Coecobrya urbana Jordana & Baquero, 2024

Baquero, Enrique, Jordana, Rafael & Fadrique, Floren, 2024, Two new species of Collembola (Arthropoda, Hexapoda) from Cova Urbana, a cave under a city, Subterranean Biology 49, pp. 163-184 : 163-184

Coecobrya urbana Jordana & Baquero sp. nov.

Figs 3 , 4 , 5 , 6 , 7 , 8

Type material.

Holotype • female on slide, Spain: Tarragona city, Tarragona province, Cova Urbana , geographic coordinates 41.114193, 1.248222, 15 m a. s. l. (the entrance is in an urban area), 6/vii/2022, dark zone of the cave, by aspirator ( MZNA code 782957 ) . Paratypes • same data as holotype, three females on two slides ( MZNA codes 782958 , 782972 to 782973 ), 10 in ethyl alcohol ( MZNA codes 782961 to 782970 ) and one mounted on stub for SEM observation ( MZNA code 782971 ) • 29/vii/2022, two females on slide ( MZNA codes 782972 to 782973 ), and two specimens in ethyl alcohol (code samples 782987 to 783988 ) • 1/vii/2023, 10 specimens in ethyl alcohol (code samples 782975 to 783985 ) and one mounted on stub for SEM observation ( MZNA code 782971 ) . All Floren Fadrique leg ( BIOSP, Associació Catalana de Biospeleologia). Specimens deposited in MZNA.

Description.

Habitus as in Fig. 3 . Body length (without antennae) up to 1.7 mm (holotype 1.6 mm). No scales. Eyes absent. Color whitish in alcohol, without any pigment. Antennae 1.41–1.85 times the length of the head (n = 4; lower proportion in smaller specimens). Abd IV 3.4 times as long as Abd III.

Antennae (Figs 4 , 5 ). Antennal segments not subdivided nor annulated. Ant I dorsally with two Mc type one (capitate), numerous Mc type two (acuminate) with different sizes ( Christiansen 1958), and three small mic at basis, forming a triangle, with the distal one bigger; ventrally with 9–10 basal smooth spiny mic of various sizes; one distal pseudopore. Ant II dorsally without paddle-like chaetae in its distal part, with small sensilla; two distal pseudopores. Ant III sensory organ as usual, with five sensillae and the special ones swollen. Ant IV 1.55–1.83 times longer than Ant II or Ant III, not subdivided, without apical bulb. Subapical organite slightly knobbed, with a basal accessory special small mic.

Head. Clypeal and labral areas in Fig. 6 A ; prelabral and labral chaetae (4 / 5, 5, 4) all smooth, central chaetae of row a thicker, and external on small papillae. Maxillary outer lobe with one apical and one basal chaeta, and three sublobal hairs (Fig. 6 B ). Papillae E of labrum in Fig. 6 C . Chaetae of labial basis all smooth (- mrel 1 l 2) similar in length except for ‘ r’ short. One or two special ‘ x’ chaetae. On each side of linea ventralis, 5–6 smooth and 1–2 ciliate chaetae (Fig. 6 D ).

Legs. Legs devoid of scales, covered with ordinary ciliated chaetae of various lengths, mic not seen. Coxa of leg I with one proximal psp and two chaetae posteriorly; coxa of leg II with eight chaetae in anterior row, two chaetae in posterior row and one proximal psp; coxa of leg III without proximal psp. Trochanteral organ with 15 smooth, straight, unequal spine-like chaetae (Fig. 7 A ). Tenent hair spatulated (22–30 μm). Tibiotarsi I – III with a single row, interior, of appressed chaetae, the most distal on tibiotarsus III smooth. Claw slender (Fig. 7 B – D ); claw I and II subequal, claw III slightly longer. All claws with a pair of basal inner teeth at approx. 35‒40 % and two unpaired inner teeth at 55 % and 80–90 % of inner edge from basis respectively. Empodium approx. 0.8 times as long as inner edge of claw, slightly swollen baso-internally, truncated apically, devoid of inner tooth, with a big outer tooth at 1 / 2 of its length.

Ventral tube (Fig. 7 E ). Anterior basal with 4 + 4 ciliated Mc; anterior distal flaps with 7 + 7 smooth chaetae; posteriorly with eight smooth chaetae, two of them as mic.

complex. Tenaculum with four large teeth and one ciliated chaeta. Manubrium covered with ciliated chaetae, and seven smooth chaetae on two rows on posterior side. Manubrial plate with two pseudopores and two ciliate chaetae, one each side. Dens without spines, annulated and covered with ciliated chaetae on both sides, and 2 + 2 basal smooth posterior chaetae. Distal smooth part of dens similar in length to mucro. Mucro falcate, basal spine long, nearly reaching the tip of the mucronal tooth (Fig. 7 F ).

