Vorteil wrote: Thu Jun 13, 2019 1:27 pm
One of my tanks lost almost off of the baby opae ula sometime between Monday & Tuesday. Outside temps here were up to 34c/93 degrees. My tank went from 23c/73 degrees to about 27c/81 degrees. I had a least 80 babies in that tank & counted only 4 last Wednesday night. Can I assume this was due to the tanks temps jumping up too fast or even to high? Temps that these weren't used to? I've had my tank in the summer hover around 86-88 degrees & the opae are fine but no babies present when it's that high. All my tanks are in the garage & can't change that. I've had a constant flow of babies present in the tank & now this. Thoughts?
I'm thinking I might add a small fan chiller to the tank. I bought the old Coolworks Ice Probe used some time ago. Currently using it now. I have this on a couple of 10 gallon tanks. It has lowered the temps right now by about 8 degrees. So non chilled tanks are at 78 and the two chilled ones at 70 degrees.
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Have you actually seen dead opae ula? In the past, you've had tanks go up to 88 with no ill effect on adults so I can't see 81 degrees being a problem for the young ones. More info please.
Vorteil wrote: Thu Jun 13, 2019 3:23 pm
The adults are fine. It's all the baby opae that are no longer there. There's only 4 left swimming around. I've had temps higher thean 88 degrees but there were never any babies present. This is what it looked like on Monday
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Perhaps they morphed into the benthic stage and are hiding. How long were they in the larval stage like your photo shows? If it was a couple of weeks or so then I suspect they are in the benthic stage and crawling/hiding.
My shrimp are in my room and during the day, we don't run the AC if we aren't using the room. In the summer, it can get to 80-degrees in the room and they have been fine. I have no idea what the actual water temp is as I don't have a thermometer on it. But I don't think that would be hot enough to harm them.
I have a tank upstairs with 9 larvae in it right now, and on warmer days it will stay at a temperature in the low 80's, up to 84 or 85. I'll have to see how well the new shrimplets survive once they are formed. My past experience suggests a significant percentage of baby shrimp don't survive anyway.
That's super strange. I have about 18 babies floating around and they all seem to have made it fine through this week's heat wave. I live in southern California, and temps were high 80s here on the coast for a solid couple of days. Any possibility some contaminant got into the tank in tiny enough amounts to harm just the babies?
How big is the tank? As others have suggested, its likely most of the babies simply metamorphosed and went into hiding. They are incredibly good at going unnoticed until they mature a bit and start acting like the older shrimp (i.e. wandering about and feeding all day). If you never actually saw any dead bodies then I have doubts there was a massive die off.
I have one of those small evaporative air coolers and I set it up to blow the air across the surface of the water. So far it has kept the tank from going over 80 even when room temperature was 86. It does cause a lot of evaporation though and the need for topping off every day. Even just a small fan will work to an extent.
I also live in SoCal. This summer heatwave is not good. My house has been as high as 90+ degrees. The temperature reader on the tank only goes to 86. Two of the mothers dropped almost all of the babies. Last time I checked I only seen one that fully developed and is still attached to the mother. Don’t know how well they’ll survive with the temp but I did buy a freezing cooler pack and I leave it on the side of the tank on the outside everyday. The shrimps migrate over and stay on that side so that tells me it’s pretty hot for them. On a side note my snail population blew up with this weather. TONS OF BABIE SNAILS.
In my experience, lower 80s is not a problem for breeding. I had tanks when I was living in NYC and the buidling we were in had steam heating which could not be regulated (except opening the windows...what a waste), so in the winter the tank temps were pretty much constantly around 82 degrees. No problem with breeding. Much higher than that, though, breeding stops. Maybe 85? Hard to say what the exact threshold is. Can't go wrong with 70s though.
