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Myriad of amphipods on the GBR

By: Rebecca Hancock, Category: Science, Date: 08 Dec 2009

A recent study has revealed hundreds of species of amphipods (shrimp-like creatures) living on the Great Barrier Reef, almost half of them new to science.

Leucothoe makrommatos

Roger Springthorpe © Australian Museum

When a group of international scientists convened for an intensive field trip and workshop on the Great Barrier Reef they were surprised to find such high levels of species diversity among the amphipod crustaceans.

Prior to a two-week field trip to the Australian Museum Research Station at Lizard Island in 2005, fewer than 50 species of benthic (living on the sea floor) amphipods were known from the Reef.

That number has now increased to 235 species, of which 112 (47%) are new, thanks to the efforts of 16 taxonomists, collection managers, students, field workers – and one cook!

It has taken four years since the field trip to describe and collate the findings into one volume, a special 930-page book published by the scientific journal Zootaxa.

Dr Jim Lowry, an Australian Museum amphipod specialist who coordinated the field trip and co-edited the book with Professor Alan Myers, commented,

‘As a result of this work, we can now say that the amphipod fauna of the Great Barrier Reef is the richest yet known from any tropical reef area.’

These small crustaceans may lack glamour (with a common name of ‘scud’ doing nothing to enhance their image) but according to Dr Lowry we just can’t do without them.

‘For instance, scavenging amphipods are like the vultures of the sea, feeding on everything that dies from the smallest worm to the largest whale. And reef-dwelling herbivorous amphipods feed on algae, helping to prevent corals from being smothered,’ he said.

'There are thousands of amphipods in every square metre of sea floor and they are one of the more common items in the diets of a wide range of fish species,’ Dr Lowry added.

For Dr Lowry, one of the most exciting moments in the amphipod project was the discovery at Lizard Island of a new species of the family Bolttsiidae, previously known only from coastal lakes in eastern South Africa and another previously known only from tropical America, the semi-terrestrial talitrid, Chelorchestia.

‘The presence of amphipods at Lizard Island that are essentially indistinguishable from those found on distant continents can only be understood by reconstructing their evolutionary past, from a time when South America, Africa and Australia were joined as part of the great land mass of Gondwana, around 200 million years ago,’ Dr Lowry explained.

‘Ancestors of these species once inhabited the same part of the world. Some have remained virtually unchanged since Gondwana broke apart,’ he said.

The Great Barrier Reef amphipod project demonstrates how collaborative studies can systematically increase our knowledge of Australia’s biodiversity and help us to understand its evolution.

Publication:

JK Lowry & AA Myers (eds), 2009. Benthic Amphipoda (Crustacea: Peracarida) of the Great Barrier Reef. Zootaxa, 2260: 1–930. Available in hardback or online.

Funding:

The workshop held at the Australian Museum’s Lizard Island Research Station was funded by the Department of Environment, Water, Heritage and the Arts and the Australian Museum Members.