Mariculture Center on monoculture of Florida pompano (Trachinotus carolinus), brown shrimp (Penaeus aztecus), and white shrimp (P. setiferus), and on polyculture of pompano with pink (P. duorarum) or brown shrimp. Three methods of stocking polyculture ponds were investigated.

Pompano production from monoculture ponds manages eeasonally for 95 to 191 days averaged 564 kg/ha with mean survival of 42%, mean feed conversion of 3.0, and mean weight of 156 g. During one growing season in 1977, consecutive 75‐ to 81‐day crops of brown and white shrimp produced mean yields of 349 and 600 kg/ha, survivals of 69 and 96%, feed conversions of 4.0 and 2.3, and weights averaging 8.3 and 10.0 g, respectively. The optimal method of stocking polyculture ponds with pompano and shrimp produced mean yields of 593 and 222 kg/ha, survivals of 30 and 53%, feed conversion of 2.6, and weights averaging 185 and 13.5 g, respectively.

Although one season's highest yield (949 kg/ha, mean) was from 2 successive crops of penaieds and the maximum yield of pompano (760 kg/ha) was in monoculture, polyculture of shrimp and pompano demonstrated both technical and economical potential.
PEARL INCIDENCE IN Mytilus edulis L. AND ITS COMMERCIAL RAFT CULTIVATION IMPLICATIONS
Authors: Lutz R. A.
Published: August 2010

The presence of pearls in Mytilus edulis L. from Gulf of Maine waters may be the result of infection by a parasitic trematode (probably Gymnophallus bursicola) morphologically very similar to the pearl‐forming distome described by various European workers. Techniques have been devised for the removal and grading of pearls from individual specimens of Mytilus edulis and for quantifying differences between pearl incidence and age structure of studied populations. The relationship between number of pearls per mussel and age has been defined for one rafted and one shore population of mussels in South Bristol, Maine. No significant age‐independent differences were found between the 2 populations with regard to the quantity of pearls present. The harvesting of mussels from floating structures which have been in the water for less than 5 years (i.e., raft cultivation of Mytilus edulis) should provide a method of obtaining a quality product even in areas where the presence of pearls in natural stocks of mussels has proven a deterrent to the commercial utilization of this species.
A NEW DISEASE OF LARVAL PACIFIC OYSTERS (Crassostrea gigas)1
Authors: Leibovitz L. , Elston R. , Lipovsky V. P. , Donaldson J.
Published: August 2010

A disease affecting larval Pacific oysters (Crassostrea gigas) was observed during a 3‐year period at a hatchery in Washington State. It was also detected at 3 other hatcheries and in wild stocks. The clinical course of the acute phase of the disease in the hatchery varied from one to 3 days. Larvae that completed metamorphosis in less than 12 days survived the infection. Under intensive cultural conditions, the mortality rate exceeded 95%. The disease occurred at water temperatures of 20 to 30°C and salinities of 13 to 28 ppt.

The earliest sign of the disease was the presence of numerous zoo‐spore‐like bodies on the cilia of the velum. These bodies progressively increased in number and the velum and mantle became eroded. Numerous thick‐walled spherical bodies, 4 to 24 μm in diameter, were found in the stomachs of apparently healthy and sick larvae that were at least 7 days of age. Moribund larvae regurgitated fascicular collections of zoospore‐like and thick‐walled spherical bodies from the stomach. The regurgitated masses became entwined on and were rotated by the velar cilia, further traumatizing the surface of the velum. The terminal stage of infection was characterized by severe velar erosion, numerous enlarged spherical bodies in the stomach, and dilated darkened intestines.

Histologic and electron microscopic study of affected larvae revealed fascicular masses on velar and mantle epithelia associated with adjacent cellular destruction. Spherical bodies were impacted in the stomach and frequently obstructed the gastro‐diverticular opening. In some cases the intestines were dilated and ruptured.

