Milax gagates

Family

Milacidae

Species

Milax gagates (Draparnaud, 1801)

Common name

Greenhouse slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
, Keeled slug

Description

Fully mature adults of this species may be as long as 70 mm. The body of the animal may be grey-brown to black, gradually becoming lighter in color towards the footFoot:
The muscular organ on the undersurface of the body of a mollusc upon which the animal rests or uses to crawl.
. There are no obvious markings on the body of neither the adults nor juveniles. The mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
is large and may be slightly granularGranular:
Bearing granules on the surface or having a rough appearance.
with a horseshoe-shaped grooveGroove:
An elongate and fairly uniform depression or indentation in the shell or soft parts of a mollusc.
in the center. There may also be 16-17 grooves between the keelKeel:
Also known as the carina. This is a longitudinal ridge that runs dorsally along the apex of the tail of the animal.
and the pneumostomePneumostome:
This is the breathing hole on the right side of the mantle of molluscs. This allows air to pass through to the lung for gas exchange.(See also breathing pore).
(breathing pore). The breathing poreBreathing pore:
This is the breathing hole on the right side of the mantle of molluscs. This allows air to pass through to the mantle for gas exchange. (See also pneumostome).
is located in the posteriorPosterior:
Directional term: the rear or tail end of an animal.
half of the mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
. There is a very prominent keelKeel:
Also known as the carina. This is a longitudinal ridge that runs dorsally along the apex of the tail of the animal.
on the back of the animal, extending from the posteriorPosterior:
Directional term: the rear or tail end of an animal.
edge of the mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
to the tip of the tail. The sole is tripartiteTripartite:
Having three distinct section/regions.
: blackish with a pale medianMedian:
Along the central line or axis.
. There are "v"-shaped grooves along the medianMedian:
Along the central line or axis.
line of the sole. The mucus produced by this slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
is clear.

Native range

Western Mediterranean, Western Europe and the Canary Islands

Distribution

North America:

• U.S.: eastern North America, Pacific Northwest, California

South America

Australasia: New Zealand, Australia

Asia: Japan, Sri Lanka

South Africa

Europe: Britain, Mediterranean region

Ecology

Milax gagates has been reported to be very destructive in Hawaii where it is decimating rare, native plants in Haleakala National Park (Hawaiian Islands). The keeled slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
is known to cause yield reduction in soybean, sunflower and oilseed rape, by causing damage to seeds and seedlings. This pest species is capable of burrowing and often damages the roots and lower stems of plants (e.g., carrot, potato). The eggs are laid in tunnels made below the soil surface. Clutch size may be as few as 16. The incubation period for the eggs is approximately 25 days, juvenile mature within about 4-5 months.

Synonyms

• Limax gagtes Draparnaud, 1801. Tableau des mollusques terrestres et fluviatiles de la France: 100. Type locality? Montpellier.
• Limax maurus Quoy and Gaimard, 1824. Voyage L'Uranie et la Physic. Zool.: 427.
• Limax fulginosus Gould, 1852. U.S. Expl. Exped. XII: 5.
• Milax antipodarum Gray. 1855. Cat. Pulmonata Brit. Mus. 1: 177.
• Limax pectinatus Selenka, 1865. Mal. Blatt.: 105.
• Milax hewstoni Cooper, 1872. Proc. Acad. Nat. Sci. Philad.: 147.
• Milax emarginata Hutton, 1879. Trans. N.Z. Inst. 11: 331.
• Milax tasmanicus Tate, 1881. Pap. Proc. R. Soc. Tas.: 16.
• Milax nigricolus Tate, 1881. Pap. Proc. R. Soc. Tas.: 17.
• Amalia antipodarum var. pallida Cockerell, 1891. Ann. Mag. Nat. Hist. VII: 340.
• Amalia parryi Collinge, 1895. J. Malac. 4(1): 7.
• Amalia babori Collinge, 1897. Proc. Malac. Soc. Lond. 2(6): 294.

References

Anderson 2005; Barker 1979; Barker 1999; Clemente et al. 2010; Cowie et al. 2009; Kerney et al. 1979; Naggs et al. 2003