Terrestrial emigration behaviour of two invasive crayfish species

Area of Science:

• Ecology
• Invasive Species Biology
• Animal Behavior

Background:

• Freshwater organisms face challenges dispersing between isolated waterbodies.
• Terrestrial movement is a key dispersal method for many aquatic species, including crayfish.
• Understanding overland dispersal is crucial for managing invasive crayfish populations.

Purpose of the Study:

• To compare the terrestrial emigration tendency of two invasive crayfish species in Great Britain: red swamp crayfish (Procambarus clarkii) and signal crayfish (Pacifastacus leniusculus).
• To assess the risk of overland dispersal and spread of these non-native crayfish species.

Main Methods:

• Directly compared the terrestrial emigration behavior of red swamp and signal crayfish under experimental conditions.
• Quantified and analyzed the overland movement tendencies of both species.

Main Results:

• Both red swamp crayfish and signal crayfish demonstrated a significant tendency to emigrate from water bodies onto land.
• No significant difference was found in the terrestrial emigration tendency between the two studied invasive crayfish species.

Conclusions:

• Terrestrial emigration is a critical behavioral trait contributing to the spread of invasive crayfish.
• Both red swamp and signal crayfish pose a similar risk for overland dispersal and colonization of new habitats.
• Invasive crayfish management strategies must consider terrestrial movement to prevent aquaculture escape and further spread.