Loxosceles amazonica Gertsch, 1967

Fukushima, Caroline Sayuri, Andrade, Rute Maria Goncalves de & Bertani, Rogerio, 2017, Two new Brazilian species of Loxosceles Heinecken & Lowe, 1832 with remarks on amazonica and rufescens groups (Araneae, Sicariidae), ZooKeys 667, pp. 67-94: 68-76

publication ID

http://dx.doi.org/10.3897/zookeys.667.11369

publication LSID

lsid:zoobank.org:pub:569BC83B-D81E-428E-8AD9-D5A664EC5F49

persistent identifier

http://treatment.plazi.org/id/09732FC5-20EB-D7C1-2C80-549D28AB3A17

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scientific name

Loxosceles amazonica Gertsch, 1967
status

 

Loxosceles amazonica Gertsch, 1967  Figs 1-6, 7-13, 14-17, 18-21, 22-25, 26-31, 32-35, 36-39, 40-47, 48-51, 78-79

Loxosceles amazonica  Gertsch, 1967: 143, pl. 4, figs 7−10, pl. 5, figs 6−7 (female holotype examined ( AMNH), Brazil, state of Mato Grosso, Santa Isabel, Araguaia river, Mato Grosso side, 15-25 July 1957, B. Malkin col., receptacles not in the vial); Lucas, Cardoso and Moraes 1986: 130, figs 3−4; Duncan et al. 2010: 241, fig. 3; World Spider Catalog 2016.

Material examined

(Table 3). BRAZIL: Piauí, Serra Branca, Parque Nacional Serra da Capivara, São Raimundo Nonato [9°00'S, 42°41'W], 1 male, 1 female and 11 immatures, R. M. Gonçalves Andrade col. ( MNRJ 6927); Rio Grande do Norte: Serra Negra do Norte, ESEC Seridó (6°34'S, 37°15'W), 2 females and 5 males, C. S. Fukushima, K. C. T. Riciluca and N. M. Gonçalves col., 14 March 2014, ref. Ser 8, 12, 2, 7, 9, 10, 33, respectively ( MNRJ 6928); 1 female, under tree bark, during the night, C. S. Fukushima col., 14 March 2014, ref. C28 ( MNRJ 6929); 1 female, C. S. Fukushima col., 14 March 2014, inside tree trunk, during the day, ref. C44 ( MNRJ 6930); 1 male, C. S. Fukushima col., 14 March 2014, ref. C41 ( MNRJ 7303); Açu, FLONA de Açu (5°34'S, 36°56'W), 1 female, under old house debris, during the night, L. Monteiro col., 30 October 2014, ref. L72 ( MNRJ 6931); 1 female, under tree bark, during the day, C. S. Fukushima col., 30 October 2014, ref. C599 ( MNRJ 6932); 1 female, near Carnaúba trees, during the day, K. C. T. Riciluca col., 26 March 2014, ref. K137 ( MNRJ 6933); 1 female, in a vacated old house during the night, C. S. Fukushima col., 23 March 2014, ref. C163 ( MNRJ 6934); 1 male, under roof tiles, C. S. Fukushima col., 23 March 2014, ref. C167g ( MNRJ 6935); 1 male, under roof tiles, C. S. Fukushima col., 23 March 2014, ref. C167o ( MNRJ 6936); 1 male, under roof tiles, C. S. Fukushima col., 30 October 2014, ref. C631 ( MNRJ 6937); 1 male, in fallen Carnaúba tree, during the night, N. M. Gonçalves col., 25 March 2014, ref. N186 ( MNRJ 6938); 1 male, under roof tiles, during the night, C. S. Fukushima col., 23 March 2014, ref. XXXI ( MNRJ 6939); 1 female, K. C. T. Riciluca col., March 2014, ref. K133 ( MNRJ 7305); Martins (6°04'S, 37°54'W), 1 female, Mirante-Casa de Pedra cave track, during the night, C. S. Fukushima col., 20 March 2014, ref. C144 ( MNRJ 6940); 1 female, near Casa de Pedra cave, during the day, N. M. Gonçalves col., 19 March 2014, ref. N 81 ( MNRJ 6941); 1 female, Mirante-Casa de Pedra cave track, during the day, N. M. Gonçalves col., 20 March 2014, ref. N91 ( MNRJ 6942); 1 female, under fallen tree, near grange of Sr. Clesinho, during the day, A. P. L. Giupponi col., 23 October 2014, ref. A132 ( MNRJ 6943), 1 female, near Casa de Pedra cave, under rock, during the night, C. S. Fukushima col., 23 October 2014, ref. C495 ( MNRJ 6944); 1 male, in a ravine near Casa de Pedra cave, during the night, K. C. T. Riciluca col., 19 March 2014, ref. K59 ( MNRJ 6945); 1 male, near Casa de Pedra cave, during the day, C. S. Fukushima col., 19 March 2014, ref. C103 ( MNRJ 6946); 1 male, in a ravine, C. S. Fukushima col., 19 March 2014, ref. C116 ( MNRJ 6947); 1 female, near Casa de Pedra cave, C. S. Fukushima col., 23 October 2014, ref. C497; 1 male, Mirante-Casa de Pedra cave track, C. S. Fukushima col., 20 March 2014, ref. C148 ( MNRJ 7306); Macaíba, Escola Agrícola de Jundiaí (5°53'S, 35°21'W), 1 male ( MNRJ 6948) and 1 female ( MNRJ 6949), in a tree trunk during the night, C. S. Fukushima and W. Pes soa col., 13 September 2013 (ref. AV046, AV047, respectively); Ceará, Santa Quitéria (4°19'S, 40°09'W), 1 male and 1 immature male, D. R. Pedroso col., 3-12 February 2014 ( MNRJ 6950); 1 male, 1 female and 9 immatures, Gruta W13, SAD’ 69, Camp 1, F. Pellegatti & D. R. Pedroso col., 3-13 February 2014 ( MNRJ 6952).

