Fisheries-pest
Guides
Carcinus maenas
European green crab, green crab, shore crab, green shore crab, European shore crab
Carcinus maenas is a highly invasive littoral crab native to the northeast Atlantic Ocean and Baltic Sea. Listed among the world's 100 worst invasive alien species, it has established populations across temperate coastlines worldwide including North America, Australia, South America, and South Africa. The species exhibits remarkable phenotypic plasticity, with color morphs ranging from green to red that differ in aggression and stress tolerance. Its successful global dispersal occurs through multiple mechanisms including ballast water, ship hull fouling, and aquaculture transfers.
Procambarus clarkii
red swamp crayfish, Louisiana crawfish, mudbug, red swamp crawfish
Procambarus clarkii is a freshwater crayfish native to northern Mexico and the south-central United States, particularly the Mississippi Basin and Gulf Coast. It is highly adaptable to warm, slow-moving freshwater habitats including marshes, rice paddies, and irrigation systems. The species tolerates low dissolved oxygen, moderate salinity, and dry spells up to four months. It has been introduced globally and is a significant invasive pest in Europe, Africa, and Asia, where it outcompetes native crayfish and vectors crayfish plague. It is also the foundation of a major aquaculture industry, particularly in Louisiana and China.
Salmincola
Salmincola is a genus of freshwater parasitic copepods in the family Lernaeopodidae. These ectoparasites are common on salmonid fishes throughout the Northern Hemisphere. The genus exhibits substantial geographic variation in infection rates across water bodies, and current taxonomic definitions based on decades-old morphological descriptions may obscure cryptic diversity. Species in this genus are considered pests by fisheries management agencies due to their impact on host fish populations.