Feeding and Nutrition :: When do RES stop hunting for prey?

[Meldrick]

Hey guys, I have 2 RESes who are about 8 years old. I've never ever given them live food, only pellets and veggies. If I put them together with some fishes, do you think they would still able to effectively hunt and eat the fishes?

[steve]

It depends... some RES are just a bit lazier than others. Given the opportunity, most will want some fishies.

[penelope]

They are little predators when it comes to little fish like gold fish and guppies.
Is possible for them to live together, but unlikely

[annar]

I just put some minnows in with my RES for the first time. He's only about 3 and he's always gotten pellets, veggies, and the occasional shrimp treat. So far he's pretty much left them alone, unless they start spending too much time around them. He bit the head off one that was harassing him, but since then he's ignored them for the most part. I do have a friend who had a goldfish live in his turtle's tank for about 2 years. Then one day the goldfish was missing. You could try putting in live fish, but I wouldn't put in anything that you're going to miss should the turtle become more hungry/adventurous.

[amwassil]

My three RES have shared their day tanks with 2 ancistrus, 2 golden algae eaters and 5 julii corys for about 8 months. No fish have been eaten yet. The first fish in the day tank were the 2 ancistrus; followed in short order the next week by the goldens and 3 corys. I added the other 2 corys a week later. Only once have I seen a turtle chase a fish, one of the ancistrus, shortly after their introduction when they were both less than 2" long. The ancistrus easily outswam the RES. All of the original fish have thrived and grown. All have reached more or less their max size.

I think one of the keys to my success is a stainless shelf I put in the bottom of the two day tanks, which gave the fish an inch and a half of relatively safe space from the turtles. In addition I added tank ornaments that provide numerous hiding places for the fish. And at night, when the fish are most active, the turtles are moved to their night tank. Turtles and fish are very aware of each other, yet each seems to ignore the other, although frequently the corys will swim around the turtles. If the turtles take more than cursory notice, the corys will swim away. The smallest turtle, in fact, seems to enjoy watching the fish and does so quite a lot, but has never tried to catch one.

Yesterday everyone moved into a new 80 gallon day tank. The turtles had to spend a few hours in their night tank while I transferred most of the water from both previous day tanks into the new tank, netted and relocated fish, and got the security grill and ornaments set up for the fish. I then topped up the new tank to 50 gallons. At that point I introduced the turtles. Everyone spent most of the rest of the day exploring their new home. Neither fish nor turtles took much notice of each other. While the fish and turtles were exploring the new tank, I added two heaters and got the primary filtration going.

Today I added two more Julii corys. I wanted to add another golden, but my LFS didn't have any. Turtles and fish spent the day together without mishap. The two new corys even swam around the turtles, likely because they don't know what they are and are curious. After removing the turtles for their evening feeding and move to the night tank, I siphoned up most of the uneaten debris/poop and topped up the tank to about 55 gallons. I haven't filled the tank for a couple of reasons. Although "new" to me and my aquatic pets, I bought the tank used. So I want to add water gradually to make sure there are no leaks and that the supporting stand shows no sign of collapsing. So far so good! I've actually had water in the tank for about a week with no signs of leakage. I imagine it will take about a week and a half to fill the tank. That gives me time to build an above the tank basking area and mount my lights.

By the way, we feed the turtles each morning in their night tank and feed them again each evening in a special feeding basin, a Rubbermaid bin. The plan has been: the turtles are never hungry enough to chase a meal in the day tank and they don't associate eating with their day tank. The only turtle food in the day tank(s) is leafy greens. They seem to like Romaine lettuce and watercress. Although they just to pick at it all day rather than eat a lot at once.

[amwassil]

Update

It's been 10 days since the move to the new 80 gallon tank. Water level is now at 65 gallons. I bought another golden algae eater the day after my previous post. All fish are alive and well; the new ones already have grown noticeably. The cory julii are much more active during the day than they were in the smaller day tanks. They swim the entire water column, even when the turtles are roaming about. The three goldens are also more active during the day. I think this is because there is a much greater volume of water for the fish to swim in and they feel less threatened by the presence of the turtles. For their part, except for the smallest of the three who seems to enjoy watching the fish, the turtles pay very little attention to the fish. On the other hand, the corys are very bold around the turtles, often swimming quite close to them. This morning one of the corys actually swam directly under the smallest turtle so close that the dorsal fin brushed the turtle's chin!

