Hey guys,
Couple non-fish species I was hoping I could get ID help on. I found the clam in a small backwater while netting minnows. It was about the largest of probably 20 that I caught. They were down in some muck near plant roots. It is just less than 1 cm long. The crawdad comes from a pond nearby that is filled with them. It is about 4-5 inches long and was the biggest one I have seen in the pond. There are very few predators in the pond so the population is booming. The one in the pic has a very hard shell but the smaller ones are softer. My questions on both:
1)What is it? Incorrect ID on crayfish or clams can cause problems in a pond environment so I want to get a good idea of what they are before I begin messing around with them in a pond enironment.

2)Harmful in a pond? I was thinking the clams might be good food for RES because of their size, is this true? They could just be juveniles of a larger species but I did not find any larger ones.
crawdad crawdad1
clam

Hey Imoore;

Travis and Bill Cody have commented about the benefits/disadvantages of clams or bivalves in general for ponds and will be along shortly to lead the way.

IMO:

1. If another watershed has abundant crayfish very near yours you will most likely find them in your watershed, too. I have noticed that crayfish shells, as they mature, tend to become more rigid - so you might be dealing with the same species just different ages. My view is - if you can't stop them from coming, and I don't know you want to, then plan to utilize them as forage. Unless your pond has tons of structure I would doubt they could ever become a serious issue with the existence of some predator fish population [LMB/SMB].

2. I've learned that bivalves can benefit a pond in two ways - maybe more. 1 - they serve as preferred forage for species like RES and PS.
2 - they could also help improve water clarity.

The negative effect of clam or any bivalve population would be their removal of many nutrients from your pond. Guess this would include plankton and zooplankton which are the building blocks of the food chain.

I hope some of this helps - experts will be along shortly I'd wager.

I can't help with identification, but I can explain the shells. Crayfish, like snakes, shed their skin to grow larger. The ones that have soft shells are called that in the bait shops, or "peelers" and fish LOVE them. Cecil should be able to help also, he has intimate knowledge of crayfish.

2 years ago I put close to 250 crayfish in the pond, but there really wasn't much cover for them. When I renovated the pond last year I didn't find a one. I did find some in CC's stomachs tho.

Imoore, the clam looks like an Asian clam I actually just put about 100 of them I collected from the Potomac River into one pond I am managing. One of my goals for the pond is to grow large RES and RES love to eat small clams, so we will see how that works out. Plus the pond I am managing is very fertile, actually too fertile so I am hoping the clams will help combat this and turn some of the excess into RES food. Here is the discussion we had about clams as forage

I am not good with crayfish ID, however they do not look like rusty crayfish which are pretty distinct looking and they are the only species that is of a real concern that is found in the Midwest. The introduction of crayfish from a nearby pond probably won't cause any harm. However, someone with crayfish IDing skills can tell you the exact species so you know their habits and what to expect.

Thanks for the help guys. CJ, I had wondered is it might be an Asian Clam. I found a site with freshwater mussells of Iowa an pics and that was the closest looking one. I didn't think the crayfish was a Rusty Crayfish as I was thinking the Rusty Crayfish had a pretty distinct dark tip to is claws. That could be incorrect but that' what I had in my head.

The Rusty's have denuded quite a few lakes in Northern Wisconsin, and the smallmouth populations in those lakes have followed suit. It hasn't helped any of the other species of fish tho. From what I remember, it doesn't look like a rusty either.

Who's your Craw Daddy?

All this talk about crawdads has made me hungry.