Isotomurus hyrcanicus, sp. nov.
Creators: name: LAFOORAKI, ELHAM YOOSEFI
name: HAJIZADEH, JALIL
name: SHAYANMEHR, MASOUMEH
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Collembola
Entomobryomorpha
Isotomidae
Isotomurus
Isotomurus hyrcanicus

description: Isotomurus hyrcanicus sp. nov. Yoosefi Lafooraki & Shayanmehr
Figs 1, 11a; Tables 1–3
Type material. Holotype:female on slide. Iran, Golestan province, Bandar Gaz, forest soil and leaf litter, 36°47′05″N, 53°57′55″E, – 23 m a.s.l., 2019.01.01, leg.: E. Yoosefi Lafooraki; Paratypes: 7 specimens in ethyl alcohol, the same data as the holotype; 1 female on slide, 2 specimens in ethyl alcohol, Golestan province, Bandar Torkaman, unvegetated ground, soil, 36°55′25″N, 54°07′19″E, – 24 m a.s.l., 2019.01.01, leg.: E. Yoosefi Lafooraki; 1 female on slide, 9 specimens in ethyl alcohol, Mazandaran province, Sari, Sangdeh, Boola forest, dead wood, and moss, N36°02′11.34″, E53°16′51.94″, 1611 m a.s.l., 2021.04.19, leg.: E. Yoosefi Lafooraki.
Material examined. Mazandaran province, Sari, Sangdeh, Boola forest, dead wood, 10 specimens, moss, 11 specimens, N36°02′11.34″, E53°16′51.94″, 1611 m a.s.l., 2021.04.19, leg.: E. Yoosefi Lafooraki; Mazandaran province, Sari, citrus orchard, soil, 36°38′56″N, 53°05′27″E, zero m a.s.l., 2020.02.21, leg.: A. Kaveh; some specimens collected from Mazandaran province were preserved in alcohol in Entomology laboratory of Sari Agricultural Sciences and Natural Resources University without collection data.
Description. Body size up to 4.3 mm. Body shape as common for the genus. Background color white to light yellow. Body with dark green or black bands and spots which turn to red in alcohol. Dorsomedial band frequently interrupted, especially on Abd. III. In darker specimens, dorsomedial band rather continuous and wide. Lateral spots create a wide band on each side with some unpigmented circles. In some specimens, bands and spots are seen as diffuse pigmentation and in others, lateral band is not seen on first body segments (Fig.1). Posterior part of head with large black medial spot. Bases of antennae with black spots (Fig. 1). Antennae and legs dark, furca paler (Fig. 1). 8+8 ocelli. PAO elliptical, 0.64 times as long as the nearest ocellus. Maxillary outer lobe with 4 sublobal hairs and bifurcate palp. Labrum with 4 prelabral setae, labral edge as common for the genus, with four sharp ridges and ventro-apical ciliation. Labium with 12–14 basomedian and 5–7 proximal setae. Antennae about twice as long as head diagonal.
Body covered with smooth setae of unequal length, macrochaetae densely ciliated. Legs with normal claws. Claw with a pair of large lateral tooth and one inner tooth. Ret. with 4+4 teeth and 10–13 setae. VT with 3+3 laterodistal and many anterior and posterior setae. Manubrium densely covered by mesochaetae. Manubrial thickening simple, without teeth in medial part. Dens rather slender, continuously narrowed, with a sparse cover of dorsal setae, in basal 1/3 only. Posterior side of dens crenulated (Fig. 11a). Mucro with four teeth and without setae. Apical tooth small. Ratio manubrium: dens: mucro as 20: 35.8:1. Ratio of mucro to outer edge of claw III as 0.27. Modified male setae on Abd. III and IV absent.
Etymology. The name reflects the type locality (Hyrcanian forests).
Ecology. It is mostly found in forest leaf litter and soil, as well as in mosses and dead wood and non-forest habitat soils.
Discussion and remarks. Our molecular results support the specific position for the populations described here as I. hyrcanicus sp. nov. There is no genetic difference between color forms of the new species and intraspecific divergences is 0.3% (Fig. 1, Table 2). The genetic divergence between I. hyrcanicus sp. nov. and the other species of the genus is ranging from 22.4% to 29.8% for COI (Table 2) which is similar to the divergence found among previously described species (ranging from 22.0% to 33.3%; Table 2). The genetic divergence between I. hyrcanicus sp. nov. and two other species of Isotomurus is 28.4 and 27.9 for 28S gene (Table 3).
Isotomurus hyrcanicus sp. nov. belongs to the group of species without setae on mucro, with 3,3,1 Trich. on Abd. II, III and IV, and with 3+3 laterodistal setae on VT. Main differences between I. hyrcanicus sp. nov. and these species are summarized in Table 1. The new species is closely related to I. palustris which can be separated by the number of setae on Ret. (14–37 in I. palustris against 10–13 in I. hyrcanicus sp. nov.). Genetic divergence between the new species and I. palustris is 29.8% for COI gene which is in the range of genetic difference between other Isotomurus species.
The new species resembles I. pseudopalustris. They can be separated by different number of basomedian setae on labium (8–12 basomedian setae in I. pseudopalustris against 12–14 setae in I. hyrcanicus sp. nov.). The new species is close to I. unifasciatus which has modified male setae on Abd. III and IV (absent in I. hyrcanicus sp. nov.). Genetic divergence between the new species and I. unifasciatus is 24.4% for COI gene.
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description: Published as part of LAFOORAKI, ELHAM YOOSEFI, HAJIZADEH, JALIL & SHAYANMEHR, MASOUMEH, 2023, A revision of the genus Isotomurus (Collembola: Isotomidae) in northern Iran using molecular evidence, pp. 48-66 in Zootaxa 5230 (1) on pages 50-52, DOI: 10.11646/zootaxa.5230.1.3, http://zenodo.org/record/7552379