Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 March 2020 | 12(4): 15495–15498
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
doi: https://doi.org/10.11609/jott.5691.12.4.15495-15498
#5691 | Received 08 January 2020 | Final
received 07 February 2020 | Finally accepted 10 March 2020
New records of Heloderma alvarezi
(Wiegmann, 1829) (Sauria: Helodermatidae) on the coast of Oaxaca and increases to its
distribution in Mexico
Jesús García-Grajales
1, Rodrigo Arrazola Bohórquez
2, María Arely Penguilly Macías
3 &
Alejandra Buenrostro
Silva 4
1 Instituto de
Recursos, Universidad del Mar campus Puerto
Escondido. Km. 2.5, Carr. Federal Puerto - Sola de
Vega,
Puerto Escondido 71980, Oaxaca, México.
2 Universidad
del Mar campus Huatulco. Ciudad Universitaria, Santa
María Huatulco 70989, Oaxaca, México.
3 Fondo Oaxaqueño para la Conservación de la Naturaleza.
Puerto Escondido 71980, Oaxaca, México.
4 Instituto de
Industrias, Universidad del Mar campus Puerto
Escondido. Km. 2.5, Carr. Federal Puerto - Sola de
Vega,
Puerto Escondido 71980, Oaxaca, México.
1 archosaurio@yahoo.com.mx,
2 rodrigo.arrazolab@gmail.com, 3 arely.penguilly@fondoax.org,
4 sba_1575@yahoo.com.mx (corresponding author)
Editor: Anonymity requested. Date
of publication: 26 March 2020 (online & print)
Citation: Grajales, J.G., R.A. Bohorquez,
M.A.P. Macias & A.B. Silva (2020). New records of Heloderma
alvarezi (Wiegmann,
1829) (Sauria: Helodermatidae)
on the coast of Oaxaca and increases to its distribution in Mexico. Journal of
Threatened Taxa 12(4): 15495–15498. https://doi.org/10.11609/jott.5691.12.4.15495-15498
Copyright: © Grajales et al. 2020. Creative
Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction,
and distribution of this article in any medium by providing adequate credit to
the author(s) and the source of publication.
Funding: Universidad del Mar.
Competing interests: The authors declare no competing interests.
Acknowledgements: We give thanks to Universidad del Mar (UMAR) for the
logistic support, and thank Alison Tai Rosewicz for
your help with the language review. JGG
thanks to Sistema Nacional de Investigadores (SNI)
for the grant.
In Mexico, the genus Heloderma
is composed of five broad-ranging species: (i) the Gila Monster H. suspectum
distributed in the Mohave Desert of extreme Nevada, southwestern Utah, extreme southeastern California and northwestern
Arizona, and throughout the Sonoran Desert region in Arizona and Sonora,
Mexico, as well as into the Chihuahuan Desert of southeastern Arizona and southwestern New Mexico (Campbell
& Lamar 2004; Beck 2005); (ii) the Rio Fuerte
Beaded Lizard H. exasperatum inhabits the
foothills of the Sierra Madre Occidental, in the transition area between the
drainage bains of Rio Mayo and Rio Fuerte and the Sonoran-Sinaloan
subtropical dry forest in southern Sonora, extreme western Chihuahua, and
northern Sinaloa (Campbell & Lamar 2004; Beck 2005); (iii) the Mexican
Beaded Lizard H. horridum is found primarily
in dry forest habitats from southern Sinaloa southward to Oaxaca and inland
into the states of Mexico and Morelos (Bogert &
del Campo 1956; Campbell & Lamar 2004; Beck 2005); (iv) the Chiapan Beaded Lizard H. alvarezi
inhabits dry forests in the Central Depression of central Chiapas and the Rio Lagartero Depression in extreme western Guatemala (Campbell
& Lamar 2004; Beck 2005); and (v) the Guatemalan Beaded Lizard H. charlesbogerti that inhabits the Rio Motagua Valley in the Atlantic slope of eastern Guatemala
(Campbell & Vannini 1988).
The beaded lizard is known coloquially
as ‘escorpión’ and is well known to local
inhabitants, yet its natural history is surrounded by mystery, notoriety and
misconception (Reiserer et al. 2013; Domínguez-Vega
et al. 2018), principally because these animals can pass up to 95% of their
lives hidden in shelters underground, which makes it difficult to detect
them. Moreover, they maintain a low population
(Beck & Jennings 2003; Domínguez-Vega et al. 2018). Furthermore, it is the only group which bears
venom-transmitting teeth with a deep venom groove in the rostral carina (Fry et
al. 2006). Although bites by the lizards
are extremely rare, envenomation is known to produce severe local pain,
dizziness, diaphoresis, vomiting, paresthesia, and
hypotension (Ariano-Sánchez 2006). Consequently, the
lizard is frequently slaughtered when encountered by humans (Beck 2005;
Domínguez-Vega et al. 2017).
