The common barking gecko, Ptenopus garrulus occurs in western arid
regions of southern Africa an...

1. Reproductive cycle of the common barking gecko, Ptenopus
garrulus (Squamata: Gekkonidae) from southern Africa.
The common barking gecko, Ptenopus garrulus occurs in western arid
regions of southern Africa and ranges from little Karoo to Kruger
National Park (Branch 1998). Hibbitts et al. (2005) studied the
reproductive ecology of P. garrulus and Girard (1997) described mating
behavior in captive specimens. Clutch sizes are in Haacke (1975), Pianka
(1986), Pianka Huey (1978). The purpose of this paper is to
provide additional information on the reproductive biology of P.
garrulus from a histological examination of museum specimens as part of
an ongoing effort to characterize the reproductive patterns of geckos
from southern Africa.
Materials and Methods
A total of 171 P. garrulus including 91 females (mean snout-vent
length, SVL = 46.7 mm [+ or -] 3.0 SD, range = 39-53 mm), 61 male (mean
SVL = 47.0 mm [+ or -] 3.6 SD, range = 38-58 mm), 10 subadults (mean SVL
= 34.1 mm [+ or -] 1.6 SD, range = 33-37 mm) and 9 presumed neonates
(mean SVL = 24.0 mm [+ or -] 1.5 SD, range = 21-25 mm) P. garrulus were
examined from the herpetology collection of the Natural History Museum
of Los Angeles County (LACM), Los Angeles, CA. Lizards were collected
1969, 1970, 1972 and 1976.
For histological examination, the left testis and epididymis were

2. removed from males and the right ovary was removed from females.
Enlarged follicles ( 4 mm length) or oviductal eggs were counted.
Tissues were embedded in paraffin and cut into sections of 5 [micro]m.
Slides were stained with Harris hematoxylin followed by eosin counterstain. Slides of testes were
examined to determine the stage of
the spermatogenic cycle. Slides of ovaries were examined for the
presence of yolk deposition or corpora lutea. Statistical analyses were
performed using Instat (vers. 3.0b, Graphpad Software, San Diego, CA).
An unpaired t-test was used to compare P. garrulus male and female mean
body sizes (SVL).
Ptenopus garrulus from southern Africa examined from the
herpetology collection of the Natural History Museum of Los Angeles
County, (LACM), Los Angeles, California.
BOTSWANA
Kgalagadi District, 11 km S Tsabong (26[degrees]08'S,
22[degrees]28'E) LACM 83270, 83275, 83281, 83288, 83292, 83293,
83295, 83296, 83299, 83313, 83316, 83321, 83324, 83325, 83330, 83334,
83335, 83342, 83346, 83350, 83351, 83353, 83354, 83358, 83362, 83366,
83371-83373, 83383, 83384, 83388, 83393, 83395, 83396, 83405, 83408,
83409, 83413, 83415, 83416, 83421, 83423, 83425, 83429, 83436, 83492,
83503, 83506, 83507, 83509, 83510, 83514, 83515, 83517, 83518, 83525; 9
km N, 11 km E Twee Rivieren (26[degrees]23'S, 20[degrees] 23'
S, 20 [degrees] 43'E) LACM 83261, 83263, 83266.
NAMIBIA

3. Erongo Region, Walvis Bay (22[degrees]95'S,
14[degrees]50'E) LACM 127468, 127469; Karas Region, 89 km ENE Koes
(26[degrees]00'S, 19[degrees]15'E) LACM 77292, 77293, 77299,
77300, 77302- 77307, 77310-77312, 77315, 77318-77323; Karas Region, 25
km WNW Helmering-hausen (25[degrees]88'S, 16[degrees]81'E)
LACM 77047, 77050, 77052; Karas Region, 46 km N, 17 km E Aroab
(26[degrees]22'S, 19[degrees]49'E) LACM 83206, 83207,
83210,83211, 83213, 83215.
REPUBLIC OF SOUTH AFRICA
Northern Cape Province, 31 km N,100 km E Upington
(28[degrees]13'S, 22[degrees]16'E) LACM 83138, 83146, 83148,
83150-83152; 24 km N, 83 km E Upington (28[degrees]17'S,
22[degrees]05'E) LACM 83223, 120 km N, 54 km W Upington
(27[degrees]22'S, 20[degrees]43'E) LACM 83038, 83041,
83044-83051; 121 km N, 16 km E Upington (27[degrees]22'S,
21[degrees]25'E) LACM 83238, 83243, 83247; 129 km N, 65 km W
Upington (27[degrees]17'S, 21[degrees]54'E) LACM 83055, 83059,
83064, 83066, 83072, 83074, 83076, 83077, 83080-83087, 83093, 83095,
83097, 83102, 83103, 83105-83111, 83113-83115, 83117, 83120-83122,
83125-83129, 83131, 83132, 83134, 83136; Kalahari-Gemsbok National Park,
1 km W. Kameelsleep (25[degrees]45'S, 20[degrees]44'E) LACM
83156, 83160, 83163, 83165, 83167, 83177, 83193, 83195, 83201-83204; 18
km S, 22 km E Witkoms (27[degrees]58'S, 21[degrees]32'E) LACM
83251, 83254; 50 km W, 7 km S of Vanzylsrus (27 [degrees]04'S,