Thus, my RES/fish cohabitation experiment continues successfully. Do I fear losing some fish sooner or later? Not much. The turtles are well fed and I don't think they see the fish as potential food. Although to help reinforce this perception we are eliminating fish from the turtle diet. We will still occasionally feed shellfish and shrimp.

[steve]

Thanks for the update!

[amwassil]

Second update

I've had about 75-76 gallons in the tank for a week with no signs of leakage or support issues. So I think all is well. I added a top brace to the tank when I noticed the glass was bowed about 3/8" in the middle of the long sides. The brace has removed most of that (less than an 1/8" residual bowing now). I also added a wooden skirt around the top of the tank to eliminate the possibility of turtle climb outs. I also built a rather more elaborate than necessary ATBA which proved to be unpopular with the turtles and the wife, who complained she couldn't see the turtles. So... I've already pulled the ATBA and replaced it with two Zoo Med floating basking platforms. We used both of these before and the turtles seem to like them; at least, now they haul out and bask extensively again. I'm also currently building an acrylic skirt to replace the wood.

Both turtles and fish seem quite happy, healthy and content. The turtles spend about half their time in the big tank basking. The Cory's and the goldens are very active all day long, regardless of whatever the turtles are doing, although the goldens are much more careful about the turtles than the Cory's. I cover that tank in the evening when I'm in the room with the lights on until late. That gives the two ancistrus enough darkness to come out to feed and explore. I'm planning to buy two more Cory julii. At that point there will be 9 Cory's, 3 goldens and 2 ancistrus sharing the tank. I think that's enough. The big tank seems to stay cleaner than the two previous, smaller tanks with less effort on my part. The fish do an excellent job of keeping the bottom cleaned up, as long as I don't overfeed them.

The turtles still spend the night in a separate and smaller night tank. They do a lot of their elimination in that tank in the morning just before and after their morning feeding. So I change the water in that tank either partially or fully each day, replenish the water in it from the day tank, then top up the day tank with fresh water. Once a week I empty and clean the night tank and refill from the day tank, which again I top up with fresh water. So during the course of the week both the day and night tanks are getting significant water changes. I also have a small Exo-Terra FX200 that I use as a portable "vacuum cleaner" to clean up the day tank bottom whenever needed. It mechanically filters the water and pumps it back into the day tank. I figure this lightens the load on the main filter.

[steve]

I don't think there should be any bowing at all, what kind of tank is it? If it's a terrarium, then the glass will be too thin to use as a regular aquarium. Do all of them go into the "night" tank?

[amwassil]

I don't think there should be any bowing at all, what kind of tank is it? If it's a terrarium, then the glass will be too thin to use as a regular aquarium. Do all of them go into the "night" tank?

When I first noticed the bowing I did a lot of googling to find out whether or not to be concerned about it. To answer your questions: it is an aquarium tank, not a terrarium; the glass is 3/8" thick, which is nominal for the size of the aquarium (48" x 16" x 24" high). What I discovered, somewhat to my surprise: 1) most large tanks bow to some extent, anywhere from an 1/8" to 5/8"; 2) many tanks up to 48" wide do NOT have a center brace (nor "European bracing"); 3) most large tanks with relatively thick glass that bow up to 5/8" don't break, even after many years under load; 4) some tanks break catastrophically without warning, depending on what glass they're made of - ie non-tempered glass usually cracks first, while tempered glass doesn't, it just "explodes" without warning. I live on the 5th floor of an apartment building and I decided I'd rather be safe than sorry; not to mention avoid the risk losing my fish and probably injuring my turtles in a blow out. In addition to adding a center brace, I also put load binding straps around the bottom and top of the tank. The bottom strap has a break strength of 3000 pounds and a safe working strength of 1000 pounds; the max weight of the water in the tank is about 680 pounds (8.5 x 80) and the tank itself weighs about 175 pounds, so the bottom strap is strong enough to reinforce the bottom seams. The top straps (I have two) have a break strength of 600 pounds each; so, I figure that's enough to reinforce the top seams.

Yes, all three turtles go to the night tank to sleep. The night tank is a 25 gallon Rubbermaid Stearilite bin with about 8-10 gallons of water. It has it's own filter, lights and a couple of Zilla "bridges" stacked on top of each other. I cover this tank with a dark blanket and after a few minutes of "jostling" all is quiet until morning. Each morning I syphon out all the poop/debris, feed the turtles and then move them to the day tank. After that, I clean the night tank and replace the water.

[steve]

I've only seen tempered glass used on the bottom of tanks. Anyway, thanks for the clarification.

