X


Włoski Abdominal

Włoski Abdominal, Ptaszniki - Pdfy
[ Pobierz całość w formacie PDF ]
2002. The Journal of Arachnology 30:316–320
THE OCCURRENCE OF ABDOMINAL URTICATING HAIRS
DURING DEVELOPMENT IN THERAPHOSINAE (ARANEAE,
THERAPHOSIDAE): PHYLOGENETIC IMPLICATIONS
Fernando P´rez-Miles
: Secci ´ n Entomolog´a, Facultad de Ciencias, Igu´ 4225,
11400 Montevideo, Uruguay. E-mail: myga@fcien.edu.uy
ABSTRACT.
The occurrence of abdominal urticating hair types throughout juvenile development is
studied in five Uruguayan theraphosid species of different genera. Adults of three of these species have
urticating hairs of Types III and IV while the other two species have Types III and I. Considering spider
size as an estimator of development, Type I or IV occurred early, in small juveniles, while Type III hairs
always occurred after the other types during development. The homology of urticating hairs and their use
in phylogenetic studies of Theraphosinae is discussed. Sexual dimorphism in the occurrence of urticating
hair types is analyzed and a hypothetical explanation is proposed.
RESUMEN.
La presencia de pelos urticantes abdominales a trav´s del desarrollo es estudiada en ju-
veniles de cinco especies de teraf ´ sidas uruguayas de g´neros diferentes. Los adultos de 3 de estas especies
presentan pelos urticantes tipo III y IV mientras que las otras dos presentan los tipos III y I. Considerando
el tama ˜ o como indicador del desarrollo los tipos I o IV aparecen tempranamente mientras que los pelos
tipo III ocurren siempre despu´s que los otros tipos, durante el desarrollo. Se discute la homolog´a de los
pelos urticantes y su uso en la filogenia de Theraphosinae. Se propone una explicaci ´ n para el dimorfismo
sexual encontrado en estos pelos para algunas especies de teraf ´ sidas.
Keywords:
Theraphosinae, urticating hairs, theraphosid ontogeny, theraphosid phylogeny
Abdominal urticating hairs of theraphosid
spiders were thoroughly described by Cooke
et al. (1972), and are only present in New
World subfamilies. These authors described
four morphological types of urticating hairs:
Type II found only in Aviculariinae and Types
I, III and IV present in Theraphosinae. Ar-
boreal Aviculariinae transfer the urticating
hairs by direct contact (Bertani & Marques
1996) while Theraphosinae release urticating
hairs by friction of the hind legs against the
abdomen, as a defensive behavior (Cooke et
al. 1972; P´rez-Miles & Prandi 1991; Bertani
& Marques 1996). Urticating hair types were
used by P´rez-Miles (1992, 2000) and P´rez-
Miles et al. (1996) for phylogenetic analysis
of the Theraphosinae. The co-occurrence of
Type III with Type IV or Type III with Type
I in the same individual caused the homology
of these to be questioned and consequently put
into question their use as a multistate char-
acter; for this reason they were coded as three
independent presence/absence characters by
these authors. Bertani & Guadanucci (1999)
found hairs of intermediate morphology be-
tween Type III and Type IV and between Type
III and Type I in adults. They proposed serial
homology and polarized Type III hairs as ple-
siomorphic. Sexual dimorphism in the occur-
rence of urticating hair types was reported by
Bertani (1997) for some theraphosid species
where males have Types I and III while fe-
males have only Type I. P´rez-Miles (2000)
also reported that
Iracema cabocla
P´rez-
Miles 2000 males have Types III and IV while
females only have Type IV.
This study tries to determine: 1. the order
of occurrence of urticating hairs during de-
velopment, and 2. if the sexual dimorphism is
caused by a loss of a hair type by females or
if it is gained by males during development.
Five species of Theraphosinae from Uruguay
were studied:
Acanthoscurria suina
Pocock
1903,
Eupalaestrus weijenberghi
(Thorell
1894),
Grammostola mollicoma
(Ausserer
1875),
Homoeomma uruguayense
(Mello-Lei-
t ˜o 1946) and
Plesiopelma longisternale
(Schiapelli & Gerschman 1942). Adults of the
two former species have Types I and III urti-
cating hairs while adults of last three species
have
Types
III
and
IV
(P´rez-Miles
et
al.
316
 P
´
REZ-MILES—URTICATING HAIRS OF THERAPHOSINAE
317
1996). The phylogeny of urticating hairs is
discussed in light of present results.
METHODS
Fifty-nine juvenile to adult specimens of
different sizes were examined and deposited
in the arachnological collection of Facultad de
Ciencias, Montevideo, Uruguay. These indi-
viduals belong to the following species:
A.
suina
(7 individuals),
E. weijenberghi
(8),
G.
mollicoma
(15),
H. uruguayense
(16), and
P.
longisternale
(13). Live juveniles were iden-
tified to species mainly using their chromatic
patterns, general morphology, ecological char-
acteristics and collection site. Although juve-
nile identification is usually difficult, my long
experience working on these taxa and the rel-
ative limited theraphosid fauna of Uruguay
