Friday, November 30, 2007

Is it bad luck when a slug crosses your path?

Yesterday I saw a late season slug cross my path on a sidewalk and then onto a manhole cover. I raced to get a camera to get a good closeup because I am a lover of nature and science, even the slimy kind.

This appears to be a dehydrated leopard slug (also called a Great Grey Slug, Limax maximus). It looks much thinner than this picture of a slug in Maryland on wikipedia. I would imagine that since it is getting to be winter, that they won't look as nice and juicy as in the middle of summer or after a rain. Perhaps a certain Ranger with more expertise on wildlife than I can offer an opinion about dehydrated slugs. I believe these slugs are an introduction from Europe so he should be familiar with them. A closeup view of the slug next to a ruler (click for large view) really shows its spots and stripes and the intricate wrinkles on its mantle.

He/she (they are hermaphrodites) moved into the mulched area, hopefully to survive the winter. I won't hold a grudge against them, though the slugs in my garden love to chew plants down to the nub. We use slug bait pellets with iron phosphate to protect our plants. Since iron phosphate naturally occurs in the soil it is safe, the slugs eat and it and they crawl away to die. I guess garden plants > slugs in my book.


The Virtual Ranger said...

Yes, that's a familiar slug! I didn't know it had made it over there. I'd have thought that if a slug dehydrates enough to shrink much it would be dead. Just like us they are pretty sensitive to changes in internal conditions (such as any increase in ion concentrations that might come with dehydration). Unlike us though they are also very sensitive to the external environment.

In my experience slugs can stretch out like that when they are in a hurry, e.g. fleeing. They shrink down and look much fatter when they are distress - perhaps to reduce their surface area. Sometimes they also blow bubbles which is a last-ditch attempt to stave off dehydration.

Richard Koehler said...

While the speed of the slug didn't make it look like it was in a hurry, I am burdened by human concepts of speed vs. a slug's. I suppose that hummingbirds think we move like slugs. I can also guess the reason the slug was fleeing - my paparazzi photography when it was just trying to get to the next mulch pile.