Heliocotyle ewingi sp. n. (Monogenea: Monocotylidae) is described from the gills of Myliobatis australis Macleay, 1881 (Myliobatididae) collected from Norfolk Bay near Hobart, Tasmania, Australia. Heliocotyle ewingi can be distinguished readily from the only other species in the genus, Heliocotyle kartasi Neifar, Euzet et Ben Hassine, 1999, by the presence of a single pseudoseptum on each of the peripheral loculi except the posteriormost, eyespots and by the morphology of the male copulatory organ which is a short, straight sclerotised tube which lacks a sclerotised accessory piece. The generic diagnosis is revised to accommodate the new species and the anterior glands are discussed.
Nine Pteromylaeus bovinus (F., Geoffroy St. Hilaire) (Euselachii: Myliobatinae) from the Tunisian coast were examined l'or ectoparasites during 1995, 1996 and 1997. A monogenean found on the gills of seven host specimens is described as a new species and a new genus, Heliocotyle, is proposed to accomodate it. The presence of a single sclerotized haptoral structure on the dorsal surface of the haptor leads us to place this species in the Heterocotylinae Chisholm, Wheeler ct Beverley-Burton, 1995. The genus Heliocotyle is characterized by a haptor with only one dorsal structure and seven loculi, six being subdivided by pseudosepta. Heliocotyle kartasi sp. n. is the type and the only species in this genus.
We studied the survival adaptation strategy of Sophora alopecuroides L. to habitat conditions in an arid desert riparian ecosystem. We examined the responses of heliotropic leaf movement to light conditions and their effects on plant photochemical performance. S. alopecuroides leaves did not show any observable nyctinastic movement but they presented sensitive diaheliotropic and paraheliotropic leaf movement in the forenoon and at midday. Solar radiation was a major factor inducing leaf movement, in addition, air temperature and vapour pressure deficit could also influence the heliotropic leaf movement in the afternoon. Both diaheliotropic leaf movement in the forenoon and paraheliotropic leaf movement at midday could help maintain higher photochemical efficiency and capability of light utilisation than fixed leaves. Paraheliotropic leaf movement at midday helped plants maintain a potentially higher photosynthetic capability and relieve a risk of photoinhibition. Our findings indicated the effective adaptation strategy of S. alopecuroides to high light, high temperature, and dry conditions in arid regions. This strategy can optimise the leaf energy balance and photochemical performance and ensure photosystem II function., C. G. Zhu, Y. N. Chen, W. H. Li, X. L. Chen, G. Z. He., and Obsahuje bibliografii