First records of extant Hispaniolan spiders of the families Mysmenidae, Symphytognathidae, and Ochyroceratidae (Araneae), including a new species of Ochyrocera

2007·2.8 MB·English

by  Hormiga, Gustavo

A tamerican museum
Novitates
PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY
CENTRAL PARK WEST AT 79TH STREET, NEW YORK, NY 10024
Number 3577, 21 pp., 15 figures June 28, 2007
First Records of Extant Hispaniolan Spiders of the
Families Mysmenidae, Symphytognathidae, and
Ochyroceratidae (Araneae), Including a New Species
of Ochyrocera
GUSTAVO HORMIGA,1 FERNANDO ALVAREZ-PADILLA,2 AND
SURESH P. BENJAMIN3
ABSTRACT
A new species of ochyroceratid spider, Ochyrocera cachote, n.sp., is described and its unique web
architecture is documented. This is the first record of Ochyroceratidae for the extant fauna of
Hispaniola. Additional new family records include Symphytognathidae (Patu sp. and
Symphytognatha sp.) and Mysmenidae (Microdipoena sp.), with the latter family having been
previously recorded from the fossil amber fauna. This makes a new total of 46 spider families
recorded from the extant Hispaniolan fauna, but on the whole the island’s araneofauna remains
poorly known and warrants further investigation.
INTRODUCTION the world where the fossil fauna is most
similar to that of the Recent fauna. The
The taxonomic knowledge of the spider spiders of the Dominican Republic preserved
fauna of the Dominican Republic is unique in amber are relatively well known (Penney,
because more families are known from fossils 2006). The Dominican amber and the extant
in Miocene amber than are recorded from fauna are ecologically comparable because the
extant species (Penney, 1999; Penney and amber was formed in a tropical climate similar
Perez-Gelabert, 2002). It is also the region of to that in the region at the present time
1 Department of Biological Sciences, The George Washington University, Washington, DC 20052; Research Associate,
Department of Invertebrates, American Museum of Natural History ([email protected]).
2 Department of Biological Sciences, The George Washington University, Washington, DC 20052 ([email protected]).
3 Department of Biological Sciences, The George Washington University, Washington, DC 20052 ([email protected]).
Copyright © American Museum of Natural History 2007 ISSN 0003-0082
2 AMERICAN MUSEUM NOVITATES NO. 3577
(Penney and Perez-Gelabert, 2002). However, Lesser Antilles (Dominica and Guadaloupe).
apart from the pioneering works by Elizabeth In this paper we describe the new species in
Bryant (1943, 1945, 1948), the extant spider detail and document its web architecture.
fauna of Hispaniola has not been studied in Additionally, we report the presence of extant
much detail (for a history of Hispaniolan species from the araneoid families Mysme¬
araneology, see Penney and Perez-Gelabert, nidae and Symphytognathidae in the island
2002). During the course of a recent field trip for the first time. Two fossil species of
to the Dominican Republic we had the Mysmenidae, Mysmenopsis lissycoleyae Pen¬
opportunity to collect and study spiders in ney, 2000 and Dominicanopsis grimaldii
four areas with different habitats and eleva¬ Wunderlich, 2004, have been described from
tions. In this paper we report on three spider Dominican amber (Penney, 2000; Wunderlich,
families that were previously undiscovered for 2004b). The family Symphytognathidae had
the extant fauna of Hispaniola: Ochyro- not been recorded before. Schawaller’s (1981)
ceratidae, Mysmenidae, and Symphyto- records of eight symphytognathid specimens
gnathidae. The ochyroceratid species is mor¬ in Dominican amber held at the Staatliches
phologically very similar to one of the species Museum fur Naturkunde (Stuttgart, Ger¬
described from amber, and it is formally many) are misidentifications of theridiids
described here. (Wunderlich, 2004c: 228).
Ochyroceratidae is a relatively small family
(146 described species in 13 genera) of small MATERIALS AND METHODS
ecribellate haplogyne spiders with a cosmotrop-
ical distribution (Platnick, 2006). Although Taxonomic descriptions follow the format
the natural history of ochyroceratids is not of Hormiga (1994, 2002). Specimens of fossil
well known (Machado, 1951; Deeleman- Ochyroceratidae in Dominican amber were
Reinhold, 1995), it seems that many of them not examined. Discussion of their relation¬
build sheet webs, sometimes with conspicuous ships is based on the published text and
parallel silk lines in the sheet (figs. 13B, 14D). figures. Specimens were examined and illus¬
Recently, Wunderlich (1988, 2004a) described trated using a Leica MZ 16A stereoscopic
two fossil species of Ochyroceratidae from the microscope with a camera lucida. Further
Dominican Republic (Arachnolithulus pyg- details were studied using a Leica DMRM
maeus Wunderlich, 1988 and A. longipes compound microscope with a drawing tube.
