Herpetology Notes, volume 14: 415-420 (2021) (published online on 23 February 2021) The westernmost record of Chalcides boulengeri Anderson, 1892: an overlooked species in the Atlantic coast of Morocco? Pablo García Antón1, David López Bosch2, Javier Lobón-Rovira3,*, Alex Torres-Riera4,5, César L. Barrio-Amorós6, and Alberto Sánchez-Vialas4,7 Morocco is one of the best sampled countries in the and reduced limbs (Carranza et al., 2008). In this sense, Maghreb in terms of herpetofauna, hosting a large former morphologically-based classifications included portion of the North African reptile biodiversity, with the elongated sand-diving species C. sphenopsiformis 107 species of squamates (Bouazza et al., 2021). During (Duméril, 1856) (usually two fingers), C. delislei the last two decades, the knowledge about Moroccan (Lataste and Rochebrune, 1876) (three fingers), and C. herpetofauna has vastly improved through the description boulengeri Anderson, 1892 (five fingers) into a separate of new species and new distribution records (e.g., Harris genus, namely Sphenops. Carranza et al. (2008) revealed et al., 2008, 2010; Crochet et al., 2015; Sánchez-Vialas the non-monophyly of Sphenops, being synonymised and Aznar-González de Rueda, 2016; Javanmardi with the genus Chalcides. The latter is currently et al., 2019; Kane et al., 2019; Miralles et al., 2020). represented in Morocco by 15 species (see Bouazza et This region also represents a source of diversification al., 2021). Chalcides boulengeri is a widespread species for different genera, such as Tarentola and Chalcides in northern Africa, ranging west from Libya to Morocco (Carranza et al., 2002, 2008; Harris et al., 2004). (Trape et al., 2012; del Mármol et al., 2019) (Fig. 1E). In The genus Chalcides Laurenti, 1768, displays a Morocco, this species has been reported in continental remarkable morphological diversity, ranging from sandy areas, from Figuig at the East to the surroundings robust, limbed, pentadactyl species to slender-bodied of Aouinet Ighoumane at the West (del Mármol et al., species with reduced limbs and digits (Lataste, 1876; 2019). Anderson, 1892; Schleich et al., 1996). Fossorial On 12 November 2017 around midday, during a morphological adaptations characterise the sand-diving herpetological survey carried out across Morocco, species, which have usually an elongated shaped body we observed an adult individual of C. boulengeri underneath plastic waste around Tarfaya, in the northern region of Laâyoune-Sakia El Hamra (27.9157°N, 12.9604°W). This region is characterised by a warm 1 Universidad Autónoma de Madrid (UAM), Ciudad desert climate with oceanic influences (Kriticos et al., Universitaria de Cantoblanco, 28049 Madrid, Spain. 2012) and is located within the Atlantic Coastal Desert 2 Museu de Ciències Naturals de Granollers, C. Palaudàries, eco-region (Burguess et al., 2004). The habitat where 102 – Jardins Antoni Jonch Cuspinera, 08402 Granollers, Catalunya, Spain. the specimen was found is formed by coastal dunes 3 Centro de Investigação em Biodiversidade e Recursos with dispersed stones covered by sparse and shrubby Genéticos, Universidade do Porto, Rua Padre Armando vegetation, dominated by Zygophyllum gaetulum Emb. Quintas, Campus de Vairão, 4485-661 Vairão, Portugal. and Maire, and Launaea arborescens (Batt.) Murb. 4 Asociación Bio+, Av. de América, 64. 7oB, 28028 Madrid, (Fig. 1D). Interestingly, C. sphenopsiformis is widely Spain. distributed along the sandy soils of the southern coastal 5 Department of Evolutionary Biology, Ecology and plain of Morocco, being the only formerly reported Environmental Sciences - Institut de Recerca de la Biodiversitat, Faculty of Biology, Universitat de Barcelona, species within the genus Chalcides in Tarfaya region. Av. Diagonal 645, 08028 Barcelona, Catalunya, Spain. Chalcides boulengeri can be readily distinguished from 6 CRWild / Doc Frog Expeditions, Uvita de Osa, Costa Rica. C. sphenopsiformis by a different account of scales rows 7 Museo Nacional de Ciencias Naturales, C/ José Gutiérrez at mid-body [22–24 in C. sphenopsiformis versus 24–28 Abascal, 2, 28006 Madrid, Spain. in C. boulengeri], limb morphology [extremely reduced * Corresponding author. E-mail: [email protected] fore-limbs in C. sphenopsiformis versus more robust © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. limbs in C. boulengeri], digit numbers [two fingers 416 Pablo García Antón et al. and four toes in C. sphenopsiformis versus five fingers have contributed to C. boulengeri gone unnoticed to and five toes in C. boulengeri], and supralabial scale date. The occurrence of C. boulengeri in coastal dunes arrangement [the fourth supralabial in contact with the with oceanic influences, different from