Adult females of Heterocope appendiculata are easily distinguished from other species by the groups of appendages in front of the genital orifice. It is an eastern species.

Key characteristics

Heterocope appendiculata is smaller and more slender than both H. borealis and H. saliens. Adult females of H. appendiculata are easily distinguished from these species by the groups of appendages in front of the genital orifice, which is found only in this species. Further the antennas reach beyond the furca in H. appendiculata, while they are shorter in both H. borealis and H. saliens. Its body is semipellucid and generally of a light greenish blue hue, while the anterior antennae and the urosome of the male are tinged with orange.

Female: Length 2.0–2.2 mm

Male: Length 1.8–2.0 mm

Ecology and distribution

Though the plankton/littoral calanoid H. appendiculata is less common than H. saliens. It is found in slightly more than 10 % of the water bodies. The great majority of records are from the eastern parts of the country between 100 and 500 m a.s.l. It has never been found above 1000 m a.s.l. The possibility to find H. appendiculata is positively correlated to lake size. It is rare when pH is below 5.5 and in electrolyte poor water.