Widmer is pulled out of the 4500g into isolation. Mar 10 to Aug 10 - 5 months hasn't taken any feed. I have no idea why.
wednesday13
Hi Russ, do you know or have you heard anything about corruscans temp requirements? It has been suggested that perhaps our corruscans hasn't fed for 5-6 months now due to warmer water (see below).
I wanted to ask Darren Palfrey aka Dazzapolypterusweeksii but he is not on the MFK anymore. He has had a corruscans for many years.
Exchange with KLT on YT:
KuhliLoachTrainer This reminds me of what happened with Twig the firewood catfish's fast from November to January, except I am not nearly as optimistic. Do you think temperature might have to do with it? I am thinking back to our June 21 2024 discussions about temperature, maybe the tropical climate of Naples is proving to be a long term detriment to Widmer just like it was to the white sturgeon…. Other than that, I don't really know what to say, this is a risky and undesirable situation. At least Widmer isn't visibly dying!
Fish-Story.. I think the corruscans natural range is wide enough to include tropics or at least subtropics, no? I'd have to look up their temp requirements. Off the top of my head, I doubt temp, although it'd be a good explanation. Well, Widmer has been now in the 80F water versus 86F. So far no natural appetite comeback. No, he is not sick visibly at all. Just an absolute zero appetite. I am hoping simply internal parasites. If he doesn't start to feed so I could give him meds through feed, I'll have to inject or forcefeed. Baths are not as efficient, especially for the poorly water-soluble praziquantel.
KuhliLoachTrainer As far as temperature requirements and range go, Wikipedia says the natural range of this species of surubi is the Sao Francisco and Parana-Paraguay rivers. Assuming climate data from cities can be used to get an idea of water temperature across the year, only the cities near the headwaters - the northernmost and warmest parts - of those rivers are on par with Naples…………… Corumba (near the headwaters of the Paraguay River), Uberlandia (near the headwaters of the Sao Francisco River) and Santa Fe do Sul (near the headwaters of the Parana River) are all tropical climates like Naples, and they have annual average temperatures in the 22-26C range which overlaps Naples' 24C annual average, so if Widmer came from the parts of the rivers around those cities, I would assume he would be fine temperature wise in Naples…………… But given that far more of the range of those rivers is further to the south, which consists of subtropical climates with considerably colder annual means than Naples, it's more likely that he comes from one of those parts. For instance, Corrientes which is close to the halfway point between the Parana's headwaters and its mouth has an annual mean 3C colder than Naples, and Buenos Aires which is near the Parana's mouth has an annual mean 3C colder than Naples. For a close-to-home-analogy, this the equivalent of the differences in the annual means between Naples and Gainesville in North Central Florida (3C) colder and Wilmington in Southeastern North Carolina (6C colder)………….. Also note that subtropical and tropical are not equivalent terms: just because the range of a fish goes into the subtropics doesn't mean it can handle the tropics. Subtropical fish have been known to tolerate year round heat very badly as
duanes
has learned by way of keeping Gymnogeophagus species from similar South American locations to P. corruscans at tropical temperatures and having them fungus up and die. You can ask them about this if you'd like more information. Hope this helps…………………. I did see that suggestion from Hukit and yes, I too think that doing what they did will be appreciably more effective than a bath. Because of the huge mouth of surubi it will surely be easier than with a smaller mouthed fish to force feed medicine or medicated food
Fish-Story Thank you so much for this homework! It surely strengthens your case for the temperature factor………………… One thing that can be added is that the air and water temps may or may not be in direct correlation. The mid and bottom waters of glacier fed rivers, like the Amazon, remain cold for great distances of hundreds of miles, if not a 1000 miles in the Amazon case. IDK if the rivers you mention are glacier or melting snow fed……………. I assumed the main difference between a fish from subtropics vs tropics was that they could handle cold snaps and the cooling of the water to 50-60F, which could not be said of the tropical fish. IDK if the subtropical fish need the cool off to remain in good health and condition. I'd assume they do not. IDK also if generalization is fair here. It may or may not be………………………………. "Also note that subtropical and tropical are not equivalent terms: just because the range of a fish goes into the subtropics doesn't mean it can handle the tropics. Subtropical fish have been known to tolerate year round heat very badly as Duanes has learned by way of keeping Gymnogeophagus species from similar South American locations to P. corruscans at tropical temperatures and having them fungus up and die. You can ask them about this if you'd like more information. Hope this helps."……………….. ***Yes, it's a great piece of intel!!! It argues against my thoughts on a factual basis, although it is a single fact. Still this is very valuable……………………….. All in all, I'd say that you are very well may be unto something here! Because Widmer showed no big problems like this with the feeding before. Why the sudden and long fast? And you point out it is coinciding with the warmest water temp. Maybe you've cracked it for me/us all!.................................... I am happy Widmer is now (accidentally) in the 6F-7F cooler water at 80F. Maybe I should leave him alone until the water begins to cool down in October and see if he begins feeding on his own and proves your hypothesis. I could even place him in the 25K because it is the same cooler temp but don't want to yank him around like that too often, given what can happen to big fish simply moving tanks.
Fish-Story One thing that doesn't quite align with the temperature hypothesis is that Widmer was moved to the 4500g in the beginning of March and still had couple cooler months to adjust and start feeding, which he didn't do. This could be have been due to his general finicky nature though, which was then in a cou0ple of months exacerbated by the temp per your explanation.………………………. I need to consult with other corruscans owners on what temperature dependence they have seen if any.