TY  - JOUR
JF  - Acarologia
T1  - Recognition of Fuscozetes spitsbergensis (Thor, 1934) n. comb. (Acari, Oribatida, Ceratozetidae), with taxonomic remarks on Fuscozetes
VL  - 66
IS  - 3
SP  - 818
EP  - 840
PY  - 2026
SN  - 0044-586X
SN  - 2107-7207
PB  - Les Amis d'Acarologia
AU  - Ermilov, Sergey G.
AU  - Makarova, Olga L.
AU  - Andrianov, Boris V.
AU  - Behan-Pelletier, Valerie M.
UR  - https://doi.org/10.24349/812s-xa4j
DO  - 10.24349/812s-xa4j
DA  - 2026-09-21
ET  - 2026-09-21
KW  - ontogenetic instars
KW  - juvenile morphology
KW  - taxonomy
KW  - barcoding
KW  - arctic-alpine distribution
KW  - cryophily
KW  - demography
KW  - Russia
AB  - All ontogenetic instars of the cryobiont, arctic-alpine oribatid mite Ceratozetes spitsbergensis Thor, 1934 (Oribatida, Ceratozetidae) were collected from moss cushions on the Chelyuskin Peninsula, Taimyr, northernmost Russia. Juvenile instars are described. The larval instar is characterized by the absence of the humeral organ and humeral sclerite, and the presence of gastronotal macrosclerite (bearing setae dp, lp, and h<sub>1</sub>) located posteriorly on the gastronotum as well as medium-sized, barbed dorsocentral gastronotal setae. Nymphal instars are characterized by the presence of a weakly defined humeral organ, large gastronotal macrosclerite, a well-developed humeral sclerite (bearing seta c<sub>1</sub>), and comparatively shorter, thinner dorsocentral gastronotal setae. Based on COI sequences and morphology of adults and juvenile instars, C. spitsbergensis is combined in the genus Fuscozetes. Because of significant similarities between the ontogenetic instars and habitats of Fuscozetes spitsbergensis and F. coulsoni (also described from Svalbard) we propose the latter as a junior synonym of the former. We revise the diagnosis of Fuscozetes and give identification keys to the known larvae and tritonymphs of Fuscozetes. COI sequences along with juvenile morphology allow differentiation of the very similar species, F. spitsbergensis and F. setiger, that are practically indistinguishable in adulthood. A summary of the distribution and habitats of F. spitsbergensis in the Holarctic region is presented, and the evident upwards altitudinal shift was confirmed for more southern populations. Direct laboratory observations have shown F. spitsbergensis feeding on various lichen species.
ER -