Distribution and Natural History of Mexican Species of Brachypelma and Brachypelmides (Theraphosidae, Theraphosinae) with Morphological Evidence for Their Synonymy

5 Pages·1999·4.5 MB·English

by  A Locht

1999. The Journal of Arachnology 27:196-200
DISTRIBUTION AND NATURAL HISTORY OF MEXICAN
SPECIES OF BRACHYPELMA AND BRACHYPELMIDES
(THERAPHOSIDAE, THERAPHOSINAE) WITH
MORPHOLOGICAL EVIDENCE FOR THEIR SYNONYMY
A. Locht, M. Yanez and I. Vazquez: Laboratorio de Acarologia “Anita Hoffmann,”
Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Coyoacan 04510,
D.E, Mexico
ABSTRACT. This comparisionofBrachypelmides andBrachypelma species isbasedonnewlycollected
spiders and more than 100 specimens from five museum collections. The results show that there are six
endemic species ofBrachypelma in western Mexico {B. auratum, B. baumgarteni, B. boehmei, B. emilia,
B. pallidum, B. smithi), presenting a gap in their distribution only where Brachypelmides klaasi is found.
Brachypelma vagans is distributed along both coasts ofMexico and Brachypelmides ruhnaui is found in
the central part ofMexico. Notes on natural history, a morphological comparison of27 characters ofthese
genera, and a discussion of the generic affinities are included.
RESUMEN. De junio de 1997 a Octubre de 1998 se hizo un estudio comparativo de Brachypelmides
y de las especies de Brachypelma. Se revisaron especimenes de ambos generos obtenidos en el campo
recientemente y mas de 100 especimenes de cinco diferentes colecciones para realizar este estudio. Los
resultados muestran que hay seis especies endemicas al Pacifico mexicano de Brachypelma {B. auratum,
B. baumgarteni, B. boehmei, B. emillia, B. pallidum, B. smithi), presentando una distribucion continua a
lo largo de la costa del Pacifico, siendo interrumpidaporla distribucion de B. klaasi. Brachypelma vagans
sedistribuye en ambas costas yBrachypelmides ruhnauienelcentrodelpais. Seincluyennotasdehistoria
natural, una comparacion morfologica de 27 caracteristicas de estos generos y una discusion de las afin-
idades genericas.
The subfamily Theraphosinae is a speciose pelma species, B. emilia, that is endemic to
group from the New World, representing some the Pacific coast of Mexico. Since then, an-
of the most beautiful species of the family other five species have been described that are
Theraphosidae (Perez-Miles 1992; Schmidt endemic to this area {B. auratum, B. baum-
1993; Smith 1993; Perez-Miles et al. 1996). garteni, B. boehmei, B. pallidum, B. smithi)
The genus Brachypelma can be found from (Schmidt 1992; Smith 1993; Schmidt & Klaas
Mexico to Costa Rica (Valerrio 1980; Smith 1994; F.O.P Cambridge 1897). Brachypelma
1994). The species from the west coast of vagans Ausserer 1875 inhabits the same area
Mexico are particularly docile and colorful. but populations also exist along the Gulf of
These traits have led to their being collected Mexico down to Costa Rica. Brachypelma ep-
in large numbers for the pet trade. The de- icureanum (Chamberlin) 1925 is found only
struction of the natural habitat and the high in the Yucatan peninsula (Smith 1994).
mortality before sexual maturity (99%) (Baerg Schmidt & Krause (1994) described a new
1958) are two factors that affect the popula- species of Theraphosinae from the west coast
tions of these species, and combined with the of Mexico. Although this tarantula is very
illegal trade that normally involves the capture similar to those of Brachypelma, they argued
ofpreadult and adult tarantulas, can cause the that it should be placed in a new genus be-
extinction of these tarantulas. To regulate this cause it has a pad of plumose hairs on the
trade and prevent their endangerment, all the femur IV, the males present a sharp tapered
species of this genus have been listed in ap- embolus, and the females have a bipartite and
pendix II of CITES. wide spermatheca. The species was named
In 1856 White described the first Brachy- Brachypelmides klaasi. However, in the same
196
LOCHT ET AL.—NOTES ON BRACHYPELMA AND BRACHYPELMIDES 197
—
Figure 1. Distribution ofthe species ofBrachypelma and Brachypelmides in Mexico.
