Shinn-Pyng Yeh

Dietary sodium alginate administration affects fingerling growth and resistance to Streptococcus sp. and iridovirus, and juvenile non-specific immune responses of the orange-spotted grouper, Epinephelus coioides

The percent weight gain (PWG) and feeding efficiency (FE) of fingerling orange-spotted grouper, Epinephelus coioides, fed diets containing sodium alginate at 1.0 and 2.0 g kg(-1) were calculated on the 2nd, 4th, 6th, and 8th weeks after feeding. Survival rates of the fingerling grouper against Streptococcus sp. and an iridovirus, and non-specific immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory bursts, superoxide dismutase (SOD) activity, and phagocytic activity of juvenile grouper were also determined when the fish were fed diets containing sodium alginate at 0.5, 1.0, or 2.0 g kg(-1). The PWG and FE of fish were better when the fish were fed diets containing sodium alginate at 1.0, and 1.0 and 2.0 g kg(-1), respectively. The PWG and FE of fish fed the 0, 1.0 and 2.0 g kg(-1) sodium alginate-containing diets after 8 weeks were 271.0%, 454.4% and 327.8%, and 0.61, 0.72 and 0.68, respectively. Fish fed a diet containing sodium alginate at the level of 2.0 g kg(-1) had a significantly higher survival rate than those fed the control diet after challenge with Streptococcus sp. and an iridovirus causing an increase of survival rate by 25.0% and 16.7%, respectively, compared to the control group. The ACH(50) level of fish fed the sodium alginate-containing diets at 2.0 g kg(-1) was significantly higher than those fed the 1.0 g kg(-1) sodium alginate diet and control diet after 12 days, and had increased to 1.9-fold, compared to those fed the control diet. The lysozyme activity, phagocytic activity, respiratory bursts, and SOD level of fish fed the sodium alginate-containing diets at 1.0 and 2.0 g kg(-1) were significantly higher than those fed the control diet after 12 days, and had increased to 1.97- and 1.68-fold, 1.35- and 1.50-fold, 1.63- and 1.81-fold, and 1.23- and 1.31-fold, respectively, compared to those fed the control diet. We therefore recommend dietary sodium alginate administration at 1.0 and 2.0 g kg(-1), respectively, to promote growth and enhance immunity and resistance against Streptococcus sp. and an iridovirus.

Immune response of white shrimp, Litopenaeus vannamei, after a concurrent infection with white spot syndrome virus and infectious hypodermal and hematopoietic necrosis virus

In the present study, we investigated immunological changes in viral-infected white shrimp, Litopenaeus vannamei. White shrimp were infected with white spot syndrome virus (WSSV) or co-infected with WSSV and infectious hypodermal and hematopoietic necrosis virus (IHHNV) as detected by polymerase chain reaction (PCR). The complete (100%) mortality rate of shrimp was caused by viral infection due to immune parameters being suppressed including decreases in phenoloxidase activity, total hemocyte counts, differential hemocyte counts, and the gene expressions of prophenoloxidase and peroxinectin. In addition, increases in lipopolysaccharide and beta-1,3-glucan-binding protein of hemocytes and the hepatopancreas, and respiratory bursts per cell, and a decrease in superoxide dismutase were found in viral-infected shrimp, which may have been related to the defense against viral infection.

The increase of immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii by feeding with selenium enriched-diet.

The effects of inorganic selenium (Se) (sodium selenate, SSe) and organic selenium (seleno-l-methionine, MSe) supplementation on the immune response, antioxidant status, and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii, were studied. Five experimental diets, including a control diet (without Se enrichment), 0.5 mg (kg diet)(-1) of MSe, 1 mg (kg diet)(-1) of MSe, 0.5 mg (kg diet)(-1) of SSe, and 1 mg (kg diet)(-1) of SSe, were used. After 75 days of culture, prawn fed the Se-enriched diets had lower mortality compared to that of prawn fed the control diet after being challenged by the pathogen, Debaryomyces hansenii. No significant differences in the total hemocyte count, superoxide dismutase activity, or clearance efficiency of prawn were recorded among the control and treated groups. Significantly increased phenoloxidase and phagocytic activities in prawn fed the Se-enriched diets were found compared to the controls. Respiratory bursts of prawn fed both forms of 1 mg Se (kg diet)(-1) significantly increased compared to control prawns. For the antioxidant status analysis, glutathione peroxidase, glutathione reductase, and glutathione s-transferase of prawn fed the SSe-enriched diet at 1 mg (kg diet)(-1) were significantly increased. The results indicated that the cheaper selenium, SSe is recommended to be added in prawn feed at the concentration of 0.5 mg resulting in 1.5 mg SSe (kg diet)(-1) increased prawn immunity and disease resistance against the pathogen, D. hansenii.

Osmotic and ionic changes in Taiwan abalone Haliotis diversicolor supertexta at different salinity levels

Abstract Osmotic and ionic changes in Taiwan abalone Haliotis diversicolor supertexta (5.4±0.28 cm) were investigated after they were transferred individually from 33 practical salinity unit (psu) to 23, 28, 33 and 38 psu after 0.25, 0.5, 1, 2, 3, 6 and 9 days. Hemolymph osmolality of abalone stabilized within 2 days after they were transferred to different salinities from 33 psu. Hemolymph osmolality, Cl−, Na+ and K+ concentrations increased directly with medium salinity. Hemolymph osmolality was 652, 789, 945 and 1103 mOsm kg−1 for the abalone transferred to 23, 28, 33 and 38 psu, respectively. Hemolymph Cl− was 275, 323, 365, 409 mmol l−1, hemolymph Na+ was 312, 376, 465, 569 mmol l−1 and hemolymph K+ was 8.2, 10.1, 11.9, 12.8 mmol l−1 for the abalone transferred to 23, 28, 33, 38 psu, respectively. It is concluded that H. diversicolor supertexta are hypo-conformic and hypo-ionic with respect to Cl− and Na+, but hyper-ionic with respect to K+ over ambient media in salinity ranges of 23–38 psu.

