The Case of the of the Saddle Case Caddisfly: Did You Really Find One?

The Saddle Case Caddisfly.

The “holy grail” for volunteers participating in the Illinois RiverWatch program. The most sensitive of the sensitive. The best of the best. This is how the mysterious Saddle Case Caddisfly (Family Glossosomatidae) if often thought of by RiverWatch Citizen Scientists. And rightfully so, this aquatic macorinvertebrate is rated a “0” on the pollution tolerance index, meaning that finding it in your stream is great news! But, since this is such an important bioindicator, how can we be sure of the identification? This article aims to correct some misidentification problems that have been occuring through the years here at RiverWatch.

What Does A True Saddle Case Caddisfly In Its Case Look Like?

A true Saddle Case Caddisfly has tortoise shell-shaped case made out of gravel. The ventral side of the case is flat, and dorsal side is rounded. There is an opening at each end of the case for its head and posterior prolegs (fleshy appendages with hooks for anchoring) to protrude.

Source: Illinois Natural History Survey
Source: Illinois Natural History Survey

Saddlecase Sketch












What Does The Saddle Case Larvae Look Like Outside The Case?

The Saddle Case larvae looks like most other caddisfly larvae, with 3 pairs of jointed legs, at least one thoracic plate, and posterior prolegs. For the saddle case larvae, look for 1 thoracic plate and 1 anal plate over the last abdominal segment.

Source: USEPA
Source: USEPA
Dorsal Plate on Last Abdominal Segment. Source: USEPA
Dorsal plate on first thoracic segment. Source: USEPA


What Could Be Confused With The Saddle Case Caddislfy? A Warning About Caddisfly Pupae.

Often times RiverWatchers find tortoise-shaped caddisflies stuck to the rocks in their stream. The case is often sealed at both ends, preventing the volunteer from seeing the animal inside. A sealed case is a “pupae”, which is what the caddisfly makes to metamorphose into an adult (much like the cocoon of a moth). Caddisfly pupae should not be counted for RiverWatch stream quality indication, so no further identification is needed once the determination of “caddisfly pupae” has been made.

Hydropsychid Caddisfly Pupae. Source:
Hydropsychid Caddisfly Pupae. Source:
Saddle Case Caddisfly pupae. Source:
Saddle Case Caddisfly pupae. Source:


But just for fun, how would you be able to know if a pupae was a Saddle Case Caddisfly? First of all, Saddle Case pupae look very similar to Hydropyschid Caddisfly pupae. To make the identification, you must look at the pupae body inside of the case. A Hydropsychid pupae will have split appendages on the end of the abdomen, while a Saddle Case pupae will not.

Hydropsychid Caddisfly Larvae with split appendages on the end of the abdomen. Source:
Hydropsychid Caddisfly Larvae with split appendages on the end of the abdomen. Source:
Saddlecase Caddisfly Pupae with no split appendage on the abdomen. Source:
Saddlecase Caddisfly Pupae with no split appendage on the abdomen. Source:


What Should Be Done With Caddisfly Pupae Then?

So, the moral of the story is to be cautious when identifying a Saddle Case Caddisfly! If it is determined that the caddisfly case is completely sealed at both ends, then it is a pupae and will not be counted for RiverWatch stream quality calculations. For best results, contact the RiverWatch coordinator if you think you have Saddle Case Caddisfly in your sample so that the coordinator can ensure proper identification.

So hopefully we can now say “case closed” with the case of the mysterious Saddle Case Caddisfly!


5 Ways to Improve Your Counting and Sorting Accuracy in the Lab

Every year hundreds of RiverWatch volunteers sample Illinois’ rivers and streams to monitor water quality trends. These volunteers come from all walks of life–some are teachers, some are retired, some are engineers, some are health professionals, and everything in between. All of them share a common concern and urgency for protecting our rivers and streams. RiverWatch aims to equip these citizens to participate in this valuable service by providing training and resources.

