Amphibians and reptiles of Isla Santay (Durán, Ecuador)

. Amphibian and reptile diversity from Isla Santay (Durán, Ecuador) has been underestimated due to the lack of monitoring throughout the island. Historically, this island has also been affected by anthropic landscape changes which limit the occurrence of certain species and favors the dispersion of opportunistic or more tolerant species. Such species dynamics tend to be more evident on islands, since their isolation limits species’ mobility. We present an updated checklist of the herpetofauna of Isla Santay Durán, Ecuador, and report for the first time the occurrence of two introduced species, Anolis sagrei Duméril & Bibron, 1837, Brown Anole, and Hemydactylus frenatus Duméril & Bibron, 1836.


Introduction
Expansion of agricultural and urban frontiers has caused deforestation, pollution, and the introduction of exotic species in ecosystems worldwide. These anthropic pressures have altered the dynamics of native communities and species compositions in fragmented ecosystems (Gascon et al. 1999;Ricketts 2001;Dixo and Metzger 2009). Terrestrial and aquatic ecosystems in Ecuador are currently highly fragmented, causing the displacement of entire groups of species, the decrease of sensitive species, and local extension events (Lehtinen et al. 2003;Lehtinen and Ramanamanjato 2006;Wilson and Townsend 2006;Cole et al. 2013;Lesbarrères et al. 2014;Steihnke 2016). Mangroves are particularly threatened, disappearing worldwide by 1-2% per year, a rate of deforestation greater than that of tropical rainforests, yet the issue has been widely unnoticed in the public eye (World Wildlife Fund 2015). Currently, mangrove forests in Ecuador occupy just 1906 km 2 (Hamilton and Casey 2016), since a large proportion of this ecosystem has been converted to aquaculture ponds and pastures. Ecuadorian coastal mangrove forests have been significantly impacted by anthropic activities in areas where diversity has not been fully characterized; this has significantly affected communities of amphibians and reptiles.
A site that has been exposed to agricultural and urban expansion in Ecuador is Isla Santay. This island is 4705 ha in area and located on the central-south Ecuadorian coast. It is part of the Municipality of Durán (Guayas province) at the delta of the Guayas River. Isla Santay is a national protected area and was declared a Ramsar site in 2000 . According to the Ecuadorian Ministry of the Environment, Water and Ecological Transition (MAE 2013), there are two native ecosystems on Isla Santay: Jama-Zapotillo Mangrove and Jama-Zapotillo lowland riparian floodplain grassland; however, there is also dry forest vegetation on the island (León-Yánez et al. 2011;Cruz-Cordovez et al. 2019). These ecosystems are affected by historical and ongoing anthropic activities. In the early 1900s, Isla Santay stood out for its cattle and rice production; consequently, native vegetation cover disappeared and was replaced by grasslands where artificial lagoons were also built. However, the island was expropriated by the Ecuadorian government in 1970, and the process of regenerating the vegetation began in the abandoned productive areas (Jaramillo et al. 2002). Currently, approximately 198 people inhabit the island′s southwest . This section makes up less than 1% of the island′s area, and it is considered a tourist attraction, as it is used for residents′ homes, schools, and meeting places . Several inventories have reported the terrestrial fauna in wetlands on the island. However, there are very few herpetofaunal records from Isla Santay, which limits conservation initiatives. Eight species were listed in the Ramsar (2000) information sheet, including three species of snakes (Boa imperator Daudin, 1803; Lepto deira ornata (Bocourt, 1884); Bothrops asper (Garman, 1884)), three species of lizards (Iguana iguana (Linnaeus, 1758); Ameiva sp., Stenocercus iridescens (Günther, 1859)), one turtle (Chelydra acutirostris Peters, 1862), and one amphibian (Rhinella horribilis (Wiegmann, 1833)). Jaramillo et al. (2002) later added five reptile species (Phyllodactylus reissii Peters, 1862; Hol cosus septemlineatus (Duméril, 1851); Drymarchon mel anurus (Duméril, Bibron & Duméril, 1854); Leptophis occidentalis (Günter, 1859); Oxybelis transandinus Torres-Carvajal, Mejía-Guerrero & Terán, 2021), and one more amphibian species (Engystomops guayaco Ron, Coloma & Cannatella, 2005). Samaniego et al. (2011) expanded the species list to 20 species by including two additional reptile species (Crocodylus acutus (Cuvier, 1807); Gonatodes caudiscutatus (Günther, 1859)) and two amphibian species (Scinax quinquefasciatus (Fowler, 1913); Leptodactylus labrosus Jiménez de la Espada, 1875); however, some were reported from interviews only, and there are synonyms reported for one species (Ophryoessoides iridescens synonym of Stenocercus iri descens). Later, Zavala-Becilla (2017) reported 12 frog species, including two arboreal species (Trachycepha lus jordani (Stejneger & Test, 1891) and Trachycephalus quadrangulum (Boulenger, 1882)) and the invasive species Lithobates catesbeianus (Shaw, 1802). Finally, Cruz-Cordovez et al. (2020 observed seven species of amphibians, including L. catesbeianus. To reflect the true herpetological diversity of the site, complementary surveys are needed. Here, we assess the composition of the herpetological community on Isla Santay in order to encourage better conservation strategies. We present an updated list of the herpetofauna of Isla Santay based on eight independent surveys.

