Pulchellophycus schwabei

This taxon is typically found in low nutrient and low conductivity environments, particularly lakes and streams in alpine and subalpine regions.

It was first described by Krasske (1939) from subalpine ponds on a terrace of a volcano near Puyuhuapi, Chile.

The population illustrated here was found in sediments of Beauty Lake, Wyoming. At present time, the lake has low conductivity (111 μS/cm), low soluble reactive phosphorus (<0.02 μM) and low nitrate (<0.01–0.072 μM) (Saros et al. 2003). It was found in sediments during phases of increased Fe and P burial ~1700 and ~ 6200 years before present (YBP) (Spaulding et al. 2020).

It was also reported from sediments ~1900 YPB in Lac La Croix, Minnesota (Serieyssol et al. 2009). Currently, Lac La Croix has an alkalinity of 12 mg/L, pH of 6.5, low conductivity (42 μS/cm), and low total phosphorus (0.017 mg/L).

This taxon has been reported (as Pinnularia schwabei) from Boyanska River in Vitosha Nature Park, Bulgaria (Isheva and Ivanov 2016). The Boyanska River is at high elevation (1210 m), low temperature (4.5°C), neutral pH (7.3), and low conductivity (192 μS/cm). It has also been reported from the Sakhalin Islands, Russia (Medvedeva and Nikulina 2014).