Life Underwater Series: Life of the Roundworm
Life of the Roundworm: the BMI cannibal
The roundworm is a fascinating benthic macroinvertebrate with a diverse and complex life that can last anywhere from two days to over a year. Today we will explore the role of roundworms in their aquatic environments. What does the roundworm prey upon to feed its energy needs? And how do they survive in a variety of environmental conditions? To explore these questions, we’ll start at the very beginning-- when roundworm eggs are first laid.
After the male roundworm has deposited his sperm into the female, fertilization occurs in the body of the female. A thick, double-layered shell will form around each fertilized egg and these will be deposited in the aquatic environment where development will take place.
Roundworms consume invertebrates (including other roundworms), vertebrates or even plants. Roundworms that do so are parasitic and are not free-living. Free-living roundworms will feed on phytoplankton, such as diatoms, algae, bacteria and fungi. Roundworms are predatory carnivores and may have teeth for feeding, or a long spear-like structure, which is used for stabbing prey and sucking their insides. One of the most fascinating characteristics about roundworms is their ability to suspend all bodily processes, essentially living in a suspended state when food and oxygen supplies are low or unavailable. While in this ‘suspended state’, they may survive extreme climatic conditions that include droughts, deep freezes and high winds. Once conditions are favorable once again they will return to their normal functioning state. As it grows, a roundworm will shed and replace its outer layer approximately four times.
Fun Fact: All freshwater roundworms will secrete a sticky mucous from the tip of their hind end which will allow them to anchor down to various substrates.
Fun Fact: Some species of roundworm can lay up to 200,000 eggs in a day.
Interested in learning more about benthic macroinvertebrates and how they can be used to measure the health of rivers and streams? Be sure to follow EcoSpark’s social media to stay updated on our Changing Currents program and our other citizen science and environmental education programs.
References
Sommer Laboratory. (2018). Worms hijack Development to foster cannibalism, study finds. Retrieved from: https://phys.org/news/2013-01-worms-hijack-foster-cannibalism.html
Carina holds a Bachelor of Honors in Environmental Studies and a diploma in Ecosystem Technology, both of which developed her interest in using geographic information systems to communicate about complex issues, such as climate change. In her role as Lead Environmental Educator, Carina designs geospatial education tools for EcoSpark’s citizen science programs. When outdoors in the field, you will often find her streamside identifying aquatic critters, communicating her enthusiasm for the outdoors, and demonstrating her dedication to stewardship practices with youth and adults throughout the GTA.