Friday, October 5, 2007

A Day at the Creek

Thursday's Field Biology lab was one of my favorites, both when I took the class and now as a TA. We took a break from looking at dead things in jars to look at live things swimming in creeks. The class hiked on over to Cascadilla Creek, just south of campus, armed with D-nets, seines, buckets, trays, and plastic baggies (they are actually quite useful as you will see).

After a brief introduction to proper use of seines and D-nets, the class broke into groups and hit the creek:

We had the class hit both pools and riffles for maximum diversity. When each group had a good, representative sample of the fish and inverts from their area, we gathered and went through them all.

First some inverts:

Water Strider (Gerridae)

Water Scorpion! (Nepidae)

Then some herps, where the baggies come in handy - for passing around and viewing all angles. Of course we only kept them in the baggie for a short time, so you don't have to worry about the herp's welfare.

Larval Salamander (Gyrinophilus)

Green Frog - Rana clamitans
What is this confused beast?

Oh, it's a Toad (Bufo americanus) and two N. Two-lined Salamanders (Eurycea bislineata)

And then, the fish!

Behold, the Fish Bowl!

The Fish Bowl, it is indeed a wonderful thing.

The biggest catch - a White Sucker, Catostomus commersonii

The biggest species of cyprinid - Common Shiner (Notropis cornuta).

Look into the bowl - what will you see?

A dace, a darter, and a sculpin, all lined up nice:

Mottled Sculpin, Cottus bairdii

Foreground: Blacknose Dace (Rhinichthys atratus)
Background: Creek Chub (Semotilus atromaculatus)

Creek Chub (Semotilus atromaculatus). Note the atro maculatus on the dorsal fin.

We let all but a few representatives of the smaller species go. Those lucky few that were chosen get to live in the aquarium in our lab for a time. They take readily to fish flakes.

I'm a big fan of darters, I always love finding these: Fantail Darter, Etheostoma flabellare. The first dorsal fin has low knobs on it, which serve as egg mimics when resting in the nest - eggs are laid to the undersides of rocks.

Longnose Dace (Rhinichthys cataractae)

Mottled Sculpin, showing very dark colors compared to before.

Another E. flabellare

School of Blacknose Dace

Hopefully, I'll be getting some better photos in the near future. I just need practice shooting through glass.


  1. That water scorpion is huge!

    Looks like a good time.

  2. Yeah, it was a great time. Just wait till you see whats coming up this week - herps! :)