Revista Mexicana de Biodiversidad Revista Mexicana de Biodiversidad 90 (2019): e902703 Conservation Shelter, ecophysiology and conservation status of Plectostylus araucanus (Pulmonata: Bothriembryontidae) in the fragmented Maulino Forest, central Chile Refugio, ecofisiología y estado de conservación de Plectostylus araucanus (Pulmonata: Bothriembryontidae) en el bosque fragmentado Maulino, Chile central Rodrigo M. Barahona-Segovia a, b, *, Andrea L. Riveros-Díaz c, Sebastián Zaror d, Ricardo Catalán e, Juan Francisco Araya f, g a Laboratorio de Ecología de Ambientes Fragmentados, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Sta. Rosa #11735, La Pintana, Santiago de Chile, Chile b Centro de Estudios en Ecología Espacial y Medio Ambiente - Ecogeografía, Av. José Miguel Claro #2550, Providencia, Santiago de Chile, Chile c Zoológico Nacional de Chile, Pío Nono #450, Recoleta, Santiago, Chile d Facultad de Medicina y Ciencias, Universidad San Sebastián, Av. Los Leones #745, Providencia, Santiago de Chile, Chile e Secretaría Regional Ministerial de Atacama, Ministerio del Medio Ambiente, Portales #830, Copiapó, Chile f Centro de Investigaciones Costeras de la Universidad de Atacama, Universidad de Atacama, Copayapu 485, Copiapó, Chile g Programa de Doctorado en Sistemática y Biodiversidad, Universidad de Concepción, Barrio Universitario s/n, Concepción, Chile *Corresponding author: [email protected] (R.M. Barahona-Segovia) Received: 15 May 2018; accepted: 21 January 2019 Abstract Terrestrial mollusks are one of the least studied groups of terrestrial invertebrates, especially in the Neotropics. In Chile, there is scarce biological and ecological information about many genera, even though the group is quite diverse and occupies different habitats along the country. Plectostylus araucanus is the most recently described species and one of the few arboreal species found only in the coastal native forest of central-south of Chile. In this study, we recorded a new locality for P. araucanus in the Maule region and described ecological and physiological characteristics. The new locality is placed 204 km northwards of the type locality. Based on different records, Plectostylus araucanus is proposed as an endangered (EN) species under the distribution criterion of IUCN. Most of the specimens of P. araucanus were found living in tree cavities and away from the edge of native forest fragments. Physiological measures showed monthly differences, especially between some months of summer and fall and between months of the same season (i.e., summer). We discuss the implications of our results in the microhabitat selection, thermoregulation and habitat use by this tree snail, and the importance of this data in management and conservation for other native malacofauna. Keywords: Habitat fragmentation; Microhabitat; Tree cavities; Tree snail; Thermoregulation ISSN versión electrónica: 2007-8706; Universidad Nacional Autónoma de México, Instituto de Biología. Open Access bajo la licencia CC BY-NC-ND (4.0) https://doi.org/10.22201/ib.20078706e.2019.90.2703 R.M. Barahona-Segovia et al. / Revista Mexicana de Biodiversidad 90 (2019): e902703 2 https://doi.org/10.22201/ib.20078706e.2019.90.2703 Resumen Los moluscos terrestres son uno de los grupos de invertebrados menos estudiados, especialmente en el neotrópico. En Chile, hay poca información biológica y ecológica sobre muchos géneros, a pesar de que el grupo es bastante diverso y ocupa diferentes hábitats a lo largo del país. Plectostylus araucanus fue la última especie descrita, con características arborícolas y restringida al bosque costero del centro-sur de Chile. En este trabajo, se describen características ecológicas y fisiológicas de P. araucanus y registramos una nueva localidad en la región del Maule, la cual se encuentra a 204 km al norte de la localidad tipo. Basados en diferentes registros, P. araucanus se propone como una especie en peligro (EN) según el criterio de distribución de la UICN. La mayoría de los especímenes de P. araucanus se encontraron viviendo en las cavidades de los árboles en fragmentos de bosque nativo y a una distancia moderada del borde de estos. Las medidas fisiológicas mostraron diferencias entre meses, especialmente entre meses de verano y otoño, y meses dentro de la misma estación (por ejemplo, verano). Se discuten las implicaciones de nuestros resultados en la selección de microhábitats, la termorregulación y el uso del hábitat de esta especie, y su uso en el manejo y conservación de otras especies de malacofauna nativa. Palabras clave: Fragmentación del hábitat; Microhábitat; Cavidades de los árboles; Caracol arborícola; Termorregulación Introduction is scarce, although these species are diverse and occupy many habitats along the climatic