Habronattus arcalorus Maddison & Maddison

Maddison, Wayne P. & Maddison, David R., 2016, Two new jumping spider species of the Habronattusclypeatus group (Araneae, Salticidae, Harmochirina), ZooKeys 625, pp. 1-10 : 4-6

Taxon classification Animalia Araneae Salticidae

Habronattus arcalorus Maddison & Maddison sp. n. Figs 10-21

Holotype.

Male in UBC-SEM, with labels: "TEXAS: Jeff Davis Co.: Davis Mountains State Park 103.939°W, 30.593°N, 22-23 April 1997 Maddison/Hedin/Hebets WPM#97-001" and “♂W167”.

Paratypes

(5♂♂ 3♀♀). 1♂ (specimen W328) 1♀ (specimen W332) in UBC-SEM; 1♂ 1♀ in AMNH; 1♂ 1♀ in MCZ; 2♂ in OSAC; all with same data as holotype.

Etymology.

The name is an arbitrary combination of letters, including the syllable “arc”, included to evoke the rainbow of colors in the male ornaments.

Diagnosis.

The large triangular patella of the third leg of males is distinctive in salticids. Habronattus viridipes (Hentz, 1846) has a triangular patella also ( Griswold 1987: figure 99), but it is different from that of Habronattus arcalorus in colour (orange-yellow with a black spot, rather than grey) and in having a terminal apophysis. Habronattus californicus (Banks, 1904), also of the clypeatus group, has a triangular patella ( Griswold 1987: figure 107), but the patella is smaller and yellow and red. Habronattus arcalorus also differs from Habronattus californicus in having green first legs with a much denser fringe. Females of Habronattus arcalorus are distinctive from most specimens of other clypeatus group species in having a distinct black triangle on the thorax (Figs 19-20).

Note.

This species was referred to by Maddison and Hedin (2003) as Habronattus sp. (CNCTY) (and possibly also Habronattus sp. (CHIH); see note below on Chihuahuan form). Molecular data suggest that Habronattus arcalorus and Habronattus forticulus (Gertsch & Mulaik, 1936) are outside the clade containing the bulk of the clypeatus group species - Habronattus aztecanus (Banks, 1898), Habronattus californicus (Banks, 1904), Habronattus clypeatus , Habronattus divaricatus (Banks, 1898), Habronattus dossenus , Habronattus formosus , and Habronattus velivolus Griswold, 1987. Habronattus arcalorus and Habronattus forticulus are the easternmost representatives of the clypeatus group.

Description.

Male (focal specimen: holotype, specimen W167). Carapace length 2.3; abdomen length 2.3. Structure of chelicerae, legs, and body typical for Habronattus and the clypeatus group. Palp (Figs 10, 11) standard for the clypeatus group ( Griswold 1987 figures 180, 181, 203), with the embolus arising at about 3:00 and the basal portion of the terminal apophysis pointing to 6:00. The tibial apophysis is hooked from ventral view (Fig. 10); in retrolateral view it narrows abruptly before its tip leans ventrally (Fig. 11). First legs (Figs 14, 15, 18, 21): Fringed laterally on the femur, patella, and tibia. Femur prolaterally and ventrally covered with spoon-shaped setae, swollen at the tips. Tibia with two large spatulate macrosetae prolaterally. Third legs (Figs 13, 16, 17): Patella swollen into a large triangle. Colour in life (Figs 14-18, 21): Chelicerae dark, with white setae medially. Palp femur and patella covered with beige scales above; cymbium with scattered white erect setae, especially retrolaterally. First leg dark above, but with light green integument below, and with dense fringes of erect setae prolaterally and retrolaterally on the femur, patella and tibia. These fringes are orange on the femur prolaterally, grading to white elsewhere on femur, patella, and tibia. Spoon-shaped setae on underside of first femur are white at tips. Femur of third leg with transverse white and dark bands (Figs 13, 16) in basal half, blue-white scales in distal half that match similar blue-white scales at front of abdomen (Figs 14-18). Third patella steel-grey with a white fringe above; tibia black with pale band rising obliquely toward the distal and dorsal (Figs 13, 17). Clypeus covered in white setae except for a dark band descending obliquely from each AME. Ocular area rust-coloured, with thin tan band arching between PMEs. Pale thoracic bands wide anteriorly, narrowing to a point at back margin. Abdomen with generous basal band of blue-white scales, broken at the front by two small black lines (Fig. 14). Longitudinal medial band of pale scales on dorsum of abdomen triangular, much wider at front than back. Colour in alcohol: more or less as in life, but with first leg integument yellow-orange, no longer green, and bluish cast of third femur and abdominal basal band not visible.

