DOES TEMPERATURE MAKE A DIFFERENCE
- Thread starter motoro magic
- Start date
Actually temp does have an impact on male to female ratios on fish and reptiles. When I bred Tropheus (an African Cichlid for those that aren't familiar) I read articles on the impact it had on the ratios. And it is well documented on reptiles. Can't speak for rays though.
I also kept my tank 78-80 degrees. My motoro had two litters with a total of 5 males and 5 females. When I raised the temp to 84-86 she had a litter of 6, all males. Too small a sample to draw conclusions as it maybe just be a coincidence, but I lowered the temperature back down anyway.
Thanks for the good feedback i will post results as i find them. Atm im going to keep the temp at 86 maybe for the next 3/4 litters at least and see what happens.
Ok so here's an update on my findings.
My female gave birth to 3 pups on saturday 3/9/2011 she had 2 female and 1 male temp 86, ph 6.5, gh3, kh4, nitrates 20ppm.
I have kept the temp constant for the last 3 months at 86.
The female only went 91 days this time, pups fully formed with no yolk sack and are 10 inches nose to tip of tail and have a disc of 4 inches.
Here are some pics of the pups at 1 day old.
My female gave birth to 3 pups on saturday 3/9/2011 she had 2 female and 1 male temp 86, ph 6.5, gh3, kh4, nitrates 20ppm.
I have kept the temp constant for the last 3 months at 86.
The female only went 91 days this time, pups fully formed with no yolk sack and are 10 inches nose to tip of tail and have a disc of 4 inches.
Here are some pics of the pups at 1 day old.
I have raised the temp by 8 degrees already, normaly keep them at 78. I dont want to risk going any higher than 86 as i dont think it would be good for my rays long term.
I want to keep the temp at 86 for another 5/6 litters if possible and that should give some kind of indication of weather temp makes a difference or not.
Im only doing this as a trial because i dont know of anyone else that has tried it.
Freshwater stingrays seem (writes seem as it is not fully resolved) to have a XY system for sex determination similar to that of mammals, however their X and Y chromosomes does not correspond to our X and Y chromosomes. Its just that someone named them X and Y in rays as well. At least Female motoros and female falkneris have a arrangement with four X chromosomes (X1X1X2X2) and males of both species have two X and one Y chromosome (X1X2Y1). This would rule out temperature dependent sex determination.
/David
/David
I think cooler temp will yield more female and Warmer temp will have more male 
From my assumption base on the cycle of life (nature); Reproduction and survival rate decline; and Food is less available when it is cold. So in order to recop, more female are produce when temp is cooler. Vice-versa for warmer temp. Food is plentiful and everyone is lookin for food.
FYI, this is my assumption hahaha
From my assumption base on the cycle of life (nature); Reproduction and survival rate decline; and Food is less available when it is cold. So in order to recop, more female are produce when temp is cooler. Vice-versa for warmer temp. Food is plentiful and everyone is lookin for food. FYI, this is my assumption
hahaha