Diagnosis.

Males of L. amazonica  resemble those of Loxosceles rufescens  , Loxosceles bentejui  Planas & Ribera, 2015, Loxosceles foutadjalloni  Millot, 1941, Loxosceles guayota  Planas & Ribera, 2015, Loxosceles hupalupa  Planas & Ribera, 2015, Loxosceles lacta  Wang, 1994, Loxosceles mahan  Planas & Ribera, 2015, Loxosceles tazarte  Planas & Ribera, 2015, Loxosceles tibicena  Planas & Ribera, 2015, Loxosceles willianilsoni  sp. n., and Loxosceles muriciensis  sp. n. by incrassated palpal tibia, longer than cymbium (Figs 1-2). They differ from those of L. hupalupa  , L. mahan  and L. tazarte  by having shorter embolus (Figs 1-2), and entire pars cephalica as well as carapace border dark brown (Fig. 14), best seen in live specimens. From those of L. rufescens  , L. bentejui  , L. foutadjalloni  , L. guayota  , L. lacta  , L. tibicena  , L. willianilsoni  sp. n. and L. muriciensis  sp. n., they can be distinguished by having embolus with a mild retrolateral curvature along its length (Fig. 11). Females of L. amazonica  resemble those of L. rufescens  , L. bentejui  , L. foutadjalloni  , L. hupalupa  , L. lacta  , L. mahan  , L. tazarte  , L. tibicena  , L. willianilsoni  sp. n. and L. muriciensis  sp. n. by having spermathecae with large seminal receptacles and dark sclerotized lateral bands (Fig. 26). Females of L. amazonica  can be distinguished from all these species by a cluster of globular lobes on apex of seminal receptacles (Figs 26-31). Additionally, L. amazonica  males and females can be distinguished from L. mahan  , L. tazarte  , L. bentejui  , L. guayota  , L. tibicena  and L. hupalupa  by lacking a conspicuous dark V-mark posteriorly on pars cephalica.

Natural history.

Despite its specific epithet, L. amazonica  specimens were found in areas covered by caatinga (Figs 36-47), a semi-arid vegetation found in northeastern Brazil (Fig. 78). At FLONA de Açu, specimens were found under rocks and tree bark, and also under or inside fallen trees, especially carnaúbas ( Copernicia prunifera  Miller) (Figs 36-39). They were also found at vacant old houses inside an area of conservation unit, and under house debris near the FLONA’s base.

The ESEC Seridó is located on a sui generis region of the state of Rio Grande do Norte characterized by a hyper-xerophilous, arboreal-shrubby caatinga, with irregular precipitation of 500 to 800 mm/year ( Varella-Freire 2002). Specimens of L. amazonica  were found throughout different landscapes of the ESEC (Figs 40-43). They were found under rocks and tree bark in shaded areas (Fig. 44), inside termite nests (Fig. 47) or cracks of rocky outcrops (Fig. 45), under fallen trees (Fig. 46) or under house debris near ESEC’s base.

Specimens of L. amazonica  were also found in Martins, state of Rio Grande do Norte, "a brejo de altitude" region, i.e. an area covered by humid forest surrounded by arid caatinga ( Pereira Filho and Montingelli 2011), usually over mountains and hillsides with an elevation of more than 500 m ( Ruiz-Esparza 2009) and that receives more than 1,200 mm of orographic rains (Prado 2003, in Ruiz-Esparza 2009). We found specimens of L. amazonica  in ravines near the town (Fig. 48), in a trail on the top on the hill (Fig. 49) and under old house debris close to more humid and higher areas (about 700 m a.s.l.) (Fig. 50), as well as under rocks and tree bark near Casa de Pedra cave, in a lower region with caatinga vegetation (about 300 m a.s.l.) (Fig. 51). No specimens were found inside Casa de Pedra cave.

Spermatheca variation

(see Fig. 79). Specimens vary in number and size of globular lobes on spermatheca apex and seminal receptacles proportions. Specimens from Martins and Macaíba in the State of Rio Grande do Norte (Figs 26 and 31, respectively), São Raimundo Nonato, state of Piauí (Fig. 27) and Santa Quitéria, state of Ceará (Fig. 30) have three to six lobes in each spermatheca, more or less similar in size. The seminal receptacles of specimens of these areas are slightly short and trapezoid. On the other hand, specimens of ESEC Seridó and FLONA de Açu, both in the state of Rio Grande do Norte (Figs 28 and 29, respectively) have four to five lobes, usually one of them larger than the others. The seminal receptacles are slightly longer, with a triangular shape.

It is not clear how these genitalic traits vary along the distribution of L. amazonica  or if these variations reflect a higher diversity in amazonica  lineage. Variation in the morphology of palps and spermatheca of other Loxosceles  species has already been noted, such as in L. rufescens  ( Brignoli 1969). However, Duncan et al. (2010) recovered a monophyletic group of specimens that morphologically resemble L. rufescens  , within which there are divergent clusters of specimens and populations, but with genetic distances high enough to be considered as cryptic species. In the same way, the slight morphological variations in L. amazonica  could correspond to separated species, only detectable through a molecular approach, which was beyond the scope of this study.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Sicariidae

Genus

Loxosceles