| Whirligig Beetle | |
|---|---|
| Gyrinus natator | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Adephaga |
| Family: | Gyrinidae Latreille, 1802 |
| Genera | |
|
Andogyrus |
|
The whirligig beetles are a family (Gyrinidae) of water beetles that normally live on the surface of the water. They get their common name from their habit of swimming rapidly in circles when alarmed, and are also notable for their divided eyes which can see both above and below water.
They are also known for their grouping behavior, a survival mechanism which helps them to avoid predation. Their places in the group are thought to be determined by a number of factors, including hunger, sex, species, water temperature, age, parasite level and stress level. Research being done on their behavior serves as a model to study the significance of chemical defense in relation to their position in the group, which relates to such fields as nanotechnology because the beetle's motion provides insight into the way in which groups of robots might coordinate movements.
Specifically, the beetles make behavioral trade-offs which lead them to different group positions. For example, relatively hungry beetles go to the outside of a group, where there is more food but higher risk of predators. Males are also more likely to be found on the outside of groups (although grouping is unrelated to mating behavior in this family). Individuals swimming against the flow of water in a stream incorporate the needs of drafting into these group positioning decisions. Drafting is when animals swim behind others to take advantage of forward-moving drafts. The determination of forward/backward positioning within a group has been found to be a complex function relating to the: speed of the water, sex of the beetle, and type of predator (bird or fish) most recently observed by a beetle.
They have a bubble of air trapped underneath their abdomens which allows them to dive and swim under the water for a long time. The family includes about 700 species worldwide.
