Synotaxus siolii, Santos, Adalberto J. & Rheims, Cristina A., 2005

Santos, Adalberto J. & Rheims, Cristina A., 2005, Four new species and new records for the spider genus Synotaxus Simon, 1895 (Araneae: Synotaxidae) from Brazil, Zootaxa 937, pp. 1-12: 7-9

publication ID 10.5281/zenodo.171147

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scientific name

Synotaxus siolii

n. sp.

Synotaxus siolii  n. sp.

Figures 11 –14View FIGURES 11 – 14, 19View FIGURE 19

Type material. ♂ holotype from Reserva Florestal Adolpho Ducke , Manaus, Amazonas, Brazil, 6.– 9.VIII. 1992, A.D. Brescovit leg., in MCN 22593View Materials.  Paratypes: 1 ♂, same locality as holotype, 18.– 25.II. 1992, A.D. Brescovit leg. ( IBSP 43383)  ; 1 ♀, Alter do Chão , Santarém, Pará, Brazil, 26.I. 1994, A.D. Brescovit leg. ( IBSP 43384). 

Additional material examined. BRAZIL: Amazonas: Manaus, Reserva Florestal Adolpho Ducke , 18.– 25.II. 1992, A.D. Brescovit, 1 ♂ ( MCN 22089View Materials)  ; Pará: Santarém, Alter do Chão , 26.I. 1994, A.D. Brescovit, 1 ♀ ( MCN 25328View Materials)  ; H. Höfer, 1 ♀ ( MCN 25287View Materials)  ; H. Höfer, 1 ♀ ( IBSP 10740). 

Etymology. This species is named after the limnologist Harald Sioli, from Max Planck Institute for Limnology, in recognition of the importance of his pioneering contributions to understanding of the Amazon forest ecology.

Note. ♂♂ and ♀♀ of this species were matched tentatively, based on their collecting localities, as well as on the distribution of S. brescoviti  , a closely related species (see diagnosis below). ♂ and ♀ specimens respectively assigned to S. siolii  and S. brescoviti  were collected in four localities in the Brazilian Amazon. Only two of these localities, Manaus and Santarém, presented both ♂ and ♀ specimens, corresponding to the ♂ S. siolii  and the ♀ S. brescoviti  , as matched in this study. They were not considered as conspecific based on ♂ and ♀ specimens collected together in Una, state of Bahia. These specimens correspond to the ♂♂ and ♀♀ of S. brescoviti  , which were also recorded in two close localities (Jussari and Porto Seguro), although not with both sexes in the same locality (see material examined for S. brescoviti  ). Hence, we presume S. brescoviti  is the only of these species to occur outside Brazilian Amazon, and this was used as a basis to match ♂♂ and ♀♀. Obviously, this matching is still hypothetical, and can be tested in the future with new collections and natural history observations.

Diagnosis. S. siolii  resembles S. brescoviti  by the patellar apophysis emerging from a patellar projection, by the shape of the paracymbium and the presence and shape of the epigynal internal armature. ♂♂ differ by the presence of two rounded apical prongs on the patellar projection and by the small pointed apex of TTA ( Figs. 11–12View FIGURES 11 – 14). ♀♀ are distinguished by the subquadrate internal armature of the epigynum and by the pear­shaped spermathecae ( Figs. 13–14View FIGURES 11 – 14).

Description. ♂ (holotype). Carapace orange, cephalic region pilose. Ocular area overhanging clypeus, with a curved median macrosetae. Ocular area, clypeus, chelicerae, labium and endites cream colored. Sternum white. Coxae and trochanter white, patella orange, other leg segments cream. Legs thin, with numerous setae. Abdomen white, pointed posteriorly and scarcely covered with setae. Total length 3.5, carapace 1.2 long, 0.9 wide. Patella­Tibia I length 4.7, II 3.0, III 2.5, IV 2.8. Abdomen 2.3 long, 0.6 wide. Paracymbium with a prolateral basal swelling, TTA posteriorly elongated and with a dorsal translucent process ( Figs. 11–12View FIGURES 11 – 14).

♀ ( MCN 25328View Materials). Cephalotorax uniformly white. Coxae and trochanter white, other leg segments cream colored, with numerous setae. Abdomen white, pilose, pointed posteriorly. Total length 4.6, carapace 1.1 long, 0.9 wide. Patella­tibia I length 4.1, II 2.3, III 1.1, IV 2.1. Abdomen 3.5 long, 1.1 wide. Copulatory openings, copulatory ducts and accessory sacs inconspicuous, fertilization ducts long and slender.

Distribution. Northeastern Brazil ( Fig. 19View FIGURE 19).


Brazil,Sao Paulo, Sao Paulo, Instituto Butantan


Brazil, Rio Grande do Sul, Porto Alegre, Museu de Ciencias Naturais da Fundacao Zoo-Botanica do Rio Grande do Sul


Instituto Biologico de Sao Paulo