helped in the recognition. If identification with
such methods failed, dissection of immature
spermathecae was attempted. When doubts
about identification still remained, specimens
were eliminated from the study.
Six fields on the patch of urticating hairs
(dorsal abdomen) were sampled as suggested
by Bertani (1997). Hairs were removed with
forceps and placed separately on microscope
slides for examination. When only one type of
hair was found in this first examination a gen-
eral sample of urticating hair patch was ex-
amined to confirm the first results. To estimate
spider size, carapace length (CL) was mea-
sured in mm with an ocular micrometer.
Figures 1–5.—Size (carapace length) and Types
of urticating hairs present in individuals of some
theraphosid species.1.
Acanthoscurria suina
.2.
Eu-
palaestrus weijenberghi
.3.
Grammostola mollico-
ma
.4.
Homoeomma uruguayense
.5.
Plesiopelma
longisternale
. (White bars indicate the presence of
Type III urticating hairs; black bars indicate the
presence of Types III
RESULTS
The presence of Types I and III urticating
hairs in adults of
A. suina
and
E. weijenberghi
is here confirmed as well as the presence of
Types III and IV in adults of
G. mollicoma
,
P. longisternale
and females of
H. urugua-
yense
. In all the species studied, urticating
hairs Types I or IV occur early in develop-
ment, from very small juveniles. Type III ur-
ticating hairs occurred later in the develop-
ment and after the occurrence of the other type
present (Figs. 1–5). The minimum size in
which Type III hairs occurred was in a rela-
tively wide range in all species: 6.0 mm in
H.
uruguayense
, 7.0 mm in
G. mollicoma
, 7.6
mm in
P. longisternale
, 9.3 mm in
E. weijen-
berghi
and 13.2 mm in
A. suina
. In these two
last species, in which adults have Types I and
III urticating hairs, Type III is acquired at
larger sizes than in the three former species
1
I in Figs. 1, 2 and the
presence of Types III
1
IV in Figs. 3–5).
having Types III and IV. The minimum size
of occurrence of Type III urticating hairs in
each
species
was not
correlated with adult
(male) size (r
0.05).
In
G. mollicoma
, one medium sized juve-
nile lacked Type III urticating hairs (Fig. 3);
a similar phenomenon was observed in three
large juveniles of
H. uruguayense
(Fig. 4).
One of these individuals of
H. uruguayense
(7.8 mm) was dissected and had immature
spermathecae.
In large individuals with Types I and III
urticating hairs present, hairs of intermediate
morphology were also found. However, in
large individuals with Types III and IV urti-
5
0.43,
P
,
 318
THE JOURNAL OF ARACHNOLOGY
cating hairs present, hairs of intermediate
morphology were not recognized.
At least some Type III hairs in individuals
which have Types I
1
III hairs showed some
differences from Type III hairs of individuals
having Types III
sexual dimorphism in adults: males have
Types III
1
IV while females have only Type
IV.
It also seems probable in species without
sexual dimorphism that juvenile females ac-
quire the Type III urticating hairs later than
males. This could explain the occurrence of
some large juveniles of
A. suina
and
G. mo-
llicoma
which lacked Type III urticating hairs.
The co-occurrence of different urticating
hair types forced P´rez-Miles et al. (1996) and
P´rez-Miles (1992, 2000) to code these types
as independent presence/absence characters,
since homology among them was not reliable
(these characters do not pass the conjuction
test). The presence of intermediate hairs be-
tween Types I and III and between III and IV
were found by Bertani & Guadanucci (1999).
Bertani & Guadanucci (1999) proposed serial
homology and considered Types I and IV as
derived from Type III. Although ontogenetic
precedence was seriously contradicted in cla-
distic analysis (Nelson 1978, 1985; De Quei-
roz 1985; Kluge 1985; Wheeler 1990), if ac-
cepted, present results would conflict with this
polarization. But if polarization is inverted an-
other conflict remains: Type III hairs could not
be derived from two different states (Type IV
and Type I). Another unexpected hypothesis
could be considered: that Type III hairs rep-
resent two different kinds of non-homologous
hairs masked by surface similarity, derived re-
spectively from Types I and IV. Presumably
ecological pressures on large spiders of the
New World are similar and this fact could ex-
plain the convergence to a Type III morphol-
ogy, probably due to their efficacy for defen-
sive purposes. This hypothesis could be
compatible with the homoplasy found for
Type III hairs in comparison with the more
congruent behavior of Types I and IV in the
cladograms of P´rez-Miles et al. (1996) and
P´rez-Miles (2000). Also the morphological
differences found between some Type III hairs
of species also having Type I with respect to
species also having Type IV, could support
this hypothesis, but further studies are neces-
sary
IV. These differences can
