Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | An SEM study of the nuchal organ in Daphnia himalaya (nov. sp.) embryos and neonates collected from the Khumbu region (Nepalese Himalayas) |
| Abstract | Zooplankton from the Khumbu region in Nepal are rarely studied, and little is known regarding their morphology and physiology. During the EV-K2-CNR Project, a collaboration between the Government of the Republic of Italy and the Nepal Academy of Science and Technology (NAST) as part of The long distance transport of micro-pollutants, zooplankton samples revealed the presence of small head shields' remains in the sediment possessing a hole in the dorsal margin. This observation led to the hypothesis that Daphnia himalaya neonates must possess a nuchal organ for osmoregulation in these alpine lakes. Here we report the presence of a nuchal organ in embryos and neonates, and explore its development, noting that the nuchal organ is retained up until the first post-embryonic moult. We also examine the chemistry of the lakes and in particular their conductivity, which is lower in lakes having D. himalaya than in lakes that do not (16 ìS and 32 ìS cm-1 respectively). |
| Source | Journal of limnology (Testo stamp.) 66(2), pp. 153–159 |
| Keywords | nuchal organsediment remainsSEMNepalese Himalayas |
| Journal | Journal of limnology (Testo stamp.) |
| Editor | Istituto per lo Studio degli Ecosistemi., Verbania Pallanza, Italia |
| Year | 2007 |
| Type | Articolo in rivista |
| Authors | Peñalva-Arana D.C.(1), Manca M. |
| Text | 52982 2007 nuchal organ sediment remains SEM Nepalese Himalayas An SEM study of the nuchal organ in Daphnia himalaya nov. sp. embryos and neonates collected from the Khumbu region Nepalese Himalayas Peñalva Arana D.C. 1 , Manca M. 1 Department of Biology, Indiana University, Bloomington, IN 47405, USA Zooplankton from the Khumbu region in Nepal are rarely studied, and little is known regarding their morphology and physiology. During the EV K2 CNR Project, a collaboration between the Government of the Republic of Italy and the Nepal Academy of Science and Technology NAST as part of The long distance transport of micro pollutants, zooplankton samples revealed the presence of small head shields remains in the sediment possessing a hole in the dorsal margin. This observation led to the hypothesis that Daphnia himalaya neonates must possess a nuchal organ for osmoregulation in these alpine lakes. Here we report the presence of a nuchal organ in embryos and neonates, and explore its development, noting that the nuchal organ is retained up until the first post embryonic moult. We also examine the chemistry of the lakes and in particular their conductivity, which is lower in lakes having D. himalaya than in lakes that do not 16 iS and 32 iS cm 1 respectively . 66 2 Published version Articolo in rivista Istituto per lo Studio degli Ecosistemi. 1129 5767 Journal of limnology Testo stamp. Journal of limnology Testo stamp. J. limnol. Testo stamp. Journal of limnology. Testo stamp. marinamarcella.manca MANCA MARINA MARCELLA TA.P02.026.002 Limnologia e paleolimnologia di laghi di alta quota |