Study Area
We surveyed Isla Santay, a Ramsar wetland ecosystem, located in Municipality of Durán at the start of the Guayas River, and in the middle Guayaquil, Durán, and Samborondón, which are three large coastal cities in Guayas province. This wetland is part of National System of Protected Areas in Ecuador (SNAP by its Spanish acronym) under the category of Recreational National Area (Samaniego et al. 2011). Based on location and floral composition, we selected three sampling areas comprised of pre-constructed paths, which are hereafter referred to as "transects" (Fig. 1): 1) Southern path: includes trails from the southern entrance of the island toward the island's ecovillage. This transect is characterized by mangrove forest, dry forest, and grassland ecosystems and was less disturbed than transects 2 and 3. Mangrove forests are dominant in the southern path and included Rhizopho ra mangle L. (Red Mangrove), Rhizophora racemose G.Mey. (Crawling Red Mangrove), Rhizophora harri sonii Leechm. (Knight Red Mangrove), and Conocar pus erectus L. (Button Mangrove). The dry forest and grassland ecosystems are characterized by the family Fabaceae, with 18 species, followed by Cyperaceae and Acanthaceae, with four species each. Trees and herbs were also predominant, with 30 and 26 species, respectively, followed by 15 species of shrubs, five species of lianas, and two species of palms.
2) Terraplén path: connects the southern path (transect 1) and our third transect that ran towards Durán city. This second transect is characterized by mangrove forest, dry forest, and grassland ecosystems, with 80 plant species from 72 genera distributed in 39 families. However, grassland and dry forest make up the most substantial vegetation cover. In contrast, the mangrove forest occurs only at the beginning and end of the transect. The mangrove forest includes Conocarpus erectus, Avicennia germinans (L.) L. (Black Mangrove), Laguncularia racemosa (L.) C.F.Gaertn. (White Mangrove), and the family Acanthaceae. In the transitional areas, herbaceous plants and trees are dominant, with 36 and 25 species, respectively, followed by 11 species of shrubs, three species of lianas, three species of epiphytes, and two species of palms.
3) Touristic path: the most impacted by anthropic pressures and comprised of several trails near the island's ecovillage and bike lane. The only remaining ecosystem in this transect was a mangrove forest, including black, white, and button mangroves. The infrastructure for tourism and the establishment of the island ecovillage have altered the natural water flow of the lagoons on the island. These alterations have helped dry forest and exotic plant species (42 tree species, 38 herb species, 14 shrub species, seven liana species, and three palm species) occupy the natural mangrove ecosystem (León-Yánez et al. 2011;Cruz-Cordovez et al. 2019).

