Performance of a shipwreck as an artificial fish habitat along Goa, west coast of India

Aim: The objective of the study was to test the hypothesis that submerged shipwrecks along the western coast of India can function as artificial fish habitats with trophic structure of fish assemblages similar to natural rocky reef habitats. Methodology: The fish assemblages on shipwreck and natural reefs were analysed from September 2013 to December 2016 using diver assisted underwater visual census (UVC). Data collected on fish assemblages were used to compare the fish trophic structure between shipwreck and natural reefs using diversity indices, permutational multivariate analysis of variance and similarity percentage analysis. Results: Fish abundance was two times greater on shipwreck than on natural reefs and the major trophic guilds on shipwreck were omnivores and carnivores. Multivariate analyses showed a distinct fish trophic structure on shipwreck from that of natural reefs and certain fish species differentiated the trophic structure of shipwreck from natural reefs. The high densities of Pomadasys furcatus, P. guoraca, Pempheris multiradiata, Lutjanus indicus, L. fulvus, Ostorhinchus compressus, Epinephelus coioides, E. erythrurus, Monodactylus argenteus and Heniochus singularis contributed significantly to the average dissimilarity for fish assemblages in shipwreck from natural reefs. This has helped to differentiate the fish communities on shipwreck from natural reefs. Interpretation: This study showed that shipwreck and natural reefs differ significantly in fish trophic structure. Fish species richness and abundance were significantly higher on shipwreck than natural reefs. Therefore, the Greater species richness, abundance and diversity of fish communities on shipwreck could be a result of unique, complex and heterogeneous habitat features existing within the wreck

Changing facades of Vibrio cholerae: An enigma in the epidemiology of cholera

Cholera, caused by the Gram-negative bacterium Vibrio cholerae, has ravaged humanity from time immemorial. Although the disease can be treated using antibiotics along with administration of oral rehydration salts and controlled by good sanitation, cholera is known to have produced mayhems in ancient times when little was known about the pathogen. By the 21st century, ample information about the pathogen, its epidemiology, genetics, treatment and control strategies was revealed. However, there is still fear of cholera outbreaks in developing countries, especially in the wake of natural calamities. Studies have proved that the bacterium is mutating and evolving, out-competing all our efforts to treat the disease with previously used antibiotics and control with existing vaccines. In this review, the major scientific insights of cholera research are discussed. Considering the important role of biofilm formation in the V. cholerae life cycle, the vast availability of next-generation sequencing data of the pathogen and multi-omic approach, the review thrusts on the identification of suitable biofilm-inhibiting targets and the discovery of anti-biofilm drugs from nature to control the disease.