Alpaida imperialis

Baptista, Renner Luiz Cerqueira, Castanheira, Pedro De Souza & Prado, André Wanderley Do, 2018, Notes on the orb-weaving spider genus Alpaida (Araneae, Araneidae) with description of four new species from Rio de Janeiro, Brazil, Zootaxa 4407 (3), pp. 321-345: 326-329

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Alpaida imperialis

new species

Alpaida imperialis  new species

( Figs. 3–4View FIGURE3View FIGURE 4, Map 1)

Type-material. Holotype ♂. BRAZIL, Rio de Janeiro  : Mendes: Centro Marista São José das Paineiras ( Sede ) 22° 30’ 35.1” S, 043° 45’ 16.5” W, 551 m, 25.II.2015, looking down, R. Baptista coll. ( MNRJ 7468View Materials)GoogleMaps  . Paratypes: BRAZIL, Rio de Janeiro  : Mendes: Centro Marista São José das Paineiras ( Cruzeiro trail) 22° 30’ 41.8” S, 043° 45’ 41.7” W, 652 m, 17.XI.2014, looking down, R. Baptista coll., 1 ♀ ( UFRJ 1421View Materials)GoogleMaps  ; 24.VIII.2014, litter sieving, A. do Prado coll., 1 ♂ (UFRJ 1422); 26.II.2015, looking down, A. do Prado coll., 1 ♀ (MNRJ 7469); idem, Centro Marista São José das Paineiras ( Sede ) 22° 30’ 35.1” S, 043° 45’ 16.5” W, 551 m, 25.II.2015, looking down, R. Baptista coll., 2 ♀ ( MNRJ 7470View Materials)GoogleMaps  ; Rio de Janeiro  : Parque Estadual da Pedra Branca, Camorim ( Açude trail) 22° 58’ 08.3” S, 43° 26’ 38.5” W, 342 m, 14.IX.2013, cryptic, R. Baptista coll., 2 ♀ ( MNRJ 7471View Materials)GoogleMaps  .

Additional material examined. BRAZIL, Rio de Janeiro  : Mendes: Fazenda Arvoredo ( Encruzilhada ) 22° 30’ 16.8” S, 043° 45’ 34.6” W, 510 m, 16.XI.2014, looking down, R. Baptista coll., 1 ♀, 1 immature ( UFRJ 1425View Materials)GoogleMaps  ; Rio de Janeiro  : Parque Estadual da Pedra Branca, Pau-da-fome ( Padaria trail) 22° 56’ 12.8” S, 043° 26’ 29.1” W, 133 m, 22.IX.2013, looking down, R. Baptista coll., 1 ♀ ( UFRJ 1426View Materials)GoogleMaps  ; 17.XII.2013, cryptic, R. Baptista coll., 1 ♀ (UFRJ 1427); 16.III.2014, looking down, R. Baptista coll., 1 ♀ (UFRJ 1428); idem, Parque Estadual da Pedra Branca, Camorim ( Açude trail) 22°58’08.3”S, 43°26’38.5”W, 342 m, 14.IX.2013, looking down, R. Baptista coll., 1 ♀ ( UFRJ 1429View Materials)GoogleMaps  .

Etymology. The specific epithet “ imperialis  ” is a Latin word meaning “from emperor”. It is a reference to the Pedro II Railway, a railroad that connects the cities of Rio de Janeiro and Mendes  and is named after Pedro II (1825–1891), last emperor of Brazil.

Diagnosis. Among closely related species, Alpaida imperialis  new species seems to be most similar to Alpaida imperatrix  new species (see diagnosis of the latter species above for details), but it differs by the absence of a contrasting medial sternal patch, and the epigynum almost rectangular, normally with a smaller notch, and less roundish lips, evidently excavated near the scape and wider at its median portion, which is projected over the sides of the posterior plate ( Fig. 4C –EView FIGURE 4). Also, the palp of A. imperialis  new species is diagnosed by its terminal apophysis much wider than long, with a median crest (instead of a tooth) and larger and inward bent distal lobe ( Fig. 3CView FIGURE3), a longer and acute tegular lobe, the wider and less slanted embolus and median apophysis longer and thinner ( Fig. 3CView FIGURE3), much shorter in ventral view ( Fig. 3DView FIGURE3).

