Natural history of coastal Peruvian solifuges with a redescription of Chinchippus peruvianus and an
additional new species (Arachnida, Solifugae, Ammotrechidae)
Alessandro Catenazzi
1
: Department of Biological Sciences, Florida International University, Miami, Florida 33199, USA
Jack O. Brookhart and Paula E. Cushing: Department of Zoology, Denver Museum of Nature and Science, 2001
Colorado Blvd., Denver, Colorado 80205-5798, USA
Abstract. Two species of Chinchippus (Ammotrechidae) were studied in central Peru. Both species are endemic to the
hyper-arid coastal desert and appear to derive most of their energy and nutrients from maritime prey, such as intertidal
amphipods feeding on beach-cast algae or as arthropod scavengers feeding upon seabird and pinniped carcasses. Data on
the spatial distribution of the two species were obtained from analyzing stomach contents of one common predator, the
gecko Phyllodactylus angustidigitus, and suggest that both species are more abundant in insular than in mainland habitats.
We redescribe Chinchippus peruvianus Chamberlin 1920, known only from a female specimen and describe the male for the
first time while C. viejaensis is recognized as new. The new species is distinguished from C. peruvianus by its darker
coloration, smaller size, and differences in cheliceral dentition.
Keywords: Camel spiders, coastal desert, ecology, Gekkonidae, Peru, Phyllodactylus angustidigitus, taxonomy
In the process of investigating the ecology of terrestrial
organisms in the coastal desert and guano islands of central
Peru, we have come across a series of Chinchippus peruvianus
Chamberlin 1920 and a closely related species. These solifuges,
along with other terrestrial predators, thrive in places that
could be defined as a barren land of gravel, sand, and granitic
outcrops – a moonscape where arachnids and lizards somehow
manage to survive, reproduce, and colonize new habitats. The
western coast of South America is among the driest places on
Earth (Dietrich & Perron 2006), where arid conditions have
persisted for the last 14 million years (Alpers & Brimhall
1988). Facing this hyper-arid ecosystem is one of the world’s
most productive marine ecosystems, the Peru-Chile cold
current (Tarazona & Arntz 2001). The stark contrast in
productivity promotes the exchange of energy and nutrients
between these two adjacent ecosystems, and marine-derived
resources subsidize terrestrial predators along the Peruvian
coast (Catenazzi & Donnelly 2007a) and in other coastal
deserts (Polis & Hurd 1996). In this study we describe the
taxonomy and natural history of the two Chinchippus species
and explore their distribution in relation to the availability of
marine-derived resources.
The genus Chinchippus was established by Chamberlin
(1920) based on a single female from the Peruvian island of
Chincha. He considered it to belong to the African family
Daesiidae. Roewer (1934) included Chinchippus in the
ammotrechid subfamily Saronominae based on the segmenta-
tion of legs I, II, and IV and the palpal spination. Muma
(1976) tentatively included it with the saronomines although
its placement was still based on Chamberlin’s sole female.
Based on Chamberlin’s single female, the genus Chinchippus
can be recognized by: all the legs having a single tarsal
segment, no claws on leg I, stridulating ridges on the mesal
surface of the chelicera, lateral plates of the ‘‘rostrum’’ shorter
than the median plates, and a recurved cephalothorax.
METHODS
One of us (AC) conducted fieldwork at the Paracas
National Reserve (PNR; 13u519S, 76u169W), ,19 km S of
the Chinchas islands, in the Peruvian Region of Ica (Fig. 1).
This reserve protects 335,000 ha of coastal waters and
subtropical Peruvian coastal desert, including a variety of
arid and hyper-arid terrestrial habitats. The PNR includes the
Paracas Peninsula, which forms the southern edge of Paracas
Bay, and the islands of Sangaya´n and La Vieja. The coastal
topography is extremely heterogeneous and includes sandy,
gravel, pebble and boulder beaches; cliffs; wind-shaped
landforms; and uplifted ancient beaches. The climate is
characteristic of the arid coastal desert of Peru and northern
Chile and receives less than 2 mm of rain per year (Craig &
Psuty 1968). Temperatures are mild and range between an
average high of 22.9u C in February to an average low of
16.3uC in August (Environmental Resources Management
2002).