year Smith (1994), after examining the types, era. All collection data were recorded. No
concluded that B. klaasi belongs to the Bra- types were studied.
chypelma group, being only “its mostextreme Fifteen field trips were made to the west
form.” PereZ“Miles et al. (1996) made a sys- coast of Mexico from June 1997 to October
tematic revision and a cladistic analysis of 1998, and two more to the east coast in this
Theraphosinae, but they did not include Bra- same period. Ecological and geographical data
chypelmides in their analysis. Schmidt (1997) were taken, and the specimens were brought
described another new Brachypelmides spe- to the lab in Mexico City Laboratorio de
cies from the central region of Mexico, B. Acarologia “Anita Hoffmann.” Live speci-
ruhnaui, adding support to his idea that Bra- mens were put in controlled environment
chypelmides is a valid genus. chambers where their reproductive behavior
Our research ofthe species ofBrachypelma was studied (Yanez & Locht 1998). The mor-
and Brachypelmides brings more data to the phological characteristics of preserved speci-
question of the distinctness ofthese genera. It mens were analyzed in more detail, and the
also adds information on the natural history figures presented in this work were made from
and distribution data for these tarantulas. them. The specific collecting data for speci-
mens are not given, but a range map (Fig. 1)
METHODS
is included because we wish to protect the
The collections visited and used for the species from the illegal pet trade.
study included the following: the American
DISTRIBUTION
Museum of National History, the California
Academy of Sciences, Field Museum, Insti- Brachypelma is a common genus in the Pa-
tuto de Biologia, UNAM, in Mexico City cific and Gulf coasts of Mexico; the distribu-
(IBUNAM), and Estacion de Biologia, Cha- tion of species along the west coast is only
mela, in Jalisco. The five collections have to- interrupted by that of Brachypelmides klaasi,
gether more than 100 specimens of both gen- and in the central part by B. ruhaui (Fig. 1).
198 THE JOURNAL OF ARACHNOLOGY
species. The following data are field and lab-
oratory observations of the—two genera.
Burrow Construction. All the species
studied live in burrows found in the soil,
sometimes near rocks or trees, sometimes in
open field, but not far from vegetation. They
have only one entrance, a little wider than the
tarantula’s body size. When the tarantula is
active this entrance is clean and some silk can
be found. When the tarantula is inactive for a
long period the entrance is covered by soil and
A
leaves that the tarantula gathers with silk.
horizontal tunnel leading from the entrance is
normally three times larger than the tarantula.
This tunnel is followed by a chamber 2-3
times biggerthan the tarantula, where itmolts,
then a vertical tunnel shorter than the first one
that ends with a larger chamber, where the ta-
rantula rests and eats its prey. The mature fe-
male’s burrow in the reproductive season has
more silk in t—he entrance than usual.
Phenology. The tarantulas ofthese genera
are long-lived. The males can reach maturity
in 7-8 years, living only one year or less after
the last molt, while the females reach maturity
in 9-10 years, then live 10 more years. Com-
pared to other genera of the same subfamily,
they grow slowly (Smith 1994). In all species
— pre-adults and adults molt at the end of the
Figures 2-5. Frontal view of the right bulbs of dry season (June-November), males begin to
four species of tarantulas. 2. Brachypelma vagans wander in search of the females after they
right bulb; 3. Brachypelmides ruhnaui right bulb; molt, and the females lay an egg-sac before
4. Brachypelmides klaasi right bulb; 5. Brachypel- they molt. The egg-sac hatches 3-4 weeks be-
ma smithi right bulb.
