Hypostomus lapatae...cool water?

[jjohnwm]

These fish are growing surprisingly quickly; they were in the 3-4 inch range back when I got them in May, and when I moved one of them into a different tank yesterday I took the opportunity to measure it; 8.5 inches! I've always considered plecos in general to be relatively slow growers; H.laplatae is a big species, 18+ inches at maturity, so perhaps it's not unexpected for them to grow quickly when still small.

I don't typically assign tank-cleaning jobs to my fish...that's my responsibility...but these guys seem to do a pretty decent job of cleaning the glass and sides; so much so that I placed the one into a different tank that had lots of algae just to see what kind of impact it had. After only one day, there are visible areas and "tracks" on the walls that show the fish is eating algae.

They're not very colourful, but they are reasonably active and usually visible, and have not been observed slime-sucking or in any other way harrassing their tankmates. I haven't actually seen them eating, other than working over the glass, rocks and driftwood...but a few algae wafers dropped into the tank before lights out are always gone an hour or so later, and they are growing, so they must be getting sufficient nutrition.

I'll be installing one of them into my single in-ground pond next summer and look forward to seeing how it fares. The in-ground pond heats up almost as quickly in spring as the above-ground stock tanks, and it actually stays warmer longer into the fall than they do. The fish are both currently at 61F and seem completely comfortable, so they should be good for at least 5 months outside, possibly even longer.

 

[jjohnwm]

The H.laplatae continue to do well, now in water that is down around 55F. I discontinued even the low-level heat I was using up till now, so that's likely the temperature in that tank until the end of February, when I will raise the temp up into the mid-60's again. That will then require the addition of heat for at least another month or so, after which it will be the ambient temperature down in the basement. I have begun to experiment with a small amount of heat in late-fall/early winter, and again in early spring, simply because I think that my ambient temperatures will result in a cool-down period which is a little longer than ideal otherwise.

This tank contains a single laplatae, a number of 5-6-inch goldfish, my adult Cichlasoma dimerus, about a dozen Gymnogeophagus rhabdotus, and a few Garra rufa doctorfish. The last two species along with my second laplatae are also present in another tank system that will remain around 65F for the duration of the winter. I am curious to see how the two groups compare at the end of winter.

I know that the fish at 65F will be fine, have kept them at that temp throughout winter before. Their appetites decrease somewhat, and the dimerus will discontinue the intraspecies aggression which forced me to separate the two pairs into separate stocktanks during warm weather. At the cooler temps, they are very mellow. The even-cooler tank has been at 55-50F for about a month now, and so far at least the fish in it are doing well and displaying no apparent discomfort.

The laplatae are growing on me; not a pleco guy per se but I appreciate their unique look and behaviour. Both of them are big enough now that an algae wafer is engulfed in the mouth and then they suck and nibble at it like a giant hard candy. The first time I saw this I was concerned that something was wrong; I thought the fish had a stone or some kind of growth in its mouth. When the fish finally popped out the wafer before quickly engulfing it again I had to laugh. Now, when a wafer is taken, it takes about 3 or 4 minutes to be ground down from its initial size of 3/4-inch until it's completely gone. It's a very efficient way of keeping one's lunch from being stolen by a big-ass goldfish!

 

[jjohnwm]

Shortly after my last update on the laplatae, the one in the cold-water 360-gallon tank...just vanished. I had moved around some large rocks and driftwood in there and came to the embarrassing and regretful conclusion that I must have crushed him; I was very careful while working in the tank, but what else could explain his abrupt disappearance? He had been very visible all along...until suddenly he wasn't. But I held out some hope, because the other laplatae, maintained in a slightly warmer tank, also seemed to have grown very shy at around the same time. With less space and less rockwork, he couldn't really disappear completely and I could usually find him if I tried, but it sometimes took some effort.

Last night...hallelujah! The missing laplatae appeared in plain view and under full lighting, working over a patch of algae with gusto and acting as if he had been around all along...which, obviously, he had, but flying very much under the radar. He's gotta be 9 inches, still very healthy and with a nice rounded belly. He's out again this morning; absolutely great to see him.

Temps in the cold tank are still in the 55F range, but the Goldies, laplatae and Garras are all very active and eating well. The Uruguayan cichlids are a bit subdued but seem healthy. At these lower temps, all traces of intraspecies aggression vanish and the Cichlasome dimerus tend to move as a loose group. During the summer, the dominant male beats the crap out of the other male if they are housed together, and I'm sure that pattern will repeat this summer as well.

 

[jjohnwm]

What the...?

Water temperature in both tanks containing a laplatae have risen naturally to about 65F. Both fish came through the winter months without any sign of trouble, although they did both periodically become inexplicably shy for a period of days and remain largely hidden.

So I'm not sure what happened, but one of them, the one that stayed in the slightly warmer tank (65F) and yet grew more slowly than the colder one...just dropped dead. Looked perfectly fine yesterday, busily sanding down a piece of driftwood...but stone dead this morning.

I have no explanation for this, other than...s**t happens.