Revista Mexicana de Biodiversidad ISSN: 1870-3453 [email protected] Universidad Nacional Autónoma de México México Eugenio Valdivia, Daniel; Pizarro-Araya, Jaime; Briones, Raúl; Ojanguren-Affilastro, Andrés A.; Cepeda-Pizarro, Jorge Species composition and abundance of solpugids (Arachnida: Solifugae) in ecotopes of the transitional coastal desert of Chile Revista Mexicana de Biodiversidad, vol. 82, núm. 4, diciembre, 2011, pp. 1234-1242 Universidad Nacional Autónoma de México Distrito Federal, México Available in: http://www.redalyc.org/articulo.oa?id=42520885017 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Revista Mexicana de Biodiversidad 82: 1234-1242, 2011 Species composition and abundance of solpugids (Arachnida: Solifugae) in ecotopes of the transitional coastal desert of Chile Composición de especies y abundancia de solífugos (Arachnida: Solifugae) en ecotopos del desierto costero transicional de Chile Daniel Eugenio Valdivia1 , Jaime Pizarro-Araya2, Raúl Briones3, Andrés A. Ojanguren-Affilastro4 and Jorge Cepeda-Pizarro2 1Laboratorio de Aracnología. Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile. 2Laboratorio de Entomología Ecológica, Departamento de Biología, Facultad de Ciencias, Universidad de La Serena, Casilla 599, La Serena, Chile. 3División Manejo Ecosistémico, Bioforets S.A. - Casilla 70-C, Concepción-Chile. 4División Aracnología, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Avenida Ángel Gallardo 470, 1405 DJR Buenos Aires, Argentina. [email protected] Abstract. Using pitfall traps, the species composition and abundance of solpugids were studied in several ecotopes of Chile’s transitional coastal desert. The study was conducted in the area around Punta de Choros (29º15’S, 71º26’W) and in Los Choros Archipelago (29º32’S, 67º61’W), in 2005 and 2006. Five species were recorded: Procleobis sp.; Sedna pirata Muma, 1971 (Ammotrechidae); Mummucia sp.; Mummucia variegata (Gervais, 1849) (Mummuciidae); and Ammotrechelis goetschi Roewer, 1934 (Daesiidae). Solpugid abundance was higher on the continent (65%) than on the islands (35%). The ANOSIM used to evaluate any difference in species richness between ecotopes revealed no significant differences (R= 0.097,p = 0.13). The similarity dendrogram obtained from the Bray-Curtis matrix indicates that there are 3 groups of ecotopes: steppe, dune, and a miscellaneous group. From the data it is inferred that the diversity and abundance of solpugids in the ecotopes studied may be related to plant structure and to the pedological conditions of the habitat. Key words: arachnids, coastal deserts, epigean arthropods, soil biodiversity, Chile. Resumen. Mediante trampas de intercepción se estudió la composición específica y la abundancia de solífugos en diversos ecotopos del desierto costero transicional de Chile. El trabajo se llevó a cabo tanto en el sector de Punta de Choros (29º15’S, 71º26’O) como en el archipiélago de Los Choros (29º32’S, 67º61’O), durante los años 2005 y 2006. Se registró la presencia de 5 especies: Procleobis sp.; Sedna pirata Muma, 1971 (Ammotrechidae), Mummucia sp.; Mummucia variegata (Gervais, 1849) (Mummuciidae) y Ammotrechelis goetschi Roewer, 1934 (Daesiidae). En el sector continental se observó mayor abundancia que en el sector insular (65% y 35%, respectivamente). El ANOSIM aplicado para evaluar la diferencia en la riqueza especifica entre ecotopos, no mostró diferencias significativas (R= 0.097; p= 0.13). El dendrograma de similitud generado a partir de la matriz Bray-Curtis mostró 3 agrupaciones de ecotopos: estepario, dunario y asociación mixta de ecotopos. De los datos se infiere que la diversidad y abundancia de solpúgidos en los ecotopos estudiados puede estar relacionada con la estructura de la vegetación y con las condiciones pedológicas del hábitat. Palabras clave: arácnidos, desiertos costeros, artrópodos epígeos, biodiversidad edáfica, Chile. Introduction Peru (Catenazzi et al., 2009); El Monte, Argentina (Flores et al., 2004); and New Mexico, USA (Muma, 1979; The order Solifugae is considered a meso-diverse Brookhart and Brantley, 2000; Duval and Whitford, taxon with almost 1 100 species described worldwide 2009). In northern Chile, the ecosystems located in (Harvey, 2002, 2003; Shultz, 2007). Solpugids inhabit the transitional desert coastal (i.e., 25-32° Lat S, TDC mainly arid and semiarid ecosystems, such as those found hereafter) are noteworthy in terms of their biological in Atacama, Chile (Cepeda-Pizarro et al., 2005); Paracas, diversity, endemism, and the prospective conservation of their biota (Rundel et al., 1991; Cepeda-Pizarro et al., 2005). Among the arthropods found in the TDC, only a Recibido: 28 abril 2010; aceptado: 02 junio 2011 small number of taxa have attracted researchers’ attention. 