fore the rainy season begins. Males ofall west
coast species wander during daylight, partic-
Brachypelma smithi has a disjunct distribu- ularly in the morning and in the evening,
tion, and B. vagans has the largest distribu- while the species of the east coast and center
tion. The only distribution that we could not wander at night. —
verify was that for B. epicureanum, which is Color pattern. Brachypelma klaasi col-
endemic to the Yucatan peninsula (Smith oration is very similar to that of the six spe-
1994). Field and collection data corresponded cies of Brachypelma that are endemic to the
in all other species. The distributions given by west coast. Brachypelma boehmei is the more
Smith (1994) did not correspond with ours in similar, having, like B. klaasi, black tarsi, or-
all cases, but they are generally not contradic- ange-yellow metatarsi, tibias and patellas,
tory. The other collecting data found in the black femora and coxae and orange-yellow
descriptions of the species coincide with the hairs on the opistosoma. It differs only in the
areas shown in Fig. 1 (White 1856; Ausserer carapace, which is yellow-orange in B. boeh-
1875, F.O.P. -Cambridge 1897; Schmidt 1992; mei and black in B. klaasi. Brachypelma
Schmidt 1993; Smith 1993; Schmidt & Klaas baumgarteni is also very similar, but it has a
1994; Schmidt 1997; Locht et al. 1998). more reddish patella. Brachypelmides ruhnaui
has the same coloration of B. vagans and B.
NATURAL HISTORY
epicureanum, differing only in having a yel-
The natural history ofBrachypelma species low carapace, rather than black as in the oth-
differs little if at all from the Brachypelmides ers. Although all the species have striking col-
LOCHT ET AL.—NOTES ON BRACHYPELMA AND BRACHYPELMIDES 199
—
Figures 6-9. Dorsal view of the cleared spermathecae of four species of tarantulas. 6. Brachypelma
auratum; 7. Brachypelma emilia; 8. Brachypelma vagans; 9. Brachypelmides klaasi.
oration, they are in fact cryptic within their pelmides has only one character that distin-
native habitat, making it very difficult to see guishes it from Brachypelma. This character
the tarantulas, even when they are out oftheir is the presence of a spermatheca with two re-
burrows in daylight. ceptacles separated or only partly fused. How-
DISCUSSION OF GENERIC AFFINITIES ever, in the genus Brachypelma some sper-
mathecae are widely fused {B. smithi, B.
The data on distribution and natural history auratum), some semi-divided {B. emilia, B.
provide support for the hypothesis that these baumgarteni, B. boehmei) and some only part-
species are closely related. In the cladistic ly fused {B. vagans) (Figs. 6-9).
analysis of Perez-Miles et al. (1996) 27 char- The palpal bulb morphology, principally in
acters were used. The characters in Brachy-
the embolus, is distinctive in all the species.
pelma are: palpal bulb with concave/convex
Brachypelmides klaasi and B. runhaui have
apical region; relative width of sclerites II + the embolus sharper and more tapered, but do
III (measured at 20% of its length, from the
not differ in the characteristics above listed
apex) wide (equal to or more than 10% ofthe
from Brachypelma. The palpal bulb of B.
length of the bulb); lack of the paraembolic
and digitiform apophysis; presence of smooth klaasi, being wider, is more similar to that of
Brachypelma species from the Pacific coast.
peripheric and supernumerary keels; and a
large subtegulum. The male’s tibia lacks a lat- The bulb of B. ruhnaui bulb is more similar
to the thinner bulb of B. vagans (Figs. 2-5).
