The symphytognathoid spiders of the Gaoligongshan, Yunnan, China (Araneae: Araneoidea): Systematics and diversity of micro-orbweavers
Author
Miller, Jeremy
Naturalis Biodiversity Center, Leiden, Netherlands
Author
Griswold, Charles
California Academy of Sciences ,, United States of America
Author
Yin, Chang
College of Life Sciences, Hunan Normal University ,, China
text
ZooKeys
2009
2009-05-31
11
11
9
195
journal article
10.3897/zookeys.11.160
6bed073a-175c-42e6-bb99-645c99d55b4f
1313–2970
576459
C631A347-306E-4773-84A4-E4712329186B
Family
Mysmenidae Petrunkevitch, 1928
Recent authors have focused on a handful of characters to define
Mysmenidae
: the presence of a sclerotized subdistal ventral spot (
Griswold et al. 1998
: fig. 10G) on femur I (and sometimes II as well) of females (and sometimes males as well), the presence of a prolateral macroseta on male metatarsus I (Fig. 17D), and a distally twisted and notched cymbium (
Platnick and Shadab 1978b
,
Griswold et al. 1998
,
Schütt 2003
). Femoral spots are not universal in mysmenids, absent from the new genus
Gaoligonga
and most species of
Mysmenopsis
Simon, 1897
(
Platnick and Shadab 1978b
), which are otherwise typical mysmenids. The mysmenid cymbium is typically very complex, featuring a series of distal lobes that interact with the embolus as a functional conductor (e.g.,
Figs 24D
,
37A
,
40C
). While this description seems to apply to most or all mysmenids (questionable in the new genus
Chanea
;
Fig. 49A
), it has apparently contributed to some confusion, such as the misplacement of the genus
Crassignatha
Wunderlich,
1995
in
Mysmenidae
(see below).
Schütt (2003)
coded the two mysmenids in her phylogenetic analysis as having non-homologous male metatarsal clasping spurs based on position (apical in
Microdipoena
Banks, 1895
, basal in
Trogloneta
Simon, 1922
). Some
Maymena
Gertsch, 1960
species also lack a metatarsal clasping spur (
Gertsch 1960
). Some male mysmenids have prolateral macrosetae on tibia I in addition to (rarely instead of) a metatarsal macroseta (e.g.,
Anjouanella
Baert, 1986
,
Microdipoena
Banks, 1895
,
Mysmenella
Brignoli, 1980
,
Simaoa
gen. n.
;
Fig. 34F
). Nevertheless, the clasping spur on male metatarsus I, whether proximal or distal, remains a key diagnostic character for
Mysmenidae
. In addition, most mysmenids have a distinctive modified seta on the PLS (Figs 19F, 42F,
Griswold et al. 1998
: fig. 28A; absent from the kleptoparasitic
Isela
Griswold, 1985
, which also lacks the triplet of spigots used to make araneoid sticky silk in both sexes;
Griswold et al. 1998
: figs 29D, 30D). The sticky silk triplet is vestigial in some Chinese mysmenid males (
Fig. 25D
) but is fully developed in some other male mysmenids (
Griswold et al. 1998
: fig. 28D).
Lateral sulci are present on the carapace of several mysmenid genera and range in form from a single pore between the lateral eyes and the margin of the carapace (Fig. 17F) and a larger hole just below the lateral eyes (
Fig. 24E
).
Lopardo and Hormiga (2008)
reported on a similar sulcus in the enigmatic genus
Acrobleps
Hickman, 1979
. Anapids have one or more pores, typically associated with a plate or sulcus, on the anterolateral margin of the carapace (
Platnick and Forster 1989
).
The distinctive web architecture and associated behavioral characters help to define the limits of
Mysmenidae
. With the exception of
Maymena
(which builds a horizontal anapid-like orb-web) and the webless kleptoparasites, mysmenids build a threedimensional spherical web, the result of typical orb-building behavior except that radii are not restricted to a single plane (
Figs 20
,
26
;
Coddington 1986b
,
Eberhard 1987
,
Griswold et al. 1998
: fig. 3B). Small clusters (6-9) of eggs are placed in the center of the web (Figs 21H, 26B, D, 43C).
The limits and diagnostic features of many mysmenid genera are not entirely clear. Work in progress (Lopardo, pers. comm.) with a global scope promises substantial progress soon. But for the purposes of this geographically limited work, we must rely on the existing literature. New species were placed in the genus
Mysmena
Simon, 1894
based on the presence of an external cymbial groove (Figs 17A, 29A), a distinct cymbial base (Figs 17B, 24C, 29B), an embolus without a switchback or process that makes approximately one spiral turn usually guided by a groove in the tegulum (Figs 17B, 29C), a cymbial tip that engages the embolus as a functional conductor (
Figs 24D
,
29C
), and male mating claspers restricted to metatarsus I (Figs 17D, 24F, 29D). The presence of an epigynum in the form of a scape with the left and right copulatory pathways well separated also influenced species placement (
Figs 11I
, 21C,E), although not all
Mysmena
described here have a scape (Fig. 21G,I). Internal structures consist of a pair of spermathecae, copulatory ducts usually with a sclerotized portion leading to the spermathecae and a membranous atrium (copulatory ducts occasionally membranous throughout their length; Fig. 21I). Sclerotized complexes (spermathecae or spermathecae plus part of copulatory ducts) are separated by at least their width (Fig. 21G). Fertilization ducts usually arise from the posterior part of the spermathecae and curve mesally, or arise from mesal part of spermathecae. A posterior tubercle on the abdomen is present (
Fig. 27F
) or absent (Fig. 15B). Also, all new
Mysmena
described here have femoral spots on legs I and II (sometimes indistinct in male), although the
type
species of
Mysmena
apparently has the femoral spot only on leg I (
Kraus 1967
).
Chinese
Maymena
described here differ from the American fauna in having the palpal patella and tibia elongated (
Fig. 54A
; compare to
Gertsch 1960
: fig. 51). Otherwise, they closely resemble typical
Maymena
in genital morphology, size and coloration, association with cave habitats, and web architecture.
Maymena
are apparently the only mysmenids with trichobothria on the palpal tibia (
Fig. 55D
), a trait shared with synaphrids and theridiosomatids among the symphytognathoids.
The remaining mysmenids were all placed in new genera.
Simaoa
,
Gaoligonga
, and
Chanea
all have novel features, especially male sexual characters.
Simaoa maku
and
S. bianjing
are known from female only and were tentatively placed in
Simaoa
based on characteristics of the female genitalia shared with
Simaoa
species known from both sexes.
Mosu
is the only new mysmenid genus known from the female only. The two species clearly share similarities in genital morphologies. Another Chinese species recently described in the genus
Mysmena
exhibits similar morphology in the female and could be congeneric. This species,
M. zhengi
Lin & Li, 2008
, is known from both sexes and so could be useful for exploring the limits of this new genus.
Diagnosis
.
Femur I (and sometimes II as well) of females (and sometimes males as well) with a sclerotized subdistal ventral spot (sometimes absent), prolateral macroseta on metatarsus I of the male (Fig. 17D) forming a clasping spur, distally twisted and notched cymbium (
Platnick and Shadab 1978b
,
Griswold et al. 1998
,
Schütt 2003
), and distinctive modified seta on the PLS (Figs 19F, 42F) characterize
Mysmenidae
. Not all characters are present in all species.