Keratosminthurus calamitosus,

Zeppelini, Douglas, Brito, Roniere A., Zampaulo, Robson & Lima, Estevam C. A., 2020, A new highly dimorphic genus of Sminthuridae (Collembola: Symphypleona) from Brazil, Zootaxa 4729 (1), pp. 25-46: 38-44

publication ID

https://doi.org/10.11646/zootaxa.4729.1.2

publication LSID

lsid:zoobank.org:pub:6EA7B4E9-CF60-44BB-A78C-F63141684A6E

persistent identifier

http://treatment.plazi.org/id/4444F169-FFAB-5E32-2DB3-FF35FCC2FBE7

treatment provided by

Plazi

scientific name

Keratosminthurus calamitosus
status

sp. nov.

Keratosminthurus calamitosus  sp. nov. Zeppelini, Brito & Lima

Figs 5CView FIGURE 5, 20–32View FIGURES 20View FIGURES 21–24View FIGURES 25–26View FIGURES 27–30View FIGURES 31–32, Table 1

Type material. Holotype adult male on slide, Brazil, Minas Gerais, Ubaí, cave of Joaquim Rodrigues farm (16°12’59.8”S; 44°38’36.0”W), 18.IV.2014, leg. Lucas et alGoogleMaps  . Holotype deposited at CRFS #8902  .

Paratype adult male on slide, idem. Paratype deposited at CRFS #8903  . Paratype adult female on slide, Brazil, Minas Gerais, Santa Barbara, Serra do Gandarela cave FP-15 (20°06’13.2”S; 43°38’24.6”W), 16.V.2014, leg. R. ZampauloGoogleMaps  . Paratype deposited at CRFS #5686  . Paratype adult female on slide, idem. Paratype deposited at CRFS #5683  . Paratype adult male on slide, Brazil, Minas Gerais, Santa Barbara, Serra do Gandarela cave FP-13 (20°06’12.7”S; 43°38’24.4”W), 16.V.2014, leg. R. ZampauloGoogleMaps  . Paratype ( CRFS #5679) deposited at CC /UFRN  . Paratype adult male on slide, Brazil, Minas Gerais, Santa Barbara, Serra do Gandarela cave FP-15 (20°06’13.2”S 43°38’24.6”W), 16.V.2014, leg. R. ZampauloGoogleMaps  . Paratype ( CRFS #5685) deposited at MUZUSP  .

Description. Holotype body length 1,088µm, head 526 µm. Color brownish yellow with purple spots on great abdomen. Legs and antennae purple, eyes in dark patch of pigments ( Fig. 5CView FIGURE 5 right).

Antennae: holotype antennal segments length (µm) I, II, III, IV = 94, 158, 233, 936 ( Fig. 20View FIGURES 20). Ant I with four normal anterior chaetae, and one chaeta and one microchaeta in apical part on posterior side ( Fig. 21View FIGURES 21–24). Ant II presents nine apical (two mic), five medial and five basal chaetae ( Fig. 22View FIGURES 21–24). Ant III apically with six chaetae (four mic) and two sensilla on AOIII, two medial and one basal whorl with eight chaetae each. AOIII of females with two sensilla in separate pits, Ai, Ap and Ae large, Ape and Api short and bristle-like, Aai minute, rod-like, blunt, tapering towards apex, other chaetae as normal. AOIII of males with two sensilla in separate pits, Ae and Ap thick and curved into a shape of a horn or hook ( Fig. 20View FIGURES 20, 23View FIGURES 21–24), Api, Ape and Ai very short and bristle-like, Aai minute, tapering towards apex.

Ant IV subdivided into 18 subsegments with 22 whorls, formula is 1 + 16 + 1 = (AI–III) + (M1,16) + (BA + BM + BB), M1 to M16 each with eight chaetae and one or two sensilla, Ant. IV subapical organ present ( Fig. 24View FIGURES 21–24).

