Acherontides serrasapoensis

Coordinates Sites Al HP R A HE Date Collectors CN

Description. Habitus. Typical to the genus (Fig. 1); body length 1200 µm (n = 10), holotype measurements as in Table 2; integument granulation strong; body with coarsely serrated chaetae and longer and fine sensory chaetae; color white when alive and in alcohol. Antenna. Ant. I with 7 dorsal chaetae; Ant. II with 12; Ant. III with 16 chaetae, sense O. with two free clubshaped microsensilla, not covered by tegumentary fold; two long guard sensilla (sgd and sgv) of same shape and size, and one ventral microsensillum. Ant. IV with 1 dorsal sensillum, 3 dorsolateral sensilla, 1 micro-sensillum, and simple apical vesicle (Fig. 2). Head. Eyes and PAO. absent. Dorsal chaetotaxy of head, Th. and Abd. Head with two chaetae in the ocular area; Th. I with 3 dorsal chaetae per side and 1 lateral; Th. II and III (Fig. 3), and Abd. IV with 3 rows of dorsal chaetae; Abd. I – III and V – VI with 2 rows of chaetae (Fig. 4). Ventral chaetotaxy of head, Th. and Abd. I. Head with 9 chaetae along mid-line (Fig. 5); Th. I without chaetae, Th. II and III with 1 + 1 chaetae; ventral tube with 4 + 4 chaetae; Abd. I without chaetae. Mouthparts. Labial palp presents 3 main papillae (a – c), plus 2 lateral papillae (d – e) with 2 chaeta each, m (f) being smaller than others, base of the palp presents 5 proximal chaetae (Fig. 6). Labrum with 4 anterior, 5 medial and 5 posterior chaetae. Ventral chaetotaxy of Abd. II – VI. Abd. II with 7 + 7 chaetae; Abd. III with 9 + 9 chaetae. Abd. IV and V with about 10 + 10 chaetae; Each anal valve with 13 regular + 2 hr chaetae (Fig. 7). Genital plates and anal spines. Genital plate of female with 2 + 2 pregenital chaetae, 3 circumgenital chaetae and 2 eugenital chaetae (Fig. 8). Genital plate of male with 9 pregenital chaetae, 7 circumgenital chaetae and 2 eugenital chaetae (Fig. 9). Anal spines, about 1 / 3 length of unguis III (Fig. 10). Legs. Chaetotaxy from I to III: coxae 4,9,10; trochanters 5,5,5; femora 12,12,10 – 12; Tita 19,19,18; pre-tarsi 2,2,2; tenent hairs clavate; pre-tarsal chaetae of same length in all legs; unguis thin, slightly bending, with a paired proximal ventral tooth, and unguiculus lacking (Figs. 12 – 14). Ratio Tita / unguis = 1: 0.84. Furca. Manubrium with 3 + 3. Mucro and dens fused, with 2 basal, dorsal chaetae; tenaculum with 3 + 3 teeth, without chaetae on corpus (Figs. 15 – 17).

Figures 1 – 16, Tables 1 – 3 urn: lsid: zoobank. org: act: 736 D 3 A 76 - AE 62 - 40 FA-B 0 C 4 - 760 F 451311 B 2

Diagnosis. The new species has Ant. I with 7 chaetae, 2 chaetae in ocular area, unguis with a paired proximal tooth, tenaculum with 3 + 3, two clavate tenent hairs, anal spines about 1 / 3 length of unguis III.

Discussion. The new species clearly differs from A. atoyacensis, A. juxtlahuacaensis, A. pappogeomysae, A. bullock, A. tanasachie, A. peruensis and A. huetheri because of its furca morphology (developed vs reduced furca). A. serrasapoensis sp. nov. is similar A. potosinus, A. spinus, and A. eleonorae based on the mucro and dens fused in a mucrodens with 2 basal dorsal chaetae. However, it differs from A. potosinus by the number of chaetae in the ocular area, and by tenaculum teeth (2 + 2 vs 3 + 3 chaetae, and 3 + 3 vs 2 + 2 teeth, respectively). A. serrasapoensis sp. nov. can be easily differentiated from A. spinus since it does not have Abd. VI with 10 heavy spine-like chaetae in addition to anal spines. A. serrasapoensis sp. nov. shares many characteristics with A. eleonorae such as 2 + 2 chaetae in the ocular area, and furca morphology, but differs from Ant. I having seven instead of six chaetae; clavate tenent hairs vs acuminate; and anal spines about 1 / 3 length of unguis III vs thin anal spines, about 1 / 5 length of unguis III. For a comparison of the morphological characteristics of all Acherontides species; see Table 3. It was observed same variation on Th. I, exceptionally presenting 4 + 4 or 3 + 4 instead 3 + 3 chaetae, manubrium 3 + 3 plus a medial instead 3 + 3 chaetae, femora III 12 instead 10 chaetae and on tenaculum which may present 3 + 4 instead 3 + 3 teeth.

Etymology. Species name is derived from the type locality, Serra do Sapo, which means “ the frog mountain range ”.

Type material. Holotype female on slide, Brazil, MG, Conceição do Mato Dentro (18 ° 56 ’ 8 ” S; 43 ° 24 ’ 43 ” W), CSS- 09 iron cave, 20 Jul. – 06 Aug. 2015, Carste team leg., deposited at the CRFS-UEPB # 9020. Paratypes: 1 male on slide, (# 9026 CRFS-UEPB), Brazil, MG, Conceição do Mato Dentro (18 ° 55 ’ 1 ” S; 43 ° 25 ’ 40 ” W), CSS- 06 iron cave, 20 Jul. – 06 Agu. 2015 Carste team leg., deposited at MN / UFRJ. 1 female on slide (# 9315 CRFS-UEPB), Brazil, MG, Conceição do Mato Dentro (18 ° 55 ’ 1 ” S; 43 ° 25 ’ 40 ” W), CSS- 06 iron cave, 20 Jul. – 06 Aug. 2015 Carste team leg., deposited at LESM-UNAM. 1 male on slide (# 9025 CRFS-UEPB), Brazil, MG, Conceição do Mato Dentro (18 ° 55 ’ 1 ” S; 43 ° 25 ’ 40 ” W), CSS- 06 iron cave, 20 Jul. – 06 Aug. 2015 Carste team leg., deposited at MZUSP. 1 male and 1 female on slides, 11 – 29 Jan. 2019 other data as holotype, deposited at the CRFS- UEPB # 7334, 7339; Additional material and details of the type material see Table 1.