Looking for Life at Lonergan Creek

By Johnica Morrow

Last Thursday was quite a day for the students taking Life 121 here at the station. The class traveled to a creek known as Lonergan Creek in search of primative plants and planarians.  Upon arrival, the students discovered masses of aquatic plants such as Elodea sp. and Potamogeton sp. They spotted a few of their crayfish friends clinging tightly to these plants as the water rushed downstream. 

Elodea (dark stuff) and Potamogeton (the bright stuff).

They also found water buttercups (Ranunculus sp.) that were in full bloom beneath cool, clear water. Students were excited to find these truly aquatic plants and to discuss pollination strategies of this particularly odd buttercup.

Ranunculus among algae and debris.

As they traveled downstream, they discovered a beaver dam that was blocking the flow, but only minorly slowing things down on the other side. It was exciting for students to see the work of a beaver! Students also flipped a few logs to find lots of amphipods and aquatic larvae of all kinds. They even saw a friendly little leech and gazed at the fascinating creature's ability to move with ease using its two suckers. They were happy to learn that not all leeches are looking to suck their blood!

 Beavers, and amphipods, and leeches, OH MY!

The students also found tiny water ferns (Azolla sp.) in this part of the creek. These interesting plants have adapted quite well to life in the water. They resemble duckweed or moss rather than other types of ferns in that they float on the water in clusters of tiny plants.

Happy students show off their Azolla. 

After a while on that side of the creek, the students walked back up to the road in order to cross over to the other side of this creek. Once on the other side, students began seeing an all new environment. Many students got the full field experience by wading into waist-deep water to look at cattails, bullrushes, and arrowheads. They searched along the banks of the creek for liverworts (Marchantia sp.) that had reproductive structures. No male structures were found, but plenty of female structures could be seen covering the vegetative parts of these primitive plants. A few students were lucky enough to see gemmae cups, asexual reproductive organs found only on liverworts.

More happy students showing off their lady liverworts.

Students also looked for the sporophyte stage of moss while at the creek. These tiny, reddish-brown generations grow on top of the leafy, green gametophyte stage in the life cycle of mosses. Frustration turned to excitement as students scoured beds of moss in search of these easy-to-miss reproductive structures.

A sporophytic moss collected by a student.

Students proud of their moss samples.

Just around the last bend before heading back to the suburbans, students began flipping rocks, rolling logs, and pulling up small plants in search of tiny flatworms known as planarians. These worms were collected into jars with water and taken back to the lab for some experiments that they will be doing next week. With very little difficulty, the students were able to bring back lots of these aquatic flatworms for this week's lab.

Students search for Planaria. 

After a long day of collecting, the students returned to CPBS for dinner and left their specimens in the lab for observation the next day. The trip was successful in showing students a variety of different forms of life, especially those not often seen by the casual passerby. The students got dirty and sweaty, but loved it enough to walk away all smiles. It was another great day to be teaching biology out in nature rather than in a traditional classroom setting.