UK aquarium fish suppliers have been trading in an illegal species of tropical crayfish, Practical Fishkeeping can exclusively reveal.
Practical Fishkeeping has learnt of two retailers and one wholesaler in England that have been selling the Mexican orange dwarf crayfish, Cambarellus patzcuarensis, a species which is illegal to import, keep or sell in this country.
With the exception of a single species of tropical crayfish, the Redclaw crayfish, Cherax quadricarinatus, all other crayfish are illegal to keep in the UK under the Prohibition of Keeping of Live Fish (Crayfish) Order 1996.
The legislation was introduced to protect our native Whiteclaw crayfish, Austropotamobius pallipes, from alien species which compete for resources and act as carriers for a virulent disease known as crayfish plague.
However, trade sources told Practical Fishkeeping that some suppliers view other tropical species as "fair game" and perceive them to pose little risk to native crayfish stocks due to their supposed temperature requirements.
Sources also said that they believed CEFAS would be unlikely to prosecute individuals keeping or selling 'tropical' species, because 'they posed less of a risk' to native species.
Tropical crayfish
Dr Paul Stebbing, a crayfish specialist at the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) told Practical Fishkeeping that although hobbyists considered any species that survived in heated tanks as 'tropical' the legislation did not.
"All crayfish are considered to be temperate species unless they can be proven not to survive in environmental conditions equivalent to those found in Great Britain.
"Most of the 'tropical' species traded elsewhere in the world have a broad temperature tolerance and can be found in mountainous regions where temperatures are lower than one would first imagine when thinking about their country of origin.
"Only one species, the Redclaw (Cherax quadricarinatus) is considered to be a tropical species under the relevant British legislation. A general licence has been issued, which allows hobbyists to keep this species in heated indoor aquaria only.
"The keeping of any other non-native crayfish species for ornamental use in Great Britain is illegal."
Stebbing said that the Mexican dwarf orange crayfish was one species that came from mountainous areas, and could feasibly tolerate cooler water.
He said that the species has been seen before in the UK aquarium trade and that CEFAS was concerned about the trade in any illegal non-native species, not just those perceived by fishkeepers to be temperate.
"Non-natives that are introduced to a country and subsequently become invasive have proven to be very damaging to native biodiversity and are difficult to control or eradicate", said Stebbing.
Illegally traded crayfish
According to CEFAS, 12 species of crayfish have been found illegally in the trade since the legislation was introduced in 1996. They are:
Astacus leptodactylus - Turkish crayfish
Procambarus clarkii - Red-swamp crayfish
Procambarus sp. - Marbled crayfish
Procambarus alleni - Chinese crayfish
Cherax destructor - Yabbie
Cherax tenuimanus - Marron
Cherax misolocus - Yabby
Cherax lorentzi - Lorentz yabby
Cherax papuanus - Zebra crayfish
Cambarellus patzcuarensis - Mexican dwarf crayfish
Cambarellus zempoalensi - Acocil crayfish
Orconectes limosus - Spiny-cheeked crayfish
Pacifastacus leniusculus - Signal crayfish
Prosecution
CEFAS told Practical Fishkeeping that those caught keeping the crayfish risked a fine, and could be prosecuted for additional offences under the Wildlife and Countryside Act, particularly if the crayfish were being kept outdoors.
Stebbing said: "Given the ability of crayfish to walk out of pond environments, anyone placing non-native species in a garden pond or other water could face legal action under this legislation. Sanctions under this Act range from fines to custodial sentences.
The Fish Health Inspectorate tries to prevent such introductions from occurring. We ask any hobbyist or trader who encounters crayfish that they believe are being kept or traded illegally to contact the Fish Health Inspectorate. All contacts will be treated in confidence.
"Any questions on the legislation concerning the keeping and trade in crayfish should also be directed to the FHI on 01305 206673 or email [email protected].
"The Inspectorate will advise callers on the safe removal of any non-native crayfish in their possession, and provide advice to ensure that ornamental fish dealers do not continue to import such animals. Information on the legislation is available at www.efishbusiness.co.uk"