Head: eyes 8 + 8 in a dark blue patch of pigment ( Fig. 20View FIGURES 20), two pairs of interocular chaetae, a pair of interocular organ present medially in adult males. Posterior cephalic spines absent, postero-dorsal chaetotaxy A, B, C, D, E as 5,3,3,5,6, posantennal area with 3+3 smooth spots; interantennal region with two α, two β and two γ chaetae and a pair of smooth spots; frontal head chaetotaxy a to g as 12,12,10,11,13,12,8 ( Fig. 25View FIGURES 25–26); two elongated narrow smooth areas present at proximal sides of clypeus, a pair of cuticular spines at distal part of clypeus is present in adult males, in juvenile males a pair of cuticular round papilla was observed. Labral chaetotaxy according to formula a, m, p, pl present 4,2,4,4 chaetae respectively. Labial ventral groove with 2+2 surrounding chaetae, four anterior labial chaetae; four labial basomedial chaetae (see Fig. 11View FIGURES 10–11). Labial palp with five proximal chaetae, formula: H, h1, h2; A (2); B, b1, b2, b3, b4, a1; C (3); D, d1, d2; E, e1, e2, l.p. (see Fig. 26View FIGURES 25–26)

Leg I: coxa, trochanter and femur with two, five (2 sensilla) and 16 (3 sensilla) chaetae respectively. Tibiotarsus as in Fig. 27View FIGURES 27–30, whorl I with nine chaetae, Ja thick and curved, region F presents three primary FP chaetae (e, ae, pe), five secondary chaetae FS (e↑, a, ai, pi and pe↓). Pretarsus with one chaetae per side. Unguis inner tooth well developed, tunica present at distal part. Unguiculus with subapical filament exceeding unguis tip, corner tooth well developed ( Fig. 27View FIGURES 27–30).

Leg II: coxa, trochanter and femur with two, five (1 sensillum) and 22 (6 sensilla) chaetae respectively. Tibiotarsus as in Fig. 28View FIGURES 27–30, whorl I with nine chaetae, Ja thick and straight, region F with three primary FP chaetae (e, ae, pe), five secondary chaetae FS (e↑, a, ai, pi and pe↓). Pretarsus with one chaetae per side. Unguis with inner tooth, tunica present at distal part. Unguiculus with subapical filament exceeding unguis tip, corner tooth well developed ( Fig. 28View FIGURES 27–30).

Leg III: coxa, trochanter and femur with four, five and 20 (2 sensilla) chaetae respectively, trochanteral spine present. Tibiotarsus as in Fig. 29View FIGURES 27–30, whorl I with nine chaetae, Ja thick and straight, region F with three primary FP chaetae (e, ae, pe), five secondary chaetae FS (e↑, a, ai, pi and pe↓). Pretarsus with one chaetae per side. Unguis with a strong inner tooth, tunica present at distal part. Unguiculus lanceolate, with subapical filament exceeding unguis tip, corner tooth well developed ( Fig. 29View FIGURES 27–30).

Ventral tube presents 1 + 1 apical anterior chaetae. Ramus of the tenaculum tridentate, corpus presents two apical chaetae.

Furca: holotype manubrium, dens, mucro length (µm) 181, 404, 165. Dens with 12 anterior chaetae, chaetotaxy I (ae, a, ai): II (ae, a): III (ae, a): IV (ae, a): V (a): VI (a): B (a), formula 3:2:2:2:1:1:1. Posterior dental chaetotaxy ( Fig. 30View FIGURES 27–30) Ie, I–VIIpe, I–VIIIp, I–VIIpi, I–IIi, Bpe, Bp, Bpi. Mucro with both lamellae smooth, asymmetric tip; mucronal chaeta absent

Great abdomen: all chaetae short, smooth and acuminated. Mesothorax with one a and three m chaetae, metathorax with four m and three p chaetae. Trichobothrial complex: ABC form an obtuse angle open backwards. AB subequal to BC (AB = 137, BC = 143, AC = 280). Abd. I six m and one p; Abd. II chaetae a1 present, b1 equidistant, a little displaced anteriorly to BC; chaetae c1 and c2 below the trichobothrium C. Central dorsal complex presents three chaetae arranged in triangular patern and two mic. Posterior lateral complex with 5 + 6 chaetae and posterior dorsal complex presents dI = 7, dII = 9 and dIII = 7. Furca base complex presents 12 chaetae and a Neosminthuroid chaeta in male and female. Ventral complex presents two chaetae (see Fig. 17View FIGURE 17). Areas marked in Fig. 17View FIGURE 17 present a smoother cuticular ornamentation.

