Nature Notes: Curious crustaceans

Published 12:01 pm Saturday, June 6, 2020

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By Kelly Bahl

Teacher/Naturalist Intern

Crayfish, Crawfish, crawdad, mud bug.  A variety of different names to describe a very abundant crustacean. Crayfish are cousins to lobsters and can be found on five continents. There are well over 200 species of crayfish in North America alone.  It can survive in diverse fresh or salt water habitats. Here in Minnesota you can find them in rivers, ponds, lakes, streams, you name it, as long as there is clean enough water and abundant food for them the crayfish will thrive.

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Crayfish are one of the most well-known freshwater crustacean and a frequent resident of Dobbins Creek out at the Hormel Nature Center. They have a lot of unique adaptations to make living in so many aquatic ecosystems around the world possible. Four pairs of walking legs make locomotion on land or in the water relatively easy. However, if the crayfish under water needs a faster mode of transportation it will swim. Crayfish move forward slow and steadily when walking, but when swimming it’s a quick propulsion backwards with a flick of their abdomen (tail part).

Large claws are used to defend themselves or crush and tear food into manageable pieces to eat. Small arm like appendages will then funnel food into its mouth. A crayfish’s food could be anything! They are omnivores so will eat whatever that they can get their hands on consuming aquatic plants, decaying leaves, shrimp, small fish or insects, and even other crayfish!

These small crustaceans are extremely territorial and will defend their dominions underwater with gusto so can be found constantly fighting. When having to rage through many battles in their lifetime, it is no surprise that there are losses that go along with it. The loser of a battle may be eaten, but other times they may just lose a limb or one of their claws. If an injury to a leg or claw gets torn off it is not the end of the world because crayfish have the ability to regrow a lost limb! If you have ever come across a crayfish with one claw, or one big and one really small the small one is just going through the process of regeneration.

Not only is regeneration of lost limbs super cool to see on crayfish, it could potentially have an impact for us humans! There are some biologists that have been studying mechanisms for neural regeneration and repair in crayfish (a fancy way of saying why crayfish can regrow a lost limb). But, not only can crayfish regenerate a leg, or one of its claws, but this organism is constantly regenerating neurons to help with their senses/brain activity. This has scientists fascinated and they have been studying the subject in depth to gain a better understanding of how it works so it can be used for human medical research! Who knows, maybe someday far in the future people will be able to regrow a lost hand thanks to understanding how a crayfish does it. A crazy thought to think about the next time you encounter these Minnesota native crustaceans.

Upcoming Events at the Hormel Nature Center

Temporary Jay C. Nature Center open hours: 9 a.m. to 5 p.m. Monday, Wednesday, Friday; 1-4 p.m.  Saturday and Sunday. Closed Tuesday and Thursday.

• June 17 — Class: Astronomy, 8:30 – 10:30 p.m. (8-10 year olds)

• June 18 — Class: Astronomy, 8:30 – 10:30 p.m. (11- 12 year olds)

• June 24 — Class: Orienteering, 9 – 11:30 a.m. (11-13 year olds)

• June 24 — Volunteer Work Party, planting pollinator garden at Ruby Auditorium, 3:30 – 5 p.m. Please RSVP by June 22.