Two new jumping spider species of the Habronattus clypeatus group (Araneae, Salticidae, Harmochirina)

Abstract Two species of the Habronattus clypeatus species group are described, Habronattus arcalorus sp. n. from Texas and Colorado, and Habronattus gilaensis sp. n. from New Mexico. Habronattus arcalorus males have extravagant ornamentation: a green first leg with an unusually dense lateral fringe of orange and white hairs, and a large grey triangular patella on the third leg with blue-white scales nearby. Habronattus gilaensis males are considerably more muted, lacking ornamentation on the third leg’s patella and tibia. Photographs of living specimens are given, as well as notes on habitat.


Introduction
The genus Habronattus F.O. Pickard-Cambridge, 1901 includes jumping spiders whose males have remarkably complex courtship displays, especially the members of a large clade with modified first and third legs (Peckham and Peckham 1890;Griswold 1987;Elias et al. 2003Elias et al. , 2012. Within this clade, the first leg of most males is laterally fringed with modified setae, and the third femur, patella and tibia have several modifications of apophyses, swellings, tufts, and colours. This clade contains 38 described species (Griswold 1987) divided into three species groups, of which the clypeatus species group is restricted to the southwestern United States and Mexico. We here describe two new species of the clypeatus group, one of which has some of the most exaggerated courtship ornamentation known in Habronattus. These two species were referred to in molecular phylogenetic and chromosome studies by the names "Habronattus sp. (CNCTY)" and "Habronattus cf. dossenus" (Maddison and Hedin 2003;Maddison and Leduc-Robert 2013), and are the current focus of continuing behavioural and molecular studies.

Methods
Preserved specimens were examined under both dissecting microscopes and a compound microscope with reflected light. Drawings were made with a drawing tube on a Nikon ME600L compound microscope. All specimens are deposited in the Spencer Entomological Museum of the University of British Columbia (UBC-SEM), except for paratypes deposited (as noted) in the AMNH (American Museum of Natural History), MCZ (Museum of Comparative Zoology, Harvard University) or OSAC (Oregon State Arthropod Collection, Oregon State University, Corvallis).
Terms are used in standard fashion for Araneae. The descriptions were written with primary reference to the focal specimen indicated, which was used for measurements and carefully checked for details, but they apply as far as known to the other specimens examined. All measurements are given in millimeters. Carapace length was measured from the base of the anterior median eyes (AME) not including the lenses to the rear margin of the carapace medially; abdomen length to the end of the anal tubercle. Positions on the bulb of the male palp (left, ventral view) are described using hours of an analog clock's face. The following abbreviations are used: ALE, anterior lateral eyes; PLE, posterior lateral eyes; PME, posterior median eyes (the "small eyes").

The Habronattus clypeatus species group
The eight described species of this group can be distinguished from one another by their male third legs (Figs 1-9) as well as other features. The group is distinctive for having the male clypeus with vertical-oblique dark bands descending from the AME, the basal white band of the abdomen divided by one or two longitudinal medial dark bands, and (usually) a medial longitudinal dark band on the underside of the abdomen. The retrolateral tibial apophysis appears as a hook in ventral view. In addition, in living males of the clypeatus group a pattern of dark spots is visible when the observer looks into the AMEs, consisting of an array of dark pigment patches (see, for example, this video: https://www.youtube.com/watch?v=Dq5ky7vjPYo). It is possible that all Habronattus have such a pigmentation pattern in the eyes, but that it has been observed only in the clypeatus group because the broad depigmented areas on the thorax let in light.  Griswold, 1987,  Species boundaries in the group are not entirely clear. Habronattus clypeatus (Banks, 1895) has two forms, a montane form in most of its range, dark and with the third femur swollen and orange terminally (Fig. 2), and a smaller paler form from the deserts of southern Arizona whose third femur is less modified (Fig. 3). The desert form appears to intergrade with H. formosus (Banks, 1906) (Fig. 5), with the third leg's patella becoming more red and swollen moving west from Phoenix to Yuma. Most recognized species are parapatric or allopatric, but there is at least one case of sympatry: H. dossenus Griswold, 1987 and H. clypeatus in southern Arizona, where they can cooccur in the same small habitat. In such situations, apparent hybrids -male specimens that blend the ornaments of both species -can be found occasionally. The two species described here are distinctive, without any known intergradation with other forms. 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.

Habronattus arcalorus
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 H. 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. H. arcalorus also differs from H. californicus in having green first legs with a much denser fringe. Females of H. 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) Griswold, 1987. H. arcalorus and H. 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 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, 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 rustcoloured, 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 : 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 Chihuahuan form. Specimens of a form that may be either a geographical variant of H. arcalorus, or a distinct species, were found in the Tomochic area of Chihuahua, . This is the form referred to by Maddison and Hedin (2003) as "H. sp. (CHIH)". The markings, robust body, and dense fringes on the male first leg match those of H. 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 H. 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 H. 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 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 H. arcalorus as 26 acrocentric autosomes plus 2 acrocentric X chromosomes in males, as is typical for salticids. Etymology. The name refers to the known distribution of this species, in the region of the Gila River drainage of New Mexico.

Habronattus gilaensis
Diagnosis. The third leg has an unornamented patella and tibia (Fig. 30), unlike all other members of the H. clypeatus group (Figs 1-9). The only other species of the group with green first legs in the male are H. dossenus and H. arcalorus. From H. arcalorus, H. gilaensis differs in many details of ornamentation, especially the third leg. H. gilaensis is most similar to H. dossenus, but differs (in males) in almost complete lack of ornamentation on the third leg, in the paler ocular area, denser and longer fringes on the first leg, denser covering of white setae on the cymbium, and in having the white scales on the side of the carapace broken by a black band extending posteriorly.
Note. This species was referred to as H. cf. dossenus by Maddison and Hedin (2003 (Figs 31,32): Chelicerae dark, with white setae medially. Palp femur and patella covered with beige scales above; cymbium fairly densely covered with white setae. First leg dark above, but with green integument below, and fringes tan to white. Femur of third leg with indistinct transverse bands (Figs 30, 32). Clypeus covered in white setae except for a dark band descending obliquely from each AME. Ocular area light brown to tan, with thin tan bands arching between PMEs. Pale thoracic bands wide anteriorly, narrowing to a point at back margin. Abdomen with basal band of white scales broken at the front by two small black lines (Fig. 31). Longitudinal medial band of pale scales on dorsum of abdomen narrow. Medial longitudinal dark band on underside of abdomen. The dark clypeal bands, pale arching band in the ocular area, and broken basal band are also typical for the clypeatus group. Colour in alcohol: more or less as in life, but with first leg integument yellow-orange, no longer green.
Female (focal specimen: paratype, "female 434"). Carapace length 2.6; abdomen length 3.2. Structure typical for Habronattus and the clypeatus group. Epigynum (Fig. 29) with long narrow central pocket in front of which is a small semicircular atrium, as is usual for the species group. Colour: uniform beige to tan scales covering body. Clypeus covered with white scales. Third femur with a hint of the transverse bands seen in the male.