Based upon observations, a mycotic etiology is hypothesized. The etiologic agent exhibits similarities to the Dermocystidium group of organisms. The relationship between the wide distribution of the diseast and reported difficulties in culturing Pacific oyster larvae is discussed.
CURRENT STATUS OF AMPHIBIAN CULTURE WITH EMPHASIS ON NUTRITION, DISEASES AND REPRODUCTION OF THE BULLFROG, Rand catesbeiana
Authors: Culley D. D. , Horseman N. D. , Amborski R. L. , Meyers S. P.
Published: August 2010

Culture techniques for some amphibians have progressed sufficiently to allow production of animals to be sold for teaching and research. The current state of the art is reviewed. Areas where additional research is needed include nutrition and feeding, immunology, reproductive control of females, and selective breeding.
THE LARGE INVERTEBRATE‐SMALL VERTEBRATE FAUNA OF SEVERAL SOUTH LOUISIANA CRAWFISH PONDS WITH EMPHASIS ON PREDACIOUS ARTHROPODS
Authors: Barr J. E. , Huner J. V. , Klarberg D. P. , Witzig J.
Published: August 2010

The large invertebrate‐small vertebrate fauna (organisms caught or retained with a 3.2 mm mesh) were sampled in several south Louisiana crawfish ponds. Arthropods were the principal predators and included, in order of abundance (lowest to highest), the insect general Lethocerus, Cybister, Pelocoris, Ranatra, Belostoma, Notonecta, Buenoa, Anax, and Pachydiplax. The arachnids, Dolomedes spp., were more abundant than Cybister. On the basis of physical size and abundance, Anax junius (Odonata: Aesnidae) appeared to be the most significant crawfish predator. Diversity of all species was greater in ponds with extensive coverage of semi‐aquatic vegetation than in those ponds dominated by annual grasses (including rice) and sedges that died and decompsed following pond flooding. The mosquitofish (Gambusia affinis), when present, appears to reduce the numbers of predacious odonate nymphs.
WATER CIRCULATION—AN ALTERNATIVE TO EMERGENCY AERATION
Authors: Busch C. D. , Goodman R. K.
Published: August 2010

A management system, replacing emergency aeration practices with gentle pond circulation, has been employed over an entire catfish growing season. Five waterblenders were used to provide pond circulation for a 1.42 ha catfish pond stocked at a density of nearly 10,000 finger‐lings/ha. Pond water circulation during the daytime hours mixed oxygen‐rich surface waters with the deeper oxygen‐poor waters. The waterblending operation continued long enough after dark to decrease the thermal gradients, so that the diurnal temperature change provided top‐to‐bottom mixing on most nights during the season.

Comparisons of yield data, power requirements, and oxygen and temperature profiles show the advantages of the pond receiving water circulation over a neighboring pond that was aerated only on an emergency basis. Comparisons of waterblending with recent aeration studies of other investigators show an order of magnitude reduction in energy uses.
INFLUENCE OF PHOTOPERIOD ON SURVIVAL AND GROWTH OF LARVAL AMERICAN LOBSTERS (Homarus americanus)
Authors: Aiken D. E. , Martin D. J. , Meisner J. D. , Sochasky J. B.
Published: August 2010

Thirty thousand American lobsters were hatched, stocked at a density of 2,000 per 40‐liter planktonkriesel, and exposed to one of three photo‐periods (LD 01:23, LD 12:12, LD 23:01) at constant 20°C. Five replicates were completed from March through May. The shortest photoperiods produced the most rapid development and the best survival to Fourth Stage. The longest daily light period produced the largest mean size and greatest size range. At all photoperiods the first larvae to reach Fourth Stage were the largest, and mean size decreased thereafter. Short daily light periods appear to be the most advantageous for larval culture under these conditions because, in addition to producing the best development and survival rates, short light periods reduce algal growth and tank maintenance requirements.
EFFECT OF POPULATION STRUCTURE AND DENSITY AT STOCKING ON PRODUCTION AND COMMERCIAL FEASIBILITY OF PRAWN (Macrobrachium rosenbergii) FARMING IN TEMPERATE CLIMATES1
Authors: Smith Theodore I. J. , Sandifer Paul A. , Jenkins Wallace E. , Stokes Alvin D.
Published: August 2010

