Taxonomic revision of the Andean harvestman genus Rhaucus Simon, 1879 (Arachnida, Opiliones, Cosmetidae)
Author
García, Andrés F.
Author
Kury, Adriano B.
text
Zootaxa
2017
2017-10-26
4338
3
401
440
journal article
31738
10.11646/zootaxa.4338.3.1
8c5ead3e-f39f-46d7-a08a-5b1693d23df8
1175-5326
1036862
0D53EB9D-2D0B-4438-851B-A98563D16DCC
Rhaucus robustus
(
Mello-Leitão, 1941
)
comb. nov.
(
Figs 1c
,
12–14
,
18d
,
23
)
Megarhaucus robustus
Mello-Leitão, 1941
: 169
, fig. 4;
Kury, 2003
: 67
.
Type
material.
Holotype
♀
(
MNRJ 150
),
Colombia
,
Boyacá
,
La Uvita
, examined.
Distribution and habitat
.
COLOMBIA
,
Boyacá Department
: La Uvita, Tipacoque.
Santander Department
:
Cerrito, Carcasí, Guaca. Between 2850 and
3585 m
a.s.l., in
Magdalena
Valley montane forests ecoregion and Northern Andean páramos. It is the northernmost species of the genus (
Fig. 23
).
Diagnosis.
DS weakly granulated (
Fig. 13a
; contrasting with all other species of
Rhaucus
); reticulated pattern of yellow blots only along lateral margins of DS (contrasting with
R. serripes
that exhibits blots all over the DS), without transverse lines (
Figs 12a
,
13a
; contrasting with
R. vulneratus
,
R. quinquelineatus
and
R. florezi
sp. nov.
); spines in area III conical and dome-shaped (
Fig. 12c
; differing from
R. serripes
that exhibits more robust and granular spines).
Redescription.
Male (ICN-AO-1161).
FIGURE 12.
Rhaucus robustus
(ICN-AO-1161). Habitus: a–d, male, a. Dorsal view, b. Ventral view, c. Frontal view, d. Lateral view. e. Female, lateral view. Scale bars = 1 mm.
Measurements:
CL=2.3, CW=5, AL=4, AW=5.6, BaCh=1, FeL III=5.5, FeL IV=7.5, TiL III=3.7, TiL IV=5. Intraespecific variation of body and appendages measurements in
Table 1
.
Dorsum
(
Figs 12a, 12c
,
13a–b
,
18d
): Dorsal scutum
alpha
type
, weakly granulate (
Fig. 12a
), with blots that resemble a reticle and reach the sides of ocularium and extend toscutal area III (
Figs 12a
,
18d
). Abdominal scutum widest at level of groove II; areas I–II mostly smooth, III–IV with some granules. Carapace with some granules on the anterior region (
Fig. 12a
). Ocularium low without median depression, armed with a row of granules (
Figs 12c– e
,
13a
). Lateral margins of DS smooth on the medial region (
Figs 13a–b
). Mesotergum delimited, divided into four areas: area I with a pair of short paramedian tubercles; area II with a pair of tiny tubercles; area III with a pair of paramedian, domed/mammilliform, coarsely granulated tubercles; area IV with a pair of small paramedian tubercles (
Figs 12c
,
13a–b
). Posterior border of scutum sub-straight and with a row of tubercles. Free tergites I–III with a row of tubercles (
Figs 13a–b
).
FIGURE 13.
Rhaucus robustus
(ICN-AO-1161). Male: a. Dorsal view, b. Lateral view, c. Tarsus I–IV, d. Leg III: dorsal, ventral and retrolateral view, e. Leg IV: dorsal, ventral and retrolateral view. Scale bars = 1 mm.
FIGURE 14.
Rhaucus robustus
SEM (ICN-AO-1161). Male: a–c, pedipalp: a. Ectal view, b. Mesal view, c. Tarsus. d–f, chelicera, d. Basichelicerite, dorso-mesal view, e. Dorso-ectal view, f. Fingers, ectal view. g–j, penis: g. Lateral view, h. Dorsal view, i. Ventral view, j. Stylus, apical view.
Venter
(
Figs 12b
): Stigmatic area with a few granules. Stigmata large, oval and transverse. Coxa I with two parallel rows of fused tubercles increasing size distally and with an anterior smooth space for pedipalps to rest; coxa II longer than coxa I, granulate; coxa III longer than I and II, granulate, with posterior margin sigmoid; coxa IV strongly backward, granulate. Genital operculum slightly granulate.
Pedipalps
(
Figs 14a–c
): Coxa dorsally and ventrally with one meso-distal granule. Trochanter with one dorsal short tubercle and one ventral tubercle; femur compressed, dorsally with a row of aligned setiferous tubercles of different sizes –not reaching the distal portion– and ventrally the same, slightly more separated from one another (the three/four basal-most setiferous tubercles fused). Patella distally depressed with some dorsal granules; tibia depressed, spoon-shaped, dorsally with some granules, with lateral borders tuberculate and some spiniferous tubercles at distal portion; inner surface slightly striated (
Fig. 14b
). Tarsus long, conical, with some dorsal granules and ventrally with two rows of thickened setae (
Fig. 14c
).