the prevailing eye in C. sphenopsiformis versus the fifth supralabial arid climate in previously known continental records, in contact with the eye in C. boulengeri] (Schleich et suggests that this species may have a wider distribution al., 1996), therefore, the specimen herein reported was than has been considered in previous research. However, identified due to unequivocal morphological features human-mediated introduction cannot be rejected (e.g., (Fig. 1A–C). throughout sand carriage from inner regions occupied This work reports the first coastal record of C. by the species and used for road works or constructions boulengeri in Morocco and the westernmost record of as the specimen was located close to the road). the species, 250 km west from the closest known locality In order to better understand the bioclimatic (del Mármol et al., 2019), being the first area of syntopy requirements of C. boulengeri, we performed an between C. boulengeri and C. sphenopsiformis (Fig. 1E). Ecological Niche Model (ENM) along its natural The high abundance of C. sphenopsiformis in this region distribution area in northern Africa (see Table 1), and the fossorial behaviour of the genus Chalcides, may using the R package Maxnet (Phillips et al., 2017). Figure 1. (A–B) Photographs showing the details of the head, the forearm, and the whole body of the individual Chalcides boulengeri observed at Tarfaya, Morocco; (C) photograph showing the details of the head and the forearm of a C. sphenopsiformis individual from the same region; (D) habitat where C. boulengeri and C. sphenopsiformis were found in syntopy; (E) geographical distribution of C. boulengeri and C. sphenopsiformis in northern Africa: green dots represent available records of C. boulengeri; blue dots represent records of C. sphenopsiformis reported by Bons and Geniez, 1996; and the red star depicts the new record of C. boulengeri; (F) bioclimatic niche model of C. boulengeri showing its potential geographic distribution in northern Africa. Photographs taken by: Javier Lobón-Rovira (A–B), Alberto Sánchez-Vialas (C), and Pablo García-Antón (D). The westernmost record of Chalcides boulengeri 417 Table 1. Occurrence localities of Chalcides boulengeri in northern Africa with information on country, locality, coordinates, and source. Country Locality Latitude Longitude Source/Reference Algeria El Oued Province 33.6543°N 7.1783°E Trape et al. (2012) Algeria Naama Province: Aïn Séfra 32.7500°N 0.5833°W GBIF Algeria Ouargla Province 33.1085°N 6.1417°E Trape et al. (2012) Algeria Gardaya Province 32.5175°N 3.6359°E Trape et al. (2012) Algeria Adrar Province 29.5775°N 0.3673°E Trape et al. (2012) Algeria Tinduf Province 27.6541°N 8.0922°W Trape et al. (2012) Algeria Tamanghasset Province 23.5905°N 5.0974°E Trape et al. (2012) Algeria Illizi Province 24.9975°N 8.4090°E Trape et al. (2012) Algeria Béchar Province 30.4622°N 2.2886°W Trape et al. (2012) Algeria Mogheul 31.9299°N 1.9199°W Philip de Pous, pers. comm. Algeria Tinduf Province: Tinduf 27.7000°N 8.1700°W del Mármol et al. (2019) Algeria Illizi Province: Tassili n’Ajjer 25.8129°N 8.1339°E Philippe Geniez, pers. comm. Libya Tripoli 32.8925°N 13.1800°E Bauer et al. (2017) Libya Mellaha 32.8950°N 13.2802°E Bauer et al. (2017) Libya Tripoli 32.7845°N 13.2143°E Bauer et al. (2017) Libya Formolga 32.5166°N 13.2666°E Bauer et al. (2017) Libya Jabal Tarrhona 32.4338°N 13.6344°E Bauer et al. (2017) Libya Nalut 31.8667°N 10.9833°E Bauer et al. (2017) Libya Cabao 31.8500°N 11.3000°E Bauer et al. (2017) Libya Badr 32.0408°N 11.5438°E Bauer et al. (2017) Libya Gadamis 30.1333°N 9.4833°E Bauer et al. (2017) Libya Bu Njem 30.6141°N 15.4005°E Bauer et al. (2017) Libya Sawknah 29.0786°N 15.7842°E Bauer et al. (2017) Libya Jufra Oasis 29.0833°N 15.8500°E Bauer et al. (2017) Tunisia Gafsa: pont Oued el Malah 34.1481°N 8.2925°E Kalboussi et al. (2006) Tunisia Daouz 32.8535°N 10.2895°E Anderson (1892) “Holotype” Tunisia Oued Tefront 32.0868°N 9.7776°E Blanc (1986) Tunisia Kasserine: Firyanah 34.9500°N 8.5670°E GBIF Tunisia 36 km SE of Naftah 33.6485°N 8.1571°E GBIF Tunisia Kebili Gobernorate 33.4607°N 9.0509°E Trape et al. 2012 Tunisia Tataouine Gobernorate 32.3972°N 9.5660°E Trape et al. 2012 Tunisia Medeine Governorate 33.1011°N 9.9485°E Trape et al. 2012 Tunisia Magrane 33.6543°N 7.1783°E Trape et al. 2012 Morocco Figuig 32.1000°N 1.2300°W del Mármol et al. (2019) Morocco Aouinet Lahna 28.4800°N 9.8700°W del Mármol et al. (2019) Morocco Taouz 30.9200°N 3.9900°W del Mármol et al. (2019) Morocco Taouz Ighrem 30.8600°N 4.0300°W del Mármol et al. (2019) Morocco Assa 28.8100°N 9.1400°W del Mármol et al. (2019) Morocco Mahmid 29.8200°N 5.7200°W del Mármol et al. (2019) Morocco Merzouga 31.9300°N 1.9200°W del Mármol et al.