During 1978–1980, 18 rearing trials were conducted in 0.25 ha ponds to examine the effects of various stocking strategies on production and economic potential. The strategies tested consisted of stocking: post‐larvae only; a mixed population of postlarvae plus juveniles; small juveniles only, at densities ranging from 2.15–8.61 prawns/m2. Prawns were fed Purina Marine Ration 25 once daily and seine‐sampled at 4‐week intervals throughout the 144–168 day rearing periods.

Clear relationships between population structure of the stocked prawns and density versus crop yields and estimated revenues were demonstrated. The stocking of postlarvae resulted in lower production levels and less valuable prawns as compared to stocking a mixture of postlarvae + juveniles or juveniles only populations. Also, survival was more variable (range 59.3–84.5%) and lower (mean 69.6%) when postlarvae were stocked. Greater crop yields were achieved at higher densities, however, mean size and unit value of the crop decreased as density increased. Feed conversions were low and averaged 1.4 (range 0.8–2.2) for all trials combined.

Preliminary economic feasibility analyses of the various stocking strategies were performed for situations where ponds and associated facilities were already available. The analyses suggested that positive net revenues were possible if a mixed population of postlarvae and juveniles or juveniles only were stocked at about 6.5/m2 and seed costs were ∑30/1,000 and the crop was marketed as a combination of large whole.
RESPONSES OF PLANKTONIC AND BENTHIC COMMUNITIES TO FERTILIZER AND FEED APPLICATIONS IN SHRIMP MARICULTURE PONDS
Authors: Rubright John S. , Harrell Jim L. , Holcomb Hoyt W. , Parker Jack C.
Published: August 2010

An experiment was performed to evaluate the responses of naturally occurring populations of plankton and benthos to applications of inorganic fertilizer and commercial marine ration in a shrimp grow‐out facility near Angleton, Texas. Ten ponds were stocked with an average of 17,000 post‐larval Penaeus stylirostris on July 8, 1980. Three of these ponds received fertilizer 19 days before stocking and again 7 days after stocking. Another 3 ponds were fed daily with Ralston Purina Experimental Marine Ration 20 beginning on the stocking day. Three other ponds received the 2 fertilizer applications and daily feed. One control pond was not given fertilizer or feed.

Beginning 19 days before stocking and continuing for 14 weeks, samples were collected and quantitatively analyzed for chlorophyll, zoo‐plankton and benthic organisms. Results indicated that fertilizer stimulates the production of chlorophyll and planktonic copepods. Planktonic rotifers varied independently of feed or fertilizer. Densities of planktonic polychaete larvae seemed to be related to changes in the populations of benthic adult polychaetes.

The benthic community was dominated by polychaetes, harpacticoid copepods and nematodes. Polychaetes tended to be more abundant when feed was present. Harpacticoids and nematodes did not seem to be affected by experimental treatments. All benthos fell to very low densities after 50 days of the study.

The best shrimp production occurred in feed and fertilized ponds, followed by feed only, fertilizer only and the control. Potential linkages between natural production and shrimp growth are discussed.
SUCCESSFUL ARTIFICIAL DIETS FOR THE CULTURE OF JUVENILE LOBSTERS
Authors: D'Abramo Louis R. , Conklin Douglas E. , Bordner Clark E. , Baum Nancy A. , Norman‐Boudreau Karen A.
Published: August 2010

Purified and semipurified diets yielding good growth and survival of lobsters (Homarus americanus) have been developed. Growth of animals fed the semipurified diet for 18 months at 20±1°C indicates that market size (.5 kg) could be attained within 2.5 years. The semipurified diet contains 53% (dry weight) protein using casein, shrimp meal, gluten, and egg white as different protein sources. Substitution of these particular sources of protein with soy protein, shrimp protein, a soy protein‐shrimp meal combination, or bacterial cell protein caused significant reductions in growth.