4. 21[degrees]48'E) LACM 83256, 83257.
RESULTS
Males followed a seasonal testicular cycle (Table 1) in which
three
stages were represented: (1) Regression (non-reproductive)
in which the
germinal epithelium is exhausted and the predominant cells are Sertoli
cells and spermatogonia; (2) Recrudescence (recovery) characterized by
renewal of the germinal epithelium for the next period of sperm
formation; primary and secondary spermatocytes are the predominant
cells; (3) Spermiogenesis (sperm production) in which the seminiferous
tubules are lined by clusters of spermatozoa and metamorphosing
spermatids; the epididymides are packed with sperm. The peak period of
sperm production occurred in austral spring when 100% of 31 males were
undergoing spermiogenesis (Table 1). Recovery for the next period of
sperm formation occurred during summer-autumn when all three stages (=
regression, recrudescence, spermiogenesis) were present in the
population (Table 1). Recovery is completed by the next spring. The
smallest reproductively active male (spermiogenesis in progress)
measured 38 mm SVL (LACM 83125) and was collected in October.
Table 1. Monthly changes in the testicular cycle of Ptenopus
garrulus from southern Africa.

5. Month n Regression Recrudescence Spermiogenesis
September 9 0 0 9
October 20 0 0 20
November 2 0 0 2
January 6 4 0 2
February 6 3 2 1
April 15 2 6 7
May 3 1 1 1
There was no significant size difference (mean SVL) between males
and females (unpaired t test). Monthly changes in the ovarian cycle are
in Table 2. Egg production was limited to the right ovary. Females with
enlarged ovarian follicles ( 4 mm), oviductal eggs or corporalute a
were recorded from October, December and January. Two females from April
were undergoing early yolk deposition (marked by the presence of
vitellogenic granules). There was no evidence (corporalute and early
yolk deposition) in the same female to suggest more than one egg clutch
is produced in the same reproductive season. Mean clutch size (n = 21)
was 1.0 [+ or -] 0.0. The smallest reproductively active females
measured 43 mm, follicles 4 mm, (LACM 77323 from October and LACM
83223 from January) or, oviductal eggs, (LACM 77299 and LACM 77332 from
October).
Table 2. Monthly changes in the ovarian cycle of Ptenopus garrulus
from southern Africa.

6. Month n No yolk Early yolk Enlarged Oviductal Corpora lutea
deposition deposition follicles eggs only
4 mm
Oct. 21 2 3 9 6 1
Dec. 5 4 0 0 0 1
Jan. 23 21 0 2 0 0
Feb. 25 25 0 0 0 0
Mar. 4 4 0 0 0 0
Apr. 12 10 2 0 0 0
May 1 1 0 0 0 0
DISCUSSION
In a previous study on the reproductive ecology of P. garrulus
Hibbitts et al. (2005) reported peak reproductive activity for both
sexes occurred in September and October. Data from this study as well as
values in Pianka (1986) and Hibbitts et al. (2005) indicate that clutch
size in P. garrulus consists of one egg. Hibbitts et al. (2005) reported
that based on the presence of two eggs in different stages of
development in 4 (8%) females, two egg clutches
in the same year were
possible; only the right ovary produced eggs.
However, in contrast, no
females were observed that would likely have
produced more than one egg
clutch in the same year (females with oviductal
eggs and concomitant
yolk deposition and/or females with corporalutea and concomitant yolk

7. deposition). This finding may be due to the small sample sizes.
Hibbitts et al. (2005) reported reproductive activity commenced at
smaller SVLs (male = 36 mm; female = 31 mm) than observed in this study.
Gonads from ten P. garrulus from October in this study, (mean SVL = 34.1
mm [+ or -] SD, range = 33-37 mm were "extremely small" and
consequently classified these lizards as sub-adults. These differences
in onset of reproductive activity may suggest regional differences in
the sizes that P. garrulus populations commence reproduction.
It is not known if the two April P. garrulus that had initiated
vitellogenesis (Table 2) would have deposited eggs or undergone
follicular atresia with the yolk being reabsorbed (see Moodley van
Wyk 2007). Follicular atresia is common late in the reproductive season
when follicles that do not complete vitellogenesis deteriorate (Goldberg
1973, Moodley van Wyk 2007).
Presumed neonates were collected in January (n = 6), February (n =
1) and May (n = 2). This is consistent with the observation of Haacke
(1975) that young of P. garrulus hatch from early summer into autumn and
Auerbach (1987) that eggs of P. garrulus probably hatch in late summer
to autumn and possibly as early as October.
To date reproductive cycles of African gekkonid lizards appear to
fall into two types: (1) a seasonal cycle in which reproduction occurs
mainly in spring-summer as found in P. garrulus described herein and in

8. Hibbitts et al. (2005), Chondrodactylus angulifer, (Goldberg 2006a),
Pachydactylus capensis, (Goldberg 2006b), Colopus wahlbergii, (Goldberg
2006c; Whiting et al. 2007), Pachydactylus bibronii, (Flemming
Bates 1995), Hemidactylus mabouia (Moodley van Wyk 2007) and; (2)
extended reproduction occurring through much of the year as appears to
be typical for Lygodactylus, (Simbotwe 1983, Vitt 1986), Goldberg 2007,
Goldberg 2008, Vences et al. 2004). Subsequent studies on additional
species of geckos are needed before the variations in the timing of
gekkonid reproductive cycles from southern Africa can be known.
KNOWLEDGEMENTS
I thank Christine Thacker (LACM) for permission to examine P.
garrulus and Sean Kark (Whittier College) for assistance with histology.
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SRG at: sgoldberg@whittier.edu
Stephen R. Goldberg
Department of Biology, Whittier College Whittier, California 90608
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