Description. Male (holotype). Carapace, endites, sternum and chelicerae beige. Carapace with a wide median dark-brown stripe from eyes to pedicel, a bit thinner after the fovea ( Fig. 3AView FIGURE3). Eyes placed in anterior black patch ( Fig. 3AView FIGURE3). Chelicerae with paturon covered by black patches over most of its length and with reddish brown fangs. Endites also with black patches at its external side. Sternum beige, with brown margins. Legs pale beige with black patches on basal articles, darker on articulations ( Fig. 3A –BView FIGURE3). Abdomen cylindrical, longer than wide. Abdomen black with some beige spots and white cardiac area ( Fig. 3AView FIGURE3), sidescovered in black, with a median interrupted beige stripe on its first and second thirds, and venter beige, with a pair of transversal thin black stripes over the book-lung openings, a large black patch on its middle third and another one at its posterior margin. Spinnerets beige with a basal black patch. Palp with huge terminal apophysis, much wider than long, bearing a median crest and robust distal lobe, with its tip projected inward; embolus wide, elongated and blade-shaped, slightly slanted ( Figs. 3CView FIGURE3); median apophysis crescent-shaped, around three times longer than wide, also projected inward ( Figs. 3CView FIGURE3); tegular lobe thin and long, laterally projected ( Figs. 3CView FIGURE3). Paracymbium short, hooked ( Fig. 3D –EView FIGURE3). Total length: 3.82. Carapace: 2.14 long, 1.62 wide. Leg I: femur 1.79, patella 0.60, tibia 1.40, metatarsus 1.10 and tarsus 0.59. Patella + tibia II 1.50; III 1.35; IV 1.78.

Female (paratype UFRJ 1421). Carapace and endites light yellow. Carapace with a wide median light-brown stripe from eyes to fovea ( Fig. 4AView FIGURE 4). Eyes, sternum and legs as in male. Chelicerae with brown paturon and reddish brown fangs. Abdomen elongated, roundish at sides and with a posterior acute tip ( Fig. 4BView FIGURE 4). Dorsum greyish, with white cardiac area, sided by a pair of dark grey patches, followed by a pair of U shaped dark grey streaks on the middle third and a big dark grey area on the posterior third ( Fig. 4AView FIGURE 4). Sides covered in black with a median interrupted brown stripe. Venter grey, with abundant guanine dots forming a white contour ( Fig. 4BView FIGURE 4). Spinnerets light brown with basal dark grey spots. Epigynum rectangular, much wider than long, with large and protruding rounded lips, excavated around the short scape, much lighter than surrounding areas ( Fig. 4C –DView FIGURE 4). Posterior plate high, but still wider that high, and slightly depressed in both sides, with lips projected over it at its middle portion ( Fig. 4EView FIGURE 4). Total length: 4.75. Carapace: 1.75 long, 1.51 wide. Leg I: femur 1.26, patella 0.69, tibia 1.20, metatarsus 1.12 and tarsus 0.50. Patella + tibia II 1.73; III 1.24; IV 1.74.

Variation. Males (n = 2): total length, 3,82–4.00; females (n = 11): total length, 3.72–5.34. Endites may vary in colour strength among specimens. Female abdomen can be darker, with black patches more strongly marked, reducing its greyish area. The amount of guanine in venter is variable among specimens of both sexes. Living specimens tend to be darker too. Epigynal notch can be rounded and not as pointed as described (e. g. UFRJ 1429).

Natural History. Alpaida imperialis  new species can be found in habitats very alike Alpaida imperatrix  new species. It was collected near ground by “sieving” litter, searching “cryptic” habitats and using “looking down” sampling techniques. During night, the small vertical orb-webs were easily spotted near rotten logs and large tree roots. The spider was usually crouched at some crevice on the wood surface, holding a signal line connected to the web hub. Sometimes, their webs were placed near the much larger webs of A. tijuca  .

Distribution. Only know from Mendes and Rio de Janeiro  cities, at Rio de Janeiro  state, Brazil (Map 1).


Universidade Federal Rural do Rio de Janeiro