The Times Australia
The Times World News

.

here's how rainbowfish survive in Australia's scorching desert

  • Written by Catherine R. M. Attard, Lecturer in Molecular Ecology, Flinders University
here's how rainbowfish survive in Australia's scorching desert

A trip into central Australia involves packing your 4WD to the brim with survival gear, water and food. Yet fish have managed to persist in that parched landscape for thousands of years – how do they do it?

We at the Flinders Molecular Ecology Lab went about finding out. Our recent research[1] examined rainbowfish in Australia, to discover how they hold onto life in isolated pockets of water in the desert.

Pockets of water in the desert can only hold small fish populations. A small population means a small gene pool – which can lead to inbreeding and poor health, as we sometimes see in endangered species.

But we found even small populations can adapt to the harsh environments of water holes and small creeks. Life finds a way – even in one of the most extreme and unpredictable environments on Earth.

Prospering in central Australia

Native desert rainbowfish (Melanotaenia splendida tatei) live in the deserts of central Australia. They grow to about 9cm[2] and are usually silver and iridescent, with a yellow and green chequered pattern on the fins.

Desert rainbowfish populations live in slow-flowing and still habitats, including impermanent rivers, waterholes, lakes, flowing bores and stock dams.

Their populations fluctuate during boom-bust cycles. During rare flooding events in the desert, rainbowfish breed in large numbers and spread along temporary streams and floodwaters.

Read more: Australia's smallest fish among 22 at risk of extinction within two decades[3]

Desert rainbowfish
Desert rainbowfish live in slow-flowing and still habitats. Gunther Schmida

Our findings

Our research sought to determine how rainbowfish populations persist in desert regions of central Australia, and whether their genomes show evidence of adaptation to the local harsh conditions.

We collected 344 desert rainbowfish from 18 rivers and waterholes from across the vast and arid Lake Eyre Basin, and from semi-arid regions of the Murray-Darling Basin.

We then compared the variation in the genomes of these fish with data from satellite images about the presence of surface water in central Australia.

We found that natural selection in rainbowfish is stronger in regions of the desert that have drier conditions. Fish from the very arid western region of central Australia adapt differently to dry conditions than those from the semi-arid eastern region.

We also found these gene variations are carried by the fish as they disperse during the floods. The fish that were pre-adapted to very harsh conditions retreated with the floodwaters to wait out the often extended drought periods in small, isolated waterholes.

This suggests genes adapted to the most arid conditions may help small populations to persist in harsh environments. These adaptations might also help the species persist in future climates, which are expected to become drier and with more extreme events.

The most intriguing adaptive difference involved a mutation in a gene coding which leads to some fish producing a slightly different guanine nucleotide-binding protein. Fish use these proteins for taste and smell, to detect salinity and water flow, and to control light sensitivity for vision.

Rainbowfish in Central Australia may survive the harsh conditions because of this difference in the protein and other adaptations. This would improve their ability to sense the environment and how it varies across seasons.

The variation can be compared to the recent Omicron COVID-19 variant. Research has found mutations in the spike protein[4] in some variants may aid its spread among humans.

shallow pool in desert landscape
Genes adapted to the most arid conditions may help small populations persist in harsh environments. Chris Brauer

Looking ahead

Our research found the genetic variation can be maintained in small rainbowfish populations to allow the species to survive in the desert.

The findings suggest that the population size of desert rainbowfish, at least during very dry periods of the year, is less than that commonly thought necessary in nature for species conservation[5] and for adaptation to future climate changes. This turns on its head traditional thinking that small populations are evolutionary dead ends.

As climate change worsens, our findings highlight the importance of conserving natural river flows to enable freshwater species to respond and adapt.

Read more: 2021 was one of the hottest years on record – and it could also be the coldest we'll ever see again[6]

Read more https://theconversation.com/life-finds-a-way-heres-how-rainbowfish-survive-in-australias-scorching-desert-173590

Times Magazine

Building a Strong Online Presence with Katoomba Web Design

Katoomba web design is more than just creating a website that looks good—it’s about building an online presence that reflects your brand, engages your audience, and drives results. For local businesses in the Blue Mountains, a well-designed website a...

September Sunset Polo

International Polo Tour To Bridge Historic Sport, Life-Changing Philanthropy, and Breath-Taking Beauty On Saturday, September 6th, history will be made as the International Polo Tour (IPT), a sports leader headquartered here in South Florida...

5 Ways Microsoft Fabric Simplifies Your Data Analytics Workflow

In today's data-driven world, businesses are constantly seeking ways to streamline their data analytics processes. The sheer volume and complexity of data can be overwhelming, often leading to bottlenecks and inefficiencies. Enter the innovative da...

7 Questions to Ask Before You Sign IT Support Companies in Sydney

Choosing an IT partner can feel like buying an insurance policy you hope you never need. The right choice keeps your team productive, your data safe, and your budget predictable. The wrong choice shows up as slow tickets, surprise bills, and risky sh...

Choosing the Right Legal Aid Lawyer in Sutherland Shire: Key Considerations

Legal aid services play an essential role in ensuring access to justice for all. For people in the Sutherland Shire who may not have the financial means to pay for private legal assistance, legal aid ensures that everyone has access to representa...

Watercolor vs. Oil vs. Digital: Which Medium Fits Your Pet's Personality?

When it comes to immortalizing your pet’s unique personality in art, choosing the right medium is essential. Each artistic medium, whether watercolor, oil, or digital, has distinct qualities that can bring out the spirit of your furry friend in dif...

The Times Features

Do I have insomnia? 5 reasons why you might not

Even a single night of sleep trouble can feel distressing and lonely. You toss and turn, stare at the ceiling, and wonder how you’ll cope tomorrow. No wonder many people star...

Wedding Photography Trends You Need to Know (Before You Regret Your Album)

Your wedding album should be a timeless keepsake, not something you cringe at years later. Trends may come and go, but choosing the right wedding photography approach ensures your ...

Can you say no to your doctor using an AI scribe?

Doctors’ offices were once private. But increasingly, artificial intelligence (AI) scribes (also known as digital scribes) are listening in. These tools can record and trans...

There’s a new vaccine for pneumococcal disease in Australia. Here’s what to know

The Australian government announced last week there’s a new vaccine[1] for pneumococcal disease on the National Immunisation Program for all children. This vaccine replaces pr...

What Makes a Small Group Tour of Italy So Memorable?

Traveling to Italy is on almost every bucket list. From the rolling hills of Tuscany to the sparkling canals of Venice, the country is filled with sights, flavors, and experiences ...

Latest data suggests Australia is overcoming its sugar addiction

Australia is now meeting the World Health Organization’s (WHO) guidelines[1] on sugar, which recommend keeping sugar below 10% of daily energy intake. New data[2] published ...