Welcome back to our sixth edition of Bug Blogs, celebrating Science Odyssey by showcasing benthic macroinvertebrates (bugs!) that we often find during our local stream studies program, Changing Currents.
This next series will cover the aquatic beetle. Beetles are considered to be the most diverse type of insect in the entire animal kingdom with over 350,000 different species discovered to date with over 5000 living in North American waters. Beetles can be easily recognized by their hard exoskeletons which in most cases protect a set of wings. Aquatic beetles, which will be the focus of this Bug Blog can be predators, herbivores or scavengers. Predatory beetles tend to be more interesting and have lots of fun ways in which they capture and consume their prey. Some beetles inject their prey with enzymes which liquefy their insides. The beetle then sucks out the liquefied insides similar to how a spider consumes its prey. Some aquatic beetles can consume larger prey like fish or tadpoles.
A terrestrial adult beetle. Source: Ontario Benthos Biomonitoring Network.
Habitat and Fun Facts
Aquatic beetles have some of the most interesting names such as the whirligig and riffle beetles. Whirligig beetles have the ability to use echolocation - an ability to use sound in order to see. Different species of aquatic beetles live in different areas of the ecosystem. The riffle beetle for example prefers streams with currents while the whirligig lives on the surface and dives to the bottom in order to feed. Some species of terrestrial beetles have the ability to mimic the odour and behavior of ants and live among them in disguise. To this day, beetles have been found everywhere in the world except Antarctica!
What do they mean?
Beetles have been found to be fairly tolerant to a variety of water conditions such as pH and pollution. Many species of beetles tend to surface in order to breathe oxygen and therefore are not good indicators of dissolved oxygen in a body of water. Different species of beetles can be used to determine healthy biodiversity and the type of ecosystem that they live in.
An aquatic beetle larvae. Source: Ontario Benthos Biomonitoring Network.
Check back in tomorrow to uncover the great truths about Canada’s crayfish!
Bug Blog is EcoSpark’s blog series in celebration of Science Odyssey, a ten-day campaign celebrating Canadian achievements in Science, Technology, Engineering and Mathematics (STEM) with hundreds of science-based outreach events across Canada for all ages. Each day of Science Odyssey (May 12-21), we will be exploring a different Benthic Macroinvertebrate (BMI), small spineless organisms that live at the bottom of waterways. These are creatures we come across all the time in EcoSpark’s Changing Currents program, where we carry out stream studies with schools around the GTA by collecting BMIs to learn about local water quality.
EcoSpark's Bug Blogs would not be possible without the support from our generous sponsor, the Natural Sciences and Engineering Research Council of Canada (NSERC) PromoScience Program.