Image: Blackbone Music
Source: Source Flickr
Question: I saw this yellow worm-like creature in the forest, was it just a normal worm?
Answer: The worm could possibly be a ‘land planarian’ or 'terrestrial flatworm' (Phylum: Platyhelminthes, Class: Turbellaria). Turbellarians are mainly aquatic, and the great majority are marine, however several groups are terrestrial.
Land planarians are invertebrate animals meaning they do not have a backbone. You may be surprised to know that 95 per cent of the world’s animals, from sponges and amoeba to starfish and insects, are invertebrates.
Land planarians are generally confined to humid areas where they hide beneath logs and leaf litter during the day, emerging at night to feed. They occur in a variety of habitats ranging from tropical rainforest to arid semi-desert. Land planarians are entirely free living and carnivorous, feeding on small invertebrates such as slugs and earthworms, or on the bodies of dead animals.
Land planarians are hermaphrodites and lay eggs in gelatinous masses under logs and in soil. Asexual reproduction, in which the animal fragments or divides transversely to form two or more individuals, often occurs.
The Australian planarian fauna consists of at least 137 known species belonging to two main families, Rhynchodemidae and Geoplanidae. The total fauna is estimated to be in excess of 300 species (Winsor 1998); eight species are introduced. A third family, ‘Bipaliidae’, consists solely of the introduced cosmopolitan species Bipalium kewense.
Introduced planarians have most likely been accidentally introduced via shipments of plants, soil, or attached to earthmoving & agricultural machinery, and are often associated with gardens, nurseries and other man modified areas.