Search results for "Nitella"
showing 7 items of 7 documents
Carbon stable isotope composition of charophyte organic matter in a small and shallow Spanish water body as a baseline for future trophic studies
2015
<p>Quantitative descriptions of foodweb structure based on isotope niche space require knowledge of producers’ isotopic signatures. In freshwater ecosystems charophytes are one of the main components of submerged vegetation and the feeding base for many herbivorous consumers, but knowledge about their organic carbon isotopic signatures is sparse. In this study, the δ<sup>13</sup>C organic values (and organic %C and %N) of the four species of submerged macrophytes (three charophytes - <em>Chara hispida</em>, <em>Nitella hyalina</em> and <em>Tolypella glomerata </em>- and one angiosperm, <em>Myriophyllum spicatum</em>) growing …
Aproximación a las comunidades de carófitos que existieron en la albufera de valencia a partir del estudio de las oósporas del sedimento
2009
14 páginas, 8 figuras, 3 tablas.
New records and observations to the Characean flora (Charales, Charophyceae) of Sicily (Italy)
2019
New records to the Characean flora of Sicily are presented. Five species (Chara baltica, C. conimbrigensis, C. oedophylla, Nitella gracilis, Tolypella salina) are new to Sicily, two of them being also new to Italy (Chara conimbrigensis, C. oedophylla). Two species are confirmed for Sicily (Chara aspera, Nitella opaca), three (Chara braunii, C. canescens, Nitella capillaris) are rare taxa. The Characean flora of Sicily, updated with these records, currently includes 25 species, distributed in four genera: Chara (13 species), Nitella (eight species), Tolypella (three species) and Lamprothamnium (one species).
Stratigraphical ranges of tegulated inoceramid bivalves in the type area of the Maastrichtian Stage (Belgium, the Netherlands)
2018
Abstract Recently collected material, in fine- to medium-grained biocalcarenites and in coeval flint nodules, of the tegulated inoceramid taxa Spyridoceramus tegulatus (von Hagenow, 1842) and Tenuipteria argentea (Conrad, 1858) from various members of the Gulpen Formation and the overlying Maastricht Formation allows their stratigraphical ranges to be refined. It is concluded that the ranges correspond closely to those in east-central Poland (Vistula [Wisla] River valley region), where S. tegulatus occurs in the lower Maastrichtian and lower upper Maastrichtian ( Endocostea typica , Trochoceramus radiosus and ‘ Inoceramus ’ ianjonaensis inoceramid zones, or Belemnella occidentalis and Belem…
Germination capability of four charophyte populations (Characeae) from Mediterranean brackish ponds under warm experimental conditions
2019
ABSTRACTThe diaspore banks from two brackish ponds within the Albufera de Valencia Natural Park (Spain) containing oospores of Chara hispida, C. aspera, C. canescens and Nitella hyalina were analys...
The role of charophytes in a Mediterranean pond created forrestoration purposes
2015
A small, shallow basin was created and flooded with groundwater in a Reserve Area in Albufera de València Natural Park (AVNP) under the scope of a restoration program intended to mimic typical environments such as freshwater springs, abundant in the past but currently suffering from deterioration (desiccation, pollution, etc.), with the ultimate goal of increasing local biodiversity of submerged macrophytes, particularly charophytes. In this study we have monitored, from April 2009 (a few months after its first flooding) to September 2012, the dynamics of charophyte growth and related physical, chemical and biotic variables to highlight the factors determining charophyte success. Just after…
Embryonic Ammonoid Shell Features: Intraspecific Variation Revisited
2001
Two samples of ammonoids belonging to the Oppeliidae, Sublunuloceras virguloidesHecticoceras (Brightii) canaliculatum, are analyzed to estimate the intraspecific variability of embryonic shell features. The study of embryonic shell characters reveals two main shapes of protoconch, flattened and round. Prosiphons may be straight or slightly curved. New parameters for area are added to the linear parameters commonly found in the literature. Prosiphon length and caecum area vary greatly whereas protoconch and ammonitella diameter vary only slightly, and the ammonitella angle is almost constant. The protoconch-to-ammonitella size ratio behaves differently in each species, suggesting different p…