Similar growth can be achieved when the protein level of the semipurified diet is reduced to 30.5%. It appears that if specific protein and energy requirements are met, diets containing low protein levels can be nutritionally adequate for optimal growth, thereby increasing the possibility of cost‐effective diets for intensive lobster culture.
COMPARATIVE GROWTH OF Isochrysis galbana PARKE AND Isochrysis aff. galbana, CLONE T‐ISO AT POUR TEMPERATURES AND THREE LIGHT INTENSITIES
Authors: Ewart John W. , Pruder Gary D.
Published: August 2010

The growth of a temperate and a tropical strain of Isochrysis was studied at four temperatures and three light intensity levels. All algal cultures were grown in an enriched artificial seawater medium under constant illumination and were bubbled with air enriched with 0.1% CO2. Culture density (cells/ml) was measured periodically during exponential growth. Average growth rates for each combination of temperature and light intensity are presented as doublings/day. Observations of growth under the various culture conditions indicate that T‐ISO (tropical strain) grows rapidly over a much broader range of temperatures than does I. galbana. Variations in growth at different light intensity levels suggest that the optimum light level increases as a function of temperature for T‐ISO and that the growth of I. galbana is inhibited by high levels of light (1500 μW/cm2). The relative value of both strains as food for larval and juvenile oysters and the advantages and limitations of large scale culture are discussed.
DEVELOPMENT OF AN INTENSIVE SHRIMP CULTURE SYSTEM IN KUWAIT1
Authors: Kneale D. C. , Al‐Hajj A. B. , Maynard E. C. L. , Farmer A. S. D.
Published: August 2010

Development of an intensive culture system is presently being conducted in Kuwait as a means of farming penaeid shrimp in arid lands. Efficiency of commercial‐scale hatchery production of Penaeus semisulcatus and P. japonicus showed significant improvement in 1981 over previous years. Three one‐month hatchery rearing cycles in three 15 m3 concrete tanks yielded a total of 9.1 million post‐larval shrimp with an average density of 160 PL/liter being obtained for one of these trials. Four other trials were discontinued due to low spawning rates and disease. Installation of a heat exchange system made it possible to begin larviculture in February, two months earlier than in previous years. Research in nursery and grow‐out phases of intensive shrimp culture is being directed towards raceways, although Shigueno culture systems are also being investigated. Experimental work with six 18 m × 1.5 m raceways demonstrated that low water exchange rates (1 tank volume/day), combined with high aeration (9.5 liter/min) yielded the highest shrimp biomass. Unheated greenhouse structures constructed over the raceways showed that a single layer of 0.25 mm clear plastic sheeting could maintain water temperatures up to 2.7°C above those in unenclosed tanks. Rearing trials in two Shigueno tank systems demonstrated the importance of high water flow rates (3 tank volumes/day minimum) and adequate aeration. Due to sub‐optimal conditions, survival was reduced to 7.5%, however, growth rates up to 6 g/month were obtained for P. semisulcatus.
POND STUDIES ON GULF KILLIFISH (Fundulus grandis) MARICULTURE
Authors: Trimble William C. , Tatum Walter M. , Styron Sherman A.
Published: August 2010

