Chaetoceros Ceratosporum Research Articles

Administration of Hot Water Extract Diatomae Caetoceros Ceratosporum via Injection Enhances the Immune Resistance of White Shrimp Litopenaeus vannamei against Infectious Myonecrosis Virus

Immune resistance of white shrimp against disease can be enhanced through the administration of immunostimulant. Some of sea microalgae extracts has been proved trough examination to be able to stimulate immune system of shrimp. The objective of this study is to know immune response of Litopenaeus vannamei injected with hot water extract Chaetoceros ceratosporum (HWEC) doses of 5, 10, 15 and 20 µg·g -1 body weight (BW) against Infectious Myonecrosis (IMNV) virus infection. The findings show that C . ceratosphorum administration can enhance immune response of L. vannamei infected by Infectious Myonecrosis virus, indicated by the increasing number of hemocytes (THC), total protein plasma (TPP), phenolokxidase (PO) activity, and respiratory burst (RB) activity. Highest immune response is achieved by injection dose of 15 µg·g -1 shrimp body weight. The increase of shrimp immune response leads to the increase of shrimp immune system against IMNV infection, so the survival rate of L. vannamei infected by IMNV is higher than positive control and similar to those of negative control.

Chaetoceros ceratosporum Diatomae in Feed Formula To Increase Growth and Post Larvae Immunity of Tiger Shrimp (Penaeus monodon Fab.) to Vibrio harveyi infection

This experiment aims to determine the effect and the best dose of Chaetoceros ceratosporum diatomae utilization in feed formula for post larvae of tiger shrimp (Penaeus monodon Fab.) growth and immunity to Vibrio harveyi infection. This research applied Completely Randomized Design (CRD) with 4 treatments and 3 replications. The treatment use  Chaetoceros ceratosporum diatomae in feed formula (iso protein 39.02% and iso energy 3.58 kcal/g diet) in different doses, i.e. treatment A = 0 %; B = 3.04 %; C = 6.0 8%; D = 9.12 %. Observed parameters were Survival Rate, Growth Rate, Food Conversion Ratio (FCR) and Protein Efficiency Ratio (PER). Result showed that Chaetoceros ceratosporum diatomae utilization in feed formula affect the increase of growth and immunity of post larvae of tiger shrimp (Penaeus monodon Fab.) to Vibrio harveyi infection. The best dose in feed formula ranged from 5,75% – 5,95%. Key words: Chaetoceros ceratosporum, balance energy, feed conversion, protein efficiency, Vibrio harveyi, tiger shrimp

Replacement of Artemia franciscana Nauplii by Microencapsulated Diets: Effect on Development, Digestive Enzymes, and Body Composition of White Shrimp, Litopenaeus vannamei, Larvae

AbstractThe effects of two microencapsulated feeds were evaluated on development, growth, survival, proteolytic activity, and biochemical composition of white shrimp, Litopenaeus vannamei, larvae. The treatments were: (1) basal microcapsules (BM), (2) microcapsules containing krill hydrolysate (BMK), and (3) live food control (LFC: Artemia franciscana nauplii) with all treatments receiving algae (Chaetoceros ceratosporum and Tetraselmis chuii). No significant differences were found in development index and survival among larvae. Growth rate was significantly higher in larvae fed LFC (15 ± 0.06%/d) as compared with those offered the BM diet (7.5 ± 0.5%/d) with the BMK (11 ± 0.04%/d) treatment producing intermediate results. The activity of total proteases and chymotrypsin decreased significantly after Mysis I (MI) in larvae fed LFC or BMK. Protein content of larvae increased significantly toward PL1. The acylglycerides content in MIII fed on LFC (2.3 ± 0.2%/dw) was higher than that MI fed BM (1 ± 0.01%/dw). No difference was observed in the cholesterol (CH) content of the larvae. The acylglycerides/protein and cholesterol/protein ratios showed a decreasing pattern between MI and PL1, indicating that these two ratios were related to ontogenetic shifts. These results demonstrate improvements in microparticulate diets when krill hydrolysates are included in the formulation.

Isolation and characterization of Noctiluca-killing bacteria from a shrimp aquaculture pond in Thailand

To control harmful algal blooms (HABs), in particular dinoflagellate Noctiluca scintillans, which causes damage to shrimp production, algicidal bacteria were isolated from shrimp pond water and screened for their killing effect against N. scintillans under laboratory condition. Among 260 bacterial isolates, 10 showed killing effects on N. scintillans. Out of 5 strains showing relatively stronger killing activity, 4 strains belonged to the Gammaproteobacteria group. Among these, strain BS2 (identified as Marinobacteria salsuginis) showed the strongest Noctiluca-killing activity. In the present study, we also investigated bacterial effects against growth of other phytoplankton species. Strain BS2 killed only N. scintillans but not any other phytoplankton (Heterosigma akashiwo NIES-6, Chatonella antique NIES-1, Chaetoceros ceratosporum, Prorocentrum lima, and Dunaliella sp.). Results of the present study lead us to expect prevention of damage by HABs, in particular dinoflagellate N. scintillans, in shrimp farming and mitigation for shrimp production in ponds using Noctiluca-killing bacteria.

