Ichthyosquama catoirensis  Soler-Zamora et al., 2023

Diagnosis: Elongated test composed of imbricated scales, bent neck. Intraspecific variability : Large variability in the general shape of the test. Most have the typical shape of the genus, with an oval, slender test, a flatter ventral side, a rounded fundus, and a curved neck. However, the shape can be more rhomboidal and the fundus can be pointier or flatter.

Measurements. length 116.21–146.77 μm, width 45.80–71.80 μm, pseudostome large axis 16.17–19.62 μm (N = 9). Type locality : Catoira, Galicia, Spain (42º40ʹN8º43ʹW). Habitat : Freshwater sediment and mosses.

Ecology: Freshwater sediment and mosses. Type locality: Rhodopes, Bulgaria (41º59ʹN24º10ʹE).

Differential diagnosis. Ichthyosquama catoirensis can be diagnosed from other members of the genus by its specific sequence of the mtDNA marker and its phylogenetic position. According to Soler-Zamora et al., 2023, morphometric analyses can separate this species from other members of the genus.