Rank Genus | ||
 | ||
Family SmeagolidaeClimo, 1980 Similar Rhodopidae, Amphiboloidea, Trimusculus, Systellommatophora, Glacidorbidae | ||
Smeagol is a genus of small air-breathing sea slugs of the upper intertidal zone, pulmonate gastropod mollusks in the superfamily Otinoidea.
Contents
Smeagol is the only genus in the family Smeagolidae. This family has no subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
Etymology
The name of the genus is in honour of Tolkien's fictional character Gollum, who was originally known as Sméagol.
Species
There are five described species and potentially one undescribed species from Tasmania in the genus Smeagol:
Anatomy
Smeagol manneringi has no tentacles and is a very active blind animal with a size of up to 10 mm.
Smeagol species have no shell. They have a weakly developed snout. The radula is unicuspid and the radular dentition is of the rhipidoglossate type. They have a radular membrane of flexoglossate type. They have no jaw. They have salivary glands with salivary ducts.
The Excretory organs are only the left ones, in the pallial cavity. In the circulatory system the haemolymph circulates as follows: mantle → nephridium or nephridia → heart.
These slugs breathe using a pallial lung. They have a contractile pneumostome.
They have a suprapedal gland.
The number of chromosomes is unknown. They have no sex chromosomes.
Ecology
These slugs inhabit the upper intertidal zone on gravel substrate in New Zealand and Australia.
The development of the veliger is completed in the egg (they do not have a trochophore larval stage).