Sarasinula plebeia ( Fischer, 1868 )

Daglio, Eduardo Daniel, Lucía, Micaela de, Gomes, Suzete Rodrigues & Gregoric, Diego Eduardo Gutiérrez, 2020, First records of the bean-slug Sarasinula plebeia (Gastropoda: Veronicellidae) in Argentina, Papéis Avulsos de Zoologia 60, pp. 1-5 : 2-3

Sarasinula plebeia ( Fischer, 1868)

Vaginulus plebeius Fischer, 1868: 145-146 ; Thomé,

1971: 34-36. Vaginula andreana Semper, 1885: 321 . Vaginula behnii Semper, 1885: 310-311 . Vaginula dubia Semper,1885:296 ; Thomé, 1972:252-253. Veronicella hedleyi Simroth, 1889: 552 ; Simroth,

1891: 863-906; Simroth, 1918: 281-292. Vaginula levucana Simroth, 1918: 262-290 . Vaginula samoana Simroth, 1918: 290-291 . Vaginula tahitiana Simroth, 1918: 290-292 . Sarasinula plebeja Grimpe& Hoffmann,1924:177 ; Grimpe

& Hoffmann, 1925a: 19-26; Grimpe & Hoffmann,

1925b: 357-362; Hoffmann, 1925: 190, 251-252;

Thomé, 1975: 25-27. Imerinia plebeja Baker, 1925 ; Hoffmann, 1934: 259-260. Veronicela discrepans Thiele, 1927: 328. Sarasinula lemei Thomé, 1967: 528-531 . Vaginulus (Sarasinula) plebeius Forcart, 1969: 149-150 ;

Aguayo, 1964; Forcart, 1973; Cowie, 1998.

Sarasinula dubia Thomé,1993:71 ; Thomé et al., 1997: 530; Simone, 2006: 96; Agudo-Padrón, 2008: 153.

Vaginula plebeia Cowie, 1997: 38 .

Sarasinula plebeia Thomé, 1975: 25-27 ; Thomé, 1989: 19-23; Thomé, 1993: 71; Thomé et al., 1997: 530; Gomes & Thomé, 2001: 141-143; Gomes & Thomé, 2002; Gomes & Thomé, 2004: 591; Simone, 2006: 97; Agudo-Padrón, 2008: 153.

Material examined: Puerto Iguazú , Misiones province (25°36′39″S, 54°34′49″W), March 2011, N = 1, MLP-Ma 15015 ; Selvas del Río de Oro, Chaco province (26°45′09″S, 58°58′30″W), July 2000, N = 1, MLP-Ma 15016 .

Description ( Fig. 1 ): Thickened notum that sometimes appears dotted ( Fig. 1A ); light brown to dark coloration without pale stripes. The tentacles are contracted and hidden underneath the notum when the slug is dormant. Penis ( Fig.1C ) short,smooth, without annular protrusion, bilaterally symmetrical, with an enlarged glans. There is no spatha. Digitiform gland (= penial gland, Fig. 1B ) with an elongated papilla with 6 short tubules with varying lengths (not bifurcate). Proximal region of the tubules meandering and covered by a thick membrane. The width to length ratio of the papilla is 2.33, and the width to length ratio of the glans is 1.52. Copulation bursa (or spermatheca) formed by a globular and thin sac seat- ed over a thick cylindrical uniform duct, which narrows slightly until it penetrates the integument, where it joins the oviduct, opening in the female genital pore. Canalis junctor (or junctor duct) thin and short, penetrating the narrowest part of the copulation bursa itself.The rectum penetrates the integument near the female genital pore, located near the middle of the right hyponotum.The two nerve pairs,pedal and pallial, originate in their respective ganglia in the periesophageal ring and stretch through the body cavity in two sets, right and left, which runs together from the nerve ganglion to the posterior end of the body, centrally along the foot.The pairs leave a small anterior space for the passage of the main artery (fide Grimpe & Hoffmann, 1925b).

Ecological notes: Both new records were found in residential gardens, under branches and trunks, so it is inferred that the trade-in plants are the pathway of dispersal of this species. The Selvas del Río de Oro locality corresponds to the Humid Chaco terrestrial ecoregion (humid temperate climate), while Puerto Iguazú locality corresponds to the Alto Paraná Atlantic Forest ecoregion (subtropical climate), ecoregions defined by Olson & Dinerstein (2002). Both records are the first to be cited for these terrestrial ecoregions ( Fig. 2 ).

Distribution in South America ( Fig. 2 ): Argentina: Misiones and Chaco provinces (This study). Brazil: States of Rio Grande do Sul, Santa Catarina, São Paulo, Rio de Janeiro, Espírito Santo, Bahia, Pará (Santarém), Paraíba, and Ceará ( Thomé, 1993; Mansur & Thomé, 1994; Thomé et al., 1997; Simone, 2006; Agudo-Padrón, 2008; GBIF, 2020). Colombia: Departments of Risaralda (Pereira),

Atlantico (Barranquilla), Valle del Cauca (Palmira) Antioquía (San NicolasValley),and Caldas.( Götting, 1978; GBIF, 2020). Andina región ( Constantino et al., 2010). Ecuador:Provinces of Zamora and Pichincha (GBIF,2020). Peru: Departments of Lambayeque and Loreto (Iquitos) (GBIF, 2020). Venezuela: States of Anzoátegui (San Tome), Aragua, Caracas (Campo Alegre), Mérida, Miranda (El Hatillo), Monagas, Sucre, and Táchira, ( Fernández de Varela, 1982; Thomé et al., 1997; GBIF, 2020).

Figures

Figure 1. Sarasinula plebeia for Misiones province (MLP-Ma 15015).(A) Dorsal view; (B-C) part of male genitalia;(B) digitiform gland;(C) penis.pe = penis;pa = papilla of the digitiform gland;rm = penis retractor muscle;tu = tubules.Scale bar:A = 1 cm;B and C:1 mm.

Figure 2. Distribution of S. plebeia in South America. Green: ecoregions where S. plebeia is recorded according to Darrigran et al. (2020) and bibliography (see Distribution in the text). Red: new ecoregions with S. plebeia. Yellow circles:newrecords for Argentina.