Wednesday, April 23, 2008

The Amazon Molly

From the website of the BBC:
A fish species, which is all female, has survived for 70,000 years without reproducing sexually, experts believe.
Scientists from the University of Edinburgh think the Amazon Molly may be employing special genetic survival "tricks" to avoid becoming extinct.
The species, found in Texas and Mexico, interacts with males of other species to trigger its reproduction process.
The offspring are clones of their mother and do not inherit any of the male's DNA.
Typically, when creatures reproduce asexually, harmful changes creep into their genes over many generations.

The species will eventually have problems reproducing and can often fall victim to extinction.
Scientists at Edinburgh University have been studying complex mathematical models on a highly powerful computing system to look at the case of the Amazon Molly.
Researchers calculated the time to extinction for the fish based on modelling genetic changes over many thousands of generations.
They are now able to say conclusively, for the first time, the fish ought to have become extinct within the past 70,000 years, based on the current simple models.
Scientists believe the fish, which are still thriving in rivers in south-east Texas and north-east Mexico, are using special genetic survival "tricks" to help them stay alive.
One theory is that the fish may occasionally be taking some of the DNA from the males that trigger reproduction, in order to refresh their gene pool.
Species tricks
Dr Laurence Loewe, of the university's School of Biological Sciences, said: "What we have shown now is that this fish really has something special going on and that some special tricks exist to help this fish survive.
"Maybe there is still occasional sex with strangers that keeps the species alive. Future research may give us some answers."
He added that their findings could also help them understand more about how other creatures operate.
"I think one of the interesting things is that we are learning more about how other species might use these tricks as well," he said.
"It might have a more general importance."
The Edinburgh-led study was carried out in collaboration with Dr Dunja Lamatsch at the University of Wuerzburg, now at the Austrian Academy of Sciences.
The research is published in the journal BMC Evolutionary Biology.
(Picture credit: Dunja K Lamatsch)

Tuesday, April 22, 2008


I apologize for the lack of material lately. Hurt my back a bit and have had some trouble sitting down for anything more than a few minutes. Feeling better, now, so I'll resume shortly.

Saturday, April 5, 2008

The Battle with Algae and Snails

As I've mentioned before, I am waging a bit of a war on the snails in my 20Long planted tank. I also have been struggling a bit with algae since adding the 65w light. After trolling the internet waters for a while I decided to just follow the advice of many fellow aquarists who smoosh up the snails and feed them to their fish. I started doing this and stopped feeding my fish regular fish food on a regular basis. Now I feed them once every few days and give them snails once every other day. The rest of the time they live off of the land, so to speak.

It is working. My snail population is not growing anymore, possibly shrinking by a little. My algae problem is also fading away. Now the issue will be finding the balance with all of this. Once the algae starts to fade more I will have to increase fish food slowly to make sure that everybody is thriving. I would recommend a similar solution to anyone. It's not a quick fix but it is an ongoing one. Just watch your fish and your water conditions to make sure all is well.

At some point I may have to try a self-sustaining tank. I'll stock it with snail eaters, scavengers and algae eaters and keep the light and CO2 flowing. Once I hit critical mass I could potentially have a tank that feeds itself. I'll just have to clean it and keep an eye on everybody, making sure that they are growing and thriving. I think the occasional supplement won't really be cheating. Just being careful.