be summarized as follows: the proximal end
of Type III hairs has a broad axis; with high
magnification, this region showed reversed
flattened barbs (Fig. 6) in specimens having
Types I
1
III hairs. In specimens with Types
III
1
IV hairs, the proximal end of Type III
hairs did not have reversed barbs and the axis
was not extended to the tip; lateral diagonal
barbs were more extended than the axis of the
hair (Fig. 7).
1
DISCUSSION
Galiano (1969) studied the development of
Grammostola pulchripes
(Simon 1891) and
indicated the occurrence of ramified hairs on
the dorsal abdomen of spiders in the fifth in-
star (2.54 mm). These hairs can now be inter-
preted as Type IV urticating hairs, taking into
account that a detailed description was done
later by Cooke et al. (1972) and personal ob-
servations. Galiano (1973) also indicated the
occurrence of Type I urticating hairs in the
fourth instar (2.03 mm) of
Acanthoscurria
sternalis
Pocock 1903. The present results
agree with Galiano (1969, 1973) in the early
occurrence of urticating hairs in theraphosids.
Although Galiano (1969, 1973) only studied
early developmental stages, her results are
congruent with the precedence of Type I hairs
in
A. sternalis
and the precedence of Type IV
hairs in
G. pulchripes
.
Sexual dimorphism was observed in some
theraphosid species by Bertani (1997) and
P´rez-Miles (2000) in which males have two
types of urticating hairs while females have
only one (lacking Type III hairs). Considering
that Type III hairs are acquired later during
development, it seems probable that in these
species with sexual dimorphism only males
differentially gained Type III hairs during de-
velopment rather than female losing these
hairs. This could explain the results for
H.
uruguayense
, in which some large juveniles
(one with immature spermathecae) lacked
Type III urticating hairs while other slightly
smaller juveniles (probably males) acquired
Type III urticating hairs. This species show
to
confirm
these
preliminary observa-
tions.
ACKNOWLEDGMENTS
I am grateful to Dr. Enrique Lessa for his
help with the English and to two anonymous
 P
´
REZ-MILES—URTICATING HAIRS OF THERAPHOSINAE
319
Figures 6–7.—SEM photographs showing apical morphology of Type III urticating hairs. 1.
Acanthos-
curria suina
(this species also has Type I hairs). 2.
Grammostola mollicoma
(this species also has Type
IV hairs).
 320
THE JOURNAL OF ARACHNOLOGY
reviewers for their comments on the manu-
script.
Kluge, A.G. 1985. Ontogeny and phylogenetic sys-
tematics. Cladistics 1:13–27.
Nelson, G. 1978. Ontogeny, phylogeny, paleontol-
ogy, and the biogenetic law. Systematic Zoology
27:324–345.
Nelson, G. 1985. Outgroups and ontogeny. Cladis-
tics 1:29–45.
P´rez-Miles, F. 1992. An´lisis clad´stico preliminar
de la subfamilia Theraphosinae (Araneae; The-
raphosidae). Bolet´n de la Sociedad Zool ´ gica
del Uruguay 7:11–12.
P´rez-Miles, F. 2000.
Iracema cabocla
new genus
and species of a theraphosid spider from Ama-
zonic Brazil (Araneae, Theraphosidae). Journal
of Arachnology 28:141–148.
P´rez-Miles, F., S.M. Lucas, P.I. da Silva Jr. and R.
Bertani. 1996. Systematic revision and cladistic
analysis of Theraphosinae (Araneae: Therapho-
sidae). Mygalomorph 1:33–68.
P´rez-Miles, F. & L. Prandi. 1991. El comporta-
miento de emisi ´ n de pelos urticantes en
Gram-
mostola mollicoma
(Araneae, Theraphosidae): un
an´lisis
LITERATURE CITED
Bertani, R. 1997. Estudo comparativo dos pˆlos ur-
ticantes em Theraphosinae (Araneae, Therapho-
sidae). Actas 1er. Encuentro Aracn ´ logos Cono
Sur, p. 29.
Bertani, R. & J.P.L. Guadanuci. 1999. Morfologia
e evolucao dos pelos urticantes em Theraphosi-
nae (Araneae, Theraphosidae). Actas 2
8
. Encon-
tro Aracn ´ logos do Cone Sul, p. 61.
Bertani, R. & O.A.V. Marques. 1996. Defensive be-
haviors in mygalomorph spiders: release of ur-
ticating hairs by some Aviculariinae (Araneae,
Theraphosidae).
Zoologisches
Anzeiger 234:
161–165.
Cooke, J.A.L., V.D. Roth & F.H. Miller. 1972. The
urticating hairs of theraphosid spiders. American
Museum Novitates 2498:1–43.
De Queiroz, K. 1985. The ontogenetic method for
determining character polarity and its relevance
to phylogenetic systematics. Systematic Zoology
34:280–299.
Galiano, M.E. 1969. El desarrollo postembrionario
larval de
Grammostola pulchripes
(Simon, 1891)
(Araneae, Theraphosidae). Physis 29:73–90.
Galiano, M.E. 1973. El desarrollo postembrionario
larval en Theraphosidae (Araneae). Physis Sec-
ci ´ n C 32:37–46.
experimental.
Bolet´n
de
la
Sociedad
Zool ´ gica del Uruguay 6:47–53.
Wheeler, Q.D. 1990. Ontogeny and character phy-
logeny. Cladistics 6:225–268.
Manuscript received 1 July 2001, revised 26 Feb-
ruary 2002.
  [ Pobierz całość w formacie PDF ]
  • zanotowane.pl
  • doc.pisz.pl
  • pdf.pisz.pl
  • diabelki.xlx.pl
  • Podobne
    Powered by wordpress | Theme: simpletex | © Spojrzeliśmy na siebie szukając słów, które nie istniały.

