Can Slugs eat Chitin ?

[fairplay]

I have in my photo library a shot of a Leopard slug sliding across the upper surface of a large Bracket Fungus in a very visible zig-zag motion.

On warm still nights when the fungus begins to shed its spores (billions of them) they initially fall by gravity but many then become trapped in warm rising air currents until they hit a cooler layer and as a result you have this strange phenomenon of all the spores landing on the upper surface of the fungus. Surely you've all seen the Artist's Fungus covered in a very fine brown dust with all the nearby leaves covered as well ? These are literally millions and millions of tiny microscopic fungal spores.

One would expect a creature to get from A to B in a straight line, but this zig-zag pattern to me suggests the slug was actively seeking out and eating the spores as it travelled and chose this method to maximise its intake.

Now the question is, can the slugs consume the spores or rather, can they obtain nourishment from them because fungal spores are coated in chitin, the same material found on beetle wing cases which you often find in fox dung droppings. This hard material does not get broken down in the ingestive tract, so I am wondering does the slug produce enzymes which break down this protective layer of chitin ?

It may simply be the case a slug is a slow digester and a long 'soak' is enough to break down the chitin in the way a long soak must break the coating of fungal spores in nature to enable them to germinate.
But I'm no biologist, and it could even be simply the case the slug was enjoying him/herself by making fancy patterns purely for my amusement

So, all you budding biologists out there, I'm 99% convinced the slug was consuming the fungi as it went rather than just pushing the spores to the side like a snow plough, for the trail behind was absolutely clean with no ridges even visible.
What do you reckon ?

Neil.

PS. I've already considered the slug was being harassed by a gay slug and he was simply trying to shake him off by leaving a false trail, and aren't slugs 'sposed to be hermaphroditish anyway ?

[Paul mabbott]

Chitin is a constituent of much else other than spores: all fungal cell walls contain it. Many molluscs eat many fungi so we can assume they're ingesting chitins but not necessarily digesting them. Chitin itself is not particularly hard or tough, it's much like cellulose in plants - so while we can eat (ingest) cellulose, we can't digest it much.
I imagine that what the slug is after in the spores is protein and other complex compounds and the chitin may pass through the intestine largely unchanged.

[Deb London]

Chitinase can be extracted from the gut of snails I read. So I'm assuming they can and will be following this thread to find out.

http://mic.sgmjournals.org/content/11/2/150.full.pdf

[fairplay]

Originally Posted by Paul mabbott

Chitin is a constituent of much else other than spores: all fungal cell walls contain it. Many molluscs eat many fungi so we can assume they're ingesting chitins but not necessarily digesting them. Chitin itself is not particularly hard or tough, it's much like cellulose in plants - so while we can eat (ingest) cellulose, we can't digest it much.
I imagine that what the slug is after in the spores is protein and other complex compounds and the chitin may pass through the intestine largely unchanged.

I realised just a few moments after I posted off this thread that I have seen slugs eating fungi (the fleshy parts) many times and that these cells too will be surrounded by chitin. I now understand the stuff is flexible but still do not know how they get at the contents inside - does the chitin fracture in some way or is the chitin porous and the contents somehow squeezed out ?

When one comes across a stinkhorn 'egg' and sees the amazing sudden emergence of the phallic shaped fungus, it is not new cells being created but the existing cells suddenly expanding in length, but for this expansion to take place there must be some sort of mechanism for material to 'pass through' the cell walls.

Hopefully, when I find time to read what looks to be a very interesting link posted by Deb (thank you Deb) I may understand the workings of chitin a bit more.

Neil.