Mesogastrura seotalensis Chang & Kim & Park 2022, sp. nov.
Creators: name: Chang, Gyu-Dong
name: Kim, Sun-Sook
name: Park, Kyung-Hwa
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Collembola
Poduromorpha
Hypogastruridae
Mesogastrura
Mesogastrura seotalensis

description: Mesogastrura seotalensis sp. nov. (Korean name: seot-al-gul-bo-ra-tok-to-gi)
(Figs 3–8)
Type material. Holotype on slide: female, “ Korea: Seotaloreumjinjidonggul cave (N 33° 12′ 19.58′′, E 126° 17′ 4.37′′), Sangmo-ri, Daejeong-eup, Seogwipo-si, Jeju-do Island ”, 5.iii.2019, approximately 200 m deep from main entrance, leg. GD Chang. Paratypes on slides: 6 males and 14 females, 50 specimens are kept in ethanol 95 %, same data as holotype.
Material deposition. Holotype is located in the National Institute of Biological Resources, Incheon, Republic of Korea (NIBR). Other types are housed in the Insect Collection of the Biology Education Department, Jeonbuk National University, Jeonju, Korea (JBNU) and in the NIBR.
Ecology. This species was collected from bat guano piles in dark zone with constant temperature (DZCT) of Seotaloreumjinjidonggul cave in Jeju-do Island.
Diagnosis. Body color white to pale yellow, with brownish or purplish pigment scattered over whole body. Head with 3 + 3 eyes, anterior two close together. PAO 4 lobed and simple form. Front, middle, and hind tibiotarsus with 19, 19, 18 chaetae each. Unguis with three inner teeth and empodium filament shape. Abd. I–III without chaetae a 2, m 1. Abd. V with chaeta m 0. Ventral tube with 4 + 4 laterodistal chaetae. Retinaculum with 3 + 3 teeth. Dens with 4 + 4 chaetae and mucro without tooth. Anal spines absent.
Descriptions. Body length of type series ranging between 0.7–1.0 mm in male (four specimens) and 0. 6– 1.1 mm in female (five specimens), holotype 1. 0 mm. Habitus as in Fig. 3b. Specimens white to pale yellowish with brownish or purplish pigment scattered over whole body. Body chaetae smooth and acuminate. Anal spines absent (Fig. 3a).
Head. Antennal segments average ratio 1: 1: 1.3: 1.7. Ant. I with 7 chaetae. AIIIO typical, with 2 small sensilla surrounded by 2 much longer guard sensilla. Ant. IV with long, simple apical bulb and 4–5 weakly differentiated sensilla (Figs 4a–c). Ocelli 3 + 3, anterior two close together (Fig. 5a). PAO oval, quadridentated simple shape, length greater than the diameter of an eye (Fig. 5a). Labrum with 5, 5, 4 labral (most apical row of chaetae much stronger than other lines) and 4 prelabral chaetae (Fig. 5d). Maxillary outer lobe with simple palp (th), and one basal chaeta (bs) and 2 sublobal hairs (hair-like processes) (Fig. 5e). Maxillary head shape as in Mesogastrura libyca (Caroli, 1914), with strong three toothed-like structure and 6 lamellae (Fjellberg, 1998; Fig. 26D). Lam. 1 featherlike shape with many filaments around apex and longer than other Lam. Lam. 2 bigger than Lam. 3, many filaments along ventral edge and denticles at base. Lam. 3 with marginal ciliation. Lam. 4 and Lam. 5 with many denticles on body. Lam. 6 with denticles along anterior edge. Labial palp with five papillae (A–E). Papilla A with one knobbed guard projection (a 1), Papilla B with 4 guards; two knobbed projections (b 1 & b 2), Papilla C without guard chaeta, Papilla D with 3 guards; d 2 short papilla, Papilla E with six guard chaetae (e 1 –e 6) (Figs 6–7). Six proximal chaetae present. Mandible typical shape of chewing type with 4 teeth and molar plate.