Methods
This research includes multiple surveys performed between 2010 and 2022, following non-systematic sampling, free and unrestricted search, acoustic and visual records, and manual captures (Rödel and Ernst 2004). Surveys were complemented with opportunistic findings, lifting rocks and detritus, scraping through leaf litter, climbing mangroves, and looking in holes in mangrove trunks. Each survey varied in effort (duration and number of observers) and area of the island sampled.

Results
During our surveys on Isla Santay from 2010 to 2022 we recorded 434 sightings, which document 32 species of herpetofauna, which include 12 amphibian and 20 reptile species belonging to 16 families (Table 1) This species was found on trails in the interior of the island, mainly in areas with human activity; few individuals were observed in less disturbed sites.
Identification. This is large to very large, brown toad, with an SVL of 95-109 mm. It lacks expanded discs on the fingers and has large and prominent parotoid glands. There are membranes between the toes. Fingers and toes are robust, with lateral skinfolds, distally ending in knots and webbed between the toes (Savage 2002;Venegas and Ron 2014;Acevedo et al. 2016).
Distribution. In Ecuador, the distribution of R. horri bilis includes the coast, western foothills of the Andes, and the inter-Andean region. In addition, this species is distributed from southern Texas (USA) to northern Peru and west to the Andes range. It occurs at altitudes of 0-2900 m above sea level (Acevedo et al. 2016; Páez-Rosales and Ron 2019).

Family Hylidae
Scinax quinquefasciatus (Fowler, 1913) Figure 2B Material examined. This species was abundant in seasonal and dry lagoons located in the island's center. Individuals were actively calling from the banks and perching on nearby branches.
Identification. This is a medium-sized, light or dark brown frog with a cream belly; the SVL is 32-36 mm. There are generally continuous dorsal stripes, and most individuals have a dark, triangular marking on the head. It has smooth to granular skin on the back, with scattered to abundant tubercles .
Distribution. It is distributed in the Pacific lowlands of Colombia and Ecuador. In Ecuador, it is found in the provinces of Esmeraldas, Pichincha, Santo Domingo de Los Tsáchilas, Manabí, Los Ríos, Guayas, Cañar, and El Oro. In addition, it is introduced on Isabela and Santa Cruz islands of the Galápagos archipelago. This species occurs between 20 and 600 m above sea level (Lever 2003;MECN 2010;ASW 2016).

Scinax tsachila Ron, Duellman, Caminer, & Pazmiño, 2018
Figure 2C Identification. This is a medium-sized (31-35 mm), cream or reddish-brown frog with or without brown dorsal lines. There are no tubercles on the heel, and the eardrum is evident. The most similar sympatric species is Scinax quinquefasciatus. It differs by the presence of small, scattered tubercles on the back (absent in S. tsachila) and in having white leg bones that are barely visible through the skin (green and very dark in S. tsachila) ; Varela-Jaramillo 2019).
Distribution. It is distributed in the Pacific basin of Ecuador, from the province of Esmeraldas to El Oro. The presence of S. tsachila in Colombia and Peru is presumed, due to its proximity to the borders of both countries, but this has not been confirmed. It occurs between 0 and 1207 m above sea level ; Varela-Jaramillo 2019). Figure 2D Material examined.   Identification. This is a large tree frog, which is very easy to distinguish due to the extreme ossification of its head; the SVL is 73-85 mm. The rostral ridge is very prominent, and the rear edge of the head is straight and elevated with respect to the rest of the back. There are expanded discs on the fingers, but this species differs from others by its size and in having a black iris with irregular golden spots (Read et al. 2019).

