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Dispersal in the desert: ephemeral water drives connectivity and phylogeography

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HayoAqua

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Krystina D. Mossop, Mark Adams, Peter J. Unmack, Katie L. Smith Date, Bob B. M. Wong and David G. Chapple: Dispersal in the desert: ephemeral water drives connectivity and phylogeography of an arid-adapted fish, Journal of Biogeography (J. Biogeogr.) (2015).

Abstract

Aim
We examine landscape processes shaping the range-wide phylogeography of a dispersal-limited, desert-dwelling fish (the desert goby, Chlamydogobius eremius) in arid Australia.

Location
South-western Lake Eyre Basin, central Australia.

Methods
We obtained sequence data for the mitochondrial cytochrome b gene (n = 513 individuals) and nuclear genetic markers (51 allozyme loci; n ≥ 128 individuals) to investigate the phylogeographic relationships among 51 populations. Sampling spanned multiple habitat types (permanent desert springs, ephemeral rivers) and sub-catchments, and the entire distribution of C. eremius and representatives of its sister species, Chlamydogobius japalpa. Phylogeographic analyses (genetic diversity, AMOVA, Tajima's D, WST, mismatch distribution) were used to explore the distribution and partitioning of mtDNA variation; principal coordinates analysis and neighbour-joining tree networks were used to explore allozyme variation.

Results
Three main genetic groups exist across C. eremius/C. japalpa populations. The geographical distributions of these groups reflected the historical and current confluence point of major rivers in the region. Surprisingly, permanent desert springs did not contain higher genetic diversity than ephemeral rivers.

Main conclusions
Genetic structuring of Chlamydogobius populations revealed unanticipated levels of connectivity, indicating that the ephemeral waters of Lake Eyre have allowed gene flow across drainage boundaries and large distances. Phylogeographic breaks reveal that connectivity relies on temporary surface water, while rapid temporal changes in diversity highlight flood-driven dispersal as the main means of gene flow between localities and habitats. Dispersal pathways reveal that ecological context (life history and tolerance of extreme conditions) has played a key role in shaping observed patterns.

http://onlinelibrary.wiley.com/doi/10.1111/jbi.12596/epdf
« Laatst bewerkt op: oktober 19, 2015, 11:09:31 pm door HayoAqua »
 

Re: Dispersal in the desert: ephemeral water drives connectivity and phylogeography
« Reactie #1 Gepost op: oktober 19, 2015, 11:16:13 pm »
 

HayoAqua

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Citaat
True love: tiny Australian desert fish travel vast distances to find new mate

The 6cm long goby is an ‘average swimmer’ but can travel hundreds of kilometres through Australia’s red centre in just a trickle of water


A desert goby fish. New research shows desert goby fish are able to travel vast distances in very little water in order to reproduce. Photograph: Andreas Svensson for the Guardian

A trickle of water running over parched earth is all the encouragement the desert goby needs. The unassuming little fish, reckoned by researchers to be a poor to average swimmer, only needs a few centimetres of water to follow a rivulet from one isolated, muddy puddle to the next. In the desert rivers region on the southern edge of Lake Eyre in Australia’s red centre, a few centimetres of water may be all it gets.

But their ability to move quickly and opportunistically when floodwaters hit has caught the attention of researchers.


A lake containing desert goby fish. The fish take advantage of floods to move from isolated waterholes, such as this mound spring, to reach new breeding partners. Photograph: David Chapple for the Guardian

“What we think they are doing is very quickly taking advantage of very little amounts of rain,” Krystina Mossop, a PhD candidate from Monash University told Guardian Australia.

“Whenever there’s opportunity for flooding to run between those pools that are otherwise isolated, then the fish are using them and they are using them quite well.”

Mossop and her research partners have spent the past few years heading out to Lake Eyre in a four-wheel drive searching for goby-containing puddles to take a sample of their fin for genetic testing. The results of that research were published in the Journal of Biogeography this month.

The study tracked genetic markers and found the fish were travelling vast distances to reach new mates.

It found close family relations stretching across hundreds of kilometres of arid country and between apparently isolated pools.

The use of flood-driven dispersal despite their poor swimming ability, which Mossop notes is “quite average”, sets the desert goby apart from other species of Australian desert fish which often show more isolated population patterns.

In the dry times, these 6cm almost eel-like yellow and blue fish hang out in water holes that can be little more than small muddy puddles, which get hotter as the daytime temperature creeps up past 40 degrees. They are remarkably hardy and can survive in water three times saltier than seawater and much lower in oxygen.

“They can do pretty well with extremely shallow channels of water and can even hop over moist areas of land for short distances, just enough to get to the next puddle and the next one after that,” said Mossop.

The flooding also creates risk. While it helps the gobies move it also attracts birds, which are happy to make a snack out of an enterprising fish attempting to flip its way across damp sand. Still more will die when the water runs out before they reach the next pool.

“It’s a risky venture but enough fish will get through and reach new patches of water and, more importantly, will reach new potential mates and be able to reproduce,” Mossop said.

Bron: www.theguardian.com/australia-news/2015/oct/19/true-love-tiny-australian-desert-fish-travel-vast-distances-to-find-new-mate
« Laatst bewerkt op: oktober 19, 2015, 11:18:17 pm door HayoAqua »
 

Re: Dispersal in the desert: ephemeral water drives connectivity and phylogeography
« Reactie #2 Gepost op: oktober 20, 2015, 10:23:29 am »
 

Hansopje

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Er moeten toch heel wat slachtoffers vallen onder deze vissen als ze trekken van de ene plas naar de andere, omdat die stroompjes ook snel weer opdrogen. Ik heb de vissen nooit gehad, maar dan lijkt me dat het aantal nakomelingen ook vrij groot is om de soort in stand te houden. Iemand ervaring met dit visje?
 

Re: Dispersal in the desert: ephemeral water drives connectivity and phylogeography
« Reactie #3 Gepost op: oktober 20, 2015, 07:06:06 pm »
 

Bowlover

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Ja jaren geleden was deze vrij populair in de hobby, en inderdaad redelijk grote nesten.
“A mind, once stretched by a new idea, never regains its original dimensions”

Oliver Wendell Holmes