    Drogi uЕјytkowniku!

    W trosce o komfort korzystania z naszego serwisu chcemy dostarczać Ci coraz lepsze usługi. By móc to robić prosimy, abyś wyraził zgodę na dopasowanie treści marketingowych do Twoich zachowań w serwisie. Zgoda ta pozwoli nam częściowo finansować rozwój świadczonych usług.

    PamiД™taj, Ејe dbamy o TwojД… prywatnoЕ›Д‡. Nie zwiД™kszamy zakresu naszych uprawnieЕ„ bez Twojej zgody. Zadbamy rГіwnieЕј o bezpieczeЕ„stwo Twoich danych. WyraЕјonД… zgodД™ moЕјesz cofnД…Д‡ w kaЕјdej chwili.

     Tak, zgadzam siД™ na nadanie mi "cookie" i korzystanie z danych przez Administratora Serwisu i jego partnerГіw w celu dopasowania treЕ›ci do moich potrzeb. PrzeczytaЕ‚em(am) PolitykД™ prywatnoЕ›ci. Rozumiem jД… i akceptujД™.

     Tak, zgadzam siД™ na przetwarzanie moich danych osobowych przez Administratora Serwisu i jego partnerГіw w celu personalizowania wyЕ›wietlanych mi reklam i dostosowania do mnie prezentowanych treЕ›ci marketingowych. PrzeczytaЕ‚em(am) PolitykД™ prywatnoЕ›ci. Rozumiem jД… i akceptujД™.

    Wyrażenie powyższych zgód jest dobrowolne i możesz je w dowolnym momencie wycofać poprzez opcję: "Twoje zgody", dostępnej w prawym, dolnym rogu strony lub poprzez usunięcie "cookies" w swojej przeglądarce dla powyżej strony, z tym, że wycofanie zgody nie będzie miało wpływu na zgodność z prawem przetwarzania na podstawie zgody, przed jej wycofaniem.