The third South American species of the genus Pectenobunus Roewer, with a new synonymy for the genus (Opiliones, Eupnoi, Sclerosomatidae, Gagrellinae)
Author
Tourinho-Davis, Ana Lúcia
text
Zootaxa
2004
2004-01-12
405
1
1
16
https://biotaxa.org/Zootaxa/article/view/zootaxa.405.1.1
journal article
4908
10.11646/zootaxa.405.1.1
b1ce99ec-afa5-4d54-aa32-ef12a643975b
11755334
5027782
2B86BEE1-44B6-4483-867A-DE1D7ABA31B6
Pectenobunus
Roewer, 1910
Opilio
[part]:
Canestrini 1888: 105–106
.
Pectenobunus
Roewer 1910: 157
;
1923: 1063
;
MelloLeitão 1932: 18
;
1938: 321
;
Roewer 1953: 185
;
Ringuelet 1954: 297–298
;
1959: 16
;
Capocasale 1967: 28
;
Cokendolpher & Hunt 1993: 1–2
;
Crawford 1992: 38
.
Caiza
Roewer 1925: 32
;
MelloLeitão 1932: 18
;
1938: 322
;
Roewer 1953: 185
,
Ringuelet 1954: 287–288
;
1959: 217
;
Crawford 1992: 14
. [
type
species is
Caiza colliculosa
Roewer, 1925
, by monotypy].
syn. nov.
Acropiliops
MelloLeitão 1933: 99
;
1938: 319
;
Crawford 1992: 11
. Synonymy established by
Cokendolpher & Hunt 1993
.
Type
species.
Pectenobunus paraguayensis
(
Canestrini, 1888
)
by original designation.
Included species.
P. colliculosus
(Roewer)
,
P. paraguayensis
(Canestrini)
and
P. ruricola
(MelloLeitão)
.
Former diagnoses (each character is numbered and referred to in a subsequent paragraph):
Roewer, 1923
—
Eye mound as wide as long (1.1), with one to five spines with three points each (1.2). Dorsum unarmed (2); femur II approximately two times longer than the body, femora I and III approximately as long as the body; femur II with 2 nodules, I, III and IV without nodules (4). Coxae armed with relatively short threepointed denticles (6), legs relatively short (9) and thin.
Roewer, 1953
—
Eye mound with two rows of four to five spines (1.2), abdominal scute evenly curved, unarmed (2); Femur with 0/2/0/0 nodules (3); femora I and III shorter than body (4).
Ringuelet, 1954
—
Eye mound with two rows of high spines divergent and variable from three to six, each one with two to four small apical points (1.2). Dorsum unarmed (2). Nodules 0/2/0/0, femur II may have less than two or none: I/2, I/I, I/0 or 0/0 (3). Femora relatively short, I to III about equal, II between 1.5 to 2.3 times, IV around 1.5 the length of the body: a little shorter in females (4). Tegument with reticulations forming alveoli (5). Coxae armed with sharp tripointed denticles (6).
Ringuelet, 1959
—
Eye mound armed with two rows of high divergent spines ending in 2, 3 or 4 small apical points (1.2). Dorsum unarmed (2). Femora I and III from a little shorter to a little longer than the body, femur II from 1.5 to two body length, formula: (
♂
) 0.9 to 1.3/1.5 to 2.3/0.9 to1.3/13 to 1.9, (
♀
) 0.8 to 1.1/1.5 to 1.8/0.8 to 1.0/1.2 to 1.4 (4). Tegument with reticulations forming alveoli (5). Coxae: teeth with three sharp points (6).
Cokendolpher & Hunt, 1993
—
Eye mound with four to seven tubercles (each tipped with three to four spines) (1b), presence of two pseudoarticular nodules in femora II (nodules lacking in other femora) (3), femora I equal to or slightly longer (up to 1.5 times) than body (4), abdomen without median spines or tubercles (2), male palpal tarsi lacking ventral rows of denticles (7), penis with a small narrow alate portion (8).
Comments on the characters used in the former diagnoses:
(1.1) (6)
These states and
(7) (8)
characters are widespread in Neotropical
Gagrellinae
and of limited use for a diagnosis.
(1.2)
Spines and tubercles are also found in species of
Holmbergiana
,
Guaranobunus
and
Parageaya
. In
Holmbergiana
they are as shorter as in
P. ruricola
, and possess three or more small points each, in
Guaranobunus
they have the same number, shape and length as
P. colliculosus
and
P. paraguayensis
and in
Parageaya
the eye mound varies from unarmed to armed.
(2)
This character is applicable to all Neotropical species of
Gagrellinae
, however it does not match the species of
Pectenobunus
.
