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Surat Thani, Thailand

Kiatmetha P.,Prince of Songkla University | Kiatmetha P.,Shrimp Genetic Improvement Center | Siangdang W.,King Mongkuts University of Technology Thonburi | Bunnag B.,King Mongkuts University of Technology Thonburi | And 2 more authors.
Aquaculture International | Year: 2011

The purpose of this study was to compare the performance of two species of diatoms, Thalassiosira weissflogii and Chaetoceros gracilis, in the larviculture of the black tiger shrimp Penaeus monodon. Shrimp larvae were fed with either C. gracilis, T. weissflogii, or a combination of the two species of diatoms. The larvae fed solely with T. weissflogii or a combination of the two types of diatom had significantly higher survival rates and faster metamorphosis than those fed solely with C. gracilis. The numbers of diatom cells consumed by larvae during 3-h periods were determined, revealing that larvae consumed significantly higher numbers of C. gracilis than T. weissflogii. However, when the protein, total fatty acid, and polyunsaturated fatty acid content of the two species of diatom are compared, significantly higher amounts of each are found in T. weissflogii. Converting the number of diatom cells consumed into equivalent protein, total fatty acid, eicosopentaenoic acid, and decosahexaenoic acid reveals that larvae fed with T. weissflogii received significantly higher amounts of all the nutrients, compared to those consuming C. gracilis. The results showed an advantage of feeding T. weissflogii to C. gracilis in enhancing survival and metamorphosis in P. monodon larvae. © 2010 Springer Science+Business Media B.V. Source

Mueangdee N.,Prince of Songkla University | Pongtippatee P.,Prince of Songkla University | Promkun P.,Prince of Songkla University | Bootterb M.,Prince of Songkla University | And 7 more authors.
Aquaculture | Year: 2013

This research is aimed at developing an automatic spawning detection system for the black tiger shrimp, Penaeus monodon. This system is composed of instruments which are attached to the inner wall of the spawning tank that contains light sensing circuits which change light intensity into electrical signals. The detection unit is composed of a polyvinyl chloride (PVC) pipe containing a light emitting diode (LED) bulb that serves as a light source transmitter, and a light-dependent resistor (LDR) that serves as a light receiver which transforms light intensity into electrical resistance. Placed between the LED bulb and the LDR is a 135μm nylon mesh screen that is stretched horizontally inside the pipe to filter out shrimp eggs. Changing signals from the LDR turns on (or off) a 220. V bulb. This device detects spawning activity as early as 22. s after the onset of spawning. There is a correlation that exists between the number of spawned eggs and the time of the onset of spawning, with earliest detection occurring with the highest number of eggs. © 2012 Elsevier B.V. Source

Tangprasittipap A.,National Center for Genetic Engineering and Biotechnology | Tangprasittipap A.,Mahidol University | Chouwdee S.,National Center for Genetic Engineering and Biotechnology | Chouwdee S.,Mahidol University | And 6 more authors.
General and Comparative Endocrinology | Year: 2012

Although many crustacean neuroendocrine hormones have been reported, the enzymes responsible for post-translational modification of neuroendocrine hormones have rarely been characterized. A prohormone convertase 2 (PC2)-like enzyme has been isolated from the optic lobe of the giant tiger shrimp, Penaeus monodon and referred as PmPC2. The full length cDNA sequence of PmPC2 has been identified and found to resemble evolutionarily conserved PC2 enzymes of vertebrates and invertebrates. PmPC2 was expressed in all larval developmental stages and in neuroendrocrine cells in the adult optic lobe. Its expression was found to be negatively related with shrimp body weight by qPCR (P< 0.05). Immunohistochemistry results using an anti-rPmPC2 antibody with adult shrimp revealed high staining intensity in specific neurosecretory cells including the sinus gland, the organ of Hanström (also referred to as the medullar terminalis X-organ) and the organ of Bellonci (also referred to as the sensory or X-organ). By using the yeast two hybrid technique, PmPC2 was found to bind with P. monodon hyperglycemic hormone (Pem-CHH1) that plays an important role in glucose metabolism. Since PmPC2 is a subtilisin-like serine proteinase, it is expected to cleave the synthetic substrate, pyr-RTKR-MCA, but the expressed recombinant catalytic domain of PmPC2 (rPmPC2-cat) showed no enzymatic activity as expected. In vivo injection of dsRNA-PmPC2 resulted in reduced transcripts for both PmPC2 and Pem-CHH1 on day 3 post injection, but there was no accompanying reduction of glucose level in the hemolymph. Taken together, PmPC2 localization, expression and activity suggest that it has a function(s) in the shrimp neuroendrocrine system and that it may not only activate Pem-CHH1 but also affect its expression. However, there is no obvious explanation for the negative correlation between PmPC2 expression level and shrimp body weight. © 2012 Elsevier Inc. Source

