Science briefs


Discovery

Shrimp, you are here 

Photo: Dr. Arthur Anker UFG

A pink-clawed shrimp that makes noise loud enough to kill small fish has been named in honour of British band Pink Floyd. 

Synalpheus pink oydi was discovered by a group of analysts from the UK, Brazil and the US, off the coast of Panama and named by Sammy De Grave, head of research at Oxford University Museum of National History in the UK. He told the BBC he and his team had long ago undertaken to honour their rock heroes if they discovered a new species of pink shrimp. 

The Pink Floyd shrimp is part of the Alpheidae family, more commonly known as snapping or pistol shrimp. Their name comes from their ability to generate lethal sonic energy by closing an enlarged claw at rapid speed, creating a cavitation bubble. 

The bubble’s implosion momentarily creates temperatures of 4400oC – about as hot as the surface of the sun – and generates noise levels of up to 210 decibels – one of the loudest sounds found in the ocean and almost twice as loud as the average rock concert (100 to 120 decibels).

Source: BBC 


Word Wise

Each issue we will try to clarify the meaning and use of some commonly misunderstood words in fisheries science, beginning with the basics. 

Illustration of orange fish with large eye in aqua-blue water

What is a 'Fish Stock'? 

A litre of water and a fish carcass or two, boil for a few hours and you have ... 

A stock is another way of saying population or sub- population. Use of the term fish stock usually implies that the particular population is more or less isolated from other stocks of the same species and hence self-sustaining. 

The Status of Australian Fish Stocks (SAFS) Reports uses the term ‘stock’ generically for populations of fish defined at any of three levels – biological, management units and populations assessed at the jurisdictional level. 

A biological stock is a discrete genetic population or
a population of sh that is not interacting with other sh populations of the same species. That means this population size can be treated as relatively constant and changes to its structure and size can be measured. It is not always practical to measure an entire biological population, so the unit may be defined in other ways such as who manages it or where it is. A key aim of fisheries management is to ensure that biological stocks are maintained at sustainable levels. 

 

Download

What disease is that?

Australia’s latest field guide on aquatic diseases is now available to download.
The Aquatic Disease Field Guide app, produced by the Australian Department of Agriculture and Water Resources provides comprehensive information on 48 diseases from Australia’s National List of Reportable Diseases of Aquatic Animals.

The FRDC has invested in the revision and expansion of several versions of the field guide. It helps commercial and recreational fishers, aquaculture workers, biosecurity staff, seafood processors, retailers, scientists and students to recognise diseases of significance in finfish, crustaceans, molluscs and, for the first time, amphibians. 

This easily accessible biosecurity information will allow faster reporting of incidents to relevant authorities and help to protect Australia’s $2.8 billion fishing industry from disease threats. 

The Aquatic Disease Field Guide app is available from iTunes, Google Play and Microsoft Store. 


Technology

Fish passage mapped 

Updated maps of Queensland waterways determining their importance for the passage of sh are now available free online. 

The Queensland Waterways for Waterway Barrier Works data is designed for developers, government agencies and landholders planning works that may affect fish movement. This work could include new dams or crossings such as bridges and culverts.

Fisheries Queensland biologist Ian Draper says the colour-coded maps clarify whether properties contain waterways and help to determine what type of development approval is required for waterway barrier works to proceed.

The updated data also highlights the importance of smaller coastal streams that flow directly out to estuaries. 

“These are valuable sh-breeding and nursery areas for Queensland’s commercial, recreational and indigenous fishers,” Ian Draper says.

The mapping is available online