Testacella haliotidea Draparnaud, 1801
The length of this semi-slug ranges from 80-120 mm. The body of this animal is light grayish-brown (sometimes yellowish), with a pale foot fringe and sole. The small (approx. 7-8 x 5-6 mm) external shell of this animal is located on the dorso-posterior tip of the tail. Members of this group (Testacellidae) characteristically have two distinct, lateral (branched) grooves that originate from the anterior margin of the much-reduced shell.
Two addition species in this group have been reported from Europe and may be distinguished by the following characters:
T. maugei: Morphology-shell larger than both species (12-16 mm long by 6-7 mm wide) and the dorsal lateral grooves are approximately 5 mm apart at the point of origin. Genitalia-the penis does not have a flagellum, and the spermathecal duct is long and thin.
T. scutulum: Morphology-the shell is of similar size to that of T. haliotidea and the dorsal lateral grooves join (just under the shell) before reaching the the point of origin. Genitalia-the penis does not have a flagellum and the spermathecal duct is intermediate between those of T. haliotidea and T. maugei.
Western Europe and Western Mediterranean region
- U.S.: California
Australia: Australia, New Zealand
This carnivorous semi-slug spends most of its time underground, where it hunts and consumes earthworms, snails and slugs. The shelled slug is commonly found in disturbed habitats like gardens, parks and agricultural fields. This slug is able to burrow to depths of up to one meter during periods of aestivation. This animal has not been reported to feed on plant material and as such should not pose a threat to agricultural produce. The ecological impact that this species may have on other terrestrial mollusc species has not been documented.
Anderson 2005; Barker 1979; Barker 1999; Kerney et al. 1979; McDonnell et al. 2009