Wunderlich, 2004). To accommodate the first Some microscopic images were recorded using
of these two Dominican fossil species he a Nikon DXM1200F digital camera and
erected the genus Arachnolithulus Wun¬ stacked using the software package Auto-
derlich, 1988. However, Wunderlich was un¬ Montage. A LEO 1430VP scanning electron
certain as to relationships of Arachnolithulus, microscope was also used to study and
pointing out the need for more specimens, photograph morphological features. Left
fossil and extant. Penney (1999) predicted structures (e.g., palps, legs) are depicted unless
extant Hispaniolan ochyroceratids (and mys- otherwise stated. Hairs and macrosetae are
menids) based on their occurrence in the usually not depicted in the final drawings. All
amber fauna. Alayon-Garcia (2001) reported morphological measurements are given in
the presence of ochyroceratids from Navassa, millimeters. Somatic morphology measure¬
a 5.2-km2 island 64 km west of Hispaniola. ments were taken using a scale reticle in the
During our fieldwork in the Dominican dissecting microscope. Eye diameters are
Republic we found a new species of Ochyro¬ taken from the span of the lens. Cephalo-
ceratidae in leaf litter, in a patch of cloud thorax length and height were measured in
forest near Paraiso (Barahona Province). This lateral view, and its width was taken at the
new species is morphologically similar to the widest point. Similarly, the length and height
extinct Dominican species Arachnolithulus of the abdomen were measured in lateral view,
longipes (known after a single male specimen and the width was taken as the widest point as
in amber) and to the extant Ochyrocera seen from a dorsal view. Measurements of the
thibauldi Emerit and Lopez, 1985 from the abdomen are only approximations because the
2007 HORMIGA ET AL.: HISPANIOLAN SPIDERS 3
abdomen size changes more easily in preserved MAP major ampullate gland spigot(s)
specimens than do other more sclerotized mAP minor ampullate gland spigot(s)
parts (e.g., the chelicerae). Total length was PI piriform gland spigot(s)
measured in lateral view and is also an PLS posterior lateral spinneret
PMS posterior median spinneret
approximation because it involves the size of
PTS posterior tracheal spiracle
the abdomen and its relative position.
Approximate femur lengths were measured
in lateral view, without detaching the legs TAXONOMY
from the animal, by positioning the article
being measured perpendicularly. Female gen¬
italia were excised using surgical blades or OCHYROCERATIDAE FAGE, 1912
OCHYROCERA SIMON, 1891
sharpened needles. Epigyna and palps were
transferred to methyl salicylate (Holm, 1979)
Type Species: Ochyrocera arietina Simon,
for examination under the microscope, tem¬
1891 by original designation.
porarily mounted as described in Grandjean
Composition: In addition to O. cachote,
(1949) and Coddington (1983). Male palps
n.sp., the genus Ochyrocera includes 21 species
examined with the SEM were first excised and
(Platnick 2006), most of them from the
transferred to a vial with 70% ethanol and
Neotropical region. There are also species
then cleaned ultrasonically for 1-3 minutes.
described from Cuba, the Lesser Antilles,
The specimen was then transferred to absolute
including the type species, and Samoa.
ethanol and left overnight. After critical point
drying, the specimens were glued to rounded
aluminum rivets using an acetone solution of Ochyrocera cachote, new species
Acryloid B-72 and coated with gold-palladium figures 1-12
for examination with the SEM. For SEM
Type: Male holotype and female paratype
examination of the tracheal system, the non-
from Barahona Province, Paraiso, Reserva
chitinous abdominal tissue was digested with
Natural Cachote, cloud forest surrounded by
SIGMA Pancreatin LP 1750 enzyme complex
secondary growth, N 18°05'54.8": W
(Alvarez-Padilla and Hormiga, in press) in
71°IF22.0", 1220 m, 6-9.IV.2005, G. Hor¬
a solution of sodium borate prepared follow¬
miga, F. Alvarez-Padilla, and S.P. Benjamin
ing the concentrations described in Dingerkus
(deposited in MCZ).
and Uhler (1977).
