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fat fish in aquaria

Posted: Thu Feb 02, 2012 8:57 pm
by glenna
Well, I was talking with my sister (she lives out of town, but has aquaria as well, salt and freshwater). I have only freshwater tanks,
Anyway, we got into a "discussion" regarding feeding.
She thinks I am scrimpy on the feeds, yet I think I err on feeding too much. Then I was reading in last month's Aquarium Intl magazine that most of us WAY overfeed our fish, and that our fish are like most Americans, fat, chubbie-buddies who are out of shape since they usually do not have the room to swim and exercise like in the wild.
Well, how much is too much. I hate the whole idea of "they should eat it all within a minute" because (esp with bottom feeders) that just isn't gonna happen. What about the fresh,blanched veg, or the algae wafer?

So, does anybody have any more specific thoughts? How can you really tell if a fish is a porker?

Re: fat fish in aquaria

Posted: Fri Feb 03, 2012 7:53 pm
by ClownLoachSharky
on the back of the hijari wafers it days no more than what fish can eat in 2 hours. i am good at overfeeding fish.

Re: fat fish in aquaria

Posted: Sat Feb 04, 2012 8:54 am
by starsplitter7
I like to think about the size of the stomach. I was told that the stomach is about the size of the eyeball. They don't need to eat as much as we do because they are cold blooded. A healthy, adult fish can go a month without eating, would not be happy, and would be very hungry, but survives. The cold blood means they do not need to regulate their temp, and that's how mammals burn a lot of calories. I still overfeed and do lots of water changes.

Re: fat fish in aquaria

Posted: Sun Feb 05, 2012 2:51 am
by ClownLoachSharky
2nd that starsplitter. used to be water changes everyday for me :mrgreen:

Re: fat fish in aquaria

Posted: Mon Feb 06, 2012 3:43 pm
by UVvis
As long as their bodies do not look emaciated, you are probably doing fine.

Honestly, what I've seen at that the hungier the fish get, the more agressively they feed. So it helps regulate. Plus just like us, the less work they do the lower their need for calories. Fish in the wild typically have stronger currents, more predators, more foraging, and do more work.

Re: fat fish in aquaria

Posted: Tue Feb 07, 2012 9:35 am
by glenna
Thanks for all the replies.
I never really considered the "cold blooded" part of the equation.
I still think I probably overfeed some. I use nitrates to help me decide about water changes, and end up doing weekly water changes on most of my tanks to keep nitrates below 10. I know that stocking levels also dictate how often I need to change water, so in my more heavily populated tank, I may even change more frequently than that.

The algae wafers are definitely gone within an hour and they are searching around for more, but I think those clowns would ALWAYS want more, no matter how much you feed them!

Re: fat fish in aquaria

Posted: Tue Feb 07, 2012 6:16 pm
by ClownLoachSharky
hehe, i guess my big yoyos a clown. When everyone gets sick of the wafer, including bristlenoses, he will eat it all and gets fat therfore growing the quickest.

Re: fat fish in aquaria

Posted: Fri Feb 10, 2012 6:33 pm
by NancyD
It can also depend on the age of the fish. I feed fry several small meals, subadults twice a day. With most adult fish I'm more casual, sometimes once or twice with occasional days off & rotate several types of food. Hmm, so at what size do clowns "need" less since they grow over a long time? I fed veggies 2-4 times a week but never really consider that feeding in the same way as meaty or prepared foods.

I'd say the majority of my fish were a "healthy weight", neither fat or thin. Some did seem chubby or even obese, mostly females carrying eggs. I give my SAE the benefit of of thinking it may have been female :D. "She" was the biggest fish in her tank & would eat as long as there was food. A slimmer SAE in with clown loaches of a similar size had more competion but may have been "male".

Most fish stop eating when full, so more food at a time will go to waste or be eaten later if left in the tank (not good, bacteria & ammonia :( ). They may still strike food but aren't really eating it. It's us "multiple meal feeders" that are apt to fish grow faster & fatter. Some people only feed a few times per week (what? don't they love their fish & want to see them?!?! :lol: ) I'm sure their water stays cleaner & they spend less money on food :roll: .

As to nitrate level, 10ppm is a good goal. I had plants