Rediscovery of Liolaemus Rabinoi (Iguania: Liolaemidae) After 35 Years: Redescription, Biological and Phylogenetic Information, and Conservation Challenges
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SALAMANDRA 53(1) 114–125 15 FebruaryCristian 2017 SimónISSN Abdala0036–3375 et al. Rediscovery of Liolaemus rabinoi (Iguania: Liolaemidae) after 35 years: redescription, biological and phylogenetic information, and conservation challenges Cristian Simón Abdala1, Romina Valeria Semhan1, Alejandro Laspiur2 & José Luis Acosta3 1) Unidad Ejecutora Lillo (CONICET-Fundación Miguel Lillo)– Facultad de Ciencias Naturales e Instituto Miguel Lillo (IML), Universidad Nacional de Tucumán. Miguel Lillo 251, 4000 Tucumán, Argentina 2) Departamento de Biología & Centro de Investigaciones de la Geósfera y Biósfera (CIGEOBIO-CONICET), Facultad de Ciencias Exactas y Naturales. Universidad Nacional de San Juan. Av. José I. de la Roza 590, 5400 San Juan, Argentina 3) Laboratorio De Herpetología, Facultad de Ciencias Exactas y Naturales y Agrimensura. Universidad Nacional del Nordeste. 25 de Mayo 868, 3400. Corrientes, Argentina Corresponding author: Alejandro Laspiur, e-mail: [email protected] Manuscript received: 31 October 2015 Accepted: 30 December 2015 by Jörn Köhler Abstract. Liolaemus is one of the most diverse genera of vertebrates, currently comprising 267 species classified into sev- eral monophyletic groups. Among them is the Liolaemus wiegmannii clade, including obligate sand-dwelling lizards with particular morphological traits and behavioural patterns associated with their habitat. One member of this group is Lio laemus rabinoi, a species from Argentina that has formerly been considered extinct. It was first found in 1972 on the mar- gins of the El Nihuil dam in San Rafael, Mendoza, Argentina. Four additional specimens of L. rabinoi were recorded in 1974–75, but subsequent searches were unsuccessful and resulted in the inclusion of this species in red conservation lists. In November 2010, new specimens of lizards assignable to L. rabinoi were found in an area of large sand dunes, 10 km from where it had been searched for in vain for years. We present a new diagnosis and redescription based on nine of these specimens (four males and five females) and provide biological, current distribution, and phylogenetic relationship data within the genus Liolaemus. We also analyse the particular human-induced effects on the environments where L. rabinoi occurs and discuss possible conservation measures to mitigate habitat loss. Key words. Squamata, Sauria, Liolaemus rabinoi, redescription, phylogeny, taxonomy, biology, conservation, Mendoza, Argentina. Introduction The significance and extent of extinction may vary ac- cording to the context; such is the case of a species that is Over the last years, human intervention has caused an ac- considered extinct when none of its representatives can be celerated increase in extinction rates worldwide (Primack found alive. However, a species can be extinct in the wild et al. 2001, Ceballos et al. 2010, 2015, Dirzo et al. 2014). but survive in captivity with “ex situ” plans, or it may be Human-induced ecosystem degradation and destruction “locally extinct” when it is no longer present in a region processes (mainly transformation and fragmentation) are where it used to occur, but still lives in other natural re- known as some of the main causes of the current envi- gions (Clark & Rosenzweig 1994, Moilanen 1999). The ronmental crisis and biodiversity loss (Turner 1996, Pri- latter definition might apply toLiolaemus rabinoi, a species mack et al. 2001, Bennet 2004, Pimm et al. 2006). Accord- that was considered extinct for several years, until 2010. ingly, habitat loss can directly result in animal mortality Liolaemus rabinoi is a small lizard (60 mm in snout– and have subsequent indirect long-term effects on surviv- vent length), belonging to a small exclusive group of sand- al and reproduction (Vitt & Caldwell 2014, Ceballos dwelling Liolaemus species that exhibit a very particular et al. 2015). This means that surviving individuals become morphology and behaviour (Etheridge 2000, Abdala demographically unstable, resulting in a reduced genetic 2005). It was described by Cei (1974) based upon two adult variability and increased susceptibility to stochastic events, specimens found in December of 1972 on the shores of the potentially reducing populations to extinction levels (Pri- El Nihuil dam, near the Club de Pescadores, San Rafael mack et al. 2001, Rocha & Gasca 2007). Department, Mendoza Province, Argentina (J.M. Cei pers. © 2017 Deutsche Gesellschaft für Herpetologie und Terrarienkunde e.V. (DGHT), Mannheim, Germany Available114 at http://www.salamandra-journal.com Redescription and systematics