Korotnevella hortobotanici, Udalov & Völcker, 2022

Udalov, Ilya A. & Völcker, Eckhard, 2022, Is scale’s structure still a good character to delimitate species of Amoebozoa? case of the genus Korotnevella (Amoebozoa, Dactylopodida), Organisms Diversity & Evolution (New York, N. Y.) 22 (1), pp. 17-33 : 31

Korotnevella hortobotanici sp. nov.

Diagnosis: length of the locomotive form 57 ‒ 106 µm, breadth 20 ‒ 61 µm, length:breadth ratio 1.2 ‒ 3.8. Single ellipsoid nucleus 6.7 ‒ 12.7 µm in length. Nucleolus either single and spherical, or consisting of several spherical parts, sometimes with a transparent lacuna. The cell surface structures include two types of scales: large basket-shaped scales and small dish-shaped scales. The basket-shaped scales include a basal plate, a closed latticework basket, six vertical columns (two apical and four lateral columns), extending from the basal plate and two spikes of equal length. Meshes of the latticework basket are differentiated by size: two rows of large meshes adjoining the upper part of the scale and many small meshes located in the central part of the latticework basket. No cysts were observed in the cultures.

ZooBank LSID: urn:lsid:zoobank.org:act:83EB6D16-EA91-4C30-AD64-1575B298AEA2 ; type locality: freshwater; pool in the greenhouse of the botanical garden of St. Petersburg State University, St. Petersburg, Northwest Russia (N 59° 56 ′ E 30° 17 ′); type material: cells embedded in epoxy resin are deposited with the collection of the “ Centre for Culture Collection of Microorganisms ” ( CCM), Saint Petersburg State University, Saint Petersburg, Russia; etymology: the species-group name hortobotanici originates from the Latin “hortus botanicum,” which means “botanical garden” and refers to the type locality, from which this species was isolated; DNA sequence data : MW544519 – MW544524 (Cox I gene).

Differences from closely related species: only Korotnevella bulla , K. monacantholepis , K. mutabilis , and Korotnevella sp. 2 are comparable in size to Korotnevella hortobotanici sp. nov. But, in comparison to all of them, Korotnevella hortobotanici sp. nov. has clear differences in its basket-shaped scale structure. Basket-shaped scales of K. bulla and K. monacantholepis have an open latticework basket consisting of two rows of rectangular meshes; also, the latter species has only one long spike, or none, while Korotnevella hortobotanici sp. nov. always has two spikes. Also, the basket-shaped scales of K. bulla have six lateral columns, and those of K. monacantholepis six or eight, while the basket-shaped scales of Korotnevella hortobotanici sp. nov. always have only four lateral columns. K. mutabilis have four to five columns on each scale’s side, not two. Unlike Korotnevella hortobotanici sp. nov., basket-shaped scales of K. mutabilis can have only one spike or no spikes at all, and do not show a differentiation of meshes of latticework basket into large and small. Basket-shaped scales of Korotnevella sp. 2 have a larger number of lateral vertical columns (ten, rarely eight or twelve) and do not have a differentiation of meshes of latticework basket into large and small. The basket-shaped scales of Korotnevella hortobotanici sp. nov. do not have a polymorphism of spikes in their length. Korotnevella sp. 1 and K. heteracantha have similar scales, but they have smaller locomotive forms (42 to 83 μm, average 59.6 μm and 36 to 92 μm, average 52.3 μm, respectively), and also differ in the structure of their nucleus and in details of basket-shaped scale structure (Table S4).