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 slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
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 mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
of this animal extends 2/3 the length of the body. There is a small, internal shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
that is flat and beak-like in this species. The shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
is partially visible through an external pore in 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 are two elevated ridges on the very large mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
of this species. The left ridge runs from the anteriorAnterior:
Directional term: located in front. Nearer the head or front end of a shell.
portion 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 posteriorPosterior:
Directional term: the rear or tail end of an animal.
edge. The other ridge on the right side of the animal runs from 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).
to the opening of the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
. There is a prominent keelKeel:
Also known as the carina. This is a longitudinal ridge that runs dorsally along the apex of the tail of the animal.
that extends 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 where it ends in the mucus pore. The footFoot:
The muscular organ on the undersurface of the body of a mollusc upon which the animal rests or uses to crawl.
is tripartiteTripartite:
Having three distinct section/regions.
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-slugSemi-slug:
A snail that possess a very reduced (no definite coiling) or small shell, that is often located on the posterior edge of the mantle. The animal is not able to retract into this minute shell.
because of a small, soft shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
that covers the back. The shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
is not large enough to cover the mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
, therefore leaving it partially exposed. The animal has the capability to cover its shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
with the mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
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 keelKeel:
Also known as the carina. This is a longitudinal ridge that runs dorsally along the apex of the tail of the animal.
that extends from the baseBase:
This is the lower or underside of the shell; opposite of apical.
of 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 mucus pore. The tentaclesTentacles:
Sensory projections on the head end of a mollusc. There are generally two pairs; upper (posterior) and smaller, lower (anterior). The upper pair bears the eyes. In many snails the eyes are located at the tips of this structure; however, in Basommatophoran snail species, the eyes are located at the base of 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 mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
in this species also appears sac-like with an opening in the middle through which the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
can be seen. The sole is tripartiteTripartite:
Having three distinct section/regions.
and the footFoot:
The muscular organ on the undersurface of the body of a mollusc upon which the animal rests or uses to crawl.
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 slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
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