P. colliculosus
,
P. paraguayensis
and
P. ruricola
have these processes or tubercles in different sizes in abdominal scute (
Figs. 7, 8, 9
). They are very subtle in
P. ruricola
, almost imperceptible (
Fig. 9
), while much more developed in
P. colliculosus
(
Fig. 7
) and intermediate in
P. paraguayensis
(
Fig. 8
). One projection in the frontal margin of the abdominal scute is found in two species of
Holmbergiana
, the only species of
Guaranobunus
and the
type
species of
Parageaya
–
Parageaya ciliata
. The presence of the armature in the abdominal scute supports the tribe
Gagrelleae
and it may be a convergence in
Pectenobunus
,
Holmbergiana
,
Guaranobunus
and
Parageaya ciliata
.
The tribes
Gagrelleae
and
Zalepteae
were established by Roewer (1954, 1955), this dichotomy was based upon two states of the same external character, presence or absence of spines on the abdominal scute. Following the concept of Roewer the New World
Gagrellinae
were recognized mainly by the absence of spines on abdominal scute, tribe
Zalepteae
, and most of the Old World species (tribe
Gagrelleae
) by the presence of one or more spines. It seems that Roewer did not consider in his analysis the well developed spines present on the abdominal scute of his
Caiza colliculosa
, much as he did with the protuberances shown in species of
Pectenobunus
,
Holmbergiana
and
Parageaya
. Martens (1987) presented several illustrations of Old World species without any spine or protuberance on the ventral surface of the body. As what happens with most of the New World
Gagrellinae
the systematics of Old World is as confused, if not more chaotic than it is in their American counterparts. Since Roewer’s publications the groups of species placed together in Old World genera have never been subject of systematic revisions. However a large number of new taxa have been described in the last years according with the Roewerian system (
Suzuki 1963
,
1969
,
1970
,
1977a
,
1977b
). The only work presenting detailed descriptions for both external and genital mophology, and discussion of the genital patterns among the Old World species (
Gagrelleae
included) were done by Martens (1987) for the Nepalese species. However for his work Martens did not revise the genus
Gagrella
(the
type
genus of the subfamily), gave descriptions or discussed the characters of the penis shared by the species within this genus. Martens studied and described a large number of species of
Gagrella
, although examining the illustrations given in the paper it can be noted that the species did not share external or genital similarities suggesting a closer relationship among them, or supporting this group as monophyletic. On the opposite there is high variety of size and shape in the stylus, glans (including the angle formed by shaftglans), winglets, and shaft among the
Gagrella
species
studied for the work. Knowing if the two tribes
Gagrelleae
and Zaleptinae make sense for the modern concept and study in
Opiliones
will depend upon systematic revisions refining descriptions, illustrations, studying genitalia and external morphology of Old World
Gagrellinae
in a deeper level.
The western South American species of
Gagrellinae
have some similarities with the Old World species of the same subfamily, not presently shared with the Tropical South American species. Cokendolpher (1984) commented about the closer affinities among the only one Colombian (Punta di Carmen) species of
Carmenia
and the eastern Asian species, including some characters present in species of other subfamilies such as Sclesomatinae. Species of
Pectenobunus
also share a set of characters with Asian
Gagrellinae
, as the presence of spines or protuberances on the abdominal scute (
Figs. 7, 8
) and the very small sclerites present on the lateral sides of the opisthosoma (
Figs. 3, 4
).
(3)
This character may be variable even in the same species, and the same number appears in several species of
Holmbergiana
, variation should be included in the statement of number.
(4)
This character varies in the three species thus it is ineffective for the generic diagnosis (
Table 1
).
(5) (9)
These states match the genus, but they are also present in all species attributed to
Guaranobunus
,
Holmbergiana
and
Parageaya
.
TABLE 1.
Measurements of the body and femora of the three species attributed to
Pectenobunus
Roewer, 1910
.
| Species (males) |
Measurements (mm) |
| Body |
Femur I |
Femur II |
Femur III |
Femur IV |
|
P. colliculosus
|
4.6 |
3.5 |
7.2 |
3.9 |
4.0 |
|
P. paraguayensis
|
4.0 |
4.0 |
7.0 |
4.0 |
5.5 |
|
P. ruricola
|
2.6 |
4.9 |
8.9 |
4.7 |
6.2 |
Emended Diagnosis.
Eye mound armed with two rows of three to seven spines or shorter tubercles with three to four apical points each (
Figs. 7a–9a
; fig.
1 in
Cokendolpher & Hunt 1993
). Abdominal scute with one subtle protuberance, three small projections or three blunt process sharply marked in both males and females (
Figs. 7–9
). Femoral formula: 0/02/0/0. Winglets of penis narrow (longer than wide), distal portion straighter without projections. Outline of winglets not very sinuous or undulated (
Figs. 10, 12, 14– 15
; fig.
4 in
Cokendolpher & Hunt 1993
). Shaft forming acute angle (less than 25º) with the glans (
Figs. 11, 13
; fig.
5 in
Cokendolpher & Hunt 1993
). Transverse section of glans elliptical. Stylus short (20% the length of glans) (
Figs. 14–15
; fig.
4 in
Cokendolpher & Hunt 1993
).
Distribution.
Southern
Brazil
,
Bolivia
,
Paraguay
,
Uruguay
and Northeastern
Argentina
(
Fig. 16
).