title: On the enigmatic scent glands of dyspnoan harvestmen (Arachnida, Opiliones): first evidence for the production of volatile secretions.
abstract: While considerable knowledge on the chemistry of the scent gland secretions from the opilionid suborders Laniatores and Cyphophthalmi has been compiled, it is the Palpatores (Eupnoi and Dyspnoi) where chemical data are scarce. In particular, the Dyspnoi have remained nearly unstudied, mainly due to their reported general reluctance to release secretions as well as to the phenomenon of production of insoluble-and inaccessible-solid secretion. We here show that at least certain nemastomatid Dyspnoi, namely all three species of genusCarinostoma, indeed produce a volatile secretion, comprising octan-3-one, 6-methyl-5-hepten-2-one and acetophenone in species-specific combinations. In allCarinostomaspp., these volatiles are embedded in a semi-volatile, naphthoquinone matrix (mainly 1,4-naphthoquinone and 6-methyl-1,4-naphthoquinone). In detail, acetophenone and traces of naphthoquinones characterize the secretions ofCarinostoma carinatum. A mixture of octan-3-one, 6-methyl-5-hepten-2-one and large amounts of naphthoquinones were found inC. elegans, and 6-methyl-5-hepten-2-one together with small amounts of naphthoquinones in the secretions ofC. ornatum. So far, exclusively naphthoquinones had been reported from a single dyspnoan hitherto studied,Paranemastoma quadripunctatum.
authors.affiliation: Institute of Zoology, Karl-Franzens-University, Universitätsplatz 2, 8010 Graz, Austria ; Research Unit of Osteology and Analytical Mass Spectrometry, Medical University, University Children's Hospital, Auenbruggerplatz 30, 8036 Graz, Austria.
authors.forename: Günther
authors.initials: G
authors.lastname: Raspotnig
authors.affiliation: Institute of Zoology, Karl-Franzens-University, Universitätsplatz 2, 8010 Graz, Austria ; Department of Limnology and Bio-Oceanography, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
authors.forename: Miriam
authors.initials: M
authors.lastname: Schaider
authors.affiliation: Institute of Plant Sciences, Karl-Franzens-University, Schubertstraße 51, 8010 Graz, Austria.
authors.forename: Edith
authors.initials: E
authors.lastname: Stabentheiner
authors.affiliation: Research Unit of Osteology and Analytical Mass Spectrometry, Medical University, University Children's Hospital, Auenbruggerplatz 30, 8036 Graz, Austria.
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Leis
authors.affiliation: Department of Biology and Ecology, Faculty of Science, University of Novi Sad, Trg Dositeja Obradovica 2, 2100 Novi Sad, Serbia.
authors.forename: Ivo
authors.initials: I
authors.lastname: Karaman
keywords: Carinostoma; Dyspnoi; Ethyl ketone; Methyl ketone; Naphthoquinones; Nemastomatidae