Helicarionidae

Family

Helicarionidae

Species

Mariaella dussumieri Gray, 1855

Parmarion martensi Simroth, 1893

Parmarion reticulates Hasselt, 1824

Common Name

Mariaella dussumieri: None reported

Parmarion martensi: Yellow-shelled semi-slug

Parmarion reticulates: None reported

Description

Mariaella dussumieri: Mature specimens of this slug will measure up to 200 mm in length. Its body color ranges from yellow-brown to olive, with black colored blotches that may coalesce in some individuals giving the animal a completely black appearance. The mantle of this animal extends 2/3 the length of the body. There is a small, internal shell that is flat and beak-like in this species. The shell is partially visible through an external pore in the mantle. There are two elevated ridges on the very large mantle of this species. The left ridge runs from the anterior portion of the mantle to the posterior edge. The other ridge on the right side of the animal runs from the breathing pore to the opening of the shell. There is a prominent keel that extends from the posterior edge of the mantle to the tip of the tail where it ends in the mucus pore. The foot is tripartite and has bands.

Parmarion martensi: This species is brown in color and is capable of attaining a length of up to 50 mm. The animal is generally called a semi-slug because of a small, soft shell that covers the back. The shell is not large enough to cover the mantle, therefore leaving it partially exposed. The animal has the capability to cover its shell with the mantle flaps adjacent to it (the entire structure looks like a 'bag' hanging over the tail of the animal). There is a very prominent, pale colored keel that extends from the base of the posterior edge of the mantle to the mucus pore. The tentacles bearing the eyes are dark-brown to black, while the lower pair is tan/cream colored.

Parmarion reticulates: This species is similar to P. martensi. The mantle in this species also appears sac-like with an opening in the middle through which the shell can be seen. The sole is tripartite and the foot has a mucus pore.

Distribution

Mariaella dussumieri:

Asia: India, Sri Lanka

Parmarion martensi:

Pacific Islands: Hawaiian Islands, Samoa, American Samoa

Asia: Japan, Taiwan, Vietnam, Malay Peninsula, Sumatra, Java, Singapore, Borneo

Ecology

Mariaella dussumieri: This species has been documented as a pest of cabbage, young rubber plants and legumes. The incubation period of eggs 4-46 days.

Parmarion martensi: This species has been intercepted on lettuce, fennel, sweet potato, banana, passion fruit, lemon grass and Heliconia sp. It has also been observed feeding on fallen fruits of avocado, guava, citrus, papaya and mango. This species is commonly found around human dwellings and is reported as a reservoir host of the human rat lungworm parasite (Angiostrongylus cantonensis). This increases the probability of the slug transmitting this potentially fatal disease-causing organism to humans.

Parmarion reticulates: This species has also been reported to feed on young plants of the rubber tree.

References

Gupta and Oli 1998; Hollingsworth et al. 2007; Mead 1961; Naggs et al. 2003; Tandon et al. 1975

Posted on