Sheryl Oliveira Fernandes¹ , R.A. Sreepada² , Shantanu S. Kulkarni² , Sheetal V. Karekar² , Resha R. Shirodkar² , Christian Vogelsang³ , P.A. Lokabharathi¹

1. Marine microbiology laboratory, CSIR-National Institute of Oceanography, Dona Paula, Goa - 403 004, India
2. Aquaculture laboratory, CSIR-National Institute of Oceanography, Dona Paula, Goa - 403004, India
3. Norwegian Institute for Water Research (NIVA), Brekkeveien 19, Kjelsaas-N-0411 Oslo, Norway
Author    Correspondence author
International Journal of Marine Science, 2013, Vol. 3, No. 40   doi: 10.5376/ijms.2013.03.0040
Received: 13 Jun., 2013    Accepted: 16 Jul., 2013    Published: 17 Aug., 2013

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Fernandes et al., 2013, Low-input Modified Extensive Shrimp Culture Systems for Penaeus monodon Restrain Vibriosis, International Journal of Marine Science, Vol.3, No.40 319-332 (doi: 10.5376/ijms.2013.03.0040)

It was hypothesized that an outbreak of vibriosis can be restrained in ponds with a low stocking density (~5 post-larvae m^-2) till harvest. Therefore, during a 135 day production cycle of Penaeus monodon at an aquaculture facility, we monitored (i) physico-chemical parameters (ii) abundance of total heterotrophic bacteria (THB), total Vibrio like organisms (TVLO) and luminescent bacteria (LB) (iii) alterations in environmental factors controlling Vibrio abundance and (iv) changes in composition of the Vibrio community. Physico-chemical parameters were within the optimum range recommended for culture of P. monodon. In source and pond water, THB abundance remained steady at 10³ CFU mL^-1 throughout the culture period whereas in sediments, they varied between 10^2-4 CFU g^-1. The abundance of TVLO and LB in pond components were below the threshold levels of 10⁴ CFU mL^-1 and 10² CFU mL^-1 respectively. THB, TVLO and LB were more abundant in the shrimp hepatopancreas (10⁵ CFU g^-1) yet apparently below the threshold for the outbreak of vibriosis in the current set up. Changes in bacterial abundance were seemingly independent of changes in environmental parameters suggesting that the systems maintained TVLO below disease-causing threshold. The Vibrio community was represented mainly by V. metschnikovii, V. fluvialis, V. mimicus and the closely related Aeromonas spp.. The vibrios in shrimp hepatopancreas were similar to other pond components with no dominance of particular species. A disease-free environment prevailed and shrimp yield was sustainable within the set framework perhaps due to the low abundance of vibrios represented by innocuous strains. 

Abundance; Bacteria; Environmental conditions; Species diversity; Shrimp culture; Vibriosis