Navigation Links
Baby fish 'smell their way home'

Marine scientists working on Australia's Great Barrier Reef have uncovered evidence that baby fish, only millimetres long, manage to find their way to their home coral reef across miles of open sea by using their sense of smell.

Remarkable in itself, the discovery by a team including Professor Mike Kingsford of the ARC Centre of Excellence for Coral Reef Studies and James Cook University and colleagues from Woods Hole, USA, also shines a new light on how the breathtaking diversity of fish on coral reefs has arisen. This has major implications for how reefs are managed.

"The babies of many coral fish species are swept off their home reef by ocean currents within days of hatching. Ordinarily you'd expect them to be thoroughly mixed up and this would mean the population of one reef would be pretty much the same, genetically, as another," he says.

"But that is not the case. There are major genetic differences between fish of the same species on reefs only a few kilometres or even hundreds of metres apart."

This diversity between populations of the same fish species is what drives evolution on the Reef and underpins the spectacular richness of its sea life, Prof. Kingsford says. "This genetic separation between reefs may be what gives rise to so many different species in coral reef systems."

The researchers were intrigued how tiny damsel and cardinal fish, born on one reef, managed to find their way back home to preserve such remarkable population differences, braving strong currents and ferocious predators in their 20 days at sea ?all when only a centimeter or so in size.

"We tested several ideas, but the most attractive seemed to be that they could smell the unique trace of their home reef ?rather like salmon can smell the home river.

"We know these late stage fish larvae, generally between about 9 and 14mm long, already have developed noses ?but the question was whether they could use them to recogni se what the home reef smelt like, when they left it only a day or so after hatching."

The team exposed tiny fish larvae in a tank to pure streams of water from four different reefs. To their amazement, within minutes a surprisingly high percentage of baby fish had congregated in the water flow from their home reef.

"It was a lot more than you'd expect to happen by pure chance ?and it applied, in differing degrees, across several species of fish," Mike says.

The fish could also be responding to other stimuli, including distant noise off a reef and the behaviour of other fish, but the team concluded that smell was probably the dominant factor leading the babies home.

"Every reef gives off its own unique chemical signature, a rich mixture of the proteins and amino acids emitted by corals, all the plankton and mucus from its life. We think baby fish can pick this up and distinguish it from other reefs.

"We think some fishes then choose currents that smell like 'home' and swim up them. The ones that cannot do this perish. The ones that get home preserve the unique 'ethnic' make-up of their tribe ?and so continue the process of evolving into separate new species."

How the fish learn the unique smell of home is a mystery still. The researchers theorise that it is imprinted on them either when they are an egg inside their mothers, a fertilised egg swept around on the bottom, or new-hatched fry loose in the stream or brooded in their parents' mouths.

"An egg, even a fry, hasn't a fully developed sense of smell, but it may have a way of absorbing the local molecules and then recognizing their signature as "home" when it grows up a bit and is ready to settle," Mike says.

"This evidence that individual coral reefs play such a key role in the emergence of new species is a fresh reason to take even greater care in how we look after them."


'"/>

Source:James Cook University


Related biology news :

1. Priming embryonic stem cells to fulfill their promise
2. Protein offers way to stop microscopic parasites in their tracks
3. Flocking together: Study shows how animal groups find their way
4. Where bacteria get their genes
5. Chickadees can help humans get their bearings
6. Bacteria use hosts immune response to their competitive advantage
7. Structures of marine toxins provide insight into their effectiveness as cancer drugs
8. Beauty queens urge girls not to sacrifice their bones
9. Researchers learn how blood vessel cells cope with their pressure-packed job
10. Stem cells electric abilities might help their safe clinical use
11. Multiple genes permit closely related fish species to mix and match their color vision
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/23/2017)... Research and Markets has announced the addition of the ... Forecast to 2025" report to their offering. ... The Global Vehicle Anti-Theft System ... over the next decade to reach approximately $14.21 billion by 2025. ... forecasts for all the given segments on global as well as ...
(Date:3/20/2017)... , March 20, 2017 PMD Healthcare ... personal spirometer and Wellness Management System (WMS), a remote, ... Founded in 2010, PMD Healthcare is a Medical Device, ... a mission dedicated to creating innovative solutions that empower ... With that intent focus, PMD developed the first ever ...
(Date:3/7/2017)... BRIGHTON, England , March 7, 2017 Brandwatch ... been chosen by The Prince,s Trust to uncover insights ... insights across The Trust. The UK,s leading youth charity ... track social campaign results and get a better understanding of the ... ...
Breaking Biology News(10 mins):
(Date:3/24/2017)... Biotech Ltd. ("Sinovac" or the "Company") (NASDAQ: SVA), a leading provider ... that its board of directors has amended its shareholder rights plan. The ... 2017 to March 27, 2018. The amendment was not in response to ... ... Ltd. is a China -based biopharmaceutical company that ...
(Date:3/23/2017)... ... ... to announce it has become the premiere team-building cooking event company in San Diego. ... as Illumina, HP and Qualcomm, and is ranked #1 in its category on Trip Advisor. ... new team building format, a way for teams to not only interact with one another ...
(Date:3/23/2017)... MENLO PARK, Calif., March 23, 2017  BioPharmX ... developing products for the dermatology market, today reported ... Jan. 31, 2017, and will provide an update ... from the year. "We are pleased ... productive year for BioPharmX," said President Anja Krammer. ...
(Date:3/23/2017)... Colo. , March 23, 2017  Agriculture technology ... Series A financing and note conversion to commercialize its ... Planet is focused on developing products that are simultaneously ... $30 million in the last 18 months. This latest ... North Bridge Venture Partners. The company,s ...
Breaking Biology Technology: