Bryocamptus (Rheocamptus) pygmaeus

Bryocamptus (Rheocamptus) pygmaeus (Sars, 1863)

(Fig. 27)

Location, ecology. Springs in the Knyszyn Primaeval Forest Landscape Park, vauclusian springs nearby Jaczno Lake (Suwalki Landscape Park) and in peatbogs surrounding dystrophic lakes in Wigry National Park. Some authors however suggest that this species apparently avoids typically highland sphagnous swamps of higher acidity (Borutzky 1952). Both females and males were observed.

General distribution and biology. Widespread in Europe and North America, except the tundra zone. Also known from North Africa. It inhabits different types of surface waterbodies and groundwater too (Fefilova 2010). It was most often found in moist moss cushions in swamps of lowland or transitional type, with avoidance of higher acidity swamps (Borutzky 1952).

D i s t i n g u i s h i n g f e a t u r e s. Body length without caudal setae about 0.45 mm. Caudal rami square-shaped, outer margin bearing 3 lateral setae with several spinules near their bases, inner margin bearing several spinules above apical setae. Antennule short, eight-segmented (Borutzky 1952). Inner lobe of proximal segment of P5 well developed, with 5 pinnate setae of unequal size (Fig. 27). Distal segment of P5 subrotund with 5 setae – middle one slender, nonpinnate (Fig. 27).