The activities of the enzymes N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT) and the hormone melatonin were studied in the optic lobe of the subadult giant tiger shrimp Penaeus monodon. Compared with the level in other species, a relatively high level of NAT activity that was temperature- and pH-dependent were observed. The NAT enzyme had a relatively high maximum velocity (Vmax, 100 pmol/hr/micrograms protein) and low Michaelis constant (Km, 22 microM), when tryptamine is used as substrate. In contrast to the high level of NAT activity, HIOMT activity and melatonin levels were low in the optic lobe of the giant tiger shrimp. Sex differences in the levels of NAT activity and melatonin, which are observed in a freshwater species Macrobrachium rosenbergii, were not noticeable in the saltwater species P. monodon, at least not when they were in their subadult stage.
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http://dx.doi.org/10.1111/j.1600-079x.1995.tb00162.x | DOI Listing |
BMC Microbiol
December 2024
Aquatic Environmental Biotechnology (AEB) Division, ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore, 700120, India.
Ecytonucleospora hepatopenaei (EHP), a microsporidian parasite first named and characterized from the Penaeus monodon (black or giant tiger shrimp), causes growth retardation and poses a significant threat to shrimp farming. We observed shrimp farms associated with disease conditions during our fish disease surveillance and health management program in West Bengal, India. Shrimp exhibited growth retardation and increased size variability, particularly in advanced stages, exhibiting soft shells, lethargy, reduced feeding and empty midguts.
View Article and Find Full Text PDFEMBO Rep
December 2024
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101, Beijing, China.
Sci Rep
September 2024
Graduate School of Science, Kobe University, Rokkodai 1-1 657-8501, Kobe, Japan.
Ganymede has an ancient impact structure called a furrow system. The furrow system is the largest impact structure in the outer solar system, and the impact should have significantly affected Ganymede's early history; however, its effects are poorly understood. No attention has been given to the center of the furrow system coinciding with Ganymede's tidal axis, indicating that mass redistribution induced by the furrow-forming impact caused a reorientation (true polar wander) of Ganymede.
View Article and Find Full Text PDFEnviron Int
August 2024
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China. Electronic address:
Genes (Basel)
March 2024
Key Laboratory of Monitoring Biological Diversity in Minshan Mountain of National Park of Giant Pandas, College of Life Science & Biotechnology, Mianyang Normal University, Mianyang 621000, China.
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