Searching for the Robust Lancetooth

Robust Lancetooth | Haplotrema (Ancomena) vancouverense
Robust Lancetooth | Haplotrema vancouverense

We’ve been keeping an eye out for some of the bigger snails during our forest walks this week – they’re much easier to identify than some of the smaller ones that we’ve discovered underneath paving stones and wood. This week we found the shell of a Robust Lancetooth (Haplotrema vancouverense), a fairly common large snail in deciduous and mixed-wood forests along the coasts of British Columbia. These snails look for shelter underneath rocks, moss, wood and leaf litter on the forest floor. The snail is omnivorous and eats earthworms, slugs, and snails (including their own species).

Robust Lancetooth showing umbilicus
Robust Lancetooth showing umbilicus

The snail is relatively easy to identify. According to Land Snails of British Columbia (Robert Forsyth) the shell of the robust lancetooth is between 22 and 32 mm in width and yellowish or olive green in colour. The body of the snail is creamy white with the head and tentacles darker. While we’ve found a few shells of this species, we’re still searching for a live animal.

Robust Lancetooth showing apertural lip
Robust Lancetooth showing apertural lip

The apertural lip is one diagnostic feature to look for when identifying the robust lancetooth. The Beaded Lancetooth (Ancotrema hybridum) looks superficially similar to the robust lancetooth but it has a beaded shell and an apertural lip that is thicker and arched forward and downward.

Snail enthusiasts are recommended to visit Forsyth’s website Mollus.ca for detailed descriptions and photographs of snails in British Columbia. You may also want to read Jocie’s blog post On The Trail of a Snail to learn about other large snails in British Columbia.

Macro Monday

4 comments

  1. I’m very interested in biology and botany. These are sharp, crisp photos- just lovely. I enjoyed the information that accompanied these. I’m new to Macro Mon. Hi!

  2. Thanks for the feedback on this post – I admit that I did pose the shell on the Big-leaf Maple leaf but it does provide some relevant information on this snail’s habitat : )

    We’re still looking for a live one to photograph!

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