A RARE example of the world’s largest species of slug has been sighted in the Isle of Man for the first time in more than a hundred years, revealing its woodland habitat to be one of the few remaining ancient forests in the island.
The news came to light after an ash black slug was discovered in a deep wooded ravine with mature oak trees near Glen Auldyn by Keith Alexander, a visiting British invertebrate expert.
The species, distinctive for its dark grey with a pale wavy crest running the length of its back, is rare but widespread in both Britain and Ireland, and can grow up to 30cm in length. More commonly they will measure 20cm, so this 15cm Manx specimen is decidedly modest.
Andree Dubbeldam of the Manx Wildlife Trust commissioned Mr Alexander for a study of molluscs in woodland areas. Experts in this field don’t often come to the Isle of Man, the main reason why this species of slug hasn’t been spotted in the island since 1905, also near Glen Auldyn.
The ash black uses large deadwood for protection, requires high humidity and feeds on lichens, moss and algae.