Worms, Planeria, Leeches? (PICS)

[KarlTh]

This is a beautiful post I agree, they'll more than likely simply become a rare delicacy for your fish.

[blushes]

All that time ruining my sight by teasing apart algae in a white dish to see what crawls out and identify the critter has left me with an almost Pavlovian ID reaction to seeing a picture of an aquatic invertebrate.

The downside is it's removed any sympathy I may have had for automatic "ew - that's gross" reactions. Most of these little characters are anything but gross, almost none of them are parasites (you generally only come across parasites actually on or in their hosts), most of them are fascinating once you get to know about them, and nearly all of them are below fish in the food chain.

Disclaimer - a Great Diving Beetle larva sucking the juices out of a tadpole is, however you slice it, gross.

 

[Lupin]

I'm still confused and intrigued to this day what those creatures exactly are. I had hundreds of these in my pond a few months ago much to my shock that I had to scoop them while they float around the surface to completely remove everything.

 

[KarlTh]

Unfortunately there are lots of species; Polychaetae is a very large group.

Having said that, only a small proportion of them are freshwater. Given that they live in the substrate, and most are marine, they could be said to be the original "stick in the muds" - they evolved in ocean mud and most of them have stayed there.

This may help: http://www.archive.org/details/freshwaterpolych00fost - a whole book of freshwater polychaetes for you