By far, the most important (and sometimes most difficult) part of the RiverWatch program is the collection and identification of aquatic macroinvertebrates (“stream bugs”). What kinds and how many of each stream bug is used to calculate water quality based on their known pollution tolerances. In this post, I share 5 ways to improve your counting and sorting accuracy in the lab as a RiverWatch volunteer.

#1. Spread out your preserved macroinvertebrates in a white pan or tray, in a well-lit area.

This will ensure that not even the tiniest macroinvertebrates escape your notice.

Spread out macroinvertebrate sample on a high contrast background in good lighting
Spread out macroinvertebrate sample on a high contrast background in good lighting

#2.  Sort into “like” groups.

The most efficient method of sorting is to separate the sample into groups of similar looking organisms in a Petri dish. Then each group of similar organisms is sorted further into specific taxa groups. The breaking down of a sample into separate groups, then into even smaller more defined groups causes one to look very closely at each organism in their sample and helps one to find the smaller organisms that may be hidden by larger ones.

Stream bugs sorted into "like" groups
Stream bugs sorted into “like” groups

#3. Sort into groups of 10.

After identification is complete, sort the different kinds of RiverWatch indicator macroinvertebrates into groups of 10 for easy counting. The most numerous group of organisms is counted first by forming smaller groups of 10 individuals in separate spaces in a Petri dish. Any remaining organisms that are in number less than 10 are placed aside. The number of groups of 10 plus the number of remaining organisms are added together to gain the total number of individuals per taxa. For example, 6 groups of 10 individual midge larvae plus 6 remaining midge larvae would equal 66 midge larvae for the sample.

Midges sorted into groups of 10
Midges sorted into groups of 10

#4.  Use the dot and line system to accurately track your counting.

We’ve all been there, your counting large number of stream bugs, then suddenly forget what number you are on. One way to avoid this is to count using the dot and line tally system. This will help you to always know which number you are one when counting those pesky midges!

Dot and line counting system
Dot and line counting system

#5.   Avoid counting empty shells and multiple broken body parts!

Just because you find a snail shell or caddisfly case does not mean it counts towards RiverWatch water quality calculation, someone must be home on the inside! A microscope with a bright light will help you shine through the shells to detect if there is a body inside. Also look for shells that are bleached or falling apart as indicators of a vacancy. Lastly, sometimes shells hold other macroinvertebrates that get stuck inside like in the picture below. Be sure to look extra close!

Another common issue when counting is the issue of broken body parts–what to count and what to discard? For RiverWatch, we only count things that have heads. The eyes are usually the easiest thing to see to know if it is a head or not. For worms though, it is very difficult to know which end is the head. The best way to solve this problem is to locate worm “ends”. It is easy under a microscope to tell the different between the broken end and the true end of a worm. For every pair of true ends, count one worm for your sample.

Two left-handed snails, one has a snail inside (left), one does not (right). Also notice swimming mayfly inside the shell on the left.
Two left-handed snails, one has a snail inside (left), one does not (right). Also notice swimming mayfly inside the shell on the left.
One complete swimming mayfly, and pieces of another one. Only two swimming mayflies would be counted since there are only two heads.
One complete swimming mayfly, and pieces of another one. Only two swimming mayflies would be counted since there are only two heads.
Broken piece of an aquatic worm.  Notice the broken end (left side) and the true end (right side)
Broken piece of an aquatic worm. Notice the broken end (left side) and the true end (right side)

This completes the 5 tips for more accurate counting and sorting of RiverWatch samples. I hope this was helpful! Please feel free to comment or ask any questions you may have!

3 Essential Things to Know Before Monitoring for the First Time

Every year RiverWatch trains many new volunteers to go stream monitoring for their first time. Just in 2014, 97 new volunteers were trained, welcome aboard!

Stream monitoring is an exciting and fulfilling volunteer service, but that does not mean it is a walk in the park! Scientific field work comes with its own set of variables and issues that arise unexpectedly, even for seasoned veterans. Problems range from high waters to streams drying up, samples being poorly preserved and samples being inadequate for calculating water quality. Below are three essential things to know for new volunteers before they go stream monitoring for the first time.

