Aquatic Health and Disease Management

The occurrence of Tilapia Parvovirus (TiPV) has been reported for the first time in India, affecting farm-bred tilapia, a popular freshwater fish species. The outbreak, causing significant mortality rates, was identified in ponds located in Walajah in Ranipet district.

Dr. Sahul Hameed, Director of the Aquatic Animal Health Laboratory (AAHL) at C. Abdul Hakeem College (CAHC) in Melvisharam, revealed that fish samples collected from ten ponds in the affected farm showed TiPV-positive results by PCR. The DNA virus led to mortality ranging from 30 to 50% in the farm and 100% mortality in laboratory settings.

Mozambique tilapia, colloquially known as “Jilabi” in Tamil, was introduced to Indian freshwater bodies in the 1950s and is considered a “poor-man’s fish.” Known for its ability to survive in low-oxygen water conditions, this fish has become invasive across the country. Nile tilapia, introduced in the 1970s, is larger and extensively cultured, available in the market for ₹100 to ₹150 per kg.

Dr. Sahul Hameed highlighted that among tilapia species, the Indian government had authorized the import of Oreochromis niloticus and red hybrids in 1970 due to their fast growth and market demand.

Tilapia farming is carried out in various parts of Andhra Pradesh and Kerala, with the fish sold in domestic markets as whole fish. In 2022, tilapia production in India was estimated at about 70,000 tonnes, with 30,000 tonnes coming from aquaculture.

The AAHL at C. Abdul Hakeem College has been regularly screening tilapia for viral pathogens under an R&D program funded by the Department of Biotechnology, Government of India, aiming to develop vaccines against such pathogens.

Dr. Sahul Hameed, leading the research team, stated that during screening in February and March 2023, the team reported the occurrence of Tilapia Parvovirus. TiPV was first reported in China in 2019 and Thailand in 2021, making India the third country to report its occurrence.

The research findings have been validated by ICAR-National Bureau of Fish Genetic Resources, Lucknow, ICAR-Central Institute of Freshwater Aquaculture, Bhubaneswar, and Kerala University of Fisheries and Ocean Studies, Cochin. The findings are now under consideration for publication in the Archives of Virology (Springer Nature Switzerland AG).

Dr. Sahul Hameed emphasized the need for research to develop a vaccine against TiPV to assist fish farmers in preventing losses. Urgent actions are also recommended to prevent the spread of TiPV to other regions of India.

Source: The Hindu

Researchers at the Federal University of São Paulo (UNIFESP) in Brazil have developed a groundbreaking biomaterial with the potential to address two critical issues in fish health and aquaculture sustainability. This bioparticle, featured in the journal Biomaterials Advances, serves as an efficient drug carrier for delivering medication directly to the gastrointestinal tract of fish, overcoming antibiotic resistance. Moreover, administered orally in powder form, it proves highly palatable to fish, maximizing treatment effectiveness while minimizing waste and pollution associated with traditional medication methods.

The key ingredient in this innovative bioparticle is a combination of chitosan and alginate, naturally derived polysaccharides from crustacean shells and seaweed, respectively. The formulation also includes arginine, an amino acid commonly found in protein-rich foods, and an antimicrobial peptide sourced from a Brazilian arachnid.

Co-author Patrick D. Mathews emphasizes the potential of this bioparticle to enhance drug efficacy in the face of bacterial resistance. Unlike conventional methods that mix medication into fish feed, the bioparticle can be administered directly in water, ensuring precise consumption by the fish and reducing environmental pollution. The research primarily focused on Schwartz’s catfish, an ornamental species native to the Amazon, with promising results in terms of the bioparticle’s penetration into the intestine without causing cytotoxic effects.

The researchers had previously demonstrated the bioparticle’s efficacy against parasites infecting ornamental fish. By delivering the anthelmintic drug praziquantel, the bioparticle successfully targeted parasites, offering potential applications in treating other fish species. An applied patent reflects the promising nature of these formulations.

With plans to extend the research to commercially farmed fish, such as Nile tilapia and Tambaqui, the team aims to address the substantial economic losses in Brazil’s freshwater fish farming industry due to diseases, estimated at USD 84 million annually. The non-toxic nature of the bioparticle to fish and its positive implications for human consumption highlight its potential for widespread application in aquaculture.