gradient of the country. Terrestrial mollusks are one of the least studied groups Plectostylus Beck 1837 (Pulmonata: Bothriem- of terrestrial invertebrates (Lydeard et al., 2004). They bryontidae) is a recognized genus of endemic South represent a key component in the decomposition and American land snails, represented in Chile by 13 species nutrient cycle in soil (Jones et al., 1994; Meyer III et distributed from Iquique, Tarapacá region, to del Diablo al., 2011, 2013; Valdovinos & Stuardo, 1988), provide Island, Aysén region (Stuardo & Vega, 1985; Valdovinos food for other invertebrates and vertebrates (Martin, & Stuardo, 1988). This genus is largely extant in different 2000; Nyffeler & Symondson, 2001), and determine plant ecosystems, inhabiting areas from coastal deserts and composition (Hulme, 1996; Peters, 2007). Land snails coastal scrublands in northern Chile (Araya, 2016; Araya are recognized as human perturbation indicators, due to & Catalán, 2014; Jackson & Jackson, 2011), to coastal their low dispersal capabilities and their dependence on and Valdivian forest in central and southern parts of microhabitats for survival and mating (Baur & Baur, 1988; the country (Smith-Ramírez et al., 2007; Valdovinos & Ström et al., 2009). Furthermore, terrestrial mollusks can Stuardo, 1988). Relevant information on taxonomy and be a good indicator for climate change, because of their the systematic position of Plectostylus has been discussed ectothermic condition (Nicolai & Ansart, 2017). by different authors (Breure & Romero, 2012; Valdovinos Neotropical overview of land snails is still poor in & Stuardo, 1988; Van Bruggen et al., 2016). On the other many countries (Régnier et al., 2015), highlighting the hand, several authors (Araya, 2016; Araya & Catalán, malacological studies performed in Argentina (Cuezzo et 2014; Jackson & Jackson, 2011; Valdovinos & Stuardo, al., 2013), Brazil (Simone, 2006), Colombia (Linares & 1988) highlight the deficiency in information about Vera, 2012), Cuba (Espinosa & Ortea, 2009), Ecuador ecology, which is still poorly understood and represent (Breure & Borrero, 2008) and Peru (Breure & Avila, critical gaps, especially concerning changes in land use 2016). In Chile, the study of land snails has been focused and global warming. These threats represent some of the especially in the description of new species (Araya & most important drivers in biodiversity loss of terrestrial Aliaga, 2015; Araya & Breure, 2016; Miquel & Araya, and freshwater mollusks worldwide (Beltramino et al., 2013, 2015; Valdovinos & Stuardo, 1988, 1989); as well 2015; Cordellier et al., 2012; Lydeard et al., 2004; Pearce as studying their distributional range and reporting new & Paustian, 2013; Régnier et al., 2009, 2015). records of exotic species (Araya, 2015a, b, 2016; Araya & Plectostylus araucanus Valdovinos & Stuardo, 1988 Catalán, 2014; Araya et al., 2016, 2017; Cádiz & Gallardo, is the most recently described species of the genus, found 2007; Martínez-de los Ríos, 2017; Stuardo & Vega, 1985; in the forest of the Araucanía region, central-southern Valdovinos, 1999; Valdovinos & Stuardo, 1989). Also, the Chile (Valdovinos & Stuardo, 1988). This species is study of their natural history and ecological characteristics characterized by its large globose-ovate shell of up to a has been poor (Cádiz & Gallardo, 2008; Jackson & Jackson, few cm in height, the presence of strong and noticeable 2011; Valdovinos & Stuardo, 1988). However, in Chile the growth lines (Fig. 1A, B), a brown periostracum, and a biological and ecological information about many genera white columellar lip with a notorious angle in its middle R.M. Barahona-Segovia et al. / Revista Mexicana de Biodiversidad 90 (2019): e902703 3 https://doi.org/10.22201/ib.20078706e.2019.90.2703 part (Valdovinos & Stuardo, 1988). Currently, the known Materials and methods distribution for this species is from the coastal forest of the Nahuelbuta Mountains and its surrounding areas. Both P. This study was conducted in the National Reserve Los araucanus, as well as Plectostylus vagabondiae Brooks, Queules, Tregulemu (35º59’14.38” S, 72º41’21.96” W) in 1936, are true tree snails that probably feed on bryophytes surrounding fragments of deciduous native forest (< 100 living on the cortex of trees (Valdovinos & Stuardo, 1988). ha) and Monterey pine tree (Pinus radiata) plantations. Due to the scarce ecological information on P. araucanus, Native fragments were variable in size, ranging from 29 to the aim of this study is to characterize the habitat type, 242 ha. Native forest is mainly composed of endemic trees shelter preferences and some physiological aspects of this such as Gomortega keule (Molina, 1782) Baill., Aextoxicon arboreal snail, in a locality