Acherontides serrasapoensis, Araujo De Lima & Stievano & Zeppelini, 2019

Araujo De Lima, Estevam C., Stievano, Luis Carlos & Zeppelini, Douglas, 2019, A new species of Acherontides (Collembola: Hypogastruridae) from Brazil, with an identification key, Zootaxa 4623 (1), pp. 141-150 : 142-146

Acherontides serrasapoensis sp. nov. Lima, Stievano & Zeppelini

Figures 1–16 , Tables 1–3

urn:lsid:zoobank.org:act:736D3A76-AE62-40FA-B0C4-760F451311B2

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 .

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.

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).

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

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.

Coordinates Sites Al HP R A HE Date Collectors CN

Figures

FIGURE 1. Acherontides serrasapoensis sp. nov. Habitus under glass slides in Hoyer’s medium, photograph with optical microscope, scale bar: 40 µm.

FIGURES 2–8. Acherontides serrasapoensis sp. nov. 2, dorsal chaetotaxy of left antenna; 3, dorsal chaetotaxy of head and Th. I–III; 4, dorsal chaetotaxy of Abd. I–VI; 5, ventral chaetotaxy of head; 6, labial palp; 7, ventral chaetotaxy of Abd. II–VI; 8, female genital chaetotaxy.

FIGURES 9–10. Acherontides serrasapoensis sp. nov. Scanning electronic microscope (photos). 9, male genital; 10, anal spines, and Abd. VI chaetae. Scale bars: 20 µm.

FIGURES 11–12. Acherontides serrasapoensis sp. nov. 11, leg III; 12; details of unguis teeth and clavate tenent hairs.

FIGURES 13­–16. Acherontides serrasapoensis sp. nov. Scanning electronic microscope (photos 13–14 and 16) and contrast face microscope (photo 15). 13, unguis, details of a pair of median ventral teeth; 14, tenaculum with 4+3 teeth; 15; dorsal furca and tenaculum with 3+3 teeth; 16, lateral view of ventral furca;. Scale bars: 20 µm.