Etymology: The species epithet is a noun
Webs were photographed after dusting
in apposition taken from the type locality.
them with cornstarch (Eberhard, 1976) and
Diagnosis: Males of Ochyrocera cachote,
photographed with a Nikon FI00 using a 60-
n.sp. can be distinguished from other species
mm macro lens and a speedlight. All photo¬
of Ochyrocera by the absence of a clypeal
graphs have associated voucher specimens.
apophysis (fig. IB) and the details of the
cheliceral teeth (fig. 2C, D), including the
Anatomical Abbreviations presence of a large tooth toward the base of
the cheliceral furrow. The cymbial apophysis
Male Palp
and the embolus shape (figs. 2A, B, 8A-C) are
E embolus
also diagnostic. The lack of a monographic
m30 claw extensor muscle
treatment of Ochyrocera and the absence of
T tegulum
detailed and uniform descriptions of the
tm29 tendon of claw flexor muscle
species currently placed in the genus make it
Female Genitalia
impossible to accurately diagnose females.
S spermatheca
Most likely the shape of the spermathecae
Somatic Morphology
(fig. 3B) combined with the cheliceral teeth
AC aciniform gland spigot(s)
(fig. 3C, D) are unique for this species.
ALE anterior lateral eye(s)
ALS anterior lateral spinneret Description: Male (holotype): Total
AME anterior median eye(s) length 2.83. Cephalothorax 1.09 long, 0.89
ATS anterior tracheal spiracle wide, 0.31 high. Sternum 0.59 long, 0.61 wide.
4 AMERICAN MUSEUM NOVITATES NO. 3577
Fig. 1. Ochyrocera cachote, n.sp. A, Male, dorsal. B, Male prosoma, dorsal. C, Female, dorsal. D,
Female prosoma, anterior. E, Female abdomen, ventral. F, Male, left leg I, mesal.
Abdomen 1.74 long, 0.6 wide, 0.65 high. parallel from clypeus through posterior cara¬
Specimens in alcohol have general bluish pace margin (fig. 1 A, B). Chelicerae yellowish,
appearance. Cephalothorax bluish yellow with fangs red brown. Six eyes in three groups; eyes
two light longitudinal bands running in slightly elevated, with black rings. AME
2007 HORMIGA ET AL.: HISPANIOLAN SPIDERS 5
Fig. 2. Ochyrocera cachote, n.sp., male. A, Palp, mesal. B, Palp, ectal. C, Chelicera, dorsal. D, Chelicera,
ventral. Scale bars 0.1 mm.
diameter 0.09, 0.3 times one AME diameter several macrosetae. Labial anterior margin
away from ALE. Clypeus height 0.29, project¬ notched (fig. 4F). Legs yellowish with black
ing forward, with two pairs of setae, with ectal blotches, no apparent pattern; tarsi with
pair longer and more robust than distal pair cuticular folds and pigmentation pattern
(fig. 4A, C, E). Sternum yellowish with dark (fig. IF) that gives appearance of pseudoseg¬
lateral margin, seven macro setae in three rows mentation. Leg formula 1432. Femur I 4.03
of 3, 2, 2 setae each; ectal setae longer and long, 3.7 times length of cephalothorax.
more robust than distal setae. Endites with Chelicerae anteriorly protruding with promi-
6 AMERICAN MUSEUM NOVITATES NO. 3577
Fig. 3. Ochyrocera cachote, n.sp., female. A, Tracheal system, ventral. B, Genital area. C, Chelicera,
dorsal. D, Chelicera, ventral. Scale bars 0.1 mm.
nent single promarginal tooth flanked distally conical, 0.66 the palpal tibia length, with long
by two small teeth and basally by six small ectal digitiform apophysis carrying a cuspule
teeth (figs. 1A, B, 2C, D, 4E). Palp (figs. 1A, at its apical end; tegulum ovoid, tapering to
B, 8A-H): tibia long and cylindrical (ca. 3.6 pointed end; sperm duct diameter tapering
times its diameter), with two dorsal, two from reniform fundus (located at tegulum
mesal, two ectal trichobothria; cymbium cymbium joint) toward opening, with one
2007 HORMIGA ET AL.: HISPANIOLAN SPIDERS 7
Fig. 4. Ochyrocera cachote, n.sp., male. A, Prosoma, dorsal. B, Prosoma, detail of cuticular surface. C,
Prosoma, lateral. D, Leg I, ectal. E, Prosoma, anterior. F, Prosoma, ventral. G, Prosoma, ventral, detail of
cuticular surface.
switchback loop; embolus ribbonlike, tapering Female (paratype): Total length 2.45.
