*** Welcome to piglix ***

Gyrinidae

Whirligig beetle
Gyrinus natator.JPG
Gyrinus natator, 1909 illustration
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Adephaga
Family: Gyrinidae
Latreille, 1802
Genera

Anagyrinus (fossil)
Andogyrus
Angarogyrus (fossil)
Aulonogyrus
Avitortor (fossil)
Baissogyrus (fossil)
Cretotortor (fossil)
Dineutus
Enhydrus
Gyretes
Gyrinoides
Gyrinopsis (fossil)
Gyrinulopsis (fossil)
Gyrinus
Heterogyrus
Macrogyrus
Mesodineutes (fossil)
Mesogyrus (fossil)
Metagyrinus
Miodineutes (fossil)

Orectogyrus
Porrorhynchus
Protogyrinus
Spanglerogyrus


Anagyrinus (fossil)
Andogyrus
Angarogyrus (fossil)
Aulonogyrus
Avitortor (fossil)
Baissogyrus (fossil)
Cretotortor (fossil)
Dineutus
Enhydrus
Gyretes
Gyrinoides
Gyrinopsis (fossil)
Gyrinulopsis (fossil)
Gyrinus
Heterogyrus
Macrogyrus
Mesodineutes (fossil)
Mesogyrus (fossil)
Metagyrinus
Miodineutes (fossil)

Orectogyrus
Porrorhynchus
Protogyrinus
Spanglerogyrus

The whirligig beetles are a family (Gyrinidae) of water beetles that usually swim on the surface of the water if undisturbed, though they swim actively underwater when threatened. They get their common name from their habit of swimming rapidly in circles when alarmed, and are also notable for their divided eyes which are believed to enable them to see both above and below water. The family includes some 700 extant species worldwide, in 15 genera, plus a few fossil species. Most species are very similar in general appearance, though they vary in size from perhaps 3 mm to 18 mm in length. They tend to be flattened and rounded in cross section, in plain view as seen from above, and in longitudinal section. In fact their shape is a good first approximation to an ellipsoid, with legs and other appendages fitting closely into a streamlined surface.


...
Wikipedia

...