Using the methods of Muma (1951), Brookhart & Muma
(1981, 1987), Muma & Brookhart (1988), and Brookhart &
Cushing (2004), we measured total length; length of palpus, leg
I, leg IV; length and width of chelicera and propeltidium;
width of base of fixed finger; and length and width of female
genital operculum using Spot Basic
TM
with an Olympus
SZX12 microscope at 253 magnification. All measurements
are in millimeters. Ratios used previously by Brookhart &
Cushing (2002, 2004) were computed. These ratios are as
follows: A/CP: the sum of the lengths of palpus, leg I, and leg
IV divided by the sum of length of chelicera and propeltidium
indicating length of appendages in relation to body size. Long-
legged species have larger A/CP ratios. Because there is no
fondal notch, the cheliceral width/fixed finger width ratio is
used to indicate whether the fixed cheliceral finger of the male
is thin or robust in relation to the size of the chelicera. Genital
operculum length/genital operculum width represents the
1
Current address: Department of Integrative Biology, University of
California, Berkeley, 3060 Valley Life Sciences Bldg #3140, Berkeley,
California 94720-3140, USA. E-mail: acatenazzi@gmail.com
2009. The Journal of Arachnology 37:151–159
151

relative size of the female genital operculum in terms of length
and width. Species determinations were based on a combina-
tion of color comparisons, the shape and dentition patterns of
the male chelicerae, palpal setation, and color patterns of the
propeltidium, palpus, and legs. The shape of the female
chelicerae and the female genital operculum margin were
observed using the method of Brookhart & Cushing (2004).
Cheliceral dentition patterns were based on the method of
Maury (1982) in which, for example, PT-1-2-AT indicates one
primary tooth, two intermediate teeth, and one anterior tooth.
Collections from which material was borrowed or deposited
include the Museum of Comparative Zoology at Harvard
University, Cambridge, Massachusetts, USA (MCZ); the
Museo de Historia Natural, Universidad Nacional Mayor
de San Marcos, Lima, Peru (MUSM); and the Denver
Museum of Nature and Science, Denver, Colorado, USA
(DMNS).
We collected solifuges by using pitfall traps or by
opportunistically collecting during nocturnal walks. We used
pitfall traps consisting of plastic cups 9 cm in diameter and
10 cm deep filled with a mix of water and detergent along the
southern end of Paracas Bay between 6–9 January and 6–11
April 2003. During the January trapping, a series of three
pitfall traps were placed near sandy/muddy beaches in coastal
dunes and the adjacent desert at 5, 10, and 15 m distance from
shore. During the April trapping, we placed pitfall traps near
shelly beaches along transects at 0, 0.1, 1, 10 and 100 m from
shore. We installed three transects, each one composed of
three lines of pitfall traps. In addition to pitfall trapping, we
also counted and measured solifuges in 90 1-m
2
plots in the
intertidal zone in March 2003. Count data of the March and
April trapping period were reported by Catenazzi & Donnelly
(2007a). Here we report count data from the January trapping,
as well as solifuge size-distribution data from the March
trapping along the shelly beach. Means are reported 6 SE and
statistical tests are considered significant at P , 0.05.
We include anecdotal observations on predators, prey, and
behavior of solifuges observed in the field. Some of these
observations were captured in photographs and video and are
available online at http://acatenazzi.googlepages.com/chinch-
ippus.
We relied upon stomach content examinations of the gecko
Phyllodactylus angustidigitus Dixon & Huey 1970, a common
and ubiquitous reptile in the coastal desert, to better
understand the distribution of solifuges in the coastal desert
of the Paracas Peninsula and the islands of Sangaya´n and La
Vieja. These geckos feed opportunistically on any live
terrestrial arthropod of appropriate size, including beach
hoppers, centipedes, arachnids, and insects (Catenazzi &
Donnelly 2007a), and do not masticate their prey, facilitating
the task of identifying prey remains in the stomachs. Stomach
contents were obtained by inserting a small catheter through
the esophagus and by flushing the geckos’ stomachs with
water (Catenazzi & Donnelly 2007a). Stomach contents (n 5
814) were collected from Isla La Vieja (4 sites), Isla Sangaya´n
(3 sites), and the Paracas Peninsula (10 sites). We considered
whole prey items only to calculate frequency of occurrence of
Chinchippus prey with respect to number of geckos sampled
and with respect to total number of prey items in all pooled
stomach contents.
Figure 1.—Map of study localities and spatial variation in the frequency of occurrence of Chinchippus peruvianus and C. viejaensis in stomach
contents of the gecko Phyllodactylus angustidigitus at Isla Sangaya´n (3 sites), the Paracas Peninsula (10 sites) and Isla La Vieja (4 sites), central
Peru. The diameter of circles represents frequency of occurrence ranging from 0% (Yumaque, Paracas Peninsula) to 100% (gull colony,
Isla Sangaya´n).
152 THE JOURNAL OF ARACHNOLOGY