Chelicera
(
Figs 12
,
13a–b
,
14d–f
): Chelicera very swollen. Basichelicerite rectangular, with a few dispersed granules, the proximal border with some separated medial tubercles and the anterior border smooth, ectal face with one large proximal tubercle and a group of three distal tubercles, the larger one with three irregularly shaped tips, mesal face with some small granules (
Figs 14d–e
). Hand with one tubercle near the joint of the movable finger. Fixed finger slightly curved with the inner surface finely grooved. Movable finger with one conical, sub-basal tooth and with the inner surface at distal portion dentate (
Fig. 14f
).
Legs
(
Figs 13c–e
): Coxae I–II dorsally with one anterior and one posterior process; coxa III with one proximal retrolateral tubercle; coxa IV granulate, with a prominent anterolateral
clavi inguines
and with a posterolateral multicapitate apophysis (
Fig. 13a
). Trochanters I–IV dorsally with some minute granules and ventrally with some tubercles; trochanter III with some large tubercles at retrolateral face (
Fig. 13d
); trochanter IV more granulate than III, with groups of small tubercles visible in retrolateral ventral view (
Fig. 13e
). Femora I–IV sigmoid, very granular; III–IV, dorsally densely granulate, ventrally with two longitudinal rows of triangular tubercles along the entire length, and one retrolateral row of tubercles, increasing in size distally: in femur III the distal-most tubercles of the prolateral side are thinner and curved than those of femur IV (
Figs 13d–e
). Patellae I–IV dorsally very granulate, curved; patellae III–IV with large tubercles in the distal border ventrally very granulate and with one or two tubercles in the retrolateral vental side. Tibiae I–IV granulate; tibiae III–IV very curved, with two longitudinal rows of tubercles –of different sizes and shapes– very close together along the entire length (in tibia IV the distal tubercles are grouped and some are fused or paddle shaped) (
Figs 13d–e
). Metatarsus I–IV with one ventrodistal seta. Tarsi I–II with one smooth claw; tarsi III–IV with 2 subparallel smooth claws and tarsal process (
Fig. 13c
). Tarsal counts: 6(3)–6(3)/15(3)–14(3)/10–10/?–11. Intraspecific variations in Table 2.
Color (in ethanol): Carapace
Dark Reddish Brown
(44), reticulated in the ocularium. Blots in carapace
Brilliant Greenish Yellow
(98). Pedipalps, coxae I–IV, free tergites and chelicerae
Strong Reddish Brown
(40). Trochanters I–IV and legs I–II
Strong Yellowish Brown
(74). Legs III–IV
Strong Reddish Brown
(40).
Male genitalia
(
Figs
14g
–j
): VP of penis subrectangular with slightly concave distal border; VP with two lateral, elongated, dense patches of
type
4 microsetae, separated by a longitudinal space in between (
Fig.
14i
). VP with two apical MS C curved and laterally inserted; two MS D, the most distal large and straight, following the same lateral row as MS C, and the other smaller, inserted dorso-laterally on the middle third of VP (
Figs
14g
–h
); two MS A straight and laterally inserted, near D2 (
Fig.
14g
); two small MS E volcano-shaped on the ventral face; one small MS B volcano-shaped inserted laterally at the base of the VP (
Fig.
14i
). Glans mostly smooth; stylus long, wattle barbels long (
Fig. 14j
), finger-like process acuminated, enlarged (
Fig.
14g
).
Female.
Similar to male, but differs by having carapace at areas I–IV level more globose; anterior part of carapace narrower and coda divergent; tubercles of all scutal areas shorter; legs III–IV thinner than male; tubercles in ventral rows of legs III–IV smaller; chelicerae not hyperthelic (
Figs 12d–e
).
Other
material examined.
3 specimens
(
1 male
,
2 females
) in 3 lots.
COLOMBIA
:
Boyacá Department
:
Tipacoque
,
1♂
(ICN-AO-1161),
Vereda La Calera
[
06°23'N
72°43'W
],
2850 m
,
2.ii.2013
,
N. Beltran
leg
.
Santander Department
:
Cerrito
,
2♀
(IAvH-3000166/IAvH-I-12),
Vereda El Mortiño
,
Parada El Almorzadero
[
6°19'N
72°33'W
] (and not
07°56'N
72°45'W
as in the original label),
3585 m
,
25.ii.1999
, E.
González
&
A. Pulido
leg.
Examined by photograph:
1♂
1♀
(
CBUP-I
),
Santander Department
:
Carcasí
[
6°37'N
72°37'W
],
2900 m
, under rocks,
C. Ríos-Malaver
leg.
; Guaca, 1♂ [6.914077 -72.756683],
3200 m
, J. Uribe leg.