Short description of Urosalpinx cinerea, American Oyster Drill

A tall, conical shell, up to four cm high and two cm broad, with a sharply pointed spire and up to eight rounded whorls bearing pronounced ridges and ribs.   Yellowish, orange or grey in colour, sometimes with irregular brown marks.  The aperture is oval with an open canal at the base.   

Impact summary: Urosalpinx cinerea, American Oyster Drill

The American oyster drill is a major pest to the commercial oyster industry and preys heavily on both native and introduced oyster species.  It feeds preferentially on oyster spat and has been reported to decimate stocks of oyster spat in some estuaries.

Habitat summary: Urosalpinx cinerea, American Oyster Drill

The American oyster drill inhabits the lower shore and shallow subtidal waters to depths of around 12-15 metres.  It prefers the muddy bottoms of estuaries and is often found feeding on oyster beds. 

Overview table

Environment	Marine and Freshwater
Species status	Non-Native
Native range	Northern America
Functional type	Predator
Status in England	Non-Native
Status in Scotland	Non-Native
Status in Wales	Non-Native
Location of first record	Essex Oyster Ground
Date of first record	1927

Origin

The American oyster drill is native to the Atlantic coast of North America, from Cape Cod to southeastern Florida. 

First Record

First reported from Essex oyster grounds in 1927, and believed to have been unintentionally introduced to GB at the beginning of the twentieth century with shipments of imported oysters from the USA.

Pathway and Method

The American oyster drill was introduced unintentionally with shipments of imported oysters from the USA. 

Species Status

Distribution in GB appears limited to Essex and Kent coasts, primarily in estuaries. Populations were severely affected by tributyl-tin (TBT) pollution during the 1980s; in some Essex estuaries breeding activity was found to have been virtually eliminated by 1990 and the local population was close to extinction. However, recent controls on the use of TBT may enable the population to recover.   No records exist from other oyster cultivation sites including Humberside, Dorset, and south Devon where Essex or American oysters have been deposited. 

Dispersal Mechanisms

This species has no free swimming stage in its life history and so any natural dispersal is slow and occurs only on a local scale.  Their range in Essex extended just two miles north and south over a 25 year period.  It is believed that all instances of marked dispersal have been as a result of transportation with oysters.

Reproduction

Spawning begins when water temperature warms to about 12 °C, and deposition of egg capsules begins during late April or early May, continuing through June and July.  Adult females deposit on average 25 egg capsules at a single laying; these tough egg capsules are attached to hard surfaces (boulders, shells, chains at low water mark are common sites) in clusters.  The incubation period lasts about eight weeks after which time fully formed juveniles emerge.  Each egg contains multiple larvae, producing on average 11 juveniles per egg.

Known Predators/Herbivores

No information was found regarding predators specific to this species, but predators are likely to include various species of crab, fish and birds.

Resistant Stages

None known.

Habitat Occupied in GB

Inhabits the lower shore and shallow subtidal waters of estuarine and marine habitats, and is reported to prefer muddy bottoms.  Found on the Essex and Kent coasts, mostly in estuaries and primarily associated with oyster beds, but also with other bivalves including mussels.

The American oyster drill is native to the Atlantic coast of North America, from Cape Cod to southeastern Florida.  In GB its distribution is limited to the Essex and Kent coasts.

Environmental Impact

The American oyster drill preys heavily on native oysters and may compete with native molluscs such as the dog whelk Nucella lapillus.  Lacking a free swimming larval phase, local populations increase rapidly as dispersal is limited.  Juveniles are able to drill oyster spat and barnacles as soon as they emerge from egg capsules. 

Health and Social Impact

As a serious pest to the commercial oyster industry, impacts to communities dependent on local fisheries may be significant.

Economic Impact

The feeding activities of the American oyster drill can decimate commercial oyster populations. 50 % mortalities among oyster spat directly attributable to this predatory snail were commonly reported from Essex oyster beds before oyster drill populations declined during the 1980s.  The UK oyster and mussel industry was worth £39.8 million in 2007.  Loss of revenue may also occur due to restrictions on movement of stock from areas known to be affected by this species. 

Identification

Oakley, J. ( 2006) Urosalpinx cinerea. American oyster drill. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http:www.marlin.ac.ukspeciesinformation.php?speciesID=4549

Biology, ecology, spread, vectors

Cole, H.A. (1942) The American whelk tingle, Urosalpinx cinerea (Say) on Essex oyster beds. Journal of the Marine Biological Association, 25, 477-508.

Faasse, M. & Ligthart, M. (2007) The American oyster drill, Urosalpinx cinerea (Say, 1822), introduced to The Netherlands – increased risks after ban on TBT?  Aquatic Invasions, 2, (4), 402-406.

Faasse, M. & Ligthart, M. (2009) American (Urosalpinx cinerea) and Japanese oyster drill (Ocinebrellus inornatus) (Gastropoda: Muricidae) flourish near shellfish culture plots in The Netherlands. Aquatic Invasions, 4, (2), 321-326.

Management and impact

Gibbs, P.E., Spencer, B.E., & Pascoe, P.L. (1991) The American oyster drill, Urosalpinx cinerea (Gastropoda): Evidence of decline in an imposex affected population (River Blackwater, Essex). Journal of the Marine Biological Association of the United Kingdom, 71, 827-838.

Hancock, D.A. (1954) The destruction of oyster spat by Urosalpinx cinerea (Say) on Essex oyster beds. Journal du Conseil Permanent International pour l’Exploration de la Mer, 20, 186-196.

General

Global Invasive Species Database (2010) Urosalpinx cinerea (mollusc) [online] Available from: http:www.issg.orgdatabasespeciesecology.asp?si=1383&fr=1&sts=sss&lang=EN

https://www.cabi.org/isc/datasheet/60187