Oligoxystre, Vellard, 1924

Bertani, Rogerio, Santos, Thiago & Righi, Alexandre, 2009, A new species of Oligoxystre Vellard 1924 (Araneae, Theraphosidae) from Brazil, ZooKeys 5 (5), pp. 41-51 : 43-44

Identification key for Oligoxystre . Modified from Guadanucci (2007). Female of Oligoxystre auratum is undescribed.

Males

1 Male palpal bulb embolus with small subapical keel ( Guadanucci 2007: Figs 2-5 , 26-28) .................................................................................................2

– Embolus without keel ( Figs 1-3 ; Guadanucci 2007: Figs 22-23, 31-32, 35- 36).............................................................................................................. 3

2 Embolus long and thin, slightly bent distally ( Guadanucci 2007: Figs 26- 28)...................................................................................... O. dominguense

– Embolus short, strongly bent medially ( Guadanucci 2007: Figs 2-5 ) ........ O. bolivianum

3 Bulb twisted on itself, prolonged by long collar, depressed at base and thin apical end, curved ( Vellard 1924: 152, pl. 10 Fig. 38)................ O. auratum

– Bulb not as above........................................................................................4

4 Embolus more than 3 times longer than tegulum ( Guadanucci 2007: Figs 22-23); spiders with cephalothorax and abdomen dark ventrally; white setae over dorsal region of cephalothorax ( Guadanucci 2007: Fig. 38) O. caatinga

– Embolus less than 2.5 times tegulum length ( Figs 1-3 , Guadannuci 2007: Figs 31-23, 35-36); spiders with coloration on ventral portion browish or yellowish; without white setae on body.......................................................5

5 Leg I tibial spur positioned in a perpendicular angle in relation to the tibia axis ( Figs 4-5 ); spiders with carapace, chelicerae, abdomen and legs covered dorsally and ventrally with metallic blue setae ( Fig. 7 )................................... ............................................................................. O. diamantinensis sp. n.

– Leg I tibial spur with branches positioned in an inclined angle in relation to the tibia axis ( Guadanucci 2007: Figs 30, 34); spiders with carapace and legs browish or reddish ...................................................................................... 6

6 Embolus slightly bent distally ( Guadanucci 2007: Figs 31 32); carapace and legs brown ............................................................................ O. tucuruiense

– Embolus slightly curved distally ( Guadanucci 2007: Figs 35-36); carapace and basal portion of legs reddish and distal portions of legs dark ( Guadanucci 2007: Fig. 39)........................................................................... O. rufoniger

Females

1 Spermatheca receptacula as long as wide ( Guadanucci 2007: Fig. 6 ) ............. ............................................................................................. O. bolivianum

– Spermatheca receptacula longer than wide ( Figs 6 ; Guadanucci 2007: Figs 24, 29, 33, 37)............................................................................................ 2

2 Spermatheca receptacula without lateral lobes ( Figs 6 ; Guadanucci 2007: Figs 24, 29)........................................................................................................3

– Spermathecae receptacula with at least one lateral lobe ( Guadanucci 2007: Figs 29, 33, 37)...........................................................................................4

3 Spermatheca receptacula long, with small apical lobes of roughtly the same size ( Guadanucci 2007: Fig. 24); white setae over dorsal region of cephalothorax, ventral cephalothorax and abdomen very dark ................ O. caatinga

– Spermatheca receptacula with a large lobe surrounded by other smaller lobes ( Fig. 6 ); spiders with carapace, chelicerae, abdomen and legs covered dorsally and ventrally with metallic blue setae ( Fig. 8 ) ....... O. diamantinensis sp. n.

4 Spermatheca receptacula very long and thin, with small lobes over entire length ( Guadanucci 2007: Fig. 29) ..................................... O. dominguense

– Spermatheca receptacula long, with wide base, bearing lateral lobe towards outside ( Guadanucci 2007: Figs 33, 37) ..................................................... 5

5 Lateral lobe bifurcated (or partly bifurcated) ( Guadanucci 2007: Fig. 33); carapace and legs brown........................................................ O. tucuruiense

– Lateral lobe not bifurcated ( Guadanucci 2007: Fig. 37); carapace and basal region of legs reddish, apical region of legs dark ........................ O. rufoniger

Figures

Figs 1-6.Oligoxystre diamantinensis sp. n. holotype male 1. left male palpal bulb, prolateral view; 2. left male palpal bulb, retrolateral view; 3. left palp, retrolateral view; 4. left leg I spur, ventral view; 5. Left leg I spur, prolateral view; Paratype female 6. spermathecae, dorsal view. Scale bar: 1 mm.

Figs 7-8.Oligoxystre diamantinensis sp. n. 7. holotype male; 8. paratype female. Photos: 7 Alexandre Righi; 8 Rogério Bertani.