Trachycephalus jordani (Stejneger & Test, 1891)
Distribution. It is distributed in the Pacific lowlands of southwestern Colombia through the coast of Ecuador to northwestern Peru, between 0 and 1000 m above sea level (Icochea et al. 2004;MECN 2010;ASW 2016). Figure 2E Material examined. Identification. This is a medium-sized frog, cream or brown in color, with dark spots on its back, and a golden iris with irregular black spots; it has expanded discs on the fingers. The SVL is 69-75 mm. Due to the color of the iris, it is like Trachycephalus jordani, a species that inhabits the same region. However, T. jordani presents a highly ossified skull, its rostral edge is very prominent, and head head has a straight posterior edge which is elevated with respect to the rest of the back (slightly distinctive rostral edge in T. quad rangulum, posterior edge of head inconspicuous and continuous with back) (Ron et al. 2016;Ron 2018 Identification. This is a very small toad with a greyishbrown back, dark markings, a creamy subocular bar, a gray flank, and an SVL of 16-18 mm. It is characterized by scattered tubercles on the skin of its back, a truncated snout in dorsal view and rounded in lateral view, the presence of parotoid glands, the absence of a tarsal tubercle, and finger I of the hand shorter than finger II (Ron et al. 2005;Ron 2018). This species was perched on natural substrates found in the lagoons.

Trachycephalus quadrangulum Boulenger, 1882
Distribution. It is distributed in the lowlands of southwestern Ecuador. It has an altitude range of 32-92 m above sea level (Ron et al. 2005;ASW 2016 Identification. This is a medium-sized toad, SVL is 56-57 mm. Unlike other Leptodactylus species, it is characterized by having a smooth belly, toes without membranes, lacking expanded discs on the fingers, and lacking tubercles on the soles of the feet. It may be brown or gray, with the back spotted or rarely uniform. A dark suborbital bar may or may not be present (Heyer 1978;de Sá et al. 2014).
Distribution. It is distributed in the western lowlands of the Andes of Ecuador and Peru, from the central coastal region of Ecuador to the central coast of Peru; it occurs between sea level and 1300 m above sea level (Heyer and Peters 1971;Heyer 1978;Cisneros-Heredia 2006a;de Sá et al. 2014;ASW 2016 Identification. This is a medium-sized toad with the following characteristics: snout rounded subelliptical or rarely subovoid in dorsal view; rounded to vertically rounded in side view; loreal region slightly concave in cross section; eardrum distinct, internal single vocal sac in males; head longer than wide, rarely equal to or shorter than wide; finger I slightly longer than or equal to II; finger I shorter than III, finger II longer than IV; male with two dorsal spines on thumb; arm not hypertrophied; ulnar edge not developed; smooth head; warty upper lid, glandular or smooth; supratympanic fold extends to shoulder; sometimes with warty dorsolateral folds; ventrolateral glands little to extensively developed; male without dorsal spines on chest; toe tips usually not enlarged; no disk; toes with welldeveloped lateral stripes; well-developed subarticular tubercles; metatarsal crease present; tarsal fold distinct, not continuous with toe stripe; smooth foot, with "apical coni" only on the outer sole of the foot; femur longer than, equal to, or usually shorter than tibia; tibia shorter than foot; foot longer than femur (Heyer 1970;Read et al. 2022).
Distribution. This species is found in the lowlands of the Atlantic and Pacific coasts of Mexico south to Panama and extends to the humid lowlands of Colombia and Ecuador. It is found from sea level to 1550 m above sea level (Solís et al. 2010;De Sá et al. 2014).

