Cyphoderus mucrominimus, Oliveira & Alves & Zeppelini, 2017

Oliveira, João Victor L. C., Alves, Jorge L. S. & Zeppelini, Douglas, 2017, Two new Cyphoderus (Collembola: Paronellidae) of “ tridenticulati ” and “ bidenticulati ” groups from Brazilian Amazon, Zootaxa 4350 (1), pp. 47-60 : 48-52

Cyphoderus mucrominimus sp. nov.

Figs 1–16

Type material. Holotype, female on slide 7384, 01–19 III 2016. Brazil, Pará, Curionópolis, S 06°00’37.1”, W 49°38’14.8”, Serra Leste , cave, leg. SPELAYON team. Holotype deposited at CRFS-UEPB, João Pessoa, Paraíba , Brazil. Paratypes: 3 females on slides, same data as holotype. labelled ref. # CRFS 7381 , # CRFS 7382 and the slide #3164 is deposited in MNUFRJ.

Other material. See Table 1.

Description. Habitus typical of the genus, length 0.8 mm (average type specimen). Body color white. Eyes lacking, no ocular patch. Scales present on antennal segments I and II, head, body and furca (ventrally on manubrium, both sides on dens), and absent on legs and ventral tube.

Antennae ( Figs. 1–4 ) 1.35 times the length of the head, segments I: II: III: IV as 1: 2.3: 1.4: 3.4. Sensilla present on all antennal segments; Ant. I ventrally with four little sensilla ( Fig. 7B ) at the base, a row with four apical ciliated chaetae, and two apical spine-like chaetae ( Fig. 7D ) in right edge; dorsally with five distal chaetae, two proximal, two sensilla ( Fig. 7B ) and two pseudopores at the base of antennal segment ( Fig. 1 ). Ant. II ( Fig. 2 ) ventrally and dorsally with three sense rods (per side) ( Fig. 7A ) and plus one short apical sensillum ( Fig. 7B ); AIIIO ( Fig. 3 ), with 3 sense rods ( Fig. 7A ), 4 bristle-like sensilla ( Fig. 7C ) and 1 apical microsensillum ( Fig. 7B ). Ant. IV ( Fig. 4 ) apical bulb absent, dorsally with 4 basal sensilla ( Fig. 7B ) and 3 distal bristle-like sensilla ( Fig. 7C ); ventrally with 3 microsensilla ( Fig. 7B ) more 2 sense rods ( Fig. 7A ).

Head dorsal chaetotaxy ( Fig. 5 ) with four macrochaetae and two mesochaetae at the An series; five chaetae at the A series (A0–A1–A2–A3–A5); M2–M4, S0–S1–S2–S4–S 4i –S5–S 5i, Ps2, Ps3 and Ps5 present in medioocellar to post-sutural areas; posterior chaetae Pa1–Pa2–Pa3, Pa5–Pa6 (bothriotrix), Pm1, Pm3, Pp2, Pp3, Pe2 and Pe3 present. Labrum with amp rows of chaetae as 4,5,5 smooth chaetae with 4 prelabral chaetae larger and longer than others ( Fig. 6 ). Labial palps with all papillae present ( Fig. 8 ), chaetae a1, b1–4, d1–4, e1–3, e6 and lateralprocess (lp) present. Labial triangle formula M1 M2 R E L1–2 A1–4 ( Fig. 9 ). Chaetae along ventral groove ciliated with one microsensillum laterally ( Fig. 9 ).

Main macrochaetae on segments Th. II to Abd. IV as 00/0226+14. Body chaetotaxy (as in Fig. 10 ), anterior hood of Th. II with a collar of two or three rows of ciliated and capitated macrochaetae (not represented in the drawing). Th. II with a2, m1–2, m4–6, p1–4, p6, p6e and one antero-lateral microchaeta. Th. III with m2, m7, m6p, p2–4, p6 and one microchaeta as. Abd. I with five chaetae m2–6 and as. Abd. II with two bothriotricha a5 and m2 each surrounded by 2 fan-shaped chaetae each. m3, m5 macrochaetae, m3e, a6, m6–7, p6–7 and as present. Abd. III with three bothriotricha a5, m2 and m5 surrounded by 3,3,2 fan-shaped chaetae respectively; chaetae a6–7, pm6, am6, p6–7 present, microchaeta as present and one extra sensillum near p6 chaetae. Abd. IV with three bothriotricha T2, T4 and E4 surrounded by 4,1,2 fan-shaped chaetae respectively; A4 and A5 with accessory sensillum. A3, A6, B3–6, C1, C1p, C2–4, T3, T5, T7, D1, D1p, D2, D3, De3, E1–4, E4p, Ee12, F1–3 and Fe2–4 present, posterior row of chaetae at the distal edge of Abd. IV with 7+7 mesochaetae, 2+2 pseudopores present on the posterior edge of the segment.