Investigations concerning spawning, hatching, and grow‐out of gulf killifish (Fundulus grandis) were conducted in 0.08‐ha, brackish‐water ponds at Alabama's Claude Peteet Mariculture Center during 1979. Adult gulf killifish stocked at 88,750 fish/ha and a 1:1 sex ratio in 3 spawning ponds deposited 499,777 eggs on 1,001 Spanish moss mats placed around pond margins between 1 March and 13 August. Rate of egg deposition was highest in March (4,103 eggs/day/pond) and lowest in July and August (36 eggs/day/pond). A total of 293,467 eggs and 416 mats transferred to 3 hatching ponds between 13 March and 8 May produced 219,921 juvenile killifish (75% survival) averaging 0.5 g at harvest on 6 June. Production and feed conversion in hatching ponds averaged 413.90 kg/ha and 1.9, respectively. Stocked on 6 June in 4 grow‐out ponds each at either 250,000 or 370,000 fish/ha and fed either 2 or 3 times daily, the juvenile gulf killifish reached marketable size (2.4 g and 57 mm total length) in 49 days. Production in grow‐out ponds averaged 658 kg/ha with 93% survival and 2.4 feed conversion. Analysis (2 × 2 factorial) of grow‐out data indicated no significant differences for effects of densities and feeding on mean weights of fish at harvest.
RESEARCH ON REARING TURBOT (Scophthalmus maximus): RESULTS AND PERSPECTIVES
Authors: Ruyet J. Person‐Le , L'Elchat D. , Nedelec G.
Published: August 2010

At the Centre Océanologique de Bretagne, a research program on turbot rearing has been in progress for several years. The life cycle is now under control. Up to 10,000 3‐month‐old juveniles can be produced per natural or shifted spawning season. Attention is now focused on the first week stages. Obtaining an average survival of 10% from hatching up to 3 months is still difficult. Weaning generally starts in 30‐day‐old larvae (75 mg wet weight) and the gross mortality during weaning is near 50%. Three‐month‐old juveniles weigh about 2 g.

In Brittany, culture necessarily begins in a nursery using heated water. The grow‐out period begins between 5 and 20 g: 5 g when winter is over, 20 g when winter is coming. At this stage they can grow either in tanks or in floating sea‐cages and they may be fed dry pellets. After 20 g, moist foods containing at least 25%, on dry basis, of trashed fish are more efficient. Pure trashed fish also gives good results. The food conversion ratio is about 1 (dry food weight/wet weight fish gain).

The first data on turbot growth in intensive conditions are encouraging. In our area, annual temperature of the open sea ranges from 7 to 18°C allowing an average weight gain of 1 kg at 2 years and 2 kg (3 kg in the best case) at 3 years of age. Control of spawning season is still necessary to obtain a good market size of about 2 kg of body weight in less than 3 years.
A STUDY ON THE MASS MORTALITY OF MUSSELS IN THE LAGUNA VENETA
Authors: Munford J. G. , DaRos L. , Strada R.
Published: August 2010

A digenetic trematode, Cercaria tenuans, was the probable causative agent of an extensive mortality of cultured mussels (Mytilus edulis = gallo‐provincialis) in the southern part of the Laguna Veneta, Italy. Sporocysts of C. tenuans occurred in the mantle tissue, the visceral mass and in the extra‐pallial fluid space between the mantle and the shell. Germballs and apparently viable cercaria, or daughter sporocysts, were observed in the sporocysts. Other microscopic parasites were found in low numbers.
MALAYSIAN PRAWN CULTURE IN BRACKISH WATER PONDS IN LOUISIANA
Authors: Perry W. Guthrie , Tarver Johnnie W.
Published: August 2010

Beginning on May 13, 1980, prawns were cultured at the Rockefeller Wildlife Refuge for 140 days from postlarvae and fed. Production in ponds receiving Ralston Purina Experimental Marine Ration #25 averaged 408 kg/ha, 619 kg/ha and 510 kg/ha for the respective replicated stocking densities of 2.5/m2, 4.9/m2 and 7.4/m2. Average feed conversion factors were 1.0, 1.0 and 1.5. Average prawn weights at harvest decreased with increased stocking density and were 21 g, 17 g and 12 g, respectively. Production per pond ranged from 390 kg/ha to 832 kg/ha. An average of 77% of prawns stocked at 2.5/m2 exceeded 115 mm TL whereas the stocking densities of 4.9/m2 and 7.4/m2 yielded only 32% and 31% over 115 mm.

