Halodromus, Muster, 2009

Muster, Christoph, 2009, The Ebo-like running crab spiders in the Old World (Araneae, Philodromidae), ZooKeys 16 (16), pp. 47-73 : 55-57

Genus Halodromus gen. n.

urn:lsid:zoobank.org:act:17BBE7AC-82E4-4E04-BF23-BA84DE086EE4

Ebo Keyserling, 1884 – Levy 1977: 207-208 (ad part.); Wunderlich 1987: 261.

Type species. Ebo patellidens Levy, 1977

Etymology. The name Halodromus refers to the habit of hiding in salt tolerant dwarf shrubs and the relationship to some Philodromus (Rhysodromus) species. Gender masculine.

Diagnosis. Philodromid spiders with enlarged AME (AME size index 0.063 - 0.087) and strongly elongated leg II (Leg II length index 1.3-1.6). Prosoma wider than long ( Figs 13-16 ). Clypeus of intermediate height (Clypeus height index 0.11-0.21, Fig. 9 ). Leg formula 2143. Spination of leg I: femur dorsal 0-1-1, prolateral 0-1-1; tibia ventral 2-2-0, pro- and retrolateral 0-1-1, dorsal 0-0-1; metatarsus ventral 2-2- 0, pro- and retrolateral 1-1-1. Metatarsus IV ventral 2-2-2. Patella of male palp with long apophysis (at least half the length of patella), tibia with rounded RTA ( Figs 17 , 21 , 25 , 29 , 33 ). Embolus stout, its tip pointing to cymbium tip ( Fig. 1 ). PTA present. Conductor a narrow membrane accompanying distal embolus ( Fig. 1 ). Epigyne with pair of both anterior and posterior guide pockets ( Figs 19 , 23 , 27 , 31 , 35 ). Glandular heads without ducts, sitting at main body of receptacula.

Description. Somatic features. Small to moderately sized philodromid spiders, total length (♁ / ♀, n=14/25) 2.0-3.7 / 2.6-5.1, cephalothorax width 0.95-1.75 / 1.15-1.85. Cephalothorax ( Figs 13-16 ) slightly wider than long (CW/CL = 1.03-1.32), dorsal shield brownish with light median band that extends to posterior declivity, metadiscus a whitish V-sign, mesodiscus with conspicuous pattern, allatum usually with reticulating dark lines, posterior edges whitish with pubescence. Eyes in two slightly recurved rows, the second row almost straight, AME distinctly larger than other eyes (AME/ PME 1.25-1.8), AME size index (AME/CW) 0.063 -0.087, AME closer to ALE than to each other, PME interdistance index (PME-PME/PME-PLE) 1.35-2.09, PME almost equidistant to PLE and ALE, lateral eyes larger than medians. Clypeus 1.5 to 3 times as high as diameter of AME ( Fig. 9 ), clypeus height index (ClyH/CW) 0.11- 0.21, often with light patch. Cheliceral furrow without promarginal teeth. Leg formula 2143, leg II strongly elongated, Fem II 1.4-1.55 times longer than Fem I (length femur I 1.15-2.2 / 1.25-2.25, length fem II 2.25-3.25 / 1.85-3.1). Spination of leg I: femur dorsal 0-1-1, prolateral 0-1-1; tibia ventral 2-2-0, pro- and retrolateral 0-1-1, dorsal 0-0-1; metatarsus ventral 2-2-0, pro- and retrolateral 1-1-1. Spination of other legs similar, only metatarsus IV ventral 2-2-2. Tarsi and distal half of metatarsi densely covered with scopulae ( Fig. 4 ). Legs yellowish to orange brown, usually mottled and with twofold annulations at femora, threefold annulations at tibiae and weak annulation at metatarsi. Opisthosoma oval, widest near middle, sides smoothly rounded, posteriorly tapering. Dorsum grey with conspicuous black cardiac mark, flanks often darkish, in posterior half with four to five chevrons.

