Please select your home edition
Edition
Southern Spars

Parenting comes at a price for male fish

by ARC Centre of Excellence Coarl Reef Studies on 9 Mar 2012
Small eyes look out from the safety of a parent’s mouth: but do cardinalfishes pay the price for good parenting? A male brooding Cheilodipterus sp. Photo: Rudie Kuiter ARC Centre of Excellence Coral Reef Studies © http://www.coralcoe.org.au/
Being a great dad can mean starving to protect the kids, putting up with a jealous spouse – and often, dying young. At least, if you’re a cardinalfish.

A survival strategy that has been a triumphant success for cardinalfishes for going on 50 million years could come unstuck under rapid global warming, scientists from the ARC Centre of Excellence for Coral Reef Studies and James Cook University have found.

'We studied how cardinalfishes have evolved over millions of years and found that these mouthbrooders haven’t changed much – their jaw cavities have become larger for keeping more young in their mouths, and their colours are different, but that’s about it,' explains Professor David Bellwood, a researcher in the study.

'While other fishes have evolved by changing shape and broadening their diet, the mouthbrooding fishes remain simple feeders that eat mainly plankton. This can be bad news when food is scarce.'

With a lifespan of about two years, cardinalfishes breed several times a year, mostly in summer. Instead of laying thousands of eggs in a batch like other fishes, they lay hundreds of slightly larger eggs. When the female releases the eggs, the male gathers them into a tight bundle which he keeps safe in his mouth for a couple of weeks until the young hatch and become free-swimming.

'These eggs occupy up to 100% of the oral cavity, and the dad’s mouth would expand and look like a large bubble,' says Dr Andrew Hoey, who conducted the study. 'It’s a wonder that they can even breathe. They don’t feed, but live on stored energy, and stay sedentary in and around corals.

'The females play the role of jealous wives. They stay close to the males, not to help rear the kids, but to prevent other females from swimming off with such a desirable mate. Our guess is these stay-at-home dads are very much in demand.'


Although the 50 million-year-old breeding technique has proved successful so far, providing large and happy families for cardinalfishes, their future is looking grim, Prof. Bellwood says.

'Apart from being left behind in terms of evolution, mouthbrooding makes them more vulnerable to the effects of climate change.

'As ocean temperatures warm, these fish will need to breathe more - and the last thing they need is having a mouthful of offspring when they need oxygen.'

The other problem is the increasing lack of shelter as corals around the world die from bleaching and disease: cardinalfishes are popular prey for larger predatory fish like coral trout.

'These fishes are very attached to their homes – they like to stay under branching corals, and will come back to the same little patch day after day.'

However, branching corals are one of the most vulnerable types to climate change, he says. If corals perish as a result of bleaching or diseases, the cardinalfishes will be exposed and vulnerable.

'When the coral cover declines, they’re going to be homeless, just sitting there with babies in their mouths and struggling to breathe. Their problems will be exacerbated by a shortage of food because of their narrow diets.'

'In short, these stay-at-home dads have sacrificed job options, and even their lives, to provide top notch parental care for their young – just imagine how life would be like if you had a toddler hanging from your teeth.'

'This has proved a highly successful survival strategy for 50 million years – but under rapid global warming, there is a big risk it could come unstuck. This is another example of the profound impact which humans are having on life on Planet Earth.'

Their paper 'To feed or to breed: morphological constraints of mouthbrooding in coral reef cardinalfishes', by Andrew S. Hoey, David R. Bellwood and Adam Barnett appears in the journal Proceedings of the Royal Society B.

http://www.coralcoe.org.au

Colligo Marine 660x82Southern Spars - 100Bakewell-White Yacht Design

Related Articles

Rio official murdered ten months before the Olympics
Rio de Janeiro is a troubled city and a reeling Olympic host, but it will always have beautiful Guanabara Bay. Does an unsolved murder of an official in Rio in charge of cleaning up Guanabara Bay say a lot about the state of platy in the magical city? Priscilla Pereira was murdered 10 months ago and the thinking is that she was murdered in relation to her work
Posted on 31 Jul
WHO statement on Zika virus
The third meeting of the EC convened by the Director-General under IHR 2005 regarding microcephaly and Zika virus The third meeting of the Emergency Committee (EC) convened by the Director-General under the International Health Regulations (2005) (IHR 2005) regarding microcephaly, other neurological disorders and Zika virus was held by teleconference on 14 June 2016, from 13:00 to 17:15 Central European Time.
Posted on 16 Jun
Atlantic Cup 2016 - a race with an environmental commitment
The Atlantic Cup continues to further its mission for the 2016 race by examining the global economic impact of the ocean The Atlantic Cup continues to further its mission for the 2016 race by examining the global economic impact of the ocean and how an unhealthy ocean can affect the economy.
Posted on 7 Apr
Zika virus situation report
From 1 January 2007 to 16 March 2016, Zika virus transmission was documented in a total of 59 countries and territories. From 1 January 2007 to 16 March 2016, Zika virus transmission was documented in a total of 59 countries and territories. Cuba and Dominica are the latest to report autochthonous (local) transmission of Zika virus on 14 and 15 March, respectively. Five of these countries and territories reported a Zika virus outbreak that is now over.
Posted on 2 Apr
Have Norway scientists solved the Bermuda Triangle mystery?
The Bermuda Triangle has been said to have claimed numerous ships and aircraft over the years The Bermuda Triangle has been said to have claimed numerous ships and aircraft over the years, and everything from aliens to remnants from the lost island of Atlantis have been fingered as the culprits.
Posted on 15 Mar
Cyclone Winston Relief Fund – Help the people of Fiji
Sea Mercy is sending volunteer fleet of small and large vessels, loaded with shelter, food and medical supplies to Fiji. Sea Mercy is once again sending our volunteer fleet of small and large vessels, loaded with shelter, food, water and medical supplies and teams to Fiji.
Posted on 27 Feb
Flying Scot Atlantic Coast Champs - Hanson Medals awarded for rescues
US Sailing Safety at Sea Committee awarded the Arthur B. Hanson Rescue Medals to eight boats for their heroic efforts The US Sailing Safety at Sea Committee awarded the Arthur B. Hanson Rescue Medals to eight boats for their heroic efforts when a microburst storm hit the 2015 Flying Scot Atlantic Coast Championship, hosted by the Blackbeard Sailing Club, in New Bern, NC on September 12.
Posted on 2 Feb
Eco-warriors Sea-Bin crowd sharing critical stage with nine days to go
The automated marina cleaning SeaBin project has raised 86% of their target with 9 days left. The automated marina cleaning SeaBin project has raised $198,020 of $230,000.00 with nine days left on their Indiegogo crowdfunding platform, but they need more help now.
Posted on 29 Dec 2015
Higher levels of Fukushima Cesium detected offshore
Scientists monitoring the spread of radiation in the ocean from the Fukushima nuclear accident report Scientists monitoring the spread of radiation in the ocean from the Fukushima nuclear accident report finding an increased number of sites off the US West Coast showing signs of contamination from Fukushima. This includes the highest detected level to date from a sample collected about 1,600 miles west of San Francisco.
Posted on 6 Dec 2015
Don’t be a Tosser – Not your usual environmental article!!
The word ‘Tosser’ in the Oxford English dictionary means – ‘a person or thing that throws something’. The word ‘Tosser’ in the Oxford English dictionary means – ‘a person or thing that throws something’. There is no need for me to tell you the other meaning that is commonly used around the world. However in this article it will refer to both at the same time as someone who tosses trash into the ocean, truly is a tosser.
Posted on 3 Dec 2015