Slit sense organs of Comaroma simonii Bertkau: a morphological atlas (Araneae, Anapidae)

The slit sense organs (SSOs) of spiders are mechanoreceptors measuring strains in the cuticle (Barth, 1978). They were discovered by Bertkau (1878) and studied quite intensively by many authors in the following decades (review in Barth, 1967). They are stimulated by a compression perpendicular to the long axis of the slit (Barth, 1972a,b, 1973). The fine structure of slit sensilla is well known (Barth & Deutschländer, 1970; Barth, 1971, 1981), but relatively few data exist about their distribution and arrangement on the body surface of spiders (McIndoo, 1911; Vogel, 1923; Barth & Libera, 1970; Peters & Pfreundt, 1985). The discovery of high variability of these organs in the small anapid spider, Comaroma simonii Bertkau, 1889 (body length 1.6 mm), and our lack of knowledge about the distribution of slit sense organs in small spiders, stimulated this study.