Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | Method for hatching resting eggs from tropical zooplankton: effects of drying or exposing to low temperatures before incubation |
| Abstract | In this study we tested the effects of drying or refrigerating (4 °C)cladoceran resting eggs from a tropical aquatic system on the hatching rates and time to hatching, in order to determine what conditions should or should not be applied to break dormancy in tropical cladocerans; Methods: Resting eggs from two cladoceran species were isolated from the sediment of a coastal lagoon and exposed to drying conditions or low temperatures for four months before incubation under control conditions;Results: For Moina micrura, drying as well as refrigerating eggs reduced the proportion of eggs hatched, but refrigeration also reduced the time to hatching. For Diaphanosoma birgei, refrigeration had no effects either in the proportion of eggs hatched or in time to hatching. Drying resting eggs of D. birgei resulted in no hatchlings after re-hydration; Conclusions: Our results indicate that the pre-exposure of tropical cladoceran resting eggs to low temperatures might not be necessary to break dormancy. Additionally,cooling might even reduce the hatching rates of some species. We suggest that tropical cladoceran resting eggs might be incubated soon after sampling the sediment or, if a period for breaking dormancy is required, they should be better kept under dark and at room temperature conditions. |
| Source | Acta Limnologica Brasiliensia (Impr.) 23 (1), pp. 42–47 |
| Keywords | Hatching rateDormancyResting eggsCladoceraTropical zooplankton |
| Journal | Acta Limnologica Brasiliensia (Impr.) |
| Editor | Sociedade Brasileira de Limnologia, Rio Claro, SP, Brasile |
| Year | 2011 |
| Type | Articolo in rivista |
| DOI | 10.4322/actalb.2011.017 |
| Authors | 1 Jayme Magalhães Santangelo ; 2 Luciana Rabelo Araújo ; 2 Francisco de Assis Esteves ; 3 Marina Manca ; 2 Reinaldo Luiz Bozelli |
| Text | 204388 2011 10.4322/actalb.2011.017 Scopus 2 s2.0 80052599634 Hatching rate Dormancy Resting eggs Cladocera Tropical zooplankton Method for hatching resting eggs from tropical zooplankton effects of drying or exposing to low temperatures before incubation 1 Jayme Magalhães Santangelo ; 2 Luciana Rabelo Araujo ; 2 Francisco de Assis Esteves ; 3 Marina Manca ; 2 Reinaldo Luiz Bozelli 1 Departamento de Ciencias Ambientais, Instituto de Florestas, Universidade Federal Rural do Rio de Janeiro UFRRJ, Rod. BR 465, Km 07, CEP 23890 000, Seropedica, RJ, Brazil ; 2 Universidade Federal do Rio de Janeiro UFRJ, Av. Carlos Chagas Filho, 373, CP 68020, CEP 21941 902, Rio de Janeiro, RJ, Brazil 3 CNR Institute for the Study of Ecosystems, Largo Tonolli 52, 28922, Verbania VB , Italy In this study we tested the effects of drying or refrigerating 4 °C cladoceran resting eggs from a tropical aquatic system on the hatching rates and time to hatching, in order to determine what conditions should or should not be applied to break dormancy in tropical cladocerans; Methods Resting eggs from two cladoceran species were isolated from the sediment of a coastal lagoon and exposed to drying conditions or low temperatures for four months before incubation under control conditions;Results For Moina micrura, drying as well as refrigerating eggs reduced the proportion of eggs hatched, but refrigeration also reduced the time to hatching. For Diaphanosoma birgei, refrigeration had no effects either in the proportion of eggs hatched or in time to hatching. Drying resting eggs of D. birgei resulted in no hatchlings after re hydration; Conclusions Our results indicate that the pre exposure of tropical cladoceran resting eggs to low temperatures might not be necessary to break dormancy. Additionally,cooling might even reduce the hatching rates of some species. We suggest that tropical cladoceran resting eggs might be incubated soon after sampling the sediment or, if a period for breaking dormancy is required, they should be better kept under dark and at room temperature conditions. 23 ID_PUMA cnr.ise/2011 A0 054 Method for hatching resting eggs from tropical zooplankton Method_for_hatching_resting_eggs_from_tropical_zooplankton.pdf Articolo in rivista Sociedade Brasileira de Limnologia 0102 6712 Acta Limnologica Brasiliensia Impr. Acta Limnologica Brasiliensia Impr. Acta Limnol. Bras. Impr. Acta Limnologica Brasiliensia. Impr. marinamarcella.manca MANCA MARINA MARCELLA DG.RSTL.094.012 Evoluzione della biodiversita e valutazione della banca degli stadi duraturi di organismi acquatici di laghi remoti |