2014 interns sorting in tray
Photo credit: Louise Jett, Lewis and Clark Community College Flickr

1.  Plan for High Water and Flooding

RiverWatch monitors during the months of May and June, when the spring floods are sometimes at their height. Flooding not only makes it dangerous for volunteers to access their stream, it can also “blow out” some of the macroinvertebrates normally found on the stream bottom. New volunteers need to be mindful of this when picking a date to monitor. My suggestion is to try to monitor earlier in the season than normal, and then if you are flooded out you will still have time to sample before the June 30th deadline. The spring flood pulse is unpredictable, so do not wait to plan your monitoring trip until the latter half of June!

2.  Sample Macroinvertebrates Thoroughly to Achieve a Valid Sample Size

RiverWatch bases its stream quality indices off of the macroinvertebrate community. It is therefore imperitive to capture enough macroinvertebrates to draw conclusions about the stream quality. With 100 macroinvertebrates, you will have a true picture of the stream conditions. With 50 macroinverterbrates, you still have enough to get an adequate picture of stream quality. Once there are less than 50 macroinverterbates captured at a site, the confidence intervals on the stream quality calculations become very large! You will not be able to say definitively if your stream is poor or good quality, because their are likely many macroinvertebrates unaccounted for in the stream. Exceptions to this rule are when low sample sizes are due to toxic pollution from mine drainage, or pesticide/herbicide. Other than that, 50 macroinvertebrates should be easy to attain in any Illinois Stream during the months of May-June. If you are monitoring for the first time, remember to thoroughly sample the two habitats you select. If you choose a riffle, kick for the full 3 minutes! If you choose a snag, thoroughly scrape it with your net and then spend a full 15 minutes looking it over for more macros! When you sort your debris in the white tray, make sure to suspend dense vegetative debris in water inside the tray to see the tiniest macros swimming around, often they cannot be seen against the dark background of the leave itself. The more macros sampled, the more confidence in the stream quality calculation we will have!

3. Monitor with an Experienced Citizen Scientist First If Possible

RiverWatch has very specific and somewhat complex methods. They may seem overwhelming to the first year volunteer, but they are there to insure that the data we collect is of high quality for our data users! I suggest that first year volunteers check out the Active Citizen Scientist Map to see if there are any experience citizen scientists already monitoring near them. Most of the groups on this map would love to have more volunteers come out, and it would be of great benefit to first year volunteers to see the sampling done one more time.

RiverWatch is a great program made up of great volunteers dedicated to protecting clean water. We very much appreciate our volunteers and want to tips and tricks to make stream monitoring as fun and easy as can be!

A Flood is Coming!

Well… not exactly a flood that will ruin your basement!

This week I had the pleasure of attending the North Elementary School Science Fair in Alton, Illinois.

This was a blast!

We brought our handy, dandy Flood Plain Simulation Model to show the students how rain water is a powerful force.

NGRREC Environmental Educator Allison Rhanor demonstrates the floodplain model at the 2014  North Elementary School Science Fair.
NGRREC Environmental Educator Allison Rhanor demonstrates the floodplain model at the 2014 North Elementary School Science Fair.

The Flood Plain Simulation Model is made up of thick Plexiglas that encloses a plastic molded landscape with a river running through the model.  This is a new tool the NGRREC Education Team has to showcase storm water runoff (And we have used it well!!). This particular model is neat because we can show the effects storm water runoff on a parking lot, a wetland, and a retention pond. The students can also rearrange the toy houses (Monopoly size) and build dams out of Play-Doh to control flood water. I really like using this tool.  It really helps the students learn in an experiential way.

To make this function properly, we attach a drain hose to the lower end of the Plexiglas tank that drains the water into a bucket.  Then we fill a pitcher of water half full and give it the students. The students pour the pitcher into the plastic rain cloud and make it rain. They love this part!!

As the water is dumped into the higher end of the model, the rain falls on to one of the three landscapes.