Tangprasittipap A.,Mahidol University | Tiensuwan M.,Mahidol University | Withyachumnarnkul B.,Mahidol University | Withyachumnarnkul B.,National Science and Technology Development Agency | Withyachumnarnkul B.,Shrimp Genetic Improvement Center
Aquaculture | Year: 2010

The optic lobe of the female-shrimp eyestalk was selected as the target tissue for suppressive subtractive hybridization (SSH) because it is a place for synthesis of many hormones and peptides/enzymes involved in molting and growth. SSH was performed to screen genes differentially expressed in the optic lobe between large female (LF; body weight>90 percentile of weight distribution curve) and small female (SF; body weight<10 percentile). A total of 426 recombinant clones were obtained from the two directions. After sequencing and analysis less than 30% of the resulting expressed sequence tag (EST) exhibited high homology to known records at GenBank (BlastX with E-value<10-4) indicating little available molecular information on the optic lobe. Among the EST with relatively high homology to GenBank records, 5 candidate ESTs had homology to records for genes involved in cell differentiation/proliferation, cell cycle and hormone processing. These included genes resembling cyclophilin, cyclophilin A, fibrillarin, SPARC and PC2. These candidate ESTs were selected to confirm the reproducibility of the SSH data using semi-quantitative RT-PCR normalized with EF-1α. Pearson's correlation analysis confirmed that the index of relative cyclophilin, SPARC and fibrillarin-like expression was negatively correlated with body weight (p<0.05) and this supported the SSH data indicating their low relative expression in LF shrimp when compared to SF shrimp. The index of relative cyclophilin-like expression showed the highest correlation coefficient with body weight (r=-0.678). The relationship could be expressed by inverse fitted equation: body weight (g)=38.243/(index of relative cyclophilin-like expression). This fitted inverse model could predict the body weight of female shrimp with 91.6 % coefficient of determination (R2) based on the index of relative cyclophilin-like expression in the optic lobe of female P. monodon. © 2010 Elsevier B.V. Source

Pongtippatee P.,Aquatic Animal Biotechnology Research Center | Laburee K.,Aquatic Animal Biotechnology Research Center | Thaweethamsewee P.,Prince of Songkla University | Hiranphan R.,Prince of Songkla University | And 5 more authors.
Aquaculture | Year: 2012

This study seeks to determine the best method for preventing the second body (PBII) extrusion as a means to induce triploidy in the black tiger shrimp Penaeus monodon. Chemical (cytochalasine-B and 6-dimethylaminopurine) and temperature (heat and cold) shocks were applied to newly fertilized eggs. Cold shock that was administered at 8 °C, for 10. min at 8. min post-spawning, was the best method for PBII triploidy induction, as evidenced by the highest percentage of forming three pronuclei in syngamy. Therefore, cold shock induction was employed to further explore the advantage of triploid over diploid shrimp. After hatching of the cold-shocked eggs, the larvae were allowed to reach juvenile and adult levels of development. The number and amount of chromosomes were determined in juveniles and adult stages, using Fluorescence Activating Cell Sorting methods, by which the shrimp were divided into diploid and triploid groups. At day 150 in culture, the average body weight of the triploid females (35.2 ± 3.2. g) and triploid males (31.5 ± 3.5. g) was significantly higher (P< 0.0001) than that of their diploid counterparts (24.5 ± 0.5. g for females and 23.1 ± 3.8. g for males), having a ratio of 2 females:1 male for triploid shrimp, and 2 females:3 males for diploid shrimp. These results reveal the advantages of growing triploid over diploid P. monodon, and its feasibility for commercial production. © 2012 Elsevier B.V. Source

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