Extra postlarvae remaining after the stocking requirements for the feeding study were met permitting additional tests. Stocking rates selected for these additional studies were 1.2/m2, 2.5/m2 and 3.7/m2. Prawns in these ponds received no supplemental feed and yielded harvests of 124 kg/ha, 224 kg/ha and 292 kg/ha, respectively. These treatments, the first two of which were not replicated, resulted in production similar to that of an earlier study of prawn production on natural forage in brackish ponds at this facility. Average prawn sizes at harvest were 18 g, 15 g and 12 g, and were inversely related to stocking densities.
THE ARTIFICIAL PROPAGATION AND CULTURE OF BEAR SHRIMP, Penaeus semisulcatus de HAAN, IN HONG KONG
Authors: Tseng Wen‐young , Cheng Wo‐wing
Published: August 2010

Penaeus semisulcatus (bear shrimp) was used for biological and culture studies. A peak of reproductive periodicity was shown in the months of May, June and July. Increase in body weight and in gonad weight coincided with the increase in sea water temperature. This suggested that sexual maturation might be a direct response to increased sea water temperature. Fecundity of mature female shrimp was estimated as 415,000 to 479,000 ova.

In most cases, half‐spent spawnings led to the production of poor eggs, characterized by irregular cytoplasmic formation and final autolysis. The embryonic and larval development of P. semisulcatus proceeded satisfactorily in a slightly alkaline medium (pH range from 7.5–8.5), and in water of salinity ranging from 28 to 35 ppt for egg and nauplius stages, and thereafter 25–35 ppt for zoea and mysis stages.

The shrimps exhibited faster increase in body length than body weight in early growth. Later, after the shrimps had reached a body length of about 7.0 cm, the growth rate of body weight increased more markedly than body length. The rate of daily increase in weight was 1.01% in 7.0 cm shrimp. The feed efficiency of the formulated shrimp pellets was found to be 31.4%.

During the nutritional study of P. semisulcatus, it was found that the combination of high dietary protein (about 40%) and low dietary lipid produced best growth and survival of bear shrimp. High increase of biomass of the shrimp fed with clam meat and high quality fish meal demonstrated the favorable response of shrimp to these diets. The use of cages for culturing bear shrimp was found to be practicable, but not efficient.
DESIGN AND OPERATION OF A LARGE‐SCALE, COMMERCIAL PENAEID SHRIMP HATCHERY
Authors: Simon Clyde M.
Published: August 2010

A hatchery for the rearing of penaeid larvae and postlarvae in raceway‐type tanks was designed and has begun operation. Details of the designs of tanks, filters, water systems, air system, and hatchery layout are presented. The culture methods employed in the raceway‐type hatchery are given along with the hatchery's technical organization and management procedures. The design and operation of the raceway‐type hatchery are compared with those of small‐tank (Galveston‐type) hatcheries and large‐tank (Japanese‐type) hatcheries, and relative advantages are discussed.
USE OF A SEINE TO DETECT STUNTED CRAWFISH POPULATIONS IN PONDS, A PRELIMINARY REPORT1
Authors: Momot Walter T. , Romaire Robert P.
Published: August 2010

A 4.5‐m long bag seine was used to sample crawfish from six 0.04 ha experimental ponds. Length‐frequency histograms were evaluated as a predictor of size structure and to detect stunted populations of crawfish. The findings demonstrated importance of determining size structure of crawfish in predicting stunting and harvest potential of a population. Distinct differences in size structure of crawfish populations were apparent by 6 and 12 weeks after flooding ponds. Crawfish populations, with over 45% of the individuals exceeding 75 mm total length after 12 weeks, produced 25 to 30% greater yields than populations in which less than 5% of the crawfish exceeded 75 mm at 12 weeks post‐flooding.
FRESHWATER PRAWN HARVESTING: A COMPARISON OF THREE METHODS
Authors: Peterson Jeffrey J.
Published: August 2010

