Most likely Euastacus crassus from the location. Internal features are required for species Identification and the location is very close to the known distribution for the recently listed Euastaus rieki. E. crassus is an important species particularly as recent genetic anaylsis has indicated that its range is much more reduced than previously thought.
The small "slugs" on its claws and bodies are temnocephalans a flat worm that lives on the crayfish.