Inter-Research > DAO > v143 > p189-193  
DAO
Diseases of Aquatic Organisms

via Mailchimp

DAO 143:189-193 (2021)  -  DOI: https://doi.org/10.3354/dao03567

NOTE
Outbreaks of epizootic ulcerative syndrome in Kerala, India following episodes of flooding

Bini C. Das1, Divya V. Haridas1, Nithin Jacob1, Arunendhu Ramakrishnan2, Anvar Ali P. H.2, Rejish Kumar V. J.1,3, Devika Pillai1,*

1Department of Aquatic Animal Health Management, Kerala University of Fisheries and Ocean Studies, Panangad, Kochi 682506, India
2Department of Fisheries Resource Management, Kerala University of Fisheries and Ocean Studies, Panangad, Kochi 682506, India
3Department of Aquaculture, Kerala University of Fisheries and Ocean Studies, Panangad, Kochi 682506, India
*Corresponding author:

ABSTRACT: Large-scale fish mortality was observed in flood-affected fish farms across several parts of Kerala following heavy rainfall in August 2018 and 2019—nearly 53% above the normal monsoon rain that the region receives. The affected fish had severe haemorrhages and ulcers, typical of the highly infectious disease epizootic ulcerative syndrome (EUS) caused by the water mould Aphanomyces invadans. In freshwater, snakeheads Channa spp. and in brackish water mullet (Mugilidae) and pearl spot (Etroplus suratensis) were severely affected. EUS was observed in 4 freshwater fishes for the first time: dotted sawfin barb Pethia punctata (Cyprinidae), Malabar leaffish Pristolepis malabarica (Pristolepididae), mahecola barb Puntius mahecola (Cyprinidae) and giant snakehead Channa pseudomarulius (Channidae). Histology and molecular diagnosis confirmed the cause of mortality to be EUS. Fungal hyphae were also observed in deeply ulcerated fish, revealed by lactophenol cotton blue staining. The severity of the EUS outbreak was linked to the sudden change in water quality associated with the flood, such as lower water temperature, and decreases in pH, total alkalinity and total hardness.


KEY WORDS: EUS · Aphanomyces invadans · Water mould · Oomycete · Kerala · Flood-induced stress · Multiple host


Full text in pdf format 
Cite this article as: Das BC, Haridas DV, Jacob N, Ramakrishnan A, PH AA, VJ RK, Pillai D (2021) Outbreaks of epizootic ulcerative syndrome in Kerala, India following episodes of flooding. Dis Aquat Org 143:189-193. https://doi.org/10.3354/dao03567

Export citation
RSS - Facebook - - linkedIn