The gold tegu, Tupinambis teguixin (Linnaeus, 1758) sensu lato (Squamata: Teiidae): evidence for an established population in Florida

Gold tegus, Tupinambis teguixin (Linnaeus, 1758), are generalist predators from South America and are ecologically similar to Argentine black and white tegus (Salvator merianae), a successful invader in Florida. We trapped gold tegus in Broward and Miami-Dade counties, Florida, USA. In Miami-Dade County, collection occurred from 2008 through 2016. We combined new trapping records with previous literature records. Ten gold tegus of both sexes and multiple size classes over a nine year period indicate a reproducing population in Miami-Dade County. Tupinambis teguixin is the sixth established non-native teiid species in Florida. Additionally, we report Tupinambis teguixin from Sarasota and Lee counties, Florida, USA. Determining population status in those counties requires further study. It is critical to differentiate this species from Salvator merianae during removal efforts. The possibility of eradicating Tupinambis teguixin exists if proper identification enables reliable monitoring of the populations.


Introduction
Florida's tropical to subtropical climate, along with major ports of entry and a large number of animal importers have contributed to a high number (n = 181) of introduced amphibian and reptile species (Fedler et al. 2016;Krysko et al. 2016).Eight teiid (Squamata, Teiidae) species have been introduced to Florida and five are established (Krysko et al. 2016), including the Argentine black and white tegu: Salvator merianae Duméril and Bibron, 1839.During trapping and removal of S. merianae, we captured ten animals identified as gold tegus, Tupinambis teguixin (Linnaeus, 1758), in a relatively small area in southern Miami-Dade County, Florida.Herein, we document T. teguixin in Miami-Dade County, elucidate previously published vouchers (Krysko et al. 2011), and provide evidence for its establishment.

Material and methods
We compiled all verified records of occurrence of gold tegus from the Florida Museum of Natural History, including those previously published (Krysko et al. 2011), to determine the introduction history and geographic distribution of this species in Florida (see Supplementary material Table S1).Additional records are available on the Early Detection & Distribution Mapping System (EDDMapS) but we did not include records unless they were independently verified with photographs or specimens.We also trapped tegus (Figure 1) using box traps baited with raw chicken eggs.Although most of the trapping effort targeted black and white tegus (Salvator merianae), we incidentally captured 10 T. teguixin.Individuals were euthanized humanely with a captive bolt gun or MS 222 following AVMA guidelines (Leary et al. 2013).Snout-vent length (SVL) and total length (TL) were measured ventrally with a flexible tape.Individuals were examined during necropsy to determine sex and diet.Specimens and photographs were deposited as vouchers in the Division of Herpetology, Florida Museum of Natural History, University of Florida (UF-Herpetology).
Murphy et al. ( 2016) described four species in the T. teguixin complex, rather than the one species historically recognized; this complicates identity of the species in Florida.We identified captured tegus as either S. merianae or T. teguixin by examining loreal scales.One pair of loreal scales is present in T. teguixin while two pair of loreal scales are present in S. merianae.Pending research to determine which of the newly-described species is present in Florida, we will identify these animals as T. teguixin sensu lato (hereafter referred to as T. teguixin).

Results and discussion
The first known T. teguixin (UF-Herpetology 153696) in Florida was captured in 1995 inside a pigeon coop at 3820 NW 65 Avenue, Hollywood, Broward County (26º02′34.65″N;80º13′14.01W″;Datum WGS84; 1.8 m elev.; see Supplementary material Table S1).This individual had probably escaped from a nearby reptile importer (Krysko et al. 2011; Figure 2  Although T. teguixin was originally introduced in Florida more than two decades ago, published records (Krysko et al. 2011) and our recent records indicating both mature and immature size classes and both sexes over a period of nine years suggest reproduction and establishment of this species in Miami-Dade County.While introductions of this species have been documented in Broward, Lee and Sarasota counties, there is currently no evidence of reproduction there.With documentation of vouchered specimens, T. teguixin appears to be the sixth established non-native species of teiid lizard in Florida.Further investigation is needed to determine which of the four species in the T. teguixin complex occurs in our study area.Due to the proximity of T. teguixin to the breeding population of S. merianae in Miami-Dade County, it is possible that both species were introduced via the same pathway (pet trade) and source (Krysko et al. 2016).Because the diet of T. teguixin includes amniote eggs from nests in their native range (Schneider et al. 2011), resource managers in Florida should be aware of potential impacts on nesting indigenous wildlife in areas where T. teguixin has been introduced.
).On 21 July 2006, one adult T. teguixin (UF-Herpetology 149983) was photographed at Crandon Park on Key Biscayne, Miami-Dade County, Florida (Krysko et al. 2011).This probably represents an isolated introduction given the distance (40 km) between this observation and those elsewhere in Miami-Dade County.Another isolated observation of T. teguixin (UF-Herpetology 167193) occurred 17 June 2012 when one was photographed in Plantation, Broward County, Florida.On 11 June 2008, an adult Tupinambis teguixin (UF-Herpetology 152989, EVER 44945; female, 35.5 cm SVL, 61.5 cm TL) was trapped in Everglades National Park (25º23′46.10″N;80º35′03.58W″) in southwestern Miami-Dade County, after first being detected by a motion sensing camera deployed as part of a mammal inventory project (Krysko et al. 2011).During rapid response activities targeting S. merianae,

Figure 2 .
Figure 2. Map of southern Florida showing the locations of gold tegus (Tupinambis teguixin).