Three methods of harvesting Hawaiian freshwater prawn ponds are described: 1) Traditional (also called “Fuji,” after Fujimura, or “hukilau,” Hawaiian for community net fishing)‐A seine is maneuvered around the pond by workers in the water who drag the net lead line with their feet as they encircle the catch. The seine is then closed into a bag and the prawns are removed. 2) Modified seining‐A seine which spans the width of the pond is pulled from both ends simultaneously by tractors. The seine is pulled from one end of the pond to the other, concentrating the catch in the bag or live car enclosure. 3) Drain harvesting‐Water is drained from the pond by gravity or by pumping, the screen is removed from the catch basin and a fish pump is used to pump the prawns into a dewatering box. The prawns are then transferred to holding tanks for sorting.

The efficiencies and cost effectiveness of all three methods are discussed with recommendations relative to farm size.
THE ASSIMILATION OF PROTEIN AND CARBOHYDRATE FROM PREPARED DIETS BY THE SHRIMP,Penaeus stylirostris
Authors: Fenucci Jorge L. , de Fenucci Alicia Casal , Lawrence Addison L. , Zein‐Eldin Zoula P.
Published: August 2010

Assimilation (apparent digestibility and absorption) of protein and carbohydrate from selected diets was tested usingPenaeus stylirostris. The largest shrimp (approximately 10 g) assimilated squid meal proteins better than α‐soy protein but smaller shrimp (1.3 and 3.8 g) did not. All sizes assimilated protein from diets containing α‐soy better than those containing brewer's yeast. Carbohydrate assimilation was less efficient than protein for all diets. There was no relation between carbohydrate and protein assimilation and the percentage in the diets over the limited range tested. Although assimilation of these two groups of compounds was greater in the larger shrimp, there was no correlation between the growth and protein and carbohydrate assimilation for the diets tested for similar size animals of the same species.
POLYCULTURE EXPERIMENTS OF POMPANO Trachinotus carolinus (CARANGIDAE) AND SPOTTED RED SHRIMP Penaeus brasiliensis (PENAEIDAE) IN CONCRETE PONDS, MARGARITA ISLAND, VENEZUELA
Authors: Gomez Alfredo , Scelzo Marcelo A.
Published: August 2010

Since 1978, polyculture experiments of pompano (Trachinotus carolinus) and shrimp have been conducted in the Centro de Investigaciones Científicas, Universidad de Oriente, Venezuela. Experiments are carried out in circular concrete ponds (28 m2) with running seawater (salinity 37–39 ppt and temperature 26.4–30.9°C) and constant aeration. In the first experiment (September‐December 1978) pompano and shrimp were stocked at a density of 10/m2 and were fed with Tivela mactroides (Mollusca, Pelecipoda) “guacuco” pellet of 60% crude protein. Pompano 0.22±0.1 g reached after 75 days 40.6±25.6 g with food conversion of 6.59 and 17.14% survival; shrimp 1.3±0.4 g reached a weight of 5.7±0.9 g and 2.68% survival during 75 days. The common food conversion was 7.57.

The second experiment (June‐August 1981) was carried out in tanks with a false bottom. Pompano and shrimp were stocked at densities of 5 and 10/m2 respectively, and were fed with a pellet named GSCA (42.8% crude protein). Pompano 4.0±1.1 g reached 62.1±10.3 g after 75 days of culture, the food conversion and survival being 3.1 and 64.29%, respectively. Shrimp stocked at 3.6±0.6 g reached 8.9±1.8 g after 75 days, and feed conversion was 10.7 with 54% survival. The common feed conversion for pompano and shrimp was 6.6. After 75 days of culture the high mortality of pompano was due to the infection of branchial parasites, the protozoa Amyloodinium ocellatum and the trematode Bicotylophora trachinoti.