682.indd 1 24/11/2011 01:13:03 p.m. Revista Mexicana de Biodiversidad 82: 1234-1242, 2011 1235 For example, the orders of Arachnida that have received Materials and methods the most study are Scorpiones (Ojanguren-Affilastro, 2002; Agusto et al., 2006; Ojanguren-Affilastro et al., Study area and ecotopes. The study was conducted in the 2007) and Acari (Covarrubias et al., 1964, 1976; Cepeda- Los Choros archipelago and on the continental area facing Pizarro, 1989; Cepeda-Pizarro et al., 1992a, 1992b, it, including the Punta de Choros peninsula and the El 1996). Research on Solifugae, in turn, is limited to 2 Apolillado beach (29º15’S, 71º26’W) (Fig. 1; Table 1). contributions, namely Cepeda-Pizarro et al. (2005) who The study area is located almost 114 km north of La Serena studied the effect of the El Niño Southern Oscillation (29º54’S, 71º15’W). The area has a Mediterranean climate (ENSO) on the soil-arthropod assemblage and Valdivia et with numerous cloudy days and morning fog (Di Castri al. (2008) who examined the arthropod density-activity and Hajek, 1976). Air temperature is mild, with a narrow in coastal dunes. temperature range due to the proximity of the Pacific From the point of view of biological diversity and Ocean (Armesto et al., 1993). Dry years (on average less endemism, one of the most important coastal ecosystems than 25 mm of annual precipitation) and wet years (more of the TDC is the Pingüino de Humboldt National than 175 mm) occur in irregular cycles. These cycles are Reserve, formed by the islands of Choros (29º32’S, thought to be related to the El Niño Southern Oscillation 67º61’W) and Damas (29º13’S, 71º31’W). These islands, (ENSO) (Novoa and Villaseca, 1989; Cepeda-Pizarro et along with Gaviota Island (29º15’S, 71º28’W), form al., 2005). In general, the landscape is characterized by a the Los Choros Archipelago (Castro and Brignardello, coastal steppe made up of smaller units (ecotopes hereafter) 2005). Most of the available biological knowledge about that can be created by the presence of water (e.g., arroyos, the archipelago is limited to the avifauna (Luna-Jorquera small wetlands), or may be pedological in nature (e.g., et al., 2000; Simeone et al., 2003, 2004; Mattern et al., sand dunes, stony patches), or geomorphologic features 2004) and vascular plants (Arancio and Jara, 2007). Only (e.g., plains, alluvial fans). The geomorphological details recently work has been done on arthropods in this zone of the study area are described by Castro and Brignardello (Pizarro-Araya and Flores, 2004; Alfaro et al., 2009). (2005). Plant characteristics are described by Marticorena Presently, there is no information on the solpugid fauna et al. (2001) and Arancio and Jara (2007). For this study, of the archipelago so the objectives of this study were (1) 13 sites representing the ecotopes found in the study area to document the species composition of the assemblages were selected. Four sites were located on the continent and of Solifugae found on the above mentioned islands and the remaining 9 on the islands (Table 1). on the continental land in front of these islands; (2) to Field techniques. Solpugids were collected using pitfall document the relative abundance of the species, and (3) traps set up at the study sites (Table 1) where 2 plots (4×5 to compare the assemblage structure of the island and m each) were set up. Each plot contained a grid of 20 continental ecotopes. pitfall traps each separated by 1 m. The trap consisted of Table 1. Study ecotopes located in the continental and island ecosystems of the transitional coastal desert of Chile Ecosystem Ecotope Abbreviation Coordinates Altitude (m.a.s.l) Coastal Steppe CS 29°15′S, 71°26′W 17 Coastal Dune CD 29°16′S, 71°23′W 18 Continent Coastal Wetland CW 29°18′S, 71°21′W 2 Interior Coastal Steppe ICS 29°19′S, 71°19′W 23 Coastal Steppe Choros CSCh 29°32′S, 67°61′W 32 Interior Stony Choros IStCh 29°28′S, 67°59′W 44 Coastal Stony Choros CStCh 29°29′S, 67°58′W 31 North Coastal Steppe Damas NCSD 29°13′S, 71°31′W 18 Archipelago Interior Coastal Steppe Damas ICSD 29°14′S, 71°31′W 3 South Coastal Steppe Damas SCSD 29°14′S, 71°31′W 2 Coastal Dunes Gaviota CDG 29°15′S, 71°28′W 5 Interior Dunes Gaviota IDG 29°15′S, 71°28′W 10 Coastal Steppe Gaviota CSG 29°15′S, 71°26′W 3 682.indd 2 24/11/2011 01:13:03 p.m. 1236 Valdivia et al.- Species composition and abundance of solpugids a plastic jar filled to two thirds with a preserving liquid as which were identified to the species level Ammotrechelis( described in Cepeda-Pizarro et al. (2005). Traps were left goetschi Roewer, 1934; Mummucia variegata (Gervais, for 3 days during each of 4 months in 2005 and 2006. The 1849), and Sedna pirata Muma, 1971), and 2 to the specimens captured were retrieved, cleaned, preserved and genus level (Procleobis sp.