Bioacoustics of Anelosimus kohi

Description Male ( Singapore , Palau Ubin, Chek Jawa, N 1.407°, E 103.991°, 30.iv.2005 , W. Maddison, D. Li, I. Agnarsson, J.X. Zhang): Total length 2.50. Prosoma 1.30 long, 1.30 wide, light or dark brown, center darkest. Sternum 1.00 long, 0.80 wide, pale yellowish. Opisthosoma 1.65 long, 1.30 wide. Pattern as in Figures 3C–D . Eyes subequal in size about 0.10 in diameter. Clypeus height about 1.8 times AME diameter. Leg I femur 1.80, patella 0.65, tibia 1.70, metatarsus 1.70, tarsus 0.70. Femur I about 4 times longer than wide. Leg formula 1243. Leg pale to dark brown, femora and distal tip of tibia darker. 3–5 small trichobothria dorsally on all tibia, 3–4 on tibia I–III, 5 on tibia IV. 2 prolateral and 1 retrolateral trichobothria on palpal tibia. Stridulatory pick row on opisthosoma distinctly curved, with distal setae compressed, consisting of approximately 16–19 modified setal bases ( Fig. 13F ). Epiandrous gland spigots in two separate groups with approximately 8–9 fusules, but less tightly arranged than in many other Anelosimus ( Fig. 13B ). Palpal organ as in Figures 11A–D , 12A–F . Female (data as male): Total length 3.80. Prosoma 1.80 long, 1.45 wide, light or dark brown, center darkest. Sternum 1.10 long, 0.95 wide, pale yellowish. Opisthosoma 2.30 long, 1.75 wide. Pattern as in Figures 3A–B, E–I . Eyes subequal in size about 0.10 in diameter. Clypeus height about 2.1 times AME diameter. Leg I femur 2.40, patella 0.80, tibia 2.10, metatarsus 2.10, tarsus 0.80. Femur I about 5 times longer than wide. Leg formula 1423. Leg pale to dark brown, femora and distal tip of tibia darker. 3–5 small trichobothria dorsally on all tibia, 3–4 on tibia I–II, 4–5 on tibia III–IV. 3 dorsal trichobothria on palpal tibia. Epigynum as in Figures 11E–H , 13A . Va r i a t i o n The color variation is striking in this species, mostly representing two rather distinct color morphs, uniformly reddish brown with dark brown dorsal folium on the opisthosoma ( Figs 3A–C ), or a morph with contrasting colors, a gray opisthosoma, and red dorsal folium bordered by a broad, bright yellow band ( Figs 3D–H ). Some lightly colored, less contrasty forms also exist ( Fig. 3I ). Male total length from 2.40–3.40, femur I from 1.70–2.40. Female total length varies from 3.70–4.40 and femur I from 2.30–2.80. The genitalia of both sexes are quite variable also ( Figs 11A–H , 12A–F , 13A ). The shape of the embolus base, and the length of the embolus tip differ considerably between specimens. The length versus the width of the palpal organ varies with some palps appearing rather long and narrow, others short and stubby. The epigyna also vary in the shape of the epigynal bursa, and of the spermathecae. None of these morphological variations seem to correlate clearly with the color morphs, or localities.