Carpathian Blue Slug

This slug turns blue when an adult and becomes 100 – 140 mm in length. It is evenly blue or bluish green (occasionally black) with a dark greyish head and tentacles, and margins pale yellowish, sole pale yellowish or whitish. Juveniles are yellowish brown with dark lateral bands. Reproductive system: Genitalia are without penis. There is only an accessory organ for copulation.

This species is endemic to the Carpathian Mountains in Central and Eastern Europe. The type locality of Bielzia coerulans is the South Carpathians in Romania.

Czech Republic - in Moravia only, vulnerable (VU) in Moravia Southern Poland Slovakia Ukraine Romania Hungary Germany (presumed introduction in Westerwald, Rhineland-Palatinate, discovered 2012)

Bielzia coerulans inhabits deciduous and coniferous forests in mountains, usually at the bottom, or under dead wood logs. Maturity is in June to July. Copulation occurs at the soil. There are 30-80 eggs laid in one clutch. Adults die after egg deposition. Half grown juveniles hibernate. Fully grown slugs appear in May.