[vear]

@amwassil I successfully kept fish with my RES for almost a year including corys until one day he went nuts and decided to eat them! He ate about 2 corys and started choking on one of them. The dorsal fin from corys is pretty sharp, and my RES was having a very difficult time trying to swallow. Once he managed to gulp them down, he tried to go for more - I immediately removed him from the tank, then got all the fish out of the tank and put my RES back in. I guess what I'm trying to say is be careful with those cory catfish,they could harm your RES.

[amwassil]

Thanks, vear, for sharing your experience. I'm watching carefully all the time. I work at home and the aquarium is in my office. So far, none of the turtles has shown much interest in the fish, except for the smallest of the three who likes to watch them. However...

Last weekend I wanted to buy two more corys to bring the total up to 9, which I think is a good number of corys in my sized tank. Unfortunately, the LFS didn't have any, so instead I bought 3 otocinclus. BIG mistake! The turtles ate two within 24 hours and I actually watched Alexander choke severely for about half an hour and feared he might choke to death. I took Alexander out of the tank and tried to help him swallow, but I don't think it did much for him. Periodically for the rest of the day, he would open his mouth very wide and scratch at it with his foreclaws. He seemed OK the next day and is back to normal again. I was able to get the third oto out of the tank alive and return him to the store.

I think the otos were just a little too small and looked a little too much like small guppies and triggered some instinctual response in the turtles: "these guys are food". The little otos were also too small to swim fast enough to get out of harm's way. My immediate concern after Alexander recovered was that eating the otos would lead to the turtles going after the corys and goldens as well. But it hasn't happened yet, they still behave just the same towards the fish as they did before. Even when the corys swim around them, the turtles show no inclination to go after them. The goldens have been and remain very cautious of the turtles and the ancistrus hardly ever come out of hiding while the turtles are in the tank.

You are absolutely correct, though, that could change at any time. Possibly, it's a size thing and once the turtles get bigger the corys and goldens will look smaller and potentially start to look more and more like "these guys are food". So vigilance is required. I accept that. Corys not only have barbs on their dorsal and pectoral fins, they also emit a toxin if attacked. As I say, I'm next to the aquarium all the time and if I see a turtle go after a fish like he/she intends to eat it, then we'll have to make new arrangements. I think the stainless wire shelf and the multiple heavy tank ornaments provide enough shelter for the fish should a turtle decide to go an a rampage.

[amwassil]

Another update

After the disaster with the otos, a day or so later I bought two more corys at Petsmart, a green and a pepper because they didn't have any juliis. I introduced both to the day tank only after I removed the turtles for their night feeding so they would have a chance to explore their new home without the risk/threat of the turtles swimming around them. This went well and the next day the two new corys managed to avoid the turtles successfully. So things seemed to be going well again and the turtles showed almost zero interest in any of the fish.

The five original corys are now fully grown and the two I bought in early July are nearly full grown. Although I bought the biggest they had in the tanks, the new green and pepper corys, of course, are noticeably smaller than all the others and rather longer than rounder like the juliis. Yesterday my smallest turtle, Antonia, went after one of the new corys. The fish got away quite easily and Antonia did not seem very interested in pursuing it, nonetheless I distracted her by tapping on the glass. This is really interesting because of the three turtles, Antonia is the milquetoast and neither Alexander nor Augustina have shown the slightest inclination to go after a fish even when they swim right in front of them.

Antonia is the one turtle who has demonstrated the greatest interest in the fish, watching them while Alexander and Augustina have mostly ignored them. I'm going to watch Antonia carefully for the next little while to see if she goes after any of the corys again. Maybe the shape of the two new corys or simply their being new to the tank got her into "they're food" mode.

More to come.

[slider_keeper]

Yep vear is right. I have been housing fish with my Turtle for about 3-4 yrs now, ever since he was a hatchling. Minnows are dinner plain and simple. Guppies and the fry are all that survive along with Chinese algae eaters. Now during the summer my turtle has decided to rid of the females and my own explanation is that Toku is eating the females because they give off more guppies making more fish in his tank. Now I only have males and maybe one really small female, too young to tell the sex. If all the females have been eliminated then my guppy population will be extinct in a few years when all the males die off. Turtles are unique and everyone has his or her own personality. You could have fish for a day or 6-7 yrs and then out of nowhere they are all gone. I tried to add a couple of females but when Toku went back in his tank he chased every last one till they all were eliminated. Didn't touch a single male, or the new Chinese algae eater I added! I don't think sliders ever stop hunting fish, it is in their nature to hunt and eat.