The effects of temperature and food ration on metabolite concentrations in newly settled king scallop ( Pecten maximus) spat

Juvenile king scallop ( Pecten maximus L.) between 0.2 and 1.5 g wet shell weight per individual, reared at 10, 14 and 17 °C, were fed either a full ration equivalent to 0.5 g (ash-free dry weight of algae) g − 1 (live weight of spat) week − 1 or a restricted algal ration of 0.07 g (ash-free dry weight of algae) g − 1 (live weight of spat) week − 1 . The algal food was a mixture of two microalgal species: Chaetoceros ceratosporum (Droop) Green and Pavlova lutheri Ostenfeld. Measurements were made of tissue concentrations of adenylate tri-, di- and mono-phosphate, lactate, succinate, acetate, pyruvate and l-alanine. The metabolite measurements were used as indicators of viability in animals exposed to a matrix of temperature and food supply conditions. It was found that the variations in metabolic responses could be correlated with those observed in a previous study that measured body condition in relation to the same set of variables. It was also found that the data from the present study were most strongly influenced by temperature-related effects and that there was an optimal temperature range between 10 and 14 °C. The metabolic responses, measured in terms of metabolite concentrations, would seem to confirm the existence of a bi-stable physiology in P. maximus in which there is a switch in state between 10 and 14 °C.

Effect of temperature and ration on growth and condition of king scallop ( Pecten maximus) spat

Hatchery-reared king scallop ( Pecten maximus L.) spat (5–14 mm shell height) were held in mesh-based Perspex cylinders suspended in 2.5 l beakers of seawater. This seawater was maintained at eight temperatures (5°C–23°C inclusive), and various rations (0.012–0.492 g (organic weight of algae) g −1 (live weight of spat) week −1) of a diet consisting of a mixture of Pavlova lutheri (Droop) Green and Chaetoceros ceratosporum Ostenfeld were fed. Size of the animals was estimated weekly by computer analysis of video images taken of the scallops in the cylinders while in seawater. The relationship between temperature and food ration was evaluated. As temperature increased, the scallops consumed a bigger ration, and the highest ration that they consumed efficiently determined their maximum growth rate. This ration, and the corresponding growth rate, both increased with temperature. At the end of each 3–4 week experiment, the condition (ratio of dry meat weight to dry shell weight) of the spat was estimated. Condition was greatest between 10°C–17°C and least below 8.0°C. Condition decreased with lower rations at all temperatures above 10°C. Comparison of results with preliminary observations made at commercial scallop cultivation sites suggest that temperature rather than food is the factor most often limiting for growth in the sea.

Feeding schedule for Penaeus setiferus larvae based on diatoms ( Chaetoceros ceratosporum), flagellates ( Tetraselmis chuii) and Artemia nauplii

This paper is the first to present a basic feeding schedule for Penaeus setiferus larvae based on diatoms ( Chaetoceros ceratosporum), flagellates ( Tetraselmis chuii) and Artemia nauplii. Growth rate (μm/day), rate of metamorphosis and survival of larvae fed 5 different concentrations of diatoms, flagellates and Artemia nauplii were measured. Survival associated with sudden changes in salinity (quality index QI) of the postlarvae harvested from each treatment was measured. A performance index was calculated from the growth rate, survival and QI. Considering all responses, a feeding schedule for P. setiferus larvae is recommended including a progressive increase in the concentration of diatoms (between protozoea and mysis; 30 and 40 × 10 3 cells/ml, respectively), flagellates (between protozoea and mysis; 2 × 10 3 cells/ml, respectively) and Artemia nauplii (0.5, 1.0 and 1.5 between PZ 3-M 1, M 1-M 2 and M 2-M 3, respectively). The increase in concentration of algae and Artemia indicates a pattern of development of the digestive system associated with development of the larvae. This pattern must be considered to improve the production of larvae of this species under controlled conditions.

Availability of Deep Seawater and Effects of Bacteria Isolated from Deep Seawater on the Mass Culture of Food Microalga Chaetoceros ceratosporum.

The possible availability of deep seawater (DSW; seawater under the euphotic layer) and bacteria isolated from DSW (BDS) for the mass culture of food microalga Chaetoceros ceratosporum was investigated. Seawater samples pumped up from a depth of 320m at the kochi Deep Seawater Laboratory in Muroto, Kochi Prefecture, were collected and used for cultivation of C. ceratosporum. Growth rate (ƒE: reciprocal of the dubling time) and maximum cell yields (MCY) of the alga in untreated DSW were 1.25-2.22 (average 1.72).day-1 and 2-11 (average 6) x 105 cells/ml, respectively. When compared with those obtained by ASP6 medium, the average ,ƒEin DSW was about 90% and the values of MCY were 5-20% of those in ASP6. The values of MCY, however, showed a relatively large variance according to the sampling season of DSW. When some BDS were added to DSW, the growth of C. ceratosporum was often stimulated significantly; the ƒE values were 1.82-2.86 (average 2.27). day-1 and MCYs were 4-12 (average 8) x 105 cells/ml. Moreover, the variance of ƒE and MCY according to the sampling season tended to decrease when BDS were added. These results suggest that DSW has a high potential for cultivating food microalgae, and it can be made more stable and effective by adding BDS.

