The defensive secretions of Pachyloidellus goliath (Opiliones, Gonyleptidae, Pachylinae).

ACOSTA, L.E.; PORETTI, T.I.; MASCARELLI, P.E.

BONNER ZOOLOGISCHE BEITRÄGE

Zoologisches Forschungsmuseum Alexander Koenig

Lugar: Bonn, Alemania; Año: 1993 vol. 44 p. 19 - 31

0006-7172

The defensive secretions of the Argentinian harvestman Pachyloidellus gohath and their spreading mechanism are studied here. It is established that they consist of two fluids: a colourless one, originating from the mouth, and a yellow one, produced by the scent glands. The former is of an aqueous nature, and reaches the gland opening and the lateral areae of the scutum by means of well-defined, tegumentary grooves; the yellow fluid is then injected into it, and diffuses along the grooves, so that ihe evaporation surface of the defensive substances becomes increased. A preliminary chemical analysis indicates that the gland fluid is composed by a mixture of phenols and quinones. What is known up to now about the dispersal mechanisms of the secretions within the order, as well as the chemical nature of the defensive compounds in Gonyleptoidea, are summarized.