Herein, we provide three new records and a significant
extension on the distribution of H. alvarezi
about different encounters between humans while performing their activities and
the species during its movement along the central coast of Oaxaca, Mexico,
particularly in three different municipalities (Figure 1).
The first observation ocurred
on 04 July 2017, when a lizard was held in captivity in the town of Santa Rosa
de Lima, municipality of Villa de Tututepec de
Melchor Ocampo. This animal was used as
an exhibition specimen to decrease the fear of this species in the town. We were prohibited from measuring it,
weighing it or determining its sex; however, to the naked eye this individual
presented good body condition (Image
1a). According to the people in charge
of the lizard, it came from the upper zone, close to the municipality.
The second observation ocurred
on 10 October 2019 at 17.15 h. An adult female H. alvarezi
was found and captured by people who were cleaning a field in a locality known
as ‘El Porvernir’ in the Municipality of Santa María Colotepec, Oaxaca.
Due to their fear of the creature, people caught the lizard in order to
slaughter it, but then they reflected on the situation and reported it to the
Universidad del Mar in the city of Puerto Escondido. The individual was measured (total length:
670mm), photographed (Image 1b) and then traslocated
and released into the Natural Protected Area El Gavilán
in San Francisco Cozoaltepec, municipality of Santa
María Tonameca, Oaxaca, to ensure that the individual
would not be harmed.
Most recently, the third observation ocurred on 03 November 2019 at 18.20h, between the
boundaries of the Universidad del Mar campus Huatulco and Huatulco National
Park, in the Municipality of Santa María Huatulco. A single juvenile was found
walking near a road and was later photographed on a tree (Image 2c). It was not manipulated in order to avoid
causing it unnecessary stress.
The identification of these lizards was possible
because this taxon is unique among the beaded lizards in that it undergoes an
ontogenetic increase in melanism (Bogert & del
Campo 1956; Beck 2005). Also distinctive
is that yellow banding on the tail, a characteristic typical of the other
species of beaded lizards, is esentially absent in
adults of H. alvarezi (Bogert
& del Campo 1956; Beck 2005).
Although Bogert & del Campo (1956) and
Beck (2005) explain that black individuals are uncommon, there is recent
photographic evidence of black individuals on the coast of Oaxaca. Neonates and juveniles often are distinctly
marked with yellow spots and bands on the tail, but the color
pattern of adults gradually transforms to an almost uniform dark brown or gray coloration.
Heloderma alvarezi was described as inhabiting dry tropical forest in
the Central Depression (Río Grijalva Depression) of central Chiapas and the Río
Lagartero Depression in extreme western Guatemala
(Campbell & Lamar 2004; Beck 2005; Köhler 2008; Johnson et al. 2010; Wilson
et al. 2010). Nontheless,
Álvarez del Toro (1983 in Campbell & Vannini
1988) indicated the probabiliy of sympatry areas
between H. horridum and H. alvarezi in the region between the Isthmus of Tehuatepec (Oaxaca) and Cintalapa
(Chiapas); however, up to this point, the literature on integration between
these two species is inconclusive (Reiserer et al.
2013), and therefore, the most recent herpetofauna list in Oaxaca does not
include H. alvarezi’s presence in the
State. Sánchez de la Vega et al. (2012)
provided, however, the photographic record of H. horridum
in the Municipality of San Pedro Mixtepec, and
previous records were made of this species in Jamiltepec
and the Isthmus of Tehuantepec (Bogert & del
Campo 1956).
Helodermatid lizards are listed as “threatened” under
Mexican law (NOM-059-SEMARNAT-2010, SEMARNAT 2010) and assessed as ‘Vulnerable’
by the Red List of International Union for Conservation of Nature (IUCN). The main threat to beaded lizards populations
is primarily the deforestation of dry tropical forests for agriculture, cattle
ranching, and the burgeoning human population (Janzen 1988; Myer et al. 2000;
Williams-Linera & Lorea
2009; Pennington et al. 2006; Domínguez-Vega et al. 2012), as well as, an
escalation of droughts and fires (Beck 2005; Miles et al. 2006). Additionally, anthropogenic pressure is a
threat.
These three photographic records represent the most northeastern (NE) geographic records of H. alvarezi, and it increases the distribution of the
species approximately 359km for the
record 3, 405km for record 2, and 470km for record 1 to the northeast from the previously
closest reported localities of Cintalapa and Ocozocoautla, Chiapas.
It is neccesary to gather more records on the
distribution of this Mexican species to amend the lack of information about
this. In conclusion, our records of this
species increase the number of reptiles present in Oaxaca to 448 species, if we
considered the recent contributions made by Carbajal-Marquez et al. (2020).
For
figure & image - - click here
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