Types of predator attacks and marks/scars on shells?

[ennss]

Can anyone point me to some information about what types of predators make the various marks/holes, scars on shells?    For example:
- pinholes
- tiny (few millimeter long) slits/cuts
- indented/eroded areas - "hoof snail" marks?
- large repaired breaks  - fish bites?  trigger fish?

Thanks!

[dmj]

the most common marks on shells are marks by parasites

(little worm like creatures that make the little holes you see on lots of shells

these are also the shells i collect because in some cases the shell will cover the holes on the inside making a little bum on it that is called a blister pearl

the other ones i have no idea how to recon them most animals that are in the water try to eat from shells from beavers to octopus

[dave r]

Pinholes are made by species of boring sponge. Slits or cuts are usually made by worms as mentioned above. Indented/eroded areas could be many things. As you say, Hoof Shell marks or Crepidula even, but they could also be attempts made by a boring predator like Muricidae or Naticidae. Large repaired breaks are usually the result of fish bites or crab attacks.
One other thing is a small hole on its own on a shell can be the result of octopus attack.