Acherontiella nezamdoosti Mehrafrooz Mayvan & Kováč sp. nov.

Figs 3, 4, 5, 6, 7, 8, 17 A, Table 2

Diagnosis.

Colour white, without pigment. Eyes, PAO, furca and retinaculum absent. Labrum with 4 / 554 setae. Four anterior setae on labrum thickened. Ant IV with simple apical vesicle and 4 subapical subglobular sensilla. VT with 4 + 4 apical setae. Tibiotarsi with 2 knobbed tenent hairs. Claws with strong internal subapical tooth, empodium absent. Two small anal spines present. Setae m 1, m 4, and m 5 on Abd IV present.

Type material.

Holotype. • ♂ on slide; Iran, Tehran province, Firouzkouh city, Herandeh village, Burnik Cave; 35°41'14"N, 52°41'24"E; 2000 m a. s. l.; 02 Aug. 2024; M. Mehrafrooz Mayvan leg.; dark zone, collected from surface of water; temperature = 8 ° C, relative humidity = 87.0 %; slide no. IrBuAc 110. Paratypes. • 5 ♀♀, 2 juveniles, on slides; Iran, same collection data as for holotype; slide no. IrBuAc 111 –117; Holotype and 5 paratypes deposited in CoPJSU, 2 paratypes (IrBuAc 116 –117) deposited in ZMFUM.

Additional material.

• 4 ♂♂, 5 ♀♀, on slides; Iran, Mazandaran province, Abbas Abad County, close to the Danial village, Danial Cave; 36°39'35"N, 51°10'53"E; 203 m a. s. l.; 13 Jul. 2024; M. Mehrafrooz Mayvan leg.; dark zone, deep section of the cave, Rizan chamber, collected from surface of water; temperature = 16 ° C, relative humidity = 84.0 %; slide no. IrDaAc 118 –126; deposited in CoPJSU.

• 10 ♂♂, 8 ♀♀, on slides; Iran, North Khorasan province, Bojnourd city, close to the Bidak village, Bidak Cave; 37°26'30"N, 57°13'14"E; 1327 m a. s. l.; 23 Jun. 2022 and 26 Jul. 2023; M. Mehrafrooz Mayvan leg.; dark zone, terminal part of the cave, collected from bat guano; slide no. IrBiAc 127 –145; deposited in CoPJSU.

• 7 ♂♂, 3 ♀♀, on slides; Iran, Razavi Khorasan province, Sarakhs county, close to Bazangan village, Bazangan Cave; 36°18'29"N, 60°22'19"E; 1401 m a. s. l.; 22 Nov. 2021, 18 Jun. 2022 and 27 Sep. 2023; M. Mehrafrooz Mayvan leg.; dark zone, terminal part of the cave, collected from bat guano, rotten wood and pitfall traps with propylene glycol; slide no. IrBaAc 146 –155; deposited in CoPJSU.

• 2 ♂♂, 2 ♀♀, on slides; Iran, Razavi Khorasan province, Chenaran city, near the industrial town, Aghol Cave; 36°33'36"N, 59°04'58"E; 1445 m a. s. l.; 07 Jul. 2022 and 08 Aug. 2023; M. Mehrafrooz Mayvan leg.; dark zone, terminal part of the cave, collected from bat guano; slide no. IrAgAc 156 –159; deposited in CoPJSU.

• 16 ♂♂, 1 juvenile, on slides; Iran, Razavi Khorasan province, Mashhad city, Kardeh village, Kardeh Cave; 36°40'15"N, 59°40'37"E; 1458 m a. s. l.; 01 Jul. 2022, 10 Jul. 2023 and 18 Aug. 2024; M. Mehrafrooz Mayvan leg.; dark zone, collected from bat guano in Bat chamber and from rotten wood in 2 nd cave floor; temperature = 16 ° C, relative humidity = 80.0 %; slide no. IrKaAc 160 –176; deposited in CoPJSU.

