Habronattus aestus Maddison

Maddison, Wayne P., 2017, New species of Habronattus and Pellenes jumping spiders (Araneae, Salticidae, Harmochirina), ZooKeys 646, pp. 45-72 : 46

Habronattus aestus Maddison sp. n. Figs 1-12

Holotype.

Male in CNAN- IBUNAM, with data: México: Sonora: Puerto Peñasco, Estero Morúa, 31.30°N 113.46-113.48°W, 22-23 February 2003, W. Maddison, WPM#03-001.

Paratypes.

(3 ♂♂ 3♀♀): Same data as holotype (1♂ in UBC-SEM, 1♂ in AMNH). México: Sonora: Puerto Peñasco, Estero Cerro Prieto, 31.418°N 113.626°W, 1 m elev., 18 August 2013, W. Maddison & A. Meza López, WPM#13-086 (1♂ [specimen AZS13-7854, Figs 5-7] 2♀♀ in UBC-SEM, 1 ♀ in AMNH).

Etymology.

From the Latin, in reference to the tides and the heat of its habitat.

Diagnosis.

This species can be placed in the americanus group by male ornamentation (shelf of projecting setae under the AME, Fig. 7; darkened first tarsus, Fig. 6) and the relatively short and pointed terminal apophysis (TmA) arising at about 120°. However, unlike other members of the group ( Griswold 1987, figures 184-186), the TmA of Habronattus aestus is thin at the base (Fig. 1), more or less lacking the elbow typical of Habronattus . The male’s scantiness of ornamentation is also distinctive - the first males found were not recognized as adult initially - as is the habitat of saline negative estuaries. Both male and female have the first tibia reddish brown, contrasting against a darker patella (Figs 6 and 9).

Description.

Male (focal specimen: holotype). Carapace length 1.9; abdomen length 1.8. Palp (Figs 1-2) with bulb little rotated, embolus arising at about 140°; TmA thin and with only a hint of an elbow. RTA triangular. First leg with tarsus and metatarsus thicker than usual. Colour: Chelicerae pale, covered with erect white setae. Palp femur, patella, tibia with partially erect white setae, especially long prolaterally. Distal 3/4 of cymbium with fine dark hairs. Legs light to medium brown in alcohol, though darker in life. First leg metatarsus and tarsus dark, with extended dark scopula. Clypeus covered with cream coloured scales, with prominent row of long cream-coloured setae extending forward, forming a shelf (Fig. 7). Carapace dark brown with bronze scales. Abdomen similar to that of the juvenile in Fig. 12, reddish brown with broad paler basal band, two distinctive cream triangles centrally, and lateral cream bands made of paired crescents.

Female (focal specimen: paratype, specimen from Estero Cerro Prieto, Figs 3-4). Carapace length 2.3; abdomen length 3.0. Epigynum with semicircular atria; central pocket broad posteriorly (Fig. 3). Colour: Chelicerae medium brown. Legs medium to pale brown, the first pair darkest. Clypeus covered with white scales, with (as in male) shelf of long white setae projecting forward (Fig. 10). Carapace and abdomen covered with cream-coloured scales except for orange-tan patches on abdomen. Central pale triangles (chevrons) on dorsum connected to lateral bands, as in Figs 8 and 10.

Additional material examined.

Two juveniles and 3 females from the type locality.

Natural history.

Found only in the negative tidal estuaries of Sonora, México. These unusual habitats have salt-tolerant plants (such as Salicornia ) on soil that is constantly wet with salt water, as the tides enter then drain to cut stream-like channels (Figs 95-96). Fresh water is rarely available in this harsh desert. Although Habronattus aestus was found at Estero Morúa, in 2013 it was considerably more common at Estero Cerro Prieta. There, it was found either in retreats in the larger salt-tolerant plants along the edges of the channels, about 20-40 cm above the substrate, or on the mud/sand of the slopes of these channels after shaking the overhanging salt-tolerant plants. The courtship involves behaviours similar to those seen in other americanus -group members, though of weak amplitude. A video of the courtship of male AZS13-7854 is available at https://youtu.be/JUkULLdOZ0w.