Female (focal specimen: paratype, specimen W332). Carapace length 2.7; abdomen length 2.8. Structure typical for Habronattus and the clypeatus group. Epigynum (Fig. 12) with long narrow central pocket in front of which is a small semicircular atrium, as is usual for the species group. Colour (Figs 19-20): Uniform beige to tan, with black triangular patch on posterior thorax. Some specimens show two longitudinal dark bands on abdomen (Fig. 20). The clypeus is covered with white scales, but a hint of the dark oblique bands of the male can be seen beneath the white scales. Likewise, there is a hint of the transverse bands on the third femur.

Additional material examined.

USA: TEXAS: Jeff Davis Co.: Davis Mountains State Park 103.939°W, 30.593°N, 22-23 April 1997 Maddison/Hedin/Hebets WPM#97-001 (11 ♂♂, 2 ♀♀, 6 subadult ♂♂, 16 other juveniles). TEXAS: Jeff Davis Co.: Davis Mountains, roadside, highway 118 104.098°W, 30.704°N, 23 April 1997 Maddison/Hedin/Hebets WPM#97-003 (2 ♂♂ 1 ♀). COLORADO: Fremont Co., Royal View Campground. ~9 mi W of Cañon City on HWY 50. N 38.495° W 105.354°. 24 May 1982 D. & W. Maddison WPM#82-108 (10 ♂♂, 6 ♀♀).

Chihuahuan form.

Specimens of a form that may be either a geographical variant of Habronattus arcalorus , or a distinct species, were found in the Tomochic area of Chihuahua, Mexico (Figs 22-26). This is the form referred to by Maddison and Hedin (2003) as " Habronattus sp. (CHIH)". The markings, robust body, and dense fringes on the male first leg match those of Habronattus arcalorus , but the third patella is different (Figs 24, 26): smaller, rounded, dark red in the distal half. The tip of the femur is dark red with white bands, not blue-white as in Habronattus arcalorus . The front of the abdomen is not bluish, nor does the basal band have two clear dark stripes. Habronattus arcalorus and the Chihuahuan form do not group together by mitochondrial data in Maddison and Hedin’s (2003) gene tree, but Maddison and Hedin suggest there is introgression from the coecatus group into the Chihuahuan form, and nuclear data are lacking. It seems likely that a diversity of geographic forms exists in satellite ranges of the Sierra Madre Occidental and Sierra Madre Oriental in Chihuahua and Coahuila, yet to be discovered. Until more detailed studies are done, we will avoid giving a new taxon name to the Chihuahan form, and call it Habronattus cf. arcalorus ( “CHIH”). The material examined of the Chihuahuan form (all in UBC-SEM) is: MEXICO: CHIHUAHUA: 1 mi E of Tomochic on HWY 16. 14 Mar 1996 Susan Masta (6 ♂♂, 5 ♀♀). CHIHUAHUA: 2.7 mi E of Tomochic on HWY 16. 14 Mar 1996 Susan Masta (2 ♀♀). CHIHUAHUA: 10.1 mi E of Tomochic on HWY 16. 14 Mar 1996 Susan Masta (4 ♂♂, 4 ♀♀). CHIHUAHUA: 15 mi N of Madera road to 40 Casas archaeological zone. 15 Mar 1996 Susan Masta (2 ♂♂, 1 ♀).

Natural history.

Habronattus arcalorus was found abundantly in both areas in which it was collected. At the Cañon City locality it was found on rocks on a dry hillside with sparse vegetation and pinyon pines (Fig. 33). In the Davis Mountains of Texas it was found on oak leaf litter mixed with grass and rocks in a stream valley, and on rocks mixed with grass in a juniper-pinyon-oak woodland. Fig. 21 shows a male in courtship pose. Maddison and Leduc-Robert (2013) report the karyotype of Habronattus arcalorus as 26 acrocentric autosomes plus 2 acrocentric X chromosomes in males, as is typical for salticids.