Dorsal chaetotaxy (Fig. 8 A, B ). Head: dorsal cephalic chaetotaxy with four antennal (An 1–3, An 3 a 1), four anterior (A 0, A 2–3, A 5), four median (M 0, M 1–2, M 4) and seven sutural (S 0, S 1–5, S 4 i) Mc. Th II with three (m 1–2, m 2 i) medio-medial (area T 1) ( Jordana and Baquero 2005), three (a 5, m 4, m 4 p) medio-sublateral (T 2) and 15‒18 posterior Mc, 1 + 1 ms and 2 + 2 sensillae laterally. Abd II without Mc above internal bothriotrichum (area A 1), three (m 3, m 3 e and m 3 ea) central (A 2) and one (m 5) lateral Mc. Abd III without Mc on areas A 3 and A 4, only one (m 3) on area A 5, and three (a 7, pm 6 and p 6) lateral Mc. Bothriotrichum not surrounded by modified chaetae. Abd IV with four central Mc (A 3, A 6, and B 4–5), four (E 2–4, D 3) lateral Mc and about nine long sensilla. Abd V with five Mc, and 3 + 3 sens. The S-chaetae formula is the usual for the family.

Ecology.

The specimens were captured in the dark area of the cave (Sala Maginet), in the deep and isothermal area of the cavity, very close to the aerial end of the cave (from here, the route is underwater), on wood with fungus. After placing a cheese bait during 15 days on that same wood, only specimens of the Folsomia candida species were captured.

Etymology.

The new species is named after the name of the cavity where it was found, Cova Urbana, which in turn is so named because its entrance is in the heart of a city.

Remarks.

The new species differs morphologically from other known Coecobrya species by presenting four internal teeth of claw. To the best of our knowledge, Coecobrya montana ( Imms, 1912) sensu Zhang, Deharveng & Chen, 2009 from India, C. submontana Stach, 1960 from Afghanistan, C. troglobia Jantarit & Nilsai, 2021 (in Nilsai et al. 2021) from Thailand and C. decemsetosa Jordana & Baquero, 2023 (in Baquero et al. 2023) from Portugal are the only four described species of Coecobrya with four teeth on the internal claw. Unfortunately, the chaetotaxy of C. montana and C. submontana are unknown (the type material was observed by the authors, and the conservation of the specimens made no possible to observe the chaetotaxy), but have small differences with C. decemsetosa and the new species described here in the morphology of the claw, a character used traditionally for differentiate the species. In addition, C. decemsetosa poses large differences in number of Mc on tergite from Th II – Abd V too. C. submontana , which has been studied after requesting some specimens deposited in Stach‘s collection of PAN ( Polska Akademia Nauk, Warszawa, Poland), from a cave near Kabul, has a short basal spine on the mucro, and the dorsal tooth of the claw in an intermediate position between the base and the paired teeth of the inner edge. Coecobrya troglobia can be differentiated from the new species because it has longer antennae (4–6.8 times the length of the head), the paired teeth on inner claw closer from the basis (30 %), the external empodium serrated at its posterior half, only two Mc on dorsal Abd II, five central Mc (each side) on Abd IV and manubrium without smooth Mc.

Figures

Figure 3. Coecobrya urbana sp. nov. habitus at SEM. Scale bar: 0.1 mm.

Figure 4. Coecobrya urbana sp. nov. A antennal segments I – IV (dorsal view except for Ant II, both) B detail of the Ant III sensory organ, and C the three types of sensilla on Ant IV. Scale bars: 0.05 mm (A); 0.005 mm (B – C).

Figure 5. Coecobrya urbana sp. nov.: antenna, detail of Ant IV and different types of Mc (a) and sensilla (b – d). Scale bar: 0.002 mm.

Figure 6. Coecobrya urbana sp. nov. A clypeal, prelabral and labral areas B maxillary outer lobe C papilla E of labrum D labial basis E head chaetotaxy. Scale bars: 0.02 mm (A – C); 0.075 mm (D).

Figure 7. Coecobrya urbana sp. nov. A trochanteral organ B claw 1 C, D claw 3; E ventral tube F tip of dentes and mucro. Scale bars: 0.02 mm (A, D, E); 0.005 mm (B – C); 0.01 mm) (F).

Figure 8. Coecobrya urbana sp. nov. A Th II – Abd II B Abd III – VI C detail of two Mc and a long sensilla of Abd IV. Scale bar: 0.05 mm (A – B); 0.01 mm (C).