Limits...
Discrimination of Oribotritia species by oil gland chemistry (Acari, Oribatida).

Raspotnig G, Leutgeb V, Krisper G, Leis HJ - Exp. Appl. Acarol. (2011)

Bottom Line: In addition a reduced set of "Astigmata compounds" (sensu Sakata and Norton in Int J Acarol 27:281-291, 2001)--namely the two monoterpenes neral and geranial--could be detected in extracts of O. banksi nevertheless indicating the classification of euphthiracaroids within the (monophyletic) group of "Astigmata compounds-bearing"-Oribatida.These compounds are considered to be apomorphically reduced in all Austrian species.Our findings emphasize the potential of chemosystematics using oil gland secretion profiles in the discrimination of morphologically very similar, syntopically living or even cryptic oribatid species.

View Article: PubMed Central - PubMed

Affiliation: Institute of Zoology, Karl-Franzens-University, Universitätsplatz 2, 8010, Graz, Austria. guenther.raspotnig@uni-graz.at

ABSTRACT
The chemical composition of secretions from opisthonotal (oil) glands in four species of the oribatid mite genus Oribotritia (Mixonomata, Euphthiracaroidea, Oribotritiidae) was compared by means of gas chromatography--mass spectrometry. The secretions of all, O. banksi (from North America) and three Austrian oribotritiids (O. berlesei, O. hermanni, O. storkani), are shown to be based on certain unusual compounds, the iridoid monoterpenes chrysomelidial and epi-chrysomelidial and the diterpene β-springene. These components probably represent general chemical characteristics of oribotriid oil glands. Their relative abundance in the secretions along with further components (mainly saturated and unsaturated C(13)-, C(15)-, C(17)-hydrocarbons, and the tentatively identified octadecadienal) led to well-distinguishable, species-specific oil gland secretions profiles. In addition a reduced set of "Astigmata compounds" (sensu Sakata and Norton in Int J Acarol 27:281-291, 2001)--namely the two monoterpenes neral and geranial--could be detected in extracts of O. banksi nevertheless indicating the classification of euphthiracaroids within the (monophyletic) group of "Astigmata compounds-bearing"-Oribatida. These compounds are considered to be apomorphically reduced in all Austrian species. Our findings emphasize the potential of chemosystematics using oil gland secretion profiles in the discrimination of morphologically very similar, syntopically living or even cryptic oribatid species.

Show MeSH
Canonical discriminant analysis of individual oil gland secretion profiles of 48 individuals of the four Oribotritia species. Four chemical groups were verified, each corresponding to one species (see text for details)
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3105237&req=5

Fig3: Canonical discriminant analysis of individual oil gland secretion profiles of 48 individuals of the four Oribotritia species. Four chemical groups were verified, each corresponding to one species (see text for details)

Mentions: Following cluster analysis, a stepwise discriminant analysis was carried out (again done with all 48 extract profiles), and four distinct chemical groups corresponding to the four species could be verified. Individuals of O. hermanni and O. storkani formed two closely adjacent groups (Fig. 3) but nevertheless appeared to be chemically completely separated. In statistical terms, 100% of cases (=individual profiles) were correctly assigned to the four previously defined morphological groups (=species). Function 1 explained 71.6% of variance (Wilks’ Lambda = 0.001, P < 0.001), whereas function 2 explained 27.1% of variance (Wilks’ Lambda = 0.036, P < 0.001) and function 3 explained only 1.3% of variance, but remained significant (Wilks’ Lambda = 0.579, P < 0.001).Fig. 3


Discrimination of Oribotritia species by oil gland chemistry (Acari, Oribatida).

Raspotnig G, Leutgeb V, Krisper G, Leis HJ - Exp. Appl. Acarol. (2011)

Canonical discriminant analysis of individual oil gland secretion profiles of 48 individuals of the four Oribotritia species. Four chemical groups were verified, each corresponding to one species (see text for details)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105237&req=5

Fig3: Canonical discriminant analysis of individual oil gland secretion profiles of 48 individuals of the four Oribotritia species. Four chemical groups were verified, each corresponding to one species (see text for details)
Mentions: Following cluster analysis, a stepwise discriminant analysis was carried out (again done with all 48 extract profiles), and four distinct chemical groups corresponding to the four species could be verified. Individuals of O. hermanni and O. storkani formed two closely adjacent groups (Fig. 3) but nevertheless appeared to be chemically completely separated. In statistical terms, 100% of cases (=individual profiles) were correctly assigned to the four previously defined morphological groups (=species). Function 1 explained 71.6% of variance (Wilks’ Lambda = 0.001, P < 0.001), whereas function 2 explained 27.1% of variance (Wilks’ Lambda = 0.036, P < 0.001) and function 3 explained only 1.3% of variance, but remained significant (Wilks’ Lambda = 0.579, P < 0.001).Fig. 3

Bottom Line: In addition a reduced set of "Astigmata compounds" (sensu Sakata and Norton in Int J Acarol 27:281-291, 2001)--namely the two monoterpenes neral and geranial--could be detected in extracts of O. banksi nevertheless indicating the classification of euphthiracaroids within the (monophyletic) group of "Astigmata compounds-bearing"-Oribatida.These compounds are considered to be apomorphically reduced in all Austrian species.Our findings emphasize the potential of chemosystematics using oil gland secretion profiles in the discrimination of morphologically very similar, syntopically living or even cryptic oribatid species.

View Article: PubMed Central - PubMed

Affiliation: Institute of Zoology, Karl-Franzens-University, Universitätsplatz 2, 8010, Graz, Austria. guenther.raspotnig@uni-graz.at

ABSTRACT
The chemical composition of secretions from opisthonotal (oil) glands in four species of the oribatid mite genus Oribotritia (Mixonomata, Euphthiracaroidea, Oribotritiidae) was compared by means of gas chromatography--mass spectrometry. The secretions of all, O. banksi (from North America) and three Austrian oribotritiids (O. berlesei, O. hermanni, O. storkani), are shown to be based on certain unusual compounds, the iridoid monoterpenes chrysomelidial and epi-chrysomelidial and the diterpene β-springene. These components probably represent general chemical characteristics of oribotriid oil glands. Their relative abundance in the secretions along with further components (mainly saturated and unsaturated C(13)-, C(15)-, C(17)-hydrocarbons, and the tentatively identified octadecadienal) led to well-distinguishable, species-specific oil gland secretions profiles. In addition a reduced set of "Astigmata compounds" (sensu Sakata and Norton in Int J Acarol 27:281-291, 2001)--namely the two monoterpenes neral and geranial--could be detected in extracts of O. banksi nevertheless indicating the classification of euphthiracaroids within the (monophyletic) group of "Astigmata compounds-bearing"-Oribatida. These compounds are considered to be apomorphically reduced in all Austrian species. Our findings emphasize the potential of chemosystematics using oil gland secretion profiles in the discrimination of morphologically very similar, syntopically living or even cryptic oribatid species.

Show MeSH