of Liolaemus rabinoi comm. 15 January 2002). Later, in 1974, Mr. Rabino (J. M. dune system about 10–15 km from the type locality in De- Cei’s chauffeur) found an additional specimen and final- cember of 2010 (Fig. 1). ly, during the course of 1975, Cei, Videla, and Tuzi (IBA While pinpointing the causes that have led to the ex- UNC-1203) found three more specimens, in both cases in tinction of the L. rabinoi population from the type local- areas adjacent to the El Nihuil dam. Several herpetolo- ity and surrounding areas can be a complex task, strategies gists and naturalists continued visiting the area in search of may and should be applied to conserve this current popu- L. rabinoi individuals; however, despite their search efforts lation found in dunes with scarce psammophilous vegeta- and planning, no other individuals were found until 2010. tion. Unfortunately, this region is used by off-road vehi- Those thirty-five years of unsuccessful searching eventu- cles for recreation and competition purposes, including the ally saw L. rabinoi being included in red conservation lists “Dakar Rally” challenge, which have left permanent scars (Avila et al. 2000, Chébez & Kacoliris 2008, IUCN in the area and certainly caused an important degradation 2013), and several authors considered it extinct (Berto- to the population structure of L. rabinoi. natti 1994, Halloy et al. 1998, Etheridge 2000, 2001, Biological, ethological, and morphological data of Avila et al. 2000, 2009). Nonetheless, despite the disheart- L. rabinoi used to be very scarce or null because the origi- ening results and 16 field surveys over 11 years of ceaseless nal description of this species (Cei 1974) is brief and very searching by the authors of the present work conducted at simple, and it was not possible to conduct a detailed a pos- the type locality and in surrounding areas, including the teriori study because the species had disappeared from the near-shore islands of El Nihuil dam (relicts of sand dunes type locality and adjacent areas. Thus, Etheridge (2000) that had never been covered by water before) and areas contributed further morphological data, but these were surrounding the dam by up to 40 km, an isolated popula- based on the material previously collected and studied by tion of L. rabinoi was eventually discovered in a large sand Cei (1974, 1986). Figure 1. Known distribution of L. rabinoi in El Nihuil, Department of San Rafael, Mendoza, Argentina. Blue circle: locations docu- mented by J. M. Cei and collaborators in 1974 and 1975 (now apparently extinct at these localities). Red circle: new population of Liolaemus rabinoi (35°05’08.0’’ S, 68°37’21.7’’ W). The arrow indicates the type locality. Yellow square: Liolaemus riojanus. Green square: Liolaemus cuyumuhue. 115 Cristian Simón Abdala et al. Table 1. Comparison of morphological characters among species of the L. wiegmannii clade. For quantitative characters, the range of values and, in parentheses, the average value are provided. SAM – number of scales around the body; DS – number of dorsal body scales; VS – number of ventral body scales; GS – number of gular scales; NS – number of scales on the neck; PPM – number of pre- cloacal pores in males; PPH – number of precloacal pores in females; Max SVL – maximum snout–vent length (in mm). Source: all species this study, except L. arambarensis (Verrastro et al. 2003). Species / Character SAM DS VS GS NS PPM PPH Max. SVL Liolaemus rabinoi 70–80 (74.1) 82–94 (88.6) 84–89 (87.3) 31–37 (33.4) 33–46 (41.3) 5–8 (6.5) 0 55.9 Liolaemus arambarensis 60–66 (62.3) 57–64 (60.1) 51–60 (55.3) –– –– 4–7 (5.2) 3–4 (3.6) 60 Liolaemus azarai 35–44 (41.5) 39–42 (40.5). 72–79 (75.5) 20–29 (23.7) 35–47 (40.5) 5–6 (5.6) 0 51.4 Liolaemus cuyumhue 63–71 (66.7) 76–83 (79.1) 88–103 (93.1) 30–33 (31.7) 36–37 (36.3) 7–9 (8.0) 0 56.5 Liolaemus lutzae 56–64 (60.7) 62–73 (67.1) 92–104 (96.0) 31–45 (37.8) 36–50 (44.6) 5–6 (5.5) 0 60.1 Liolaemus multimaculatus 68–81 (73.7) 73–85 (80.1) 85–96 (90.1) 30–34 (31.8) 45–55 (50.9) 6–9 (7.7) 0 67.4 Liolaemus occipitalis 65–75 (69.8) 73–80 (77.0) 89–97 (92.6) 35–42 (38.8) 46–58 (52.4) 8–11 (9.6) 0 66.9 Liolaemus riojanus 63–72 (68.1) 77–89 (83.1) 82–97 (89.0) 33–42 (36.1) 43–49 (45.7) 8–9 (8.3) 0–3 57.5 Liolaemus salinicola 60–70 (64.4) 71–82 (75.7) 87–106 (96.3) 35–46 (41.5) 49–56 (52.6) 7–9 (7.4) 0–5 76.6 Liolaemus scapularis 54–66 (58.7) 60–68 (63.1) 79–86 (82.9) 30–41 (36.3) 43–54 (47.7) 7–9 (8.0) 0–5 73.6 Liolaemus wiegmannii 48–56 (51.8) 49–57 (53.6) 72–87 (81.7) 26–36 (28.6) 41–49 (46.1) 5–7 (5.9) 0–4 54.5 Within the framework of our findings, we here rede- in the last five years to observe behaviour and study the mi- scribe L. rabinoi, provide for the first time biological and crohabitat and state of conservation of the place.