Revision of the Peruvian tarantula Homoeomma peruvianum (Chamberlin, 1916): description of a new genus with eleven new species and insights to the evolution of montane tarantulas (Araneae: Theraphosidae: Theraphosinae)
Author
Radan Kaderka
Roztoky u Prahy, Czech Republic
radan.kaderka@seznam.cz
Author
Tim Lüddecke
Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany; cLOEWE Centre for Translational Biodiversity Genomics TBG, Frankfurt am Main, Germany
Author
Milan Řezáč
Crop Research Institute, Prague 6, Czech Republic
Author
Veronika Řezáčová
Crop Research Institute, Prague 6, Czech Republic
Author
Martin Hüsser
Rudolfstetten, Switzerland
text
Journal of Natural History
2023
2023-11-30
57
41 - 44
1710
1824
journal article
10.1080/00222933.2023.2265621
1464-5262
Genus
Homoeomma
Ausserer, 1871
Agathostola
Simon, 1892
, type species
Agathostola strabo
Simon, 1892
, male
holotype
from
Colombia
in MNHP (
Gerschman de Pikelin and Schiapelli, 1972
).
Calopelma
Chamberlin, 1917
, type species
Calopelma brasilianum
Chamberlin, 1917
, male
holotype
from
Brazil
,
Rio de Janeiro
, in MCZ (
Gerschman de Pikelin and Schiapelli, 1972
).
Cyclothoracoides
Strand, 1929
,
type
species
Cyclothoracoides cyclothorax
(Mello-Leitão, 1923)
, male from
Brazil
(
Lucas and Indicatti, 2015
).
Butantania
Mello-Leitão, 1935
,
type
species
Butantania hirsuta
Mello-Leitão, 1935
, male from
Brazil
,
State
of
Rio de Janeiro
,
Itatyaia
, in IBSP (
Pérez-Miles
et al
., 1996
).
Type
species
Homoeomma stradlingi
O.
Pickard-Cambridge, 1881
, female
holotype
from
Bahía
,
Brazil
, and
two male
paratypes
from
Brazil
(in NHM, not examined).
Diagnosis
Homoeomma
differs from all other
Theraphosinae
genera in the presence of subparallel PS and PI keel on embolus and digitiform basal apophysis (TA) on tegulum of male palpal bulb, in combination with abdominal urticating setae of
type
III+IV. Males of some species have a retrolateral basal nodule in metatarsus I, more or less developed. This structure is similar to that found in
Plesiopelma
Pocock, 1901
(
Pérez-Miles
et al
., 1996
). Two unequal subapical apophyses are present on male tibia I, metatarsus I, when flexed touches both of them. Labium with numerous cuspules in apical third (
Gerschman de Pikelin and Schiapelli, 1973
).
Distribution
Brazil
,
Argentina
,
Uruguay
,
Chile
.
Remarks
The genus
Homoeomma
Ausserer, 1871
was established to accommodate
Mygale versicolor
C.L.
Koch, 1842
, male and female from
Rio de Janeiro
,
Brazil
, collected by the Novara Expedition (
Ausserer, 1871
;
Gerschman de Pikelin and Schiapelli, 1972
).
Ausserer (1871)
diagnosed
Homoeomma
by the almost congruent size of AME and PME. In a brief description he emphasised the following characters associated with this genus: cephalothorax is slightly longer than wide, moderately elevated, with deep and procurved thoracic fovea, eye tubercle is high, widely oval, lateral eyes are of the largest size, and AME and PME of almost congruent size, the distance between AME is greater than their diameter, labium is quadrangular and elevated, legs spinose, leg formula 4, 1, 2, 3, scopulae are thick but narrow, tibia IV is shorter than metatarsus IV, PLS as long as tarsus I (
Ausserer, 1871
).
As
Mygale versicolor
C.L.
Koch, 1842
was a different species to
Mygale versicolor
Walckenaer, 1837
from
Guadeloupe
and
Martinique
(today̾s
Caribena versicolor
(Walckenaer, 1837))
, and because the name was thus preoccupied, O.
Pickard-Cambridge (1881)
described
Homoeomma stradlingi
O.
Pickard-Cambridge, 1881
based on the female
holotype
from
Bahía
,
Brazil
(type in NHM), and transferred
two adult
males of
M. versicolor
C.L.
Koch, 1842
from his private collection to
H. stradlingi
(O.
Pickard-Cambridge, 1881
)
. He believed that the mentioned female and both males of
M. versicolor
C.L.
Koch, 1842
from
Brazil
belonged to the same species. However, in the bulb, which was figured by
Pickard-Cambridge (1881)
, a digitiform basal apophysis on tegulum is missing which casts doubts on the placement of this species in
Homoeomma
.
Pickard-Cambridge (1881)
also synonymised
Mygale versicolor
C.L.
Koch, 1842
from
Rio de Janeiro
,
Brazil
, with
Homoeomma stradlingi
from
Bahía
,
Brazil
(
Pickard-Cambridge, 1881
), albeit it is unclear whether the type specimens of the two species were compared. It is presumable that
H. stradlingi
may represent a complex of species.
Later, although the male
holotype
of
H. stradlingi
had never been described or designated by
Pickard-Cambridge (1881)
,
Gerschman de Pikelin and Schiapelli (1972)
examined male
holotype
no. 42–43 from NHM, perhaps one of the
two males
from Pickard-Cambridge̾s private collection, but the jar contained in total
three males
from
Bahía
,
Brazil
.
Gerschman de Pikelin and Schiapelli (1972)
figured male and female genitalia of known
Homoeomma
spp.
for the first time, including male palpal bulb, palpal tibia and tibia I of
H. stradlingi
, and modified the generic diagnosis.
Pérez-Miles
et al
. (1996)
also examined the male
type
of
H. stradlingi
from NHM. He diagnosed
Homoeomma
by the presence of a digitiform basal apophysis in male palpal bulbs. Some species may have a retrolateral basal nodule on metatarsi I, similar to that found in
Plesiopelma
(
Pérez-Miles
et al
., 1996
)
.
Bertani (2000)
examined
H.
stradlingi
from
Téresopolis
,
Rio de Janeiro
,
Brazil
(
IBSP 4683
), and
H.
montanum
from
Paranapiacaba
,
São Paulo
,
Brazil
(
IBSP 7045
), and pointed out the presence of tegular apophysis and two almost parallel prolateral keels in male palpal bulb morphology.
The
apical keel is mentioned as absent in palpal bulb (
Bertani, 2000
)
.
Montenegro
, Aguilera and Casanueva (2018)
published a new diagnosis for
Homoeomma
: males have bulbs with tegular apophysis, the embolus shows an angle of 90° to 135° in relation to the axis of the bulb (except for
Tmesiphantes
), and the metatarsus when flexed touches both branches of tibial apophysis. Females differ from other theraphosids in the shape of spermathecae, without constriction in the apex or granules (
Montenegro
, Aguilera and Casanueva, 2018
).
Revision of the
type
specimens of
Homoeomma stradlingi
O.
Pickard-Cambridge, 1881
,
Mygale nigrum
Walckenaer, 1837
and
Mygale versicolor
C.L.
Koch, 1842
is needed to stabilise the generic
type
of the genus
Homoeomma
.