The students find that with the parking lot, the water runs into the river very quickly which causes flooding.  When we use the retention pond we find that the flooding is controlled for a time, until the pond overflows and causing flooding eventually.  Then we use the wetland option.  We see that the wetland (modeled by sponges) has a large capacity to store rain water. But we also see that the amount of flooding is reduced significantly because it releases the water slowly into the river.

This is such a great model and I am thankful for this tool! Have you ever seen one of these models?

Kids Love Bugs!

Hello again!!

I am excited to be back again this week!

This weekend National Great Rivers Research and Education Center (NGRREC) and Lewis and Clark Community hosted the Mississippi River Watershed Education Symposium #MRWES2014.  Environmental Educators, professionals and students gathered from across the United States came to learn about the issues in watersheds.  Moreover, we learned techniques and methods to communicate to the public and our students about the issues and concerns for watershed rehabilitation and sustainability. I am so glad I got to be a part of this event!

MRWES 2014 conference
MRWES 2014 at Lewis and Clark Community College. Photo Credit: Louise Jett

I had been asked to host a session on our Stream Discovery program on Friday afternoon.  I had the pleasure of teaching 9 teachers the program. Before I proceed, a little background on Stream Discovery is needed!  Stream Discovery is a stream monitoring program for grades 5 through 12.  This program equips students to monitor water quality in wadeable streams. What this really means is that kids get to look at macroinvertebrates (also known as bugs!!) to gage the stream’s health! And yes, they love it!

Alright now back to Friday afternoon…The goal of the workshop was to train the teachers the ins and outs of Stream Discovery so that they can take this program back to their classrooms to teach to their students.  First, we had some classroom time where we talked about the goals and expected outcomes of the program.   Next, we got suited up to go outside to the stream to put what we just learned in to practice. It was a bit chilly on Friday but we did find a few scuds, a lonely crane fly and a lonely damselfly larva.  All the bugs were moving SLOOOWWW because the water was 6 degrees Celsius

New Stream Discovery trainees learn about Stream Monitoring on a cold November afternoon at the Mississippi River Watershed Education Symposium. Photo credit: Matthew Young.


This is one of my favorite programs to teach!  The teachers love the bugs and the extra training to get to take the program back to their class.  It seems that we all learn so well when we can attach a fun experience with it!

Click here to visit the Stream Discovery website.

Also check out our super neat Stream Discovery database on the National Geographic’s FieldScope Platform.

Interested in becoming Stream Discovery certified? Workshops for Spring 2015 are in the works, email me @ to sign up!

Our first blog post at RiverWatch

Hey RiverWatchers and friends of Illinois rivers!

Welcome to the new Illinois RiverWatch blog!

My name is Matt! I am the Illinois RiverWatch Coordinator.  Almost like the Terminator but less deadly!! Ha! I came to NGRREC in August 2013.  I am originally from Little Rock, Arkansas.   I graduated from Arkansas Tech University with my undergraduate degree in Fisheries and Wildlife Biology. In 2012 I graduated from Southern Illinois University Carbondale with a Master’s of Science in Zoology.

I have always had a passion for rivers, lakes, streams, fish, and all the critters in water!  I am so glad that my job allows me to be involved with water and the animals that are effected by water quality.  I also enjoy traveling to different parts of the state to meet new volunteers.

Whenever I am not working at Lewis & Clark Community College for RiverWatch I like to spend my time with my wife, Beth, and our dog, Lucy.  We enjoy fishing, camping, paddling, and watching re-runs of Parks and Recreation!

My purpose of starting a blog is to keep all our volunteers and friends of Illinois rivers informed on the happenings of RiverWatch.  I will be posting some photos of our awesome macroinvertebrates you find, the latest information on RiverWatch, and my travels to different parts of the state.  I am excited to share all of this with you!

If you have any questions please feel free to reply to any posts, shares your photos, or send me an email!

If you have any suggestions on the type of posts you would like to see from your RiverWatch Coordinator, let me know!  You can also Like RiverWatch on Facebook at and follow us on Twitter at . Or you can email me at!


I am excited about our new blog!  Thanks for reading!