Antimicrobial activity of tissue and associated bacteria from benthic sea anemone Stichodactyla haddoni against microbial pathogens.

Associated bacteria from Stichodactyla haddoni are found maximum in tentacle tissues than the body tissue. There are eight associated bacterial species viz., Alcaligenes sp, Corynebacterium sp, Aeromonas sp, Sporosarcina sp, Renibacterium sp, Camobacterium sp1, Camobacterium sp2 and Salinococcus sp were recorded. The culture extracts from the associated bacterial species showed sensitivity against human bacterial and fungalpathogens. However, the hexane tissue extract of sea anemone showed maximum sensitivity (24 mm dia.) against the fish bacterial pathogen Aeromonas hydrophila than the other chosen pathogens. Comparatively the tissue extracts showed promising antimicrobial sensitivity than the cell free extracts of associated bacteria, and hence, the tissue samples from the sea anemone Stichodactyla haddoni is recommended for further exploration of novel antimicrobial drugs than the associated bacteria.

Physiological correlates of surfacing behaviour--effect of aquarium depth on surfacing, growth and metamorphosis in Rana tigrina.

Rana tigrina were reared from hatching to metamorphosis in aquaria containing different depths but equal volume of water. To exchange atmospheric air, tadpoles in the shallow aquarium surfaced less frequently, travelled shorter distance at less metabolic energy cost and hence grew larger (3.1 g) at a higher (25%) efficiency than those (2.5 g; 19% efficiency) reared in the deepest aquarium. Aquarium depth is a more potent factor than pO2 in the regulation of surfacing behaviour. The significant and positive correlations observed between feeding, metabolism and growth, on one hand, and surfacing behaviour, on the other, can serve as an index of metabolism of the tadpole.