Trunk. Claw with three inner teeth at 1/3, 2/3 and near apex of the inner edge, and 2 chaetae on basal part; empodium reduced to chaeta-like, reaching about half of unguis inner length (Fig. 8a). Tibiotarsi I–III with 19 (8 on the middle, 11 on the tip) (Fig. 8a), 19 (8 on the middle, 11 on the tip), 18 (7 on the middle, 11 on the tip) chaetae, respectively; 2 of them (A 1 and A 7) elongated, knobbed tenent hairs (Fig. 8a). Ventral tube with 4 + 4 laterodistal chaetae. Furca present; manubrium, dens, and mucro ratio as 1: 2: 2.5; dens with 4 + 4 chaetae, mucro spear headlike shaped and without tooth.
Chaetotaxy. Dorsal chaetotaxy of head and trunk (Th. I–Abd. V) as in Fig. 3a.
Head. a0 (not paired), d1–5, sd1–5, oc1–3, g2–5, v1–2, c2–5, p1–6 chaetae on each half.
Trunk. Thoracic tergum I with 2 + 2 chaetae; thoracic tergum II with 6 - 3 - 6 chaetae on anterior, medial and posterior row of each half, respectively; chaetae m 1, m 2, m 5, and m 6 absent, ‘sensory chaetae’ s = m 7 and p 4; thoracic tergum III with 5 - 3 - 6 chaetae on anterior, medial and posterior row of each half, respectively; chaetae a 2, m 1, m 2, m 5, and m 6 absent, ‘sensory chaetae’ s = m 7 and p 4; abdominal terga I–III without chaetae a 2, m 1, ‘sensory chaeta’ s = p5; abdominal tergum IV variable with 4 - 4 (5) - 5 chaetae on anterior, medial and posterior line of each half, respectively; chaetae m 1 absent or present, ‘sensory chaeta’ s = p 4; abdominal tergum V with m 0 chaeta; ‘sensory chaeta’ s = p 3. Microsensillum on Th. II absent.
Etymology. The species is named after the cave (Seotaloreumjinjidonggul cave) in which it was collected.
Distribution. South Korea.
Remark. M. seotalensis sp. nov. showed the similar pattern of body chaetotaxy with M. ojcoviensis, however, several characters were different (Table 2). Most noticeable differences between two species were the body color (light brown or much less and light purple in M. seotalensis sp. nov. (Fig. 3b) vs totally white in M. ojcoviensis (Fig. 3c)), claw teeth (unguis with three teeth in M. seotalensis sp. nov. (Fig. 8a) vs unguis without (rarely 1) tooth in M. ojcoviensis (Fig. 8b–d)) and number of eyes (3 + 3 in M. seotalensis sp. nov. (Fig. 5a) vs 2 + 2 in M. ojcoviensis (Fig. 5b)).
The number of eyes is rather similar to M. boneti and M. kuzuuensis Yosii, 1956 as 3 + 3. However this new species differs from M. boneti in the arrangement of the eyes (close each other in M. boneti (Tarsia in Curia 1941; Fig. 5c) vs anterior two close together, but one separated in M. seotalensis sp. nov.). Apart from this these two species can be easily identified by the number of m-chaetae in medial row of Abd. I–III (4 + 4 chaetae in M. seotalensis sp. nov. vs 1 + 1, rarely 2 + 2 in M. boneti). Otherwise, M. seotalensis sp. nov. and Mesogastrura kuzuuensis Yosii, 1956 have same arrangement of the eyes and mixed color pigment over whole body. However, two species showed differences in sensilla in Ant. IV. (five in M. seotalensis sp. nov. (Fig. 4a) vs four in M. kuzuuensis), claw teeth (unguis with three teeth in M. seotalensis sp. nov. (Fig. 8a) vs unguis with two teeth in M. kuzuuensis), and body chaetotaxy (absent a 2 in Th. III in M. seotalensis sp. nov. (Fig. 3a) vs a 2 present in Th. III in M. kuzuuensis; a4 on Abd. I–III as normal chaetae in M. seotalensis sp. nov. (Fig. 3a) vs a4 on Abd. I–III as sensory chaetae in M. kuzuuensis.
description: Published as part of Chang, Gyu-Dong, Kim, Sun-Sook & Park, Kyung-Hwa, 2022, One new species and one new record for the genus Mesogastrura (Collembola, Hypogastruridae) from Korean caves, with DNA barcodes, pp. 325-342 in Zootaxa 5222 (4) on pages 329-331, DOI: 10.11646/zootaxa.5222.4.2, http://zenodo.org/record/7466656