I am looking for examples of species that have been known as specialists in a particular ecosystem or niche type (e.g. fish that has evolved life history for a lotic or river environment) and has expanded its niche to exist in a lacustrine environment. Basically, I am interested in examples of niche expansions, particularly in fish. But by niche expansions, I mean an expansion of the entire habitat type that can be exploited, rather than just a single or several life-history traits.
Large river basins (like the amazon, zaire, mekong, ganga-brahmaputra etc) have many areas with environments switching between lotic and lentic on an annual basis. These areas are huge, and there are numerous fish species who adjust to these seasonal changes. Air-breathing fishes are particularly suited to the transition from a flowing system to a stillwater environment with consequent rapid depletion of DO. Winemuller and Golding are two researchers that come to mind who have worked in Africa and the Amazon respectively. Another amazonian ichthyologistt is Cesar Enrique de Melo, whose book is available online..
http://www.entrelinhaseditora.com.br/uploads/produtopdf/0001720139591.pdf
The mahaseer (Tor tor) was a river fish. The British introduced the mahaseer to the lakes of Uttarakhand, in the western Himalaya, India, during the 19th century. Today, they have wiped out the original inhabitants and are well adjusted to life in lakes, along with mirror carps, which were also introduced.
This paper comes to mind: http://rsbl.royalsocietypublishing.org/content/6/6/803.short
It's not spot on what you look for, but may be interesting as an example of a fish adapting to lentic environment.
In Europe there were two good examples of cyprinids I guess. One is asp Aspius aspius living in rivers but very easily adapting to life in lakes and reservoirs. Second is razorfish Pelecus cultratus living in rivers but also in some bigger lakes as Balaton, Neusiedler Lake, Ladoga and Onega lakes and in several reservoirs in Russia and Ukraine.
These are excellent suggestions, and exactly what i have been looking for. They are the same species but can establish these peripheral populations with these alternative or dichotomous life histories.
And thank you, Joacim, that paper is exactly what I needed. It is similar to the rainbow fish example (cited in the paper you sent) by McGuigan (2003). The only question is, are these fish ecological generalists, or are the lake adapted populations, novel strains or races?
”The only question is, are these fish ecological generalists, or are the lake adapted populations, novel strains or races?”
Well, if they are generalist, it is nice of them - especially if You take into account such examples as the one of Salmo trutta... which is usually occurring in the running waters of the mountains, but some of these fish are also present in the Black Sea (at least in the north-western part of this sea - even if the specimens are a little bit bigger and a little bit darker than the ones from the mountain rivers...).
Yes, Zsolt, are you talking about steel-head trout? There are two life-history types. Freshwater spawning populations, and the sea run (steel head trout) which live most of their life times in marine or estuarine waters and then return to rivers to spawn, much like other salmonids (if I'm not mistaken.
Well, I did not know the English vernacular name of the subspecies, but the populations from the mountains are considered as belonging to subspecies Salmo trutta fario, meanwhile the populations from the Black Sea are considered as belonging to the subspecies Salmo trutta labrax.
P:S: may be in the last few decades the species was ”transferred” (or at least proposed to be changed) from the genus Salmo to other one, but the fish is practically the (same) trout...
Hi Daniel,
as I know, Coregonus lavaretus and C. albula primarily live in large, deep and clear lakes but they have small populations in large rivers (like Danube) too.
I think the Omul (Coregonus migratorius) is a good example from Lake Baikal, but correct me if I'm wrong.
In North America the brook trout (aka speckled trout - Salvelinus fontinalis) is normally a stream dewelling char that has anadromous and lake-dwelling populations that differ somewhat morphologially.
We found that clarias gariepinus strains adapts to hydrodynamic reservoir environments through variation in anal fin length. Anal fin is a median fin which plays important role in acceleration in swimming. Long anal fin contributes to fast starts and manoeuvres by increasing thrust-producing surface area of the caudal peduncle region while small anal fin would be beneficial in improving flow regimes across the caudal peduncle
- Badges
- Science method
- Similar topics
- Mathematics
- Statistics
- Statistical Techniques
- Meta-Analysis