Study shows tropical fish able to adapt body temperature by environment

Such responses are present in the fish's genes and suggest that a reaction to cold induces an energy-conserving or stress-reduced response.

November 21, 2018 17:53
1 minute read.
Blue Tilapia

Picture of a Blue Tilapia. (photo credit: Courtesy)


Dear Reader,
As you can imagine, more people are reading The Jerusalem Post than ever before. Nevertheless, traditional business models are no longer sustainable and high-quality publications, like ours, are being forced to look for new ways to keep going. Unlike many other news organizations, we have not put up a paywall. We want to keep our journalism open and accessible and be able to keep providing you with news and analysis from the frontlines of Israel, the Middle East and the Jewish World.

As one of our loyal readers, we ask you to be our partner.

For $5 a month you will receive access to the following:

  • A user experience almost completely free of ads
  • Access to our Premium Section
  • Content from the award-winning Jerusalem Report and our monthly magazine to learn Hebrew - Ivrit
  • A brand new ePaper featuring the daily newspaper as it appears in print in Israel

Help us grow and continue telling Israel’s story to the world.

Thank you,

Ronit Hasin-Hochman, CEO, Jerusalem Post Group
Yaakov Katz, Editor-in-Chief


Researchers at Ben-Gurion University of the Negev revealed that certain species of tropical fish are able to adjust body temperature based on their environment.

The research, which was carried out by Fotini Kokou, a post-doctoral fellow and Itzhak Mizrahi, an associate professor of microbial ecogenomics, discovered that host organisms are affected by the microbes that live within them, suggesting that they possess a symbiotic relationship – each benefiting from the other.

“One of the most significant environmental pressures that affects the fitness of a host organism is temperature,” said Kokou, adding, “We wanted to test whether acclimatization to temperature is facilitated by changes in the host’s microbiome.”

The research used a unique species of tropical fish – the blue tilapia – which exhibit extreme sensitivity to colder temperatures. New higher resistant strains to freezing temperatures were bred. This allowed researchers to compare reactions to stimuli between the sensitive and resistant breeds, and analyze whether it affected the microbes.

Researchers exposed fish with either cold tolerance or intolerance to temperatures of 12 and 24 degrees centigrade. The gut microbiomes of the fish were then examined, showing a large decline in the amount of microbes in either group, who were exposed to the colder temperature. The study discovered that colder temperatures can reduce the amount of microbes in fish. It also found that each fish contained microbes which can either “switch off” during energy expedient processes (such as metabolism), or turn on during times of stress.

The study revealed that such responses are present in the fish’s genes and suggest that a reaction to cold induces an energy-conserving or stress-reduced response. This may explain how certain breeds have survived through the process of natural selection.

“Our study shows that the genetic background of the tilapia fish and its tolerance to temperature-induced stress determines the response of the gut microbiome to temperature,” said Mizrahi. “Microbes and their hosts work together in a survival of the fittest as part of the natural selection process,” he added.

Join Jerusalem Post Premium Plus now for just $5 and upgrade your experience with an ads-free website and exclusive content. Click here>>

Related Content

July 23, 2019
Bones recovered in Vatican may be teen's who went missing 36 years ago


Cookie Settings