Legs ( Figs. 11–15 ) without scales, trochanteral organ V-shaped with 9 ciliated chaetae ( Fig. 13 ). Tibiotarsi with tenent hair apically clavated ( Fig. 15 ). Claws broad, with one tooth in external lamella; a pair of inner basal teeth of unequal size and one unpaired subapical tooth ( Fig. 15 ). Unguiculi pointed and broad ( Fig. 15 ).

Ventral tube without scales, anteriorly with 6+6 macrochaetae, 2+2 distal mesochaetae and with 4+4 macrochaetae in posterior side, all ciliated ( Fig. 16 ).

Furcula ( Fig. 17 ). Manubrium 1.4 times as long as dens; Manubrial plate with 2 ciliate chaetae and 2 pseudopores. Dens 8 times longer than mucro, dorsally with 2 rows of feathered scales, 6 external and 3 internal, and 4 ciliated between the two rows; proximal outer part of dens with 3 ciliated chaetae and 3 smooth apical chaetae on ventral side, 2 at the base of external scale and one at the base of internal scale. Mucro vestigial (9,5µm), bidentate apically, with one small subapical tooth (aAI).

Etymology. The species is named after the reduced size of mucro.

Distribution. The species was recorded from Amazon Rainforest iron caves at Curionópolis (Serra Leste) and Parauapebas, Pará State, northern Brazil.

Ecology. Collected in four iron caves in Serra Leste and five iron caves in Parauapebas. These caves are inserted in the Amazon forest, mostly small caves whose conditions vary according to the surface weather. The altitude is between 500– 670m. The climate according to Köppen’s system is Af: Equatorial rainforest, fully humid ( Köppen 1936, Kottek et al. 2006).

Remarks. C. mucrominimus sp. nov. differs from Brazilian tridenticulati, Cyphoderus arlei in the reduced size of mucro which is less than 1/5 the length of the dens. They also differ in the shape of the chaetae r in labial triangle, which is a normal seta in the new species and is reduced in C. arlei , the TO with 9 chaeta (versus 12 in C. arlei ), dens with 6 external and 3 internal feathered scales (versus 6~7 external and 5~7 internal feathered scales in C. arlei ).

The new species resembles somehow those of the genus Pseudocyphoderus Imms, 1912, mainly in the shape and size of the mucro. Nevertheless, the new species clearly belongs to the genus Cyphoderus by presenting fully developed mouth parts, while the species of Pseudocyphoderus are known to present a reduction of the pars incisiva on the mandible and a rather hypognath position ( Delamare-Debouteville 1948). Mari-Mutt (1977) described a species (P. mellitophilous Mari-Mutt 1977) with well-developed mouth parts and lacking mucro as in C. mucrominimus sp. nov., nevertheless, P. mellitophilous presents a set of morphological features, adaptive modifications and a large body size, which clearly differs from the new species, as examples body length over 3 mm, dorsoventrally flattened body, “Lepismiform” aspect, large trochanters, modified metathoracic legs and large tenent hairs. Furthermore, the ventral tube chaetotaxy strikingly differs from that of Cyphoderus ( Yoshii 1987) .

Figures

FIGURES 1 − 7. Cyphoderus mucrominimus sp. nov.: Antennal segments, right is ventral view; left is dorsal view. 1, first antennal segment; 2, second antennal segment, apical sensilla; 3, third antennal segment, ventroapical AIIIO; 4, fourth antennal segment; 5, dorsal cephalic chaetotaxy; 6, clypeo-labral chaetotaxy; 7, Antennal and body chaetae: A) sense rod. B) microsensillum. C) bristle-like. D) spine-like chaeta. E) ciliated chaeta. F) smooth chaeta. G) bothriotrix. H) fan-shaped chaeta. Micro, meso and macrochaeta symbols equal to Fig. 7 E.

FIGURES 8 − 10. Cyphoderus mucrominimus sp. nov.: 8, labial palp chaetotaxy; 9, labial triangle chaetotaxy, left side; 10, trunk chaetotaxy, left side. Symbols as in Fig. 5.

FIGURES 11 − 15. Cyphoderus mucrominimus sp. nov.: 11, coxae; 12, trochanter; 13, trochanteral organ; 14, femur; 15, empodial complexes (column A, leg I; column B, leg II; column C, leg III).

FIGURES 16 − 21. 16 − 17 Cyphoderus mucrominimus sp. nov.: 16, ventral tube anterior (left) and posterior (right) chaetotaxy; 17, dentes and mucros (dorsal view). 18 − 21 Cyphoderus mucrostrimenus sp. nov.: 18, first antennal segment; 19, second antennal segment; 20, third antennal segment; 21, fourth antennal segment. Antennal segments, right is ventral view; left is dorsal view (ventral chaetae—grayed).