Challenges in Controlling Vibriosis in Shrimp Farms

*Hethesh Chellapandian, Jeyachandran Sivakamavalli, A. Vijay Anand and Balamuralikrishnan Balasubramanian*

## **Abstract**

Recently the shrimp farming has blooming as a crucial counterpart in the aquaculture industry which contribute the remarkable role in sea food production as well economy of the country. However, this could be fluctuated every year through several circumstances such as unfavorable (Poor water and soil quality) environmental factors. The environmental factors includes disease causing bacterial pathogens in the soil and water which causes the bacterial diseases in the aquatic animals, like this hectic problems are prevented through bioaugmentation strategies. The pond environment plays a vital role in determining the healthy culture system, but there is high risk for manipulation by bacterial community which takes care of waste generated in the system through *in situ* bioremediation. Due to the impact of rapidly growing bacterial diseases of shrimps throughout the world, numerous studies have been carried out to find immunostimulants, immunomodulators and biotic component that can be used against vibrio causing pathogens, and can also be used as an alternative for antibiotics. Recent research focus towards the marine resources such as microalgae, seaweed, live feeds (like artemia, copepods, rotifers), bacteriophage, and probiotics have been found to have higher potential in reducing vibriosis. Eco-based shrimp farming includes green water technology, phage therapy bio-floc technology (BFT) and integrated multitrophic aquaculture (IMTA), these methods hold a promising alternative to antibiotics in the near future. Bacterial diseases caused by vibrios have been reported in penaeid shrimp culture systems implicating at least 14 species and they are *Vibrio harveyi, V. splendidus, V. parahaemolyticus, V. alginolyticus, V. anguillarum, V. vulnificuslogei* etc.

**Keywords:** Immunity, Hypoxia, Salinity, pH, Vibriosis, Probiotics

#### **1. Introduction**

Vibriosis is a bacterial disease caused by *Vibrio* which is Gram-negative, motile, facultative anaerobe bacteria of the family Vibrionaceae. It is ubiquitous throughout the world and in all marine crustaceans, including shrimp. Vibriosis is one of the major disease problems in shellfish and finfish aquaculture, especially in shrimp farming. Vibriosis is a bacterial disease responsible for mortality of cultured shrimp worldwide. Various studies has been done to find a remedy for vibriosis in rearing as well as shrimp culture ponds. Certain studies show that usage of microalgae, bacteriophage, and probiotic bacteria have been found to have higher potential in reducing vibriosis. Vibriosis is a series of bacterial infections caused by a bacterium belongs to the genus *Vibrio*. Black shell disease, bacterial septicemia,

hepatopancreatic necrosis, brown gill disease, swollen hindgut syndrome and luminous bacterial disease [1]. High density of the bacterial species in culture pond increases the probability of getting viral diseases, especially white spot syndrome

The pacific white shrimp (*Litopenaeus vannamei*), Indian white shrimp (*Fenneropenaeus indicus*), Black tiger shrimp (*Penaeus monodon)* are important commercial species of the penaeid family. *Fenneropenaeus indicus* supports commercial fisheries in both marine and brackish water environments on the east and west coasts of India. India is one of the major suppliers of shrimp to Japan, Europe, Thailand and USA [2]. The secondary infection of vibrios in *P. monodon* occurs due to poor water quality, stress, high stocking density, unstable environmental conditions, toxins and virion particles. Vibriosis is caused by a number of bacteria belongs to *vibrio* species which includes; *Vibrio harveyi, V. splendidus, V. parahaemolyticus, V. alginolyticus*. There have been occasional reports of vibriosis caused *by V. damsella, V. fluvalis* and other undefined *vibrio* species [3].