Plaque Formation by Algicidal Saprospira sp. on a Lawn of Chaetoceros ceratosporum.

The bacterial strains belonging to the genus Saprospira were isolated from sea water samples in Kagoshima Bay and shrimp aquaculture ponds by using of the mixed culture with marine diatoms and double layer agar techniques. A Saprospira strain SS90-1 formed crater-like plaques on a lawn of Chaetoceros ceratosporum, which enlarged unlimitedly in the way of concentric cycles during an incubation period under illumination. The plaque formation by Saprospira SS90-1 was repressed with antibiotics including penicillin G, ampicillin, strepto-mycin, erythromycin, and tetracycline.

Exposure of phytoplankton to ekofisk crude oil

Solutions of Ekofisk crude oil in sea water were prepared by slow stirring for 21h in a closed system. Headspace and GC/MS techniques were applied to establish dose composition and levels. The standardized test medium produced in a closed system contained approximately 14 mg oil per litre and was dominated by low molecular weight aromatic hydrocarbons and phenols. The toxicity of the standarized oil-containing medium to three marine diatoms was studied in a cage culture turbidostat and by conventional batch culture technique. The three algal species differed in sensitivity to the oil compounds, but showed identical ranking in both test systems. Standardized test medium diluted to 50% with respect to oil content stopped the growth of the most sensitive alga, Skeletonema costatum. For comparison naphthalene was applied and gave 50 % growth reduction at a concentration of 400 μg litre −1. The growth of Chaetoceros ceratosporum was only slighty affected by the full strength standard test medium, which had no influence on the growth of Phaeodactylum tricornutum, the least sensitive organism. The presence of an oil layer on the surface of the standard test medium during the growth test greatly increased its toxicity and blocked completely the photosynthesis even of P. tricornutum after 4 days.

Values of net compensation irradiation and their dependence on photosynthetic efficiency and respiration in marine unicellular algae

Daily compensation irradiation for net photosynthetic rates (ΣIcomp) of Skeletonema costatum (Greville) Cleve, Chaetoceros ceratosporum Ostenfeld, Nitzschia sp., Thalassiosira nordenskioldii Cleve, and Chroomonas salina (Wislouch) Butcher were measured during 1979 to obtain values for use in ecological models describing compensation and critical depths of marine phytoplankton. Batch cultures of these unicellular algae were exposed to temperatures and photoperiods varying from 6° to 15°C and 8.4 to 16.0 h, conditions typical of surface water in Saanich Inlet, a fjord in Vancouver Island, British Columbia, Canada. Results obtained with S. costatum and T. nordenskioldii provided estimates of ΣIcomp varying between 1.8 and 13 J cm-2 d-1, from which a mean value of 7.0 J cm-2 d-1 was calculated for use in ecological models with neritic phytoplankton. No seasonal variation in compensation irradiation was noted because photosynthetic efficiencies, which increased as division rates increased, were balanced by respiration rates, which increased as temperature increased. Results obtained with Chaetoceros ceratosporum, Nitzschia sp., and Chroomonas salina were difficult to interpret, because respiration rates were stimulated and depressed by light, respectively, for the first two species and the last one. This light effect was greatest when cells grew under conditions of low temperature and short photoperiod. Also, under winter and spring conditions, cells of Nitzschia sp. appeared to fix CO2 in the dark and with low irradiances by mechanisms other than photosynthesis.

Preliminary rearing experiments on the larvae of Sergestes lucens (Penaedia, Natantia, Decapoda)

Sergestes lucensHansen, a mesopelagic shrimp fished commercially in Suruga Bay, Japan, was successfully reared from egg to post-larval stage V under laboratory conditions. Chaetoceros ceratosporum and Artemia nauplii were found to be satisfactory food in the laboratory during rearing. Growth, mortality, food preference, and feeding and swimming activities during the various developmental stages were investigated. Temperature changes greatly affected the speed of development and the mortality of the larvae. The optimum temperature range for larval development was 18° to 25°C. The growth rate (length) of larval stages was as rapid as 0.16mm/ day at 20 °C and 0.21 mm/day at 23 °C. The larvae first started feeding on phytoplankton at elaphocaris stage I, and then gradually became predators in the post-larval stages. It is suggested that the critical period for the species occurs in the elaphocaris stages. Environmental data, vertical distribution of the species, and data obtained from laboratory experiments suggest that the fluctuation in the abundance of S. lucens is greatly influenced by the water temperature at around 50 m from June to August. Feeding mechanisms observed in the post-larval stages are described.