Bielzia


Bielzia coerulans, commonly known as the Carpathian blue slug or simply the blue slug, is a species of very large land slug, a terrestrial pulmonate gastropod in the family Limacidae, the keelback slugs.

Taxonomy

Bielzia coerulans was discovered in 1847 and described under the name Limax coerulans by Austrian–Hungarian malacologist
in 1851.
Bielzia coerulans is the only species in the genus Bielzia.
Some authors, for example Russian malacologists, have classified Bielzia as the only genus within the family Limacopsidae or the subfamily Bielziinae. Others disagree and consider the Limacopsidae and Bielziinae as synonyms of Limacidae and Limacinae.

Distribution

This species is endemic to the Carpathian Mountains in Central and Eastern Europe.
The type locality of Bielzia coerulans is South Carpathians in Romania.
This slug turns blue when an adult and becomes 100 – 140 mm in length. It is evenly blue or bluish green 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.

Ecology

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.