• 5 ♂♂, 5 ♀♀, on slides; Iran, Razavi Khorasan province, Mashhad city, Kardeh village, AL Cave; 36°40'0.2"N, 59°39'19"E; 1693 m a. s. l.; 13 Oct. 2023 and 24 May 2024; M. Mehrafrooz Mayvan leg.; dark zone, collected on bat guano with an aspirator; slide no. IrAlAc 177 –186; deposited in CoPJSU.

• 4 ♂♂, 9 ♀♀, on slides; Iran, Razavi Khorasan province, Chenaran city, Kenan 1 (Big Kenan) Cave; 36°33'58"N, 59°04'19"E; 1451 m a. s. l.; 29 Jun. 2022 and 24 May 2024; M. Mehrafrooz Mayvan leg.; dark zone, collected on bat guano with an aspirator; slide no. IrKeAc 187 –199; deposited in CoPJSU.

Description.

Body. Length 0.76 mm on average (n = 8, maximum length 0.84 mm). Habitus and buccal cone typical of genus Acherontiella. Eyes, PAO, retinaculum, and furca absent. Body fusiform, covered by serrate mesosetae; two small anal spines present (Fig. 17 A). Colour white, without traces of pigment. Cuticular granulation rather uniform.

Antennae. Antennae slightly shorter than head, 0.134 mm and 0.165 mm, respectively (Fig. 3 A). Length of Ant I: II: III and IV (Ant III – IV fused dorsally) in holotype as 0.024: 0.026: 0.083 mm, respectively. All setae on Ant I – II serrate. Ant I with 7 setae; Ant II with 12 setae. Ant III and IV fused dorsally, intersegmental suture on ventral side well marked, 23 dorsal and 26 ventral setae, all normal, smooth (lateral setae longer than others). Ant IIIO with 2 central short and curved rods (microsensilla) flanked by 2 long guard sensilla of very characteristic constitution (Fig. 3 B) (Deharveng and Díaz 1984); small ventrolateral microsensillum in a ventral pit. Ant IV with a protrusible simple ventroapical vesicle (Fig. 5 B), 4 subglobular sensilla – 2 ventral (lateroexternal) and 2 dorsal (1 lateroexternal, 1 laterointernal) (Fig. 5 A, B), dorsoexternal subapical ms and apical os near external sensilla (see D’Haese 2003).

Head. Eyes and PAO absent. Setal formula of labrum 4 / 5, 5, 4, four anterior labral setae thickened (Figs 4 B, 5 C). Labium and labial triangle as in Fig. 4 C, with 5 main papillae (A – E), 6 proximal smooth setae, 4 basomedial and 5 basolateral smooth setae. Maxillary outer lobe with 3 sublobal hairs (Fig. 4 E). Left mandible with 3 teeth and right mandible with 4 teeth (Fig. 4 D).

Legs. Legs I – III with normal setae, tibiotarsi with 2 knobbed tenent hairs (Fig. 5 F). Setal pattern as in Fig. 6 A – C. Leg I: coxa with 3 setae, trochanter with 5 dorsal setae, femur with 13 setae, Tib with 19 setae, including 2 knobbed apical tenent hairs. Leg II: coxa with 8 setae, trochanter with 5 setae, femur with 13 setae, Tib with 19 setae, including 2 knobbed apical tenent hairs. Leg III: coxa with 7 setae, trochanter with 4 setae, femur with 11 setae, Tib with 18 setae, including 2 knobbed apical tenent hairs; Claw slender, internal edge with strong subapical tooth (Fig. 5 E); empodium absent; pretarsus with 2 setae (1 internal, 1 external) shorter than half of the length of claw (Fig. 6 D – F).

Abdomen. Ventral tube with 4 + 4 apical setae. Retinaculum and furca absent. 2 small anal spines present. Ratio ASp: claw III = 0.36: 1

Setal pattern. Dorsal setal pattern generally of type I with mesosetae (after Jordana et al. 1997). Setae on head and body serrate (Fig. 5 D), sensilla longer and smooth.

Head. Dorsal setal pattern as in Fig. 3 C. Seta a 0 often present (absent in some specimens); d 1 – d 5; sd 3 – sd 5 (sd 1 and sd 2 absent); v 1 [v 2 absent]; c 2 – c 5 (c 1 absent); p 1 – p 5; oc 1 – oc 2 (oc 3 absent). Ventral setal pattern as in Fig. 4 A, with smooth setae.