Spatial Distributions of Phyllosoma Larvae (Crustacea: Decapoda: Palinuridae and Scyllaridae) in Taiwanese Waters

Distributions and taxonomy of phyllosoma larvae were examined in Taiwanese waters, based on ichthyoplankton samples collected from May 1990 to July 1995. Phyllosoma larvae belonged to the two families Scyllaridae and Palinuridae representing 6 genera and 13 species. Of the collected phyllosoma larvae, those of Scyllarus and Panulirus species were most abundant, forming 90% of total numbers. Early stage Scyllarus and Panulirus phyllosoma larvae were abundant in Taiwanese waters. Middle to late stages (except the final stage) of Panulirus phyllosoma larvae were absent from the waters throughout the year, while those of Scyllarus phyllosoma larvae were collected in the waters. This suggests that all stages of Scyllarus phyllosoma larvae may be retained in the northern part of the waters around northern Taiwan while middle to late stages of Panulirus phyllosoma larvae may be flushed out from the waters, the sub-final and final stages then possibly returning to the waters. An anticlockwise eddy existed in the waters off northeastern Taiwan, which may be closely related to flushing out and returning of Panulirus phyllosoma larvae through a much longer planktonic period.

Improved Survival Under Vibrio Challenge and Enhanced Immunogene Transcription of the Pacific White Shrimp, Litopenaeus vannamei, which were Oral Administrated with Brown Algae Extract, Endarachne binghamiae, Via Enriched Artemia

White shrimp, Litopenaeus vannamei (5±0.6 g), which received the extract from the brown alga, Endarachne binghamiae (EB), at 20 μg shrimp^(-1) showed a significantly increased survival rate after challenge with Vibrio alginolyticus. Lipopolysaccharide- and β-1, 3-glucan-binding protein (LGBP), prophenoloxidase (proPO), peroxinectin (PE), glutathione peroxidase (GPX), lysozyme (LYS), and serine proteinase (SP) gene expression were used as immune indicators to evaluate the state of immunity of white shrimp postlarvae (PL10) after having been individually fed Artemia nauplii which had been exposed to 0, 5, and 10 gl^(-1) of the extract of EB for 4 h. Results showed that the expressions of LGBP, PE, GPX, and LYS were significantly elevated in shrimp postlarvae fed the extract of EB-enriched Artemia nauplii after 144 h. It was concluded that administration of the extract of EB induces immune modulation, enhances the immune ability of L. vannamei, and increase its resistance to V. alginolyticus infection.

The Influence of Epistylis sp. on Osmotic, Ionic, and Respiratory Physiology of the Giant Freshwater Prawn, "Macrobrachium rosenbergii" in the Terminal-growth Stage

Differences in osmolality, ion concentrations, and respiratory metabolism of the hemolymph were investigated in terminal-growth male and other morphotypes of healthy prawn, including males of orangeclaw and blue-claw, and females of the giant freshwater prawn, Macrobrachium rosenbergii. In addition, gill-injured prawns were also used to analyze those same parameters in this study. No significant differences in hemolymph osmolality, ion levels, or respiratory metabolism among blue-claw males, orange-claw males, and females were found. Hemolymph osmolality, chloride, potassium, sodium, calcium, and magnesium concentrations in terminal-growth males were significant lower than in other types of prawn. Significantly lower oxyhemocyanin and protein, and significantly higher hemolymph pH and PCO2 in terminal-growth males were found compared to other types of prawn. Insignificant differences in the ratio of oxyhemocyanin and protein, and in hemolymph PO2 among terminal-growth males and other types of prawn were recorded. Histopathological lesions in gills of terminal-growth males caused by an Epistylis sp. infestation and impurities covering the gills were found, that may have involved interference with gas exchange, hemolymph osmolality, and ion regulation. Prawns with partially injured gills had significantly decreased regulation of osmolality and ions in the hemolymph, but no significant change in respiratory metabolism compared to control prawn. Prawn gills are considered the main tissuefor hemolymph osmolality and ion regulation because hemolymph osmolality and ion levels of prawn decreased when gills of prawn were partially injured. However, respiratory metabolism was compensated for by normal gills in prawns with partially injured gills. The information obtained from this study adds to knowledge of prawn pathophysiology and may give a clearer profile of changes in hemolymph osmolality, ion concentrations, and respiratory metabolism caused by gill injury.

Effects of Temperature on Color Metamorphosis and Growth Performance of Hybrid Ornamental Fish, Blood Parrotfish (Cichlasoma citrinellum × Cichlasoma synspilum)

The color metamorphosis, growth performance, food intake, total harvest weight and survival rate of a juvenile hybrid ornamental fish, blood parrotfish fish (Cichlasoma citrinellum × Cichlasoma synspilum) was studied at three different temperature, 18oC, the temperature of natural variation (24.4-28.7℃) and 32℃ for 84 days, respectively. The results showed that growth rate of blood parrotfish reared at 32℃ was significant higher than that of blood parrotfish reared fish at 18℃ and natural temperature variation, resulted from the increase of food intake accompanying a decrease of feed conversion ratio. In addition, an adverse temperature of 18℃ results in an insignificant growth and no color metamorphosis in blood parrotfish during 84 days of culture. Results of the present study strongly suggested that better rearing temperature of blood parrotfish is 32℃.