Asymmetric genitalia, eye stalks and exaggerated palps: the Panjange lanthana group
(published in European J. Taxonomy, 2015)
 

In this paper we describe several new species of the previously monotypic Panjange lanthana species group from the Philippines and document their extraordinary morphology. Some species show strong male genital asymmetry, a phenomenon that seems to be exceedingly rare in spiders. Shown above are the male palps (genitalia) of Panjange malagos, the left one in both lateral views (images 1 and 2) and the right one in the same views (images 3 and 4).



Males of most species have eye stalks, and in two species these eye stalks are among the longest ever recorded in spiders. The biological significance of these stalks (images above: Panjange casaroro) remain a mystery.

Some species show a tendency for male genital (pedipalp) elongation, and Panjange hamiguitan (above, right) has the longest and thinnest palps ever recorded in Pholcidae.