Bacteria Living on Fish Gills Can Make Their Own Food

Topic: Biology

Scientists discovered that bacteria living in fish gills can make their own food through a process called chemosynthesis. This is a new finding, as previously thought to be only found in certain marine environments and invertebrates.

Scientists from the Leibniz Centre for Tropical Marine Research (ZMT) and the Institute of Coastal Ecology and Management (ICBM) studied bacteria living on coral reef fish gills. They used data from previous studies of tropical reef fish called hamlets (Hypoplectrus spp.) across the Greater Caribbean, which included hundreds of gill samples.

The researchers initially planned to discard the microbial DNA and focus on the fish DNA, but they decided to take a closer look at the microorganisms living in the gills. They found that more than 95% of the DNA came from the hamlet hosts, with microbial DNA accounting for less than 5%. However, this small fraction was enough to discover something new about the fish gill microbiome.

The scientists reconstructed 70 bacterial genomes from 17 bacterial groups and found that most are new to science. They also showed that the gill microbiome is different from the community of microorganisms in the surrounding seawater. This suggests that the gill microbiome is specialized to live on the gills rather than reflecting the seawater microbiome.

The genes in these new bacterial genomes indicate that the microorganisms found in the gills can carry out a wide variety of metabolic functions, including many potential metabolic interactions between different bacteria and between bacteria and the fish.

Why It Matters

This discovery is important for understanding how fish maintain their health and immunity. It could also lead to new ways to improve fish farming and aquaculture practices in India.

Key Facts

• Scientists discovered that bacteria living on coral reef fish gills can make their own food through chemosynthesis.
• The study used data from previous studies of tropical reef fish called hamlets (Hypoplectrus spp.) across the Greater Caribbean.
• More than 95% of the DNA came from the hamlet hosts, with microbial DNA accounting for less than 5%.
• The researchers reconstructed 70 bacterial genomes from 17 bacterial groups and found that most are new to science.
• The study was published in the journal PLOS Genetics.

Key Terms

Chemosynthesis

A process where certain microorganisms make their own food using chemical energy rather than sunlight.

Metagenome

The complete set of genetic material from all the microorganisms in a particular environment or sample.

Microbiome

The community of microorganisms living in a particular environment or host organism.

Implications

This discovery is important for understanding how fish maintain their health and immunity. It could also lead to new ways to improve fish farming and aquaculture practices in India.