The effectiveness of 2 phenoxyethanol (2 PE), quinaldine (2-methyl quinoline), benzocaine (ethyl 4 aminobenzoate) and tertiary amyl alcohol (TAA) was tested to determine their optimal dosages for rapid induction and recovery in the first experiment, while the second experiment evaluated the effects of low dose quinaldine (175 µl/L) and 2 PE (250 µl/L) with oxygen for 1, 3, 6 and 9 h on the mortality and water qualities at 400 g/L rohu Labeo rohita fingerlings in a truck transport simulation. Optimum dosages of 2 PE (250 µl/L), quinaldine (175 µl/L), benzocaine (40 mg/L) and TAA (1.5 ml/L) were found to have rapid (within 6 min) immobilization and recovery. Very low level of immediate and delayed mortality (<1%) was found across all three transport methods. While 2 PE had dissolved oxygen (DO) concentration above 13 mg/L, quinaldine had lower level. Results suggest that rohu fingerlings at 400 g/L can be transported for 9 hours with oxygen with or without sedatives.

Costus speciosus (J. Koenig) Sm., commonly known as crepe ginger, is primarily used as an ornamental plant worldwide. The aim of this research was to study the phytoconstituents of locally collected C. speciosus plant samples and test their antimicrobial effect against selected bacterial strains. Phytochemical analysis showed the presence of alkaloids, flavonoids, steroids, phenolic compounds, tannins, glycosides, and cardiac glycosides in the extracts. The extracts displayed variable degrees of antibacterial activity against the microorganisms in a bioautography experiment based on thin-layer chromatography. All the extracts showed activity against S. aureus, and none showed any activity against P. aeuroginosa. The ethanol and ethyl acetate extracts from the plant leaf and stem showed efficacy against S. typhi and B. subtilis, while the ethyl acetate extracts prevented the growth of S. pneumoniae. Only the ethanol extract from plant leaves had a negligible effect on K. pneumoniae. Bangladesh J Microbiol, Volume 39, Number 2, December 2022, pp 46-52