Thorax. Dorsal setal pattern as in Fig. 7. Position of ss in p row of setae on Th II – III is 4 and 4, respectively. Th I with 3 + 3 setae (m 1, m 3 and m 4); Th II and III with 3 rows of setae – a: 4 + 4 as a 1, a 2, a 4 and a 5 [a 3 absent]; m: 3 + 3 between m 6 (s) as m 1, m 4 and m 5 [m 2 and m 3 absent]; p: 3 + 3 between p 4 (s) as p 1 – p 3. Thoracic sterna without setae.

Abdomen. Dorsal setal pattern as in Fig. 8 A, ventral setal pattern as in Fig. 8 B. The position of ss in p row on Abd I – V as 5, 5, 5, 4, 3, respectively. Abd I – III with 2 rows of setae – a: 5 + 5 as a 1 – a 5; p: 4 + 4 between p 5 (s) as p 1 – p 4. Abd IV with 3 rows of setae – a: 4 + 4 as a 1, a 2, a 4 and a 5 [a 3 absent]; m: 3 + 3 as m 1, m 4 and m 5 [m 2 and m 3 absent]; p: 3 + 3 between p 4 (s) as p 1 – p 3. Abd V with 2 rows of setae – a: 3 + 3 as a 1 – a 3; p: 2 + 2 between p 3 (s) as p 1 and p 2.

Etymology.

The new species is dedicated to Javad Nezamdoost, the founder and former director of the Cave and Speleology Association (ISCA) of Iran who has made a lot of efforts in exploration and protection of Iranian caves.

Taxonomic remarks.

So far, 22 species of Acherontiella have been described (Table 2), which may be divided into two groups based on the presence of anal spines. There are 10 Acherontiella species with anal spines: A. nezamdoosti sp. nov., A. aokii Tamura & Yue, 1999, A. bougisi, A. cavernicola (Tarsia in Curia, 1941), A. epigea Bonet, 1945, A. mac (Palacios-Vargas & Thibaud, 1985), A. prominentia Thibaud & Weiner, 1997, A. sabina Bonet, 1945, A. thai Thibaud, 1990 and A. thibaudi Barra, 1994. Of these, the new species along with A. bougisi, A. epigea, and A. sabina have claws with strong tooth, while claws in A. aokii, A. cavernicola, A. mac, and A. thai are toothless. Acherontiella nezamdoosti sp. nov. and A. sabina differ from A. epigea and A. bougisi by 2 knobbed tenent hairs on tibiotarsi, while A. epigea and A. bougisi has just 1 more or less knobbed tenent hair. Moreover, A. nezamdoosti sp. nov. differs from A. sabina in Ant IV with 4 short subglobular sensilla, Th 1 with setae m 1, m 3, and m 4 and Th II – III without setae a 3, m 2, and m 3. In the contrary, A. sabina has Ant IV with 4 long cylindrical sensilla, Th 1 with setae m 1, m 2, m 4 and Th II – III with setae a 3, m 2, and m 3. Additionally, A. bougisi is the only species of this genus that has been recorded from Iran so far. Acherontiella nezamdoosti sp. nov. clearly differs from A. bougisi in several diagnostic characters: 4 sensilla on Ant IV are subglobular, and fully exposed (not concealed by tegumentary folds), whereas in A. bougisi, they are thick, cylindrical, and partially hidden by tegumentary folds. Setae d 1 and oc 3 are absent on the dorsal side of head in the new species, but present in A. bougisi. Seta a 7 (la 1) is present on Th II – III in A. nezamdoosti sp. nov., while it is absent in A. bougisi. Furthermore, seta a 3 is present on Abd I – III in the new species but it is absent in A. bougisi. The two species also differ in the p row of Abd IV, where A. nezamdoosti sp. nov. bears ss in position p 4, in contrast to p 5 in A. bougisi. Finally, seta a 2 is present on Abd V in the new species, whereas it is absent in A. bougisi.