Asian paddle crab, Charybdis japonica. (Photo Credit: Anonymous Powered/CC BY-SA 3.0)
AUSTRALIAThursday, January 22, 2015, 23:50 (GMT + 9)
Scientific confirmation that a crab, caught recently in Matilda Bay, is an Asian paddle crab (Charybdis japonica) has prompted a fresh reminder for fishers to be on the lookout for the pest species.
An alert fisher, who caught the crab in a drop net on the Swan River late last month, helpfully reported his find through FishWatch.
Senior Biosecurity Management Officer with the Department of Fisheries, Marion Massam called on other crab fishers to also continue their vigilance, in the ongoing efforts required to prevent the pest species from establishing itself in Western Australia.
“Their assistance is crucial – the three paddle crabs previously detected at Mosman Bay in 2012 were all caught by recreational fishers,” Massam said.
“This particular Asian paddle crab was light tan, but we know the species varies greatly in colour – its definitive features are the sharp spines between the eyes and the six spines down each side, as identified in the department’s pest alert."
An alert fisher, who caught the crab in a drop net on the Swan River late last month, helpfully reported his find through FishWatch.
Senior Biosecurity Management Officer with the Department of Fisheries, Marion Massam called on other crab fishers to also continue their vigilance, in the ongoing efforts required to prevent the pest species from establishing itself in Western Australia.
“Their assistance is crucial – the three paddle crabs previously detected at Mosman Bay in 2012 were all caught by recreational fishers,” Massam said.
“This particular Asian paddle crab was light tan, but we know the species varies greatly in colour – its definitive features are the sharp spines between the eyes and the six spines down each side, as identified in the department’s pest alert."
“The biosecurity alert also shows pictures of native crabs (particularly the small four-lobed swimming crab) that have sometimes been confused with the Asian paddle crab.
“The native small, brownish swimming crab has no spines between the eyes – take a close look. If there are no spines then it’s the native crab.”
In general, fishers should first look at any small crabs with a shell width up to 120 mm that look different to blue swimmers and then check for the spines between the eyes. Massam said people should not eat the pest crab, because the species can carry a disease that could cause poisoning in humans.
“We need to make sure the Asian paddle crab doesn't establish in Western Australia, as it could out-compete native species like the blue swimmer, could spread diseases to other crabs and prawns and would probably be impossible to eradicate,” she said.
The Department of Fisheries urges crab fishers to check their catches and, if in doubt; take photographs, retain suspect crabs, note the fishing location and contact authorities.
Aquatic pests and diseases are a significant threat to WA's precious oceans and rivers. Therefore, the Department of Fisheries is leading the effort to prevent them arriving and establishing themselves in the state's waters.
“The native small, brownish swimming crab has no spines between the eyes – take a close look. If there are no spines then it’s the native crab.”
In general, fishers should first look at any small crabs with a shell width up to 120 mm that look different to blue swimmers and then check for the spines between the eyes. Massam said people should not eat the pest crab, because the species can carry a disease that could cause poisoning in humans.
“We need to make sure the Asian paddle crab doesn't establish in Western Australia, as it could out-compete native species like the blue swimmer, could spread diseases to other crabs and prawns and would probably be impossible to eradicate,” she said.
The Department of Fisheries urges crab fishers to check their catches and, if in doubt; take photographs, retain suspect crabs, note the fishing location and contact authorities.
Aquatic pests and diseases are a significant threat to WA's precious oceans and rivers. Therefore, the Department of Fisheries is leading the effort to prevent them arriving and establishing themselves in the state's waters.