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German wasp | Vespula germanica

German wasp

Vespula germanica

Coral bush | Ardisia crenata

Coral bush

Ardisia crenata

Purple loosestrife | Lythrum salicaria

Purple loosestrife

Lythrum salicaria

Pom pom weed | Campuloclinium macrocephalum

Pom pom weed

Campuloclinium macrocephalum

Canarybird bush | Crotalaria agatiflora

Canarybird bush

Crotalaria agatiflora

Peanut butter cassia | Senna didymobotrya

Peanut butter cassia

Senna didymobotrya

Rubber vine | Cryptostegia grandiflora

Rubber vine

Cryptostegia grandiflora

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Environmental Programmes

In order to tackle our country’s socio-economic challenges, the government adopted the Outcomes based approach to improve government performance and providing focus on service delivery. find out more

European shore crab

Carcinus maenas

Common name:

European shore crab

Scientific name:

Carcinus maenas

Alternative common names:

European Green Crab,Green Shore Crab.

A large crab measuring 10cm across the carapace width. The front margin of the carapace has three ‘teeth’ between the eyes and five prominent ‘teeth’ along either margin. It is mottled green in colour on its upperside with a semicircular pattern of white dots across the carapace. The underside is yellow or orange. This crab is competitive and has largely eliminated mussels and other shellfish in the area.

Additional Info

  • Where does this species come from?

    European coastal regions.

    What is its invasive status in South Africa?

    NEMBA Category 1b.

    Where in South Africa is it a problem?

    Hout Bay a town near Cape Town.

    How does it spread?

    The spread is by natural dispersal in oceanic currents, boats and ships or accidental transportation within oyster farming equipment and infrastructure.

    Why is it a problem?

    This crab is competitive and has largely eliminated mussels and other shellfish in the area. This crab poses a serious threat to the shellfish industry, especially if it reaches the Saldanha Bay-Langebaan Lagoon system where important fisheries exist.

    What does it look like?

    Description: A large crab measuring 10cm across the carapace width. The front margin of the carapace has three ‘teeth’ between the eyes and five prominent ‘teeth’ along either margin. It is mottled green in colour on its upperside with a semicircular pattern of white dots across the carapace. The underside is yellow or orange. Habitat: Marine environment in the vicinity of harbours and rocky bays. Breeding: Mating takes place after females moult in winter and females extrude their eggs during spring. Successful embryonic development takes place when water temperature is between 11 and 25◦C.

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General News Updates

2019 National Symposium on Biological Invasio…

26-02-2019

This is your invitation to South Africa's 2019 National Symposium on Biological Invasions. The convention is hosted by the Centre for Invasion Biology (CIB), University of Stellenbosch, and the Biolo... Read more

2019 Invasive Species Training

22-01-2019

During the past five years (2014-2018), ISSA invasive species trainers have trained 4 000 in the identification of invasive species and laws pertaining to invasive species across South Africa.  ... Read more

Alien Grass Working Group

04-09-2018

Who are we? The South African National Alien Grass Working Group was jointly initiated by the South African Biodiversity Institute (SANBI) and the Centre for Excellence in Invasion Biology (C·I·B) in... Read more

Permits for planting indigenous Cynodon?

01-03-2018

On 16 February, 2018, South Africa's Department of Environmental Affairs issued amendments to the regulations and lists relating to the National List of Invasive Species.  Updates to the draft&n... Read more

Invasive species training 2018 dates released

28-02-2018

Interested in invasive species?  How much do you know about NEMBA invasive species compliance for landowners and organs of state? The South African Green Industries Council (SAGIC) have released... Read more

Communications post for Africa advertised

25-01-2018

The Nature Conservancy has advertised a brand new post:  Communications Manager, Africa Region. Knowledge of invasive species and water would be an asset in this post. See details below:    Job Titl... Read more