Family Ranidae
Lithobates catesbeianus (Shaw, 1802) Figure 2H Material examined. Identification. This frog is the largest in North America and is distinguished by lacking dorsolateral folds and having large tympanums (larger than the eye in males). The tips of the fingers and toes are blunt. The skin on the back of this species is rough with tiny tubercles. There is no dorsolateral fold, but there is a prominent supratympanic fold. The mean SVL for males is 152 mm and for females is 162 mm. Males have pigmented nuptial pads, and the vocal openings are at the corner of the mouth (AmphibiaWeb 2022). The dorsum is green, with or without a net-like pattern of gray or brown on top. The venter is slightly white and sometimes mottled with gray or yellow. Coloration varies depending on the locality (Conant and Collins 1991).
Distribution. This species is widely distributed in eastern North America. It has been widely introduced for various purposes and is now common in western North America, Europe, Asia, and South America. Lithobates catesbeianus is aquatic and can be found primarily at the edges of lakes, swamps, and other water bodies (Conant and Collins 1991).

Family Strabomantidae
Barycholos pulcher (Boulenger, 1898) Figure 2I Material examined. Identification. This is is a small-sized frog with the following combination of characters: back smooth with an hourglass pattern that runs from the interorbital region to the sacrum, which may be interrupted in the middle by a slight median dorsal stripe that extends from the tip of snout to cloaca; belly smooth, with scattered melanophores that are usually concentrated under the throat; ventral discoid fold present; head as long as wide; snout rounded in side view, as long as diameter of orbit; tongue oval, entire; distinctive rostral ridge; concave loreal region; nostrils closer to tip of snout than to eye; interorbital space as wide as upper eyelid; very distinctive tympanum, ⅔ eye diameter; vomerine teeth in two long, arched series extending beyond choana; moderate fingers, finger I slightly longer than finger II; moderate toes, no skin ridges; swollen tips of digits on hands and feet; prominent subarticular tubercles; two small prominent metatarsal tubercles; tarsal tubercles small, closer to foot than tibia; tibiotarsal joint reaching the level between the eye and the tip of the snout (  Figure 2J Observations. ECUADOR -Guayas • Durán, Isla Santay, Touristic path; 02°13′26″S, 079°51′57″W; alt. 6 m; 16.IV.2016; K. Cruz-García obs.; perched in a shrub 2 m above the ground; 1 (sex indet.).

Pristimantis achatinus (Boulenger, 1898)
Identification. This species is characterized by the following characteristics: finely granulated dorsal skin with low granular dorsolateral folds and smooth belly. Subacuminate face in dorsal view, with a sharp rostral ridge. Upper eyelid without tubers; large eardrum. Males with vocal clefts. Truncated discs on finger III-IV, wider discs on fingers I and II but narrower than discs on toes; adult males with a non-thorny nuptial pad on thumb. The cantal and postorbital region has dark brown or black bands and pale cream lips. The iris is finely reticulated in black, with the pupil on a reddish-brown horizontal band that divides the eye into golden upper and greyish lower halves. The dorsal coloration varies from pale yellow to dark brown, and the back surface of the thighs is brown with small patches of cream to red (Lynch and Myers 1983;Lynch and Duellman 1997).
Distribution. This species is distributed from the eastern lowlands and mountain ranges in Panama through the lowlands and western foothills of the western Andes in Colombia and Ecuador. Its altitudinal distribution ranges from sea level to 2330 m above sea level (Ruiz-Carranza et al. 1996;Ibáñez et al. 2000;Padial et al. 2014;Ron 2018).
Identification. This is a large crocodile; males can exceed 6 m and females can be more than 4 m. Its color is variable, from pale gray with somewhat yellowish or greenish tints to dark gray or blackish in older individuals. It has an elevation or preocular hump, which encompasses the prefrontal and nasal bones of the snout, better displayed in adult males (Álvarez del Toro 1974;Medem 1981;Thorbjarnarson 2010;Seijas 2011

Identification.
A transparent film covers the eyes; the pupils are elliptically vertical and have serrated edges. The head, chin, and body are covered by granular scales, among which some slightly keeled scales can be seen. The ventral scales are smooth, overlapping, and much larger than the granular dorsal scales. The coloration on the back is pale gray, cinnamon, or brown with darker spots (Lee 1996).  Identification. This species belongs to the punctatus group; it is characterized by small adults with an SVL of up to 50 mm. It has a slim body, elongated face, an olive-green coloration and an immaculate belly. It is white with a black base, and there is a large gular sac in males. The iris is blue. It is the only anole species with black coloration at the base of its gular sac and an immaculate belly (MECN 2010).

Anolis sagrei Duméril & Bibron, 1837
Identification. This species is distinguished by the combination of the following characteristics: small and slender body reaching a maximum total length of 21 cm; elongated, narrow head; long tail in both sexes, almost twice as long as the rostro-cloacal length; limbs long, with slender digits which are delineated on their lower sides by expanded digital pads, each composed of a series of lamellae. Body light brown to almost black able to change coloration. Males have a large, orange to red gular fold with a whitish border; females and juveniles are brown to gray on the dorsum, with dark or pale markings on the sides and a conspicuous whitish, dorsomedial stripe with dark, wavy edges. Iris brown or green; ear openings visible; body covered with small keeled, granular scales (Conant and Collins 1991;Rodriguez-Schettino 1999;Norval et al. 2002;Tan and Lim 2012). Identification. The combination of the following characteristics distinguishes this species: large dorsal crest that extends to more than a third of the tail and is not interrupted on the sacrum; enlarged, smooth, nacreous scale near the rear margin of the head below the tympanum on the side of throat; gular pouch with spikes at the front; 7 or 8 supra and infralabials to the midpoint of the eye; and nasal scale less elevated; no conspicuously large scale rows along lower jaw; and well-developed tuberculate scales in the neck region (Taylor 1956;Köhler 1999;Savage 2002 Identification. This species differs from most other medium-sized diurnal and terrestrial lizards in its area of distribution by having keeled dorsal scales with pointed ends instead of granular scales (Peters and Donoso-Barros 1970 Family Phyllodactylidae Figure 3I Observations. ECUADOR -Guayas • Durán, Isla Santay, Touristic path; 02°13′34″S, 079°52′1″W; alt. 10 m; 03.III.2022; M. Barreno obs.; foraging on a trunk; 1 (sex indet.).

Phyllodactylus reissii Peters, 1862
Identification. Phyllodactylus reissii can be separated from most other geckos in Ecuador by its large body size (males 42-75 mm, females 37-73 mm), dorsum with spaced enlarged scales arranged in parallel rows, and lack of enlarged scales on the tail (Arteaga and Aguiar 2020).
Distribution. This species is distributed from sea level to 1461 m above sea level in Ecuador and northern Peru. In Ecuador, it is found in the provinces of Azuay, Cañar, Santa Elena, Guayas, Esmeraldas, Manabí, Loja, El Oro, and introduced to the Galápagos ( Identification. This species differs from other Holcosus species by the combination of the following characteristics: frontal scale absent instead of several small scales; mesoptychium with enlarged scales; anterior aspect of the humerus with a row of large smooth scales; six longitudinal rows of ventrals throughout the belly; several small scales separating prefrontals; dorsal head scales strongly furrowed and usually sunken (Peters 1964). Identification. This species differs from other Gona todes in having round pupils, a supraciliary spine that is not distinctively enlarged, 17-21 lamellae under the fourth finger, 21-27 lamellae under the fourth toe, and proximal lamellae as wide as digits. Males can be identified based on their distinctive head coloration: bright yellow to orange with contrasting dark brown to black reticulations and a white post humeral ocelli with black margin. Females and juveniles are brownish overall (Arteaga and Guayasamin 2020). Identification. The combination of the following characteristics distinguishes this species: ventral scales 196-214; subcaudals 71-93; color change along the back of adults, paler above and darker behind; oblique black mark to the side of neck present; dark tone in the posterior region of the belly; ventral region of tail dark, and dark or pale subcaudals absent (Wüster et al. 2001;Valencia et al. 2008).

Distribution. Gonatodes caudiscutatus is native to the Chocoan and Tumbesian lowlands of western Ecuador and northwestern Peru and has been introduced into eastern Ecuador and the Galápagos (Olmedo and
Distribution. This species is distributed from Mexico, through Central America to South America, in northern Venezuela, western Colombia, and Ecuador, and in extreme northwestern Peru (Peters and Orejas-Miranda 1970;Wüster et al. 2001;Cisneros-Heredia 2006b Figure 3N Observations. Distribution. This species inhabits the western tropical and subtropical zones, at sea level to 1940 m above sea level (Uetz and Hošek 2016;Garzón-Santomaro et al. 2019). In Ecuador, it has been reported in the provinces of Esmeraldas, Pichincha, Manabí, Los Ríos, El Oro, Guayas, Bolívar, Loja, and Santo Domingo de Los Tsáchilas (Kuch 2002;Almendáriz and Carr 2012;Garzón-Santomaro et al. 2019).

Lampropeltis micropholis Cope, 1860
Leptophis occidentalis (Günther, 1859) Figure 3P Material examined. Identification. This species is distinguished from other species of the Oxybelis aeneus complex by the combination of the following characteristics: second pair of geneials in contact for most of their length; distinctive dark midventral stripe on the first quarter of belly; supraocular longer than prefrontals; ventrals 176-187 in females; ventral 178-190 in males; throat without dark spots; last supralabial longer than the first temporal; preocular shorter than eye diameter; usually three supralabials in contact with orbit; and usually nine supralabials (Torres-Carvajal et al. 2021).
Distribution. This species is distributed on the Pacific coast of Ecuador below 1044 m above sea level. It has been reported in the provinces of Azuay, Cañar, El Oro, Esmeraldas, Guayas, Loja, Manabí, and Santa Elena, which mainly inhabit dry forests (Torres-Carvajal et al. 2021).
Identification. The combination of the following characters distinguishes this species: supralabials 8 or 9 (4 and 5 or 5 and 6 in contact with the orbit); infralabials 10 (1-6 in contact with the geneials, rarely 1-5), rarely 11 infralabials (when it is the case, usually 1-7 in contact with the geneials); temporary 2+3
Distribution. This species is distributed from the province of Imbabura in northern Ecuador to the vicinity of latitude 08°S in Peru at 5-2700 m above sea level. Most of the records are on the western slope of the Andes of Ecuador, although it has also been found in the Huancabamba depression, a lower area that divides southern Ecuador and Peru and in the inter-Andean valley of northern Peru. In Ecuador, it has been reported in the provinces of Azuay, Chimborazo, Cotopaxi, El Oro, Esmeraldas, Guayas, Imbabura, Los Ríos, Manabí, Pichincha, Santo Domingo de Los Tsáchilas and Loja (Peters and Orejas-Miranda 1970;Cadle 2010;Garzón-Santomaro et al. 2019; Rodríguez-Guerra and Guerra-Correa 2020).
Identification. The combination of the following characteristics distinguishes this species: non-prehensile tail; lacunolabial scale present; lipsticks usually unmarked; subcaudal scales divided, 53-81 in males and 46-73 in females; intersupraocular scales usually keeled 6-9; ventral scales in both sexes usually 185-220; thin postocular stripe that may not occupy either supralabial or present only on the last two; dorsomedial scale rows usually 25-29, long keels on dorsomedial scales extending to head edge of scale but not to the distal edge of scale; back of body tan, brown, olive green, grey, greyish-brown, pinkish or nearly black with edges of dorsal markings aligned diagonally (Campbell and Lamar 2004

Identification.
The following characters characterize this species: flattened and broad carapace with 24 marginal posterior toothed plates and three undetermined keels that disappear with age, five vertebral and eight coastal; third anterior vertebral less wide than the carapace; rigid plastron, very reduced and cross-shaped with the long and narrow, yellowish bridge, so that a large portion of the soft parts of the animal is exposed; gular shield subdivided into two; triangular head with a pointed snout that has a powerful apical hook; chin rods usually 4-6; round warty and not very pronounced neck tubers; long tail and presents three rows of large and keeled scales on the dorsal side (Ernst et al. 1989;Rueda-Almonacid et al. 2007;MECN 2009;Regalado et al. 2012 (2000) reported Ameiva sp. and Anolis sp. which we consider to be Holcosus sep temlineatus and one of the native species of anoles here reported (Anolis festae or Anolis binotatus). To avoid possible misidentification, we strongly encourage taking photographic records before collecting and preserving specimens. While Jaramillo (2002) and Samaniego (2011) reported Eleutherodactylus sp., Clelia equatoriana, Micru rus sp., and Kinosternum leucostomus, we did not find any of these species in our surveys.
All the species that we report here easily adapt to disturbed ecosystems. However, we found two threatened species, Engystoos guayaco (Vulnerable) and Crocody lus acutus (Vulnerable), and one Near Threatened species, Anolis festae (IUCN 2022). Despite some historical environmental damage on Isla Santay, populations of these three species appear not to be exposed to major local threats except for the presence of introduced species, as mentioned previously. In addition, light and noise pollution may have negative effects due to the proximity to three nearby cities (Guayaquil, Samborondón, and Durán); light and noise pollution has been reported to alter behavioral patterns of herpetofauna, such as activity periods and communication systems (Perry et al. 2008;French et al. 2018). Cruz-Cordovez et al. (2020) previously examined the bullfrog population in Santay, and based on the small population, these authors have suggested that this species may have recently established itself or has been enriched by occasional immigration from upstream populations. Although Cruz-Cordovez et al. (2020) hypothesized that this exotic species may be preying on tadpoles or adults of native species, a more recent analysis of the bullfrog diet (Cruz-Cordovez et al. 2021) found no evidence of amphibian predation. However, Cruz-Cordovez et al. (2020) still recommend controlling bullfrog populations and identifying potential sources of colonizers to minimize the spread of bullfrogs to Santay. Since the bullfrog is one of the five exotic species with a high occurrence and negative impact on local biodiversity (MAE 2019), and the population detected in Santay is apparently small, we suggest implementing permanent monitoring of the species to conduct a risk analysis and develop strategies for the exclusion or eradication of this invasive frog.
Hemydactylus frenatus is reported for the first time in Isla Santay. Jadin et al. (2009) first recorded H. fre natus in Ecuador, in Manabí, and this species has successfully colonized the coastal and Amazonian regions of Ecuador (Torres-Carvajal 2015). While there is no indication of direct competition with other native species, the prevalence of this reptile on the island implies a potential dominance within the community. Nevertheless, to determine appropriate measures for management or exclusion of this species, a comprehensive evaluation of its population status is necessary.
For the first time, we recorded Anolis sagrei on Isla Santay. This island is characterized by its native vegetation and geographic isolation from the A. sagrei mainland population (~1 km apart). Previous reports (Amador 2017; Narváez et al. 2020) suggested that A. sagrei is associated only with urban habitats in Ecuador. Nonetheless, we found two individuals in a native mangrove ecosystem near the island ecovillage. We hypothesize that lizards or eggs have been accidentally transported one or more accidental times on plants from mainland Ecuador nurseries where A. sagrei is common. Considering that we found two native anole species on Isla Santay (A. binotatus and A. festae) and that A. sagrei is highly competitive and can displace other species (Bush et al. 2022), we expect potential interspecific competition on the island. Thus, we suggest two lines of action. First, permanent monitoring of the population of A. sagrei in Santay is recommended, and second, in accordance with the recommendations of environmental authorities (MAE 2019) and considering the early detection of the brown anole in a native environment, it is imperative to rapidly implement controls to dispersal caused by reforestation with infested plants and take immediate action to eradicate the exotic lizard from the Santay.