Heptacanthella, Gao & Potapov & Bu, 2022

Gao, Yan, Potapov, Mikhail & Bu, Yun, 2022, A new blind genus of Anurophorinae (Collembola: Isotomidae) with seven anal spines from Northwest China, Zootaxa 5104 (1), pp. 80-88 : 81

Heptacanthella gen. nov.

Type species. Heptacanthella yinae gen. et sp. nov. here designated.

Diagnosis. Blind Anurophorinae without furca and with four and three anal spines on Abd.V and VI, respectively. Spines on Abd.VI larger than on Abd.V. Body slender. Pigmentation and eyes absent. With few setae on body. Integument finely reticulated, primary granules fused forming polygons of different shape. Unpaired median seta p0 absent on Abd. IV. Furca and tenaculum absent. Macrosetae and s-seta on body well differentiated.

Etymology. The genus name refers the Latin “ hepta ” indicating seven anal spines at the end of abdomen.

Species included. Only the type species, Heptacanthella yinae sp. nov.

Remarks. The new genus has an unpaired anal spine in m0 position in Abd.VI. This uncommon character is shared only with Tuvia , Octodonthophora and Pentacanthella ( Table 1 ). Considering homology of all anal spines, the new genus most closely resembles and is probably related to the Asiatic genus Tuvia . The two genera have three anal spines in m0 and m1 position on Abd. VI, and two in p1 position on Abd. V. Heptacanthella gen. nov. has further p2 setae modified to spines. Accordingly, the new genus has four (vs. two in Tuvia ) anal spines on Abd. V. Tuvia has eyes, pigmentation and furca (vs. absent in the new genus).

* 1 medial conical protuberance in Sahacanthella

Considering only characters associated with dwelling in deep soil layers (no pigmenatatioan and eyes, no furca) the new genus is formally similar to Yosiiella , Martynovella , and Dimorphacanthella . The four genera share absence of eyes, pigmentation, furca and tenaculum. Heptacanthella gen. nov. resembles more closely Yosiiella (South America) by the presence of anal spines on Abd.VI. The two genera differ in number of spines (as a whole, four and three in the new genus vs. two and two in Yosiiella , on Abd. V and VI, respectively) and cuticle (clearly reticulated vs. smooth). Martynovella and Dimorphacanthella (Asia) have no anal spines on Abd. VI (present in Heptacanthella gen. nov. and Yosiiella ).