Kryptochroma septata Machado & Teixeira, 2021

Machado, Miguel, Viecelli, Rafaela, Guzati, Catherine, Grismado, Cristian J. & Teixeira, Renato A., 2021, Kryptochroma: a new genus of bark-dwelling crab spiders (Araneae, Thomisidae), European Journal of Taxonomy 778, pp. 26-70 : 55-63

Kryptochroma septata Machado & Teixeira gen. et sp. nov.

urn:lsid:zoobank.org:act:96E641ED-BE48-4D11-A39B-DED89D51FE29

Figs 16–18 , 20A , 22C

Diagnosis

The female of K. septata sp. nov. is similar to that of K. pentacantha by its general body shape, prominent MS and well-developed median opisthosomal projection. However, females of K. septata sp. nov. can be recognized by the large median septum on the epigynal plate and by the deep excavations where the elliptical copulatory openings are located ( Figs 16C, E , 22C ). The male is similar to that of S. quadrata sp. nov. by the rounded tegulum and to K. pentacantha by the stout and conical RTA, however, can be distinguished from these two species by its shorter, thicker and more curved embolus ( Figs 17C, E , 20A ). Differently from K. pentacantha , in males of K. septata sp. nov. the RTA presents a terminal curvature that makes this apophysis points vertically rather to the backwards of the cymbium ( Figs 17D, F , 20A ).

Etymology

The name is a reference to the remarkable median septum on the epigynal plate of females.

Material examined

Holotype BRAZIL • ♀; Minas Gerais, Vale Verde, Parque Nacional do Caparaó ; 20°25′5.9″ S, 41°50′48.7″ W; 24–30 Nov. 2014; B.T. Faleiro leg.; UFMG 18269 .

Paratype BRAZIL • 1 ♂; same collection data as for holotype; UFMG 22431 .

Additional material

None.

Description

Female (holotype, UFMG 18296)

PROSOMA. Anterior row eye strongly recurved and posterior slightly procurved ( Fig. 16B ); ALE slightly larger than AME; carapace predominantly dark-yellow with cephalic region dark-brown; clypeus yellow; sternum slightly longer than wide, dark-brown with a central yellow stain; labium truncated and totally dark-brown; chelicerae dark-yellow

LEGS. Anterior legs (I and II) dark-yellow with dark taints randomly distributed; posterior legs (III and IV) predominantly yellow.

OPISTHOSOMA. Rough surfaced, predominantly dark-yellow, with dark-brown stains bypassing the upperlateral opisthosomal projections and the median posterior one; a central white macula can be observed on the dorsum ( Fig. 16A ); spermathecae smooth surfaced and kidney-shaped ( Fig. 16D, F ).

MEASUREMENTS. Eye diameters and eye interdistances:AME 0.10,ALE 0.16, PME 0.14, PLE 0.14, AME– AME 0.12, AME–ALE 0.14, PME–PME 0.22, PME–PLE 0.07, MOQ length 0.12, MOQ width 0.20; leg formula: 1-2-4-3: leg I – femur 4/ patella 2.15/ tibiae 2.75/ metatarsus 1.75/ tarsus 1.15/ total 11.80; II – 3.25/ 1.80/ 2.25/ 1.50/ 1.15/ 9.95; III – 1.75/ 1/ 1.50/ 0.90/ 0.90/ 6.05; IV – 2.25/ 0.75/ 1.75/ 1/ 0.80/

6.55. Total body length 7.80; carapace 3.65 length, 3.75 width; opisthosoma length 4.15; clypeus 0.40 height; sternum 1.70 length, 1.50 width; endites 0.90 length, 0.46 width; labium 0.48 length, 0.74 width.

Male (paratype, UFMG 22431)

PROSOMA. Reddish-brown with lighter median area and clypeus ( Fig. 17A–B ).

LEGS. Anterior legs (I and II) reddish-brown with macrosetae sockets yellowish-white; posterior femora (III and IV) bicolor, yellow on their proximal half and reddish-brown on its distal part.

OPISTHOSOMA. Predominantly brown with black punctuations; opisthosomal projections are reddish and bear white maculae on its basis; a dorsal white guanine spot can be also observed on the median region of the dorsum ( Fig. 17A ).

MEASUREMENTS. Eye diameters and eye interdistances: AME 0.07, ALE 0.09, PME 0.07, PLE 0.07, AME–AME 0.09, AME–ALE 0.09, PME–PME 0.16, PME–PLE 0.07, MOQ length 0.28, MOQ width 0.23; leg formula: 1-2-4-3: leg I – femur 1.71/ patella 0.92/ tibiae 1.35/ metatarsus 1.02/ tarsus 0.57/ total 5.57; II – 1.33/ 0.83/ 1.04/ 0.80/ 0.59/ 4.59; III – 0.88/ 0.57/ 0.78/ 0.54/ 0.38/ 3.15; IV – 1.09/ 0.57/ 0.85/ 0.64/ 0.42/ 3.57. Total body length 4.16; carapace 1.97 length, 1.85 width; opisthosoma length 2.19; clypeus 0.23 height; sternum 0.88 length, 0.88width; endites 0.40 length, 0.21 width; labium 0.21 length, 0.30 width.

Distribution

Brazil (Espírito Santo and Minas Gerais) ( Fig. 18 ).

Additional taxonomic acts

The type material of all other Neotropical species hitherto assigned to Stephanopis was examined. The following species do not share the diagnostic characters proposed for Kryptochroma gen. nov., therefore

.

they are being considered as nomina dubia or transferred to other genera recently revised by Teixeira et al. (2014), Silva-Moreira & Machado (2016) and Machado et al. (2018, 2019a).

Figures

Fig. 16. Kryptochroma septata Machado & Teixeira gen. et sp. nov., holotype, ♀ (UFMG 18269). A. Habitus, dorsal view. B. Front. C, E. Epigynal plate, ventral view. D, F. Spermathecae, dorsal view.

Fig. 17. Male of Kryptochroma septata Machado & Teixeira gen. et sp. nov., paratype (22431). A. Habitus, dorsal view. B. Front. C–F. Left male palp. C, E. Ventral view. D, F. Retrolateral view.

Fig. 18. Distribution records of species of Kryptochroma Machado gen. nov.

Fig. 20. Illustrations of the left male palp in ventral and retrolateral view. A. Kryptochroma septata Machado & Teixeira gen. et sp. nov., paratype (UFMG 22431). B. K. hilaris Machado & Teixeira gen. et sp. nov. (MPEG 13239). C. K. macrostyla (Mello-Leitão, 1929) gen. et comb. nov. (MZSP 15320). D. K. parahybana (Mello-Leitão, 1929) gen. et comb. nov. (MPEG 09069)

Fig. 22. Illustrations of epigynum in ventral and dorsal view. A. Kryptochroma pentacantha (Mello- Leitão, 1929) gen. et comb. nov. (MCTP 38671). B. K. quadrata Machado & Viecelli gen. et sp. nov., apratype (MPEG 13297). C. K. septata Machado & Teixeira gen. et sp. nov., holotype (UFMG 18296).