|scientific name Gyrinus minutus |
Surface of most lentic and lotic waters. Prefer edges of water bodies (Oygur and Wolfe 1991).
March to October. Most frequently collected July to August.
Dorsum black, body short and narrow (Fall 1922). Dorsal surface dull from scale like microreticulation (net-like pattern visible at 40x magnification) (Oygur and Wolfe 1991). Dorsum of abdominal segments 4-7 black, 8th abdominal segment, thorax, and legs reddish orange (Oygur and Wolfe 1991). Underside of mid-thoracic segment (mesosternum) with a medial groove running anterior-posteriorly (Oygur and Wolfe 1991). Triangular plate (scutellum) between hardened fore-wings (elytra) with a raised ridge running anterior-posteriorally. Gender can be determined by the presence of an expansion of footpads (pro-tarsi) on the front legs of males. Size: male length 3.3-4.9 mm and width 1.7-2.0 mm. Female length 3.7-4.4mm and width 2.0-2.3 mm.
Has been collected in schools of mixed species also containing G. maculiventris, G. pectoralis, and G. picipes (Fall 1922). Gyrinus minutus does not produce toxic, volatile chemicals at the same intensity of may other Gyrinus sp. (Ivarsson et al 1996). This may be reflective of G. minutus apparently favoring smaller bodies of water less likely to support predatory fish (Ivarsson et al 1996). These chemicals may function instead in chemical communicatioin (Ivarsson et al 1996).
Not apparently threatened.
Records from Alaska to Kansas, Newfoundland to B.C.
Ectoparasitic fungi Laboulbeniales has been reported on G. minutus (Oygur and Wolfe 1991).
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