Pedipalp ( Figs 1 , 17-18 , 21-22 , 25-26 , 29-30 , 33-34 ). Patella with long retrolateral apophysis that is 0.4 to 1.2 times as long as tibia. Tibia with relatively short, broadly rounded RTA, VTA absent, tibia approximately half as long as cymbium. Cymbium drop-like, cymbial tip relatively short, covered with chemosensitive hairs. Cymbium length (CyL) 0.44- 0.74, width (CyW) 0.2-0.44, ratio CyL/cephalothorax width 0.36-0.46. Subtegulum visible in ventral view. Tegulum with large, hooked PTA in retrolateral-distal position. Sperm duct opening between 7 and 9 o’clock position. Conductor a narrow, membranous distal outgrowth of tegulum, partially hidden behind embolus. Embolus at prolateral side of tegulum, divided in basal and distal embolus. Basal embolus widely merged with tegulum, distally often bulged. Distal embolus a stiff, thorn-like structure, pointing to cymbial tip.

Epigyne-vulva ( Figs 19-20 , 23-24 , 27-28 , 31-32 , 35-36 ). Median septum divides the atrium in two epigynal grooves (e.g. Fig. 27 ), or epigynal sutures may be covered by lateral plates, leaving no atrium visible ( Fig. 35 ). Epigyne with two pairs of lateral guide pockets, the posterior guide pockets may be indistinct, anterior guide pockets are heavily sclerotised. Anterior guide pockets may serve for fixation of palpal patella during copulation, the intromittant orifice is presumably situated at the anterior end of the epigynal suture. Receptacula of variable shape, situated near the epigastric furrow ( Fig. 32 ) or shifted anteriorly ( Figs 24 , 36 ), touching each other ( Figs 20 , 36 ) or well separated ( Fig. 32 ). Glandular heads in anterior position at receptacula, ducts very short or absent, independent from intromittent canal. No glandular mounds appreciable at walls of receptacula. Fertilisation ducts at posterior end of receptacula.

Composition and distribution. Five species from Northern Africa (including the Canary and Cape Verde islands) and the Middle East (one presumably reaching the Iberian Peninsula) are included in the new genus. Two of them were hitherto placed in the genus Ebo , three species are newly described. While all species are present in the region around the Red Sea, three are rather widespread in the area outlined above ( Fig. 37 ).

Figures

Figure 37. Distribution of Halodromus species.

Figures 7-16. 7, 11 Ebo pepinensis from Utah Lake 8, 12 Titanebo parabolis from Utah 9, 15 Halodromus patellaris, from Monastir 10 Philodromus lepidus from Kebili, Tunisia 13 Halodromus patellidens from Kuwait 14 Halodromus barbarae sp. n. from Cartagena 16 Halodromus gershomi sp. n. from Massawa 7-10 Female clypeus and chelicerae, frontal view 11-16 Female cephalothorax, dorsal view. Scale lines = 0.5 mm.

Figures 17-20. Halodromus barbarae sp. n. from Cartagena. 17-18 Left male palp (17 ventral, 18 retrolateral) 19 Epigyne, ventral 20 Vulva, dorsal. Scale line = 0.1 mm.

Figures 21-24. Halodromus deltshevi sp. n. from Aden. 21-22 Left male palp (21 ventral, 22 retrolate- ral) 23 Epigyne, ventral 24 Vulva, dorsal. Scale line = 0.1 mm.

Figures 25-28. Halodromus gershomi sp. n. from Aden. 25-26 Left male palp (25 ventral, 26 retrolateral) 27 Epigyne, ventral 28 Vulva, dorsal. Scale line = 0.1 mm.

Figures 29-32. Halodromus patellaris from Monastir. 29-30 Left male palp (29 ventral, 30 retrolateral) 31 Epigyne, ventral 32 Vulva, dorsal. Scale line = 0.1 mm.

Figures 33-36. Halodromus patellidens from Aden. 33-34 Left male palp (33 ventral, 34 retrolateral) 35 Epigyne, ventral 36 Vulva, dorsal. Scale line = 0.1 mm.

Figures 1-6. 1, 4 Halodromus patellaris from Monastir 2 Ebo pepinensis from Utah Lake 3 Titanebo albocaudatus from Abilene 5-6 Titanebo andreaannae from Tucson 1-3 Left male palp, ventral view 4 Tarsal claws and scopulae 5 Epigyne, dorsal view, showing schematic course of the internal ducts (broken black line) and the demarcation between bursa copulatrix and copulatory ducts (white line) 6 Details of receptacula, showing numerous pores in the torus region.