toward the end and oriented perpendicularly Cephalothorax 0.81 long, 0.7 wide. Sternum
to longitudinal axis of tegulum. Tarsal organ 0.43 long, 0.48 wide. Abdomen 1.64 long, 0.81
fusiform, apical region divided into three wide. Coloration and markings as in male,
points (fig. 4G). Epiandrous fusules: (fig. 9F) although females seem slightly darker than
six fusules with globular base linearly ar¬ males (fig. 1C-E). Six eyes in three groups;
ranged in anterior margin of circular de¬ slightly elevated, with black rings. AME
pression anterior to epigastric furrow. diameter 0.06, 0.3 times one AME diameter
Spinnerets (fig. 9A-E): colulus fleshy and long away from ALE. Clypeus height 0.22, project¬
(fig. 9A); ALS with one major ampullate ing forward, with two pairs of setae, ectal pair
gland spigot accompanied by nubbin and longer and more robust than distal pair
seven piriform spigots (fig. 9C); PMS with (fig. 5A-C). Sternum coloration as in male,
a single spigot, probably a minor ampullate labial anterior margin notched (fig. 5F).
(fig. 9D); PLS has tightly packed row of 26 Pedipalpal tarsal claw a small conical struc¬
aciniform gland spigots with very long bases ture (fig. 51). Legs yellowish with black
(fig. 9B, E). blotches, no apparent pattern. Pseudoseg-
AMERICAN MUSEUM NOVITATES NO. 3577
Fig. 5. Ochyrocera cachote, n.sp., female. A, Prosoma, dorsal. B, Prosoma, anterior. C, Prosoma, lateral.
D, Prosoma, detail of cuticular surface. E, Prosoma, ventral. F, Endites and labium (arrow, labial incision).
G, Sternum, detail and cuticular sockets of macrosetae. H, Pedipalp. I, Pedipalpal claw.
mentation present but less apparent than in (fig. 3B) provided with pair of elongated
males. Leg formula 1423. Femur I 2.03 long, spermathecae, lightly sclerotized; sclerotized
2.5 times length of cephalothorax. Chelicerae structure of uncertain nature seen between the
with eight small teeth (fig. 3C, D). Vulva spermathecae. Spinnerets (fig. 10A-F): colu-
2007 HORMIGA ET AL.: HISPANIOLAN SPIDERS 9
Fig. 6. Ochyrocera cachote, n.sp., male. A, Abdomen, ventral (arrows, from top to bottom, anterior
tracheal spiracle, unidentified cuticular structure, and posterior tracheal spiracle). B, Unidentified cuticular
structure. D, Detail of cuticular surface and setal socket. D, Posterior tracheal spiracle.
lus, fleshy and long (fig. 7A); ALS with one of study material): booklungs modified into
major ampullate gland spigot accompanied by tracheae that open through anterior spiracles.
nubbin and seven piriform spigots (fig. 10E); In male, anterior tracheal system consists of
PMS with single spigot, probably minor two bundles of three short tracheae confined
ampullate (fig. 10C); PLS has tightly packed to abdomen plus leaflike trachea of about half
row of 23 aciniform gland spigots with very length of other three tracheae (fig. 11A-C).
long bases (fig. 10A, B, D, F). Female anterior tracheal system very similar
Tracheal system (figs. 3A, 7A, D, 11A-C, but lacks leaflike tracheae (fig. 3A). Posterior
12A-D; description is based on single male tracheal system consists of pair of tracheal
and female specimen dissection due to paucity bundles that open to small atrium (figs. 3A,
10 AMERICAN MUSEUM NOVITATES NO. 3577
Fig. 7. Ochyrocera cachote, n.sp. A, Female, abdomen, lateral (top arrow, pit; bottom arrow, posterior
tracheal spiracle). B, Male, abdomen, lateral. C, Detail of female abdominal pit. D, Female, posterior
tracheal spiracle. E, Female, spinnerets, lateral. F, Male, spinnerets, lateral.
11A-C, 12A-D). Each bundle has four (fig. 12C). In addition, each bundle has a pair
anteriorly directed tracheae that enter pro¬ of smaller tracheae (both in diameter and
soma. In the male at least some of those length) that branches into multiple tracheoles.
tracheae divide into smaller tracheoles. Posterior tracheal spiracle positioned approx¬
Female specimen had tracheae broken off in imately halfway between colulus and epigas¬
area near pedicel (fig. 11 A); their diameter tric furrow (fig. 10A).
suggests that these tracheae continue into Natural History: Ochyrocera cachote,
prosoma through pedicel. In female, one of n.sp. was collected in the leaf litter and in
four tracheae of each anteriorly directed small cavities in the ground in Dominican
bundle branches into smaller tracheoles cloud forests at ca. 940-1200 m of elevation.