The Antarctic continent is separated and isolated by the Antarctic Circumpolar Current from more northern water masses since millions of years, and hence characterised by low and stable temperatures throughout the whole year. Due to this long isolation a large number of endemic marine
algae and animals have developed in this southern polar region, which probably might respond negatively to the predicted climate change as already observed around the Antarctic Peninsula. For algae the degree of endemism in the Antarctic flora had been well analysed for macroalgae, while for
microalgae such as phytoplankton, sea ice algae or microphytobenthos only few data exist until now. From an ecophysiological standpoint the evaluation and characterisation of the temperature requirements for growth represents a widely used approach to identify algae endemic to Antarctica because
of their adaptation to low temperatures. Since such data on polar diatoms are rare, an Antarctic isolate of the genus Navicula was incubated under a range of temperatures (1, 5, 15, 20, 25 °C) and the growth response followed. In addition, since salinity represents also a variable
parameter along the ice-edges of Antarctica, growth was measured under various salinities between 5 and 50 S
A . Navicula cf. normaloides Cholnoky grew under all salinities between 5 and 50 S
A, but with different rates indicating a broad tolerance
range. This diatom grew between 1°C and 15 °C with an optimum at 5 °C, but at 20 °C and 25 °C growth was completely inhibited. Hence this Navicula species can be described as a stenothermal/psychrotolerant species, because it has a broader temperature tolerance and
prefers higher temperatures compared to other micro- and macroalgae endemic to Antarctica. Navicula cf. normaloides Cholnoky exhibited an unexpectedly broad temperature tolerance, and hence might certainly not be considered as an endemic species, although it can well cope with
cold to temperate conditions.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: 01 September 2016
This article was made available online on 19 May 2016 as a Fast Track article with title: "Growth of the Antarctic sea ice diatom <i>Navicula</i> cf. <i>normaloides</i> Cholnoky at different temperatures and salinities ".
More about this publication?
Algological Studies publishes peer reviewed, original scientific papers of international significance from the entire field of phycology: taxonomy, systematics and floristics, physiology, biochemistry, genetic studies, hydrobiology, phytogeography, cultivation. This includes contributions to algal biotechnology and applied phycology.
Algolgical Studies were published continously since 1968 when they were founded as a supplement series of then Archiv für Hydrobiologie. Beginning in 2007, Algological Studies are published and edited as an independent journal.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Ingenta Connect is not responsible for the content or availability of external websites