Bioacoustics of Euathlus

Diagnosis Differs from most Theraphosinae by the presence of type IV urticating setae. Male differs by the palpal organ morphology with two prolateral keels ( PI and PS ) and the tip directed retrolaterally ( Figures 4A,B , 5A,B , 6C–E , 7A,B , 8B,C ), tibial apophysis with retrolateral spines, subapical spine on RB and a basal spine on PB ( Figures 4D , 5D , 8A ). Female differs by the presence of two spermathecal receptacles with a lateral spheroid chamber ( Figures 3A , 4C , 5C , 7D ) and only one patch of the urticating setae ( Figures 3C , 4F , 5F ) . Generic redescription Carapace: oval, hirsute, red-brown to black-brown. Caput strongly arched. Fovea: short, transverse to slightly recurved. Well-defined ocular tubercle, wider than long. Clypeus: narrow. Anterior eye row procurved, posterior eye row slightly recurved. Chelicerae: normal, with 6–9 well-developed teeth on promargin of furrow and 6–12 small teeth on the proximal area of furrow. Labium wider than long, with 7–117 cuspules on the subapical margin, broad suture. Maxillae longer than wide, prolateral distal angle slightly produced, with numerous cuspules. Sternum longer than wide, posterior sigilla oval, submarginal. Stridulatory setae absent. Legs black-brown, hirsute, spines present even on femora. Paired claws without teeth on legs and well-developed claw tufts. Retrolateral scopulae on femur IV absent. All tarsi with dense scopulae. Metatarsi I at least scopulated on distal two-thirds. Metatarsi II scopulated on the distal half. Metatarsi III scopulated on the distal one-third. Metatarsi IV scopulated on distal portion. Trichobothria of three types on tarsi; clavate (short), filiform (long) and fusiform (medium-sized) randomly dispersed in a dorsal longitudinal arrangement. Metatarsi and tibiae with only filiform trichobothria arranged in a median, longitudinal and dorsal strip. Abdomen hirsute, with one large patch of urticating setae clearly defined in the central dorsum. Type III and IV urticating setae present. PMS well-developed, PLS normal, apical segment digitiform. Tibia I of males with paired distal prolateroventral strong apophysis, with fused bases and retrolateral spines. RB with an internal subapical spine and 1–3 external spines, PB with an internal spine at basal or medial position. Curved male metatarsi I, except in E.truculentus . Palpal tibiae without spines on retrolateral face and with spines on prolateral face. Femora and tibiae with a prolateral curved spine. Palpal organ piriform with extended subtegulum and curved embolus with two prolateral keels (PI and PS); very flat and serrated PI in E.truculentus . Female palpal tibiae with numerous spines. Spermathecae with two seminal receptacles, each one with a lateral spheroid chamber.