Please select your home edition
Edition
Marine Resources 2019 - Leaderboard

Tiny fish live fast, die young

by Melissa Lyne 30 May 07:16 UTC
Redeye Gobies ( Bryaninops natans ) hover in small groups above coral heads, on which they rely for shelter. By living fast and dying young, these tiny (<2cm) fishes fuel reef fish biomass production. © Tane Sinclair-Taylor

New research has revealed that the short lives and violent deaths of some of coral reefs' smallest tenants may be vital to the health of reef systems, including the iconic Great Barrier Reef.

Dr Simon Brandl, from Simon Fraser University in Canada, led an international team of researchers searching for answers to the longstanding puzzle of 'Darwin's paradox'.

Co-author Prof David Bellwood from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University (JCU) said: "Charles Darwin wondered how fish on coral reefs manage to thrive in isolated areas where there are very low levels of nutrients for them to use. We thought the answer may lie in the tiny fish that live in the gaps in the coral structure."

"These tiny fish are less than five centimetres long and are known as 'cryptobenthics'. They include gobies, blennies, cardinalfish, and several other families," Prof Bellwood said.

The team surveyed reefs around the globe and records of larval abundance. They discovered that cryptobenthics and their larvae make up nearly 60% of all fish flesh eaten on the reef.

"Because of their size and tendency to hide, these little fish are commonly overlooked," Dr Brandl said, "but their unique demographics make them a cornerstone of the ecosystem."

"Their populations are completely renewed seven times a year, with individuals in some species living only a few days before they are eaten. The only way they can sustain this is by a spectacular supply of local larvae," added co-author Renato Morais, a PhD student at JCU.

Prof Bellwood said almost anything capable of eating cryptobenthics does so, including juvenile fish and invertebrates such as mantis shrimps, which then became food for other creatures.

"These factors have made it hard for researchers in the past to realise the importance of cryptobenthics and discover the food supply that the 'crypto-pump' supplies."

He said that the cryptobenthics have finally emerged from the shadows. "Their extraordinary larval dynamics, rapid growth, and extreme mortality underpins their newly discovered role as a critical functional group on coral reefs."

Paper: Brandl S, Tornabene L, Goatley C, Casey J, Morais R, Cote I, Baldwin C, Parravicini V, Schiettekatte N, Bellwood D (2019). 'Demographic dynamics of the smallest marine vertebrates fuel coral-reef ecosystem functioning'. Science. DOI: 10.1126/science.aav3384

More information available here.

Related Articles

Coral study prompts rethink of scientific theory
World-first study is challenging long-held assumptions about role of sunlight in coral biodiversity The research questions a classic theory that predicts coral biodiversity is highest in the shallowest waters where more energy is available in the form of sunlight. Posted on 6 Nov
Clear goals but murky path to sustainability
International sustainability policies set clear goals for protecting ecosystems As biodiversity loss continues at an alarming rate across the globe a new study identifies what is needed to tackle the root causes of the problems. Posted on 6 Nov
New study shows climate change is good investment
Scientists calling on world leaders to urgently accelerate efforts to tackle climate change. Almost every aspect of the environment and ecology is changing in response to global warming. Some of these changes will be profound, if not catastrophic, in the future. Posted on 23 Sep
Actions to save coral reefs
A new, holistic approach to safeguarding coral reefs Scientists say bolder actions to protect coral reefs from the effects of global warming will benefit all ecosystems, including those on land. Posted on 20 Sep
Marine heatwaves a bigger threat to coral reefs
With effects that go beyond coral bleaching New research reveals marine heatwaves are a much bigger threat to coral reefs than previously thought, with effects that go beyond coral bleaching. Posted on 22 Aug
Fussy fish can have their coral, and eat it too
Being a fussy eater is a problem for reef fish Being a fussy eater is a problem for reef fish who seek refuge from climate change on deeper reefs. But, scientists discovered, the coral that these fussy fish eat can support them. Posted on 17 Jul
Climate vulnerability of World Heritage properties
Australian scientists have created a world-first tool Australian scientists have created a world-first tool that can systematically assess climate change risks to all types of World Heritage properties: marine and terrestrial, natural and cultural. Posted on 7 Jul
Cardinalfish caught sneaking a bit on the side
The male fish of this species carries the eggs in his mouth until they are ready to hatch Scientists have revealed the torrid, adulterous love lives of the mouth-brooding cardinalfish, with cuckoldry going hand-in-hand with cannibalism of the young. Posted on 15 Jun
Breaking bread with rivals leads to more fish
Cooperation is key to most successful endeavours Dr Michele Barnes, a senior research fellow from the ARC Centre of Excellence for Coral Reef Studies, is the lead author of study published today that looks at the relationships between competing fishers, the fish species they hunt, and their local reefs. Posted on 7 May
Corals light the way to a healthy partnership
Corals know how to attract good company Corals know how to attract good company. New research finds that corals emit an enticing fluorescent green light that attracts the mobile microalgae, known as Symbiodinium, that are critical to the establishment of a healthy partnership. Posted on 24 Jan
Sailing Holidays 2019 - BOTTOMGrapefruit Graphics 2019 - FooterNorth Sails 2019 - NSVictoryList - Footer