Thames Anglers' Conservancy Members Forum
TAC Members-Only Forum
If you have arrived here and not yet signed up as a member, then please first join at using your real name.

Forum Membership is with Real Names only.
Please create a Username that is your First Name and Surname eg. "Joe Bloggs"
(This will save our Admin team the need to contact you about changing it)

Thames Anglers' Conservancy Members Forum
HomeHome  TAC Home PageTAC Home Page  SearchSearch  FAQFAQ  RegisterRegister  Log in  

Display results as :
Rechercher Advanced Search
Latest topics
» Hampton Riviera removed
Thu Aug 16, 2018 10:41 pm by Ed Randall

» Roads closed everywhere ~ July 29th/30th ~ bike race
Mon Aug 06, 2018 10:14 am by John LeSurf

» *Thames Tunnel (Tideway Tunnel)*
Wed Jul 18, 2018 9:56 am by John LeSurf

» new hotel at hampton court means loss of fishing
Wed Jul 04, 2018 1:26 pm by Ed Randall

» Eel Trap Clean Up/ training 5th May 2018 10am
Sat Jun 09, 2018 3:46 pm by Ed Randall

» FORCE clean-up in Donkey Wood ~ Sun 13th May 2018
Thu May 17, 2018 10:16 am by JeffHowe

Thu Apr 05, 2018 2:23 pm by John LeSurf

» penton hook tidy up.
Wed Mar 07, 2018 7:05 am by John LeSurf

» Riverfly & Clean-up Donkey Woods Saturday 18th Nov 2017
Sat Dec 23, 2017 1:02 pm by Ed Randall

» Biggest fish of all book
Fri Dec 22, 2017 5:43 pm by Adrian Hoare

» Wandle Trust - eel pass installation - call for volunteers
Thu Dec 07, 2017 8:53 am by Ed Randall

» Outfall Safari across London - call for Volunteers!
Thu Dec 07, 2017 8:47 am by Ed Randall

» Fishing the Thames at Medley
Thu Nov 02, 2017 2:33 pm by Trevor Rowe

» Thames Semi-Tidal Draw Off 2017
Fri Oct 20, 2017 9:08 pm by Ed Randall

» Eel Trap Results 2017
Tue Oct 17, 2017 6:07 pm by patrick barker

» Fish-swallowing Angler "lucky to be alive"
Sat Oct 14, 2017 8:01 am by Ed Randall

» River Mole polluted at Horley
Fri Oct 13, 2017 8:52 am by Ed Randall

» Petition to stop the export of elvers
Thu Sep 21, 2017 2:16 pm by Ed Randall

» Riverfly Training ~ Hogsmill ~ 30th Sept 2017
Sat Sep 16, 2017 6:56 am by Ed Randall

» Monster fatberg in Whitechapel
Tue Sep 12, 2017 1:40 pm by Ed Randall

» Radio 4 ~ Macquarie: The Tale of the River Bank
Tue Sep 12, 2017 12:28 pm by Ed Randall

» Thames TideFest 10th September 2017
Tue Sep 12, 2017 9:00 am by John LeSurf

» Invitation to the 2017 Eel Forum ~ 17th October
Sat Sep 09, 2017 8:32 am by Ed Randall

» Do you recognise any of these men?
Sat Aug 19, 2017 8:44 pm by Ed Randall

» Better access to free Thames fishing in Reading
Fri Jun 16, 2017 10:08 am by Ed Randall

» Eel screens on Water Works intakes
Tue May 23, 2017 10:26 pm by Julian Jones

» River Thames Conditions - Quick Dial Numbers
Sun May 21, 2017 10:00 am by Ed Randall

» Ap[ril showers? If only! Drought beckons...
Thu May 04, 2017 6:56 pm by Ed Randall

» Abbey river this Saturday (12/5/2012)
Thu Apr 27, 2017 4:41 pm by Ed Randall

» Molesey Eel Monitoring Training ~ 29th April 2017
Mon Apr 24, 2017 11:12 am by David Harvey

Angling Data View
River Levels
UK Map

Thames Tides

Share | 

 Asiatic Clam

Go down 
Chris Daphne

Male Posts : 141
Join date : 2010-01-28
Location : Highlands of Scotland

PostSubject: Asiatic Clam   Mon Mar 01, 2010 1:04 am

Hi All,
Found this and thought it might be of interest

Asiatic clam, Corbicula fluminea

Taxonomy: Mollusca, Bivalvia, Veneroida, Corbicula fluminea (Muller, 1774).
Quarantine Status: N/A

Description: A bivalve mollusc with a yellowish brown to black shell with concentric, evenly spaced ridges on the shell surface. Adult clams are usually less than 25mm but can grow up to 50 to 65mm in length (Aguirre & Poss 1999).
Signs & Symptoms: N/A

Native Range: Korea, South-eastern China and southeastern Russia, including Ussuri Basin.
Introduced Range: South America (Argentina, Panama), USA (introduced to 38 states and the District of Columbia), Japan, widespread in Europe. England: Invaded in 1998. It remained confined to an isolated network of rivers in Eastern Britain until 2004, when it was discovered in low densities in the River Thames, London.

General: It requires well-oxygenated waters and prefers fine, clean sand, clay, and coarse sand substrates. Maximum densities can range from 10,000 to 20,000 per square metre. Average lifespan is 2 to 4 years. Movement and dispersal: Hermaphrodite capable of self-fertilisation. Larvae are released into the water column. Spawning requires water temperatures >16 C and this is the minimum temperature for the clams to release their larvae. A single clam can release up to 400 juveniles a day and 70,000 per year. Larvae spawned late in spring and early summer can reach sexual maturity by the next autumn. C. fluminea spreads when it is attached to boats or carried in ballast water, used as bait, sold through the aquarium trade, and carried with water currents.

Environmental Impact: It may cause much damage to intake pipes used by power, water, and other industries that is very expensive to remedy. Many native clams are declining as C. fluminea outcompetes them for food and space. Invasion Stage (England): Since 2004 it has been discovered at three more sites on the tidal River Thames. Surveys indicate that the clam has now established dense populations at Ham, with evidence of annual recruitment. Given the substantial connectedness of the Thames to many of Britain‟s other rivers, it is likely that it will now continue to spread through Britain‟s waterways (Elliott & zu Ermgassen, 2008).

Introduction Pathways: Ballast water, hull fouling, live bait, aquarium trade.

Control: Where possible, heat treatment (>37 C) is effective. Mechanical measures, such as using screens and traps, can eliminate older clams and remove body tissue and shells from pipe systems. Chemicals, such as small concentrations of chlorine or bromine, are very effective for killing juveniles and sometimes adults.

B1 Medium/Isolated Populations

References Aguirre, W. and Poss, S. G. 1999. Non-Indigenous Species In the Gulf of Mexico Ecosystem: Corbicula fluminea (Muller, 1774). Gulf States Marine Fisheries Commission (GSMFC). Elliott, P. and zu Ermgassen, P.S.E. 2008. The Asian clam (Corbicula fluminea) in the River Thames, London, England Aquatic Invasions 3, 54-60.

Taken from Natural England Comissioned Report NECR0009
Horizon Scanning for new invasive non native animal species in England.
Back to top Go down
Asiatic Clam
Back to top 
Page 1 of 1
 Similar topics
» Clam beds and how to find them
» MLB Draft 2012
» Fold Up Rake

Permissions in this forum:You cannot reply to topics in this forum
Thames Anglers' Conservancy Members Forum :: Open Section :: Conservation Issues-
Jump to: