> = the journal of Ch eck Lis t Baitesy data a) NOTES ON GEOGRAPHIC DISTRIBUTIO New record and range extension of Scarthyla goinorum Bokermann, 1962 (Amphibia, Hylidae) from Ouanary, French Guiana Vincent Premel', Benoit Villette’, Thibaut Ferrieux’, Julien Piolain* 1 Independent researcher, Cayenne, French Guiana, France; v.premel@yahoo.fr 2 Association Trésor, Cayenne, French Guiana, France 3 Office National des Foréts de Guyane, Cayenne, French Guiana, France 4 Antilles Guyane Environnement, Cayenne, French Guiana, France Corresponding author: Vincent Premel (v.oremel@yahoo.fr) Abstract. French Guiana is a French overseas territory located in northern South America. Here we report the first record of Scarthyla goinorum (Bokermann, 1962) from this territory, which represents a range exten- sion of 450 km northward from the nearest previously known occurrence in Amapa state, Brazil. This is also the first occurrence outside the Amazon Basin and indicates the ability of the species to disperse efficiently to other watersheds possibly via floating rafts drifting along the coast. Key words. Amazon Basin, Guiana Shield, Coastal Forest Premel V, Villette B, Ferrieux T, Piolain J (2024) New record and range extension of Scarthyla goino- rum Bokermann, 1962 (Amphibia, Hylidae) from Ouanary, French Guiana. Check List 20 (4): 1004-1007. https://doi.org/10.15560/20.4.1004 INTRODUCTION Scarthyla (Duellman & De Sa, 1988) is a Neotropical genus of frog comprising only two recognized species: Scarthyla goinorum (Bokermann, 1962) and Scarthyla vigilans (Solano, 1971). These frogs are characterized by their small size, slender body shape, unwebbed fingers, and nearly fully webbed toes (Duellman and De Sa 1988). Both species have a similar morphology but have distinct calls and morphologically distinct tad- poles (Barrio-Amorés et al. 2006; Duellman and De Sa 1988). Moreover, these two species are allopatrically distributed. Scarthyla vigilans is located to the north of the Andes (Colombia and Venezuela), in the Orinoco Basin, and in Trinidad and Tobago (Barrio-Amords et al. 2006). While S. goinorum is widely distributed throughout the Amazon Basin (Bolivia, Brazil, Colombia, and Peru) (Carmo Telles et al. 2017; De la Riva et al. 2000; Lynch and Suaréz 2011; Upton et al. 2014). METHODS In December 2022, we conducted a biodiversity survey organized by the Office National des Foréts carried out in the municipality of Ouanary, in the western part of French Guiana at a place called Monts de |’Obser- OPEN Qaccess vatoire. The survey was carried out over 5 days, with a base camp and a 1 km long trail from this camp. We found one specimen of S. goinorum (Fig. 1). Despite significant prospecting effort, only one individual was seen and no calls were heard. Academic editor: Javier Ernesto Cortés Suarez Received: 9 August 2023 Accepted: 13 August 2024 RESULTS Published: 21 August 2024 Scarthyla goinorum (Bokermann, 1962) Copyright © The authors. This is an open-access Figure 1 article distributed under terms of the Creative nee te oaeian root. : Commons Attribution License (Attribution 4.0 New records. FRANCE — FRENCH GUIANA « Ouanary municipality; 04°15'13”N, 051°42’53"W; 26 m alt.; International — CC BY 4.0) 14.XII.2023; Vincent Premel & Benoit Villette leg.; in a lowland mature forest; QM 1774. 1004 Premel et al. - New record of Scarthyla goinorum 1005 Figure 1. Scarthyla goinorum from Ouanary, French Guiana. Photo by Vincent Premel Identification. The observed specimen matched the description by Duellman and De Sa (1988). Body elongated (SVL: 19.0 mm), slender, head (HW: 5.5 mm, HL: 5.5 mm) as wide as body longer than wide. Snout long, acuminate in dorsal view and in profile (IND: 2.0 mm). Nostril—orbit distance about 2/3 of the distance between orbit and tip of snout. Ulnar fold and tubercles absent, fingers long, slender with narrow lateral fringes extending to small round discs. Subarticular tubercles moderately large, palmar tubercle low, flat. Hind limbs moderately slender, foot length 41.4—50.5% of snout—vent length (TL: 11.5 mm ; FL: 8.0 mm). Inner tarsal fold evident on distal 2/3 of tarsus, outer metatarsal tubercle absent, inner metatarsal tubercle small, nearly round. Toes long, slender with small round discs nearly as large as those on fingers. DISCUSSION Besides increasing the geographic range of Scarthyla goinorum by more than 450 km and reporting the northernmost known population (Fig. 2), we document here the first record from the Guiana Shield, which is most likely, its range boundary. Nevertheless, more investigations are needed to know if the species extends further into French Guiana. In recent decades, numerous naturalistic inventories have been carried out throughout French Guiana. In addition, citizen science is also a significant contribution of occurrence data (Faune-Guyane and iNatural- ist, two citizen science initiatives) gathered more than 1.5 million naturalist observations in French Guiana. Despite this, there is no previous record from French Guiana of S. goinorum in collections or the literature. This new discovery can be explained by three main reasons: (1) Scarthyla goinorum has a very low intensity call and becomes inaudible in a chorus of other species. As amphibians are mostly acoustically detected, this is potentially why this species has never been con- tacted before. (2) Considering the current range of S. goinorum, this species seems to reach its northeast- ern range boundary in French Guiana where it probably remains confined to its narrow northeastern corner. The extreme north-east of French Guiana is difficult to access because there is no road access to the few villages, which are only accessible by boat. These villages are surrounded by swamp forest, mangroves, or humid palm forests, which makes prospection particularly difficult. Consequently, these remote areas are Still little explored compared to the rest of the territory. (3) Finally, just like Scarthyla vigilans (Rojas-Runjaic et al. 2008), it is possible that S. goinorum is under expansion, colonizing new space from the mouth of the Amazon River to the neighboring regions. Colonization can occur progressively through continuous suitable habitats or by long distance jumps on floating rafts of water hyacinth Eichhornia spp. (Barrio-Amorés et al. 2006; Schiesari et al. 2003) even along the coast between the Amazon River delta to French Guiana. ACKNOWLEDGEMENTS We sincerely thank the Office National des Foréts for the organization and logistics of this mission. Thank you to the whole team for this week of very intense fieldwork. We also thank Antoine Fouquet and Javier Ernesto Cortés Suarez for their comments and review. Check List 20 (4) - https://doi.org/10.15560/20.4.1004 Premel et al. - New record of Scarthyla goinorum 1006 Figure 2. Occurrence record of Scarthyla goinorum on the Amazon basin. Green diamond: records in literature (Carmo Telles et al. 2017; De la Riva et al. 2000; Duellman 2005; Lynch and Suaréz 2011; Upton et al. 2014), blue diamond: records from iNaturalist, orange dot: type locality, red diamond: record in French Guiana. -80°0,000’ -70°0,000’ -60°0,000’ -50°0,000’ 10°0,000’ FRENCH GUIANA COLOMBIA t=) c=] = i=) i] to) - 7 BOLIVIA ~ 4 ©2023 Google, IMTCAN, CNES/Airbus -80°0,000' -70°0,000’ -60°0,000’ -50°0,000’ ADDITIONAL INFORMATION Conflict of interest The authors declare that no competing interests exist. Ethical statement No ethical statement is reported. Funding The data of this publication is based upon the fieldwork led and funded by the Office National des Foréts. This publication is financially supported by Vincent Premel, the first author of this publication. Author contributions Conceptualization: VP. Investigation: BV, JP, TF, VP. Methodology: VP. Resources: VP. Supervision: VP. Writing — original draft: VP. Writing — review and editing: BV, JP, TF, VP. Author ORCID iDs Vincent Premel © https://orcid.org/0009-0008-1725-9736 REFERENCES Barrio-Amoros CL, De Pascual AD, Mueses-Cisneros JJ, Infante E, Chacon A (2006) Hy/a vigilans Solano, 1971, a second species for the genus Scarthyla, redescription and distribution in Venezuela and Colombia. Zootaxa 1349: 1-18. https://doi.org/10.11646/zootaxa 1349.11 Carmo Telles DO, De Carvalho VT, Gordo M, Kaefer IL, Marin da Fonte LF, Menin M (2017) Scarthyla goinorum (Bokermann, 1962): new records for the states of Amazonas and Para, Brazil. Herpetozoa 30 (1-2): 88-92. 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