Small abdomen of female: Abd. V with four chaetae and trichobothrium D in a papilla at row a, one superior and three inferior chaetae in row p. Abd. VI axial chaetae ams1, ms1 and ps1 present, as1 absent; chaetae as2 and ai6 absent, ams2 and ams3 present; mps1–3 bigger than other chaetae, somewhat swollen at the base; subanal appendage mi5 large, thick curved and acuminated, reaching the upper valve ( Fig. 31View FIGURES 31–32).

Small abdomen of male: Abd. V with three chaetae and trichobothrium D in a papilla at row a, two superior and three inferior chaetae in row p. Abd. VI axial chaetae as1 and ams1 absent, ms1 and ps1 present; chaetae as2 and ai6 absent, ams2 and ams3 present; mps1–3 normal; male genital papilla with 4 rows (pre genital, a, m, p) with 3 (1 mic), 8, 4, 4 chaetae respectively ( Fig. 32View FIGURES 31–32).

Etymology: Calamitosus from Latin is that which causes or results from a calamity; disastrous; damaged. The species was named in memoriam to the people who died after the dam ruptures in 2015 and 2019 in the State of Minas Gerais, Southeastern Brazil, in the iron ore exploitation areas.

Distribution and habitat. Good’s Biogeographic zone 27 ( Good 1974, Culik & Zeppelini 2003). The Köppen’s climate is As ( Köppen 1936, Shear 1966, Kottek et al. 2006), with predominance of dry winter and wet summer, mean temperatures of 18°C during winter and 22°C in the summer.

Keratosminthurus calamitosus  sp. nov. was found in iron caves, just like K. tapigu  sp. nov., in the area known as “Iron Quadrangle” (from Portuguese Quadrilátero Ferrífero), at the south of the State of Minas Gerais, Southeastern Brazil. Along with Carajás, this is one of main mineral provinces of Brazil, due to its iron and gold beds. In this region the iron caves usually are less than 30m long in linear development, despite temperature, general surrounding environmental conditions are very similar to those found in Carajás, Northern Brazil. In the iron Quadrangle, the caves where the new species was recorded are inserted in the geomorphologic unit of Gandarela range and oriental cliff of Caraça ( Oliveira et al. 2011), in altitudes between 900–1400m, with vegetation composed by altitudinal rupestrian grasslands ( Fig. 5View FIGURE 5 A–B right). This region presents great variation in temperatures and high level of solar radiation along the day. Keratosminthurus calamitosus  sp. nov. was also found in the north of Minas Gerais State in limestone caves, extending the known distribution of the species across different geomorphologic units. Brazil is the second biggest iron ore producer worldwide, 60% of the annual production comes from Iron Quadrangle, this region is exploited since beginnings of XX century, and the mining promotes a complete change in the landscape, with irreversible impacts on different ecosystems. Impacts include the total suppression of caves ranked as low, medium or high relevance according to the Federal decree 6,640 ( Brasil 2008). At last, when the ore processing is made by washing and sifting, an enormous amount of liquid mud is produced and deposited in dams build up on natural valleys. The implantation of these structures demands the suppression of natural drains, caves and forest, with drastic impact on the whole environment and biodiversity; in drastic occasions, the rupture of these dams have catastrophic environmental and humanitarian effects.

Remarks. Keratosminthurus calamitosus  sp. nov. is the second species assigned to the new genus. What differentiate this species from Keratosminthurus tapigu  sp. nov. is the presence of 12 chaetae (3,2,2,2,1,1,1) in the anterior dens (13 in Keratosminthurus tapigu  sp. nov., 3,2,2,2,2,1,1), the Ant. IV divided into 18 subsegments (20 in Keratosminthurus tapigu  sp. nov.), and the presence of tunica and clear corner tooth in first unguiculus (respectivelly absent and reduced in Keratosminthurus tapigu  sp. nov.).

R

Departamento de Geologia, Universidad de Chile

CC

CSIRO Canberra Rhizobium Collection