eral process in the retrolateral region, a retro-
The diagnosis ofBrachypelma (Perez-Miles
lateral cluster of spines and a prolateral pro-
cleascsk.sItahabsastawloptriboicaelssapoapnhdyseiss;nmoettasttarrosnugslyI hetavael.re1t9ro9l6a)tersahloswcsoptuhlaatetohnisfegemnuursIVdoWese enxo-t
curved, its flexion provided by the outer side amined the two species of Brachypelmides,
of the tibial spurs. Spermatheca widely fused and we found no scopulae on the retrolateral
and with unilobulated receptacles; femur III face ofthe femur IV. We found plumose hairs
and tibia IV not incrassate; femur IV without in both genera. The patch of plumose hairs
a retrolateral scopula; urticating hairs type I mentioned for B. klaasi as a new character
and III present, type IV are absent. Trochan- separating these genera is not mentioned in B.
teral and coxal stridulatory hairs absent; coxal ruhnaui (Schmidt & Krause 1994; Schmidt
spinules are absent; numerous labial cusps 1997); and we could not find it in this species,
present; fovea without a spherical process. so this would only be a characteristic that dis-
We compared all 27 characters among the tinguishes B. klaasi. Another characteristic
10 species analyzed and found that Brachy- that Brachypelmides klaasi shares with the
200 THE JOURNAL OF ARACHNOLOGY
species ofBrachypelma is that it is very pop- Perez-Miles, E, S.M. Lucas, PI. da Silva, Jr. & R.
ular in the pet trade, but Brachypelmides is Bertani. 1996. Systematic revision and cladistic
not listed in appendix II of CITES. analysis of Theraphosinae (Araneae, Theraphos-
Although, the distribution and morphology idae). Mygalomorph, 1:33-68.
Raven, R.J. 1985. The spider infraorder Mygalo-
likely provide strong evidence that Brachy-
morphae (Araneae): Cladistics and systematics.
pelmides and Brachypelma are one and the
Bull. American Mus. Nat. Hist., 182:1-180.
same genus, a revision of all the species of Schmidt, G. 1992. Brachypelma auratum sp. n.,
these genera, notjust those from Mexico, us- die so genannte HochlandformvonBrachypelma
ing cladistic analysis will provide a strong ba- smithi (Araneida: Theraphosidae: Theraphosi-
sis for placing the two species of Brachypel- nae). Arach. Anz. 3(8):9-14.
mides in the genus Brachypelma. Schmidt, G. 1993. Vogelspinnen. Landbuch Ver-
ACKNOWLEDGMENTS lag. Miinchen. 146 pp.
&
Schmidt, G. P. Klaas. 1994. Eine neue Brachy-
We thank Dr. Norman I. Platnick, American pc/ma-Spezies aus Mexico Brachypelma boeh-
Museum of Natural History; Dr. Charles E. mei sp. n. (Araneida: Theraphosidae: Theraphos-
Griswold, California Academy of Sciences; inae). Arach. Mag., 7(2):7-15.
and Dr. Tila M. Perez, Laboratorio de Acar- Schmidt, G. & R.H. Krause. 1994. Eine neue Vo-
UNAM gelspinnen-Spezies aus Mexico, Brachypelmides
ologia, Institute de Biologia, for giv-
klaasi sp. n. (Araneida, Theraphosidae, Thera-
ing us the facilities to study the collections of phosinae). Stu. Neotrop. Fauna and Environ.,
tarantulas ofwhich they are in charge. We are 29(1):7-10.
grateful to Graham Floater for helping with Schmidt, G. 1997. zweiicBrachypelmides-Axi
the English translation. We are specially aus Mexico: Brachypelmides ruhnaui n. sp.
thankful to Dr. Anita Hoffmann for encour- (Arachnida: Araneae: Theraphosidae:Theraphos-
aging us to write this paper. Thanks to DGA- inae). Entomol. Z. (Essen), 107(5):205-208.
PA, UNAM for the financial support grant IN- Smith, A. 1993. A New Mygalomorph Spider
217397. From Mexico {Brachypelma, Theraphosidae,
Arachnida) Brachypelma baumgarteni n. sp.
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