|scientific name Gyrinus picipes |
Found more frequently on surface of lentic waters, also ocurs in lotic waters.
January to August.
Appears highly polished, dorsally black with sides distinctly bronzed (Fall, 1922). Elytra usually without visible microreticulation (netlike structure) at 50x magnification (Oygur and Wolfe 1991). The 11th (most lateral) row of punctures (stria) close to margin in apical third of hardened forewing (elytra) (Oygur and Wolfe 1991). Abdominal segments 4-7 uniformly black (Oygur and Wolfe 1991). Strial punctures finer near suture (medially) (Fall 1922). Male genitalia (aedeagus) flattened throughout, tapering slightly towards apex, apex blunt. Most closely resembles G. sayi and G. dubius. Gyrinus picipes can be separated from G. sayi by absence of or non-uniform microreticulation in G. picipes which are present and uniform in G. sayi (Oygur and Wolfe 1991). Females of G. picipes have the same microreticulations as males, whereas females of G. sayi have more distinct microreticulations than males. Male length 4.6-5.3 mm and width 2.6-2.9 mm. Female length 5.6-6.2 mm, width 2.9-3.3 mm (Oygur and Wolfe 1991).
Has been collected in schools of mixed species also containing G. maculiventris, G. minutus, and G. pectoralis (Fall 1922). A detailed study of G. picipes has shown that the characteristic "whirling" swimming pattern of gyrinids is not haphazard but the most efficient way to conduct a search for food items that will only remain trapped in the surface film for a brief period (Winkleman and Vinyard 1991).
Southern California to Alaska. West coast to southern Ontario.
A large number of specimens were collected from a hot sulfur spring at Vermillion Lake in Jasper, Alberta. This phenomenon has been recognized by geologist (Jones and Renaut 2003) but requires greater attention from entomologists.
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