Population Explosion!

[JoeG]

I have a 5 gallon tank that has seen a population explosion this summer. I fed the shrimp this morning some spirulina powder and counted 50+ floaters, five berried females, and one female releasing her fry. Each of the months this summer has seen a few floaters and berried females but this is definitely a record.

Feeding and some of the floaters:

[Dch48]

I had the same thing during the summer when the water temp hit 80-82. I only have a one gallon tank and there are shrimp everywhere now.

[JoeG]

It’s a good problem, right? The house is air conditioned and runs between 70-75 deg. I was thinking the longer amount of daylight had something to do with the breeding.

[Vorteil]

Look great. I like the lower temps for the opae. Especially for me in the winter since my tanks are in the garage it hovers around 65 degrees.

[JDillon]

So does the higher water temp promote breeding then? Wonder if I need to add a heater? I keep my house temp around 68 to 70 degrees year round. Any thoughts on this?

[Vorteil]

For me personally I prefer the lower temps & if I could keep it around 70 I'd be happy. The prefer the cooler temps. From what I've read the female opae tend to be in the lava tools where the temps are consistent & cooler. I never run a heater and in the winter my tanks are around 65 degrees.

[Dch48]

Since my temperature has gone down to right about 70, I have not seen any more breeding activity. No floaters and no berried females. So for me, I would have to say that higher temps promote more breeding.

[JDillon]

I think I’m going to look into it and maybe do an experiment and see if raising the temp promotes breeding. My shrimps are mature now but haven’t seen any breeding though I have seen the molts. Will be interesting to try anyway. The challenge will be to find a small enough heater with a thermostat for a 1 gallon or less tank.

[ryangiggs]

I lived in a tropical country where it is 30-32deg C on avg in the day... so far my tanks had experienced a few breeding blooms when there was a prolonged raining period for around 1-2 weeks which brings down the avg temperature to ard 25-28... the breeding bloom coincided with this drop in temperature...

My theory is that a sudden and prolong drop or increase in temperature will encourage them to breed... so it probably doesn’t matter what temp it is... as long there is a slight difference in temperature for a pro long period... it will probably trigger them to breed...

Just my theory...

[Dch48]

Or, maybe 78-82F which is 26-28C is the ideal temp range for breeding. Warmer or cooler and they slow down or stop. That's my theory.

[JDillon]

I found a small enough heater with a thermostat and will start to test that theory shortly. Right now my office is at 70 and I’ll probably set the tank at 75 degrees Fahrenheit for a couple of weeks to see if that has any effect. If that doesn’t work I’ll try raising it to 78 for a couple weeks.

Question is how long after the temperature change did you see they population explosion?

[Vorteil]

I don't think it's that simple and that the opae will breed based on temp fluctuations. Some of my tanks breed, some don't. All have the same setup. With all the studies that Dr. Scott Santos of Auburn University has done wouldn't you think this would be announced?There's still not a whole lot of information put there. If the females & the young tend to stay in the lava tubes the water temps is more consistent but I assume cooler. Just a guess. It would be interesting in breeding is based on temps changing but I've seen more success when my temps are in the low 70's. Even in the winter they still consistently breed at 65 degrees.

[JoeG]

The one gallon tank set up in the basement two months ago has its first berried female today. The basement stays in the mid to upper 60’s year round. I just checked the temp and it is 69.3 deg. I will keep track of the breeding going on at the lower temps. There’s only 10 shrimp in the tank but we’ll see how it goes at temps consistently in the 60’s.

[Dch48]

It may also depend on food availability. Maybe , in my case, the biofilm and algae might grow faster at the higher temps. Or a longer period of daylight may affect them. Who knows? I can only go by what I have seen. I don't use a light timer on my tank so the light goes on and off whenever i do it which is rarely at the same time every day. There have been times when it stayed on until 3AM and other times when it didn't go on until 3 PM. I don't live on a schedule. I'm up when I'm up, and sleeping when I'm sleeping. It varies widely.

[JoeG]

Dch48 the only light the one gallon tank gets is the natural daylight. No light on this jar. They have plenty of algae, pretty consistent temperatures, in the 60’s, and natural light. It will be interesting to see how it works out in each season. Thank you very much for your comments.

The five gallon tank, on the other hand, has lights that are turned on and off manually. They are usually on at least 12 hours a day. These shrimp get supplemental feeding once per month. Alternating between freeze dried spirulina powder and shrimp pellets. The temperature of this tank is definitely higher then the basement tank. Stays in the 70’s.