Welcome to mollus.ca

Discus whitneyi, Tyhee Lake

Discus whitneyi, Tyhee Lake, near Telkwa, BC.

Online database: Bibliography of the Terrestrial Molluscs of Canada

News and General Information

Wanted: leaf litter samples from anywhere in Canada
While the minute land molluscs that dwell in leaf litter are a major component of the terrestrial mollusc fauna of Canada, they have historically been neglected in many parts of Canada. Their small size has usually meant that they have been overlooked by all but the most dedicated naturalists and malacologists. Many gaps in our knowledge of these animals is the direct result of insufficient collections from almost all regions of the country. I am looking for donations of leaf litter samples (each 1–2 L in volume), or drift samples containing terrestrial species from anywhere in Canada. More information here.

Interactive maps at E-Fauna BC
October 2011 — New and updated data have been uploaded to E-Fauna BC, the Electronic Atlas of the Wildlife of British Columbia. Records are now available for terrestrial gastropods.

Need a mollusc identified?
Do you require identifications made of land snails or slugs? I can do these from specimens, or often from photographs. Please contact me for more information. I frequently help photographers, naturalists and others identify slugs and snails in their photos — just ask! Contact me here.

Latest Post

An invasive semi-slug

Not a Canadian species, Parmarion martinsi Simroth, 1893 is an invasive semi-slug in Hawaii. I photographed these individuals in January on the undersides of woody debris at Puu Kukae (a cinder-cone hill) in Puna District, Hawaii Co., Hawaii.

Parmarion martinsi, Puu Kukae, Puna District, Hawaii Co., Hawaii, USA. 30 January 2017.

This semi-slug (that is, midway in body form between a slug and a snail) is likely native to Southeast Asia, according to a paper that I found on the internet (Hollingsworth et al. 2007). First noticed on Oahu in 1996, it was found the Puna District in 2005. Apparently it is also in Kailua-Kona.

Parmarion martinsi is also a vector for Rat Lung Worm (more here).


  • Hollingsworth, R.G., R. Kaneta, J.J. Sullivan, H.S. Bishop, Y. Qvarnstrom, A.J. da Silva & D.G. Robinson. Distribution of Parmarion cf. martensi (Pulmonata: Helicarionidae), a new semi-slug pest on Hawai‘i island, and Its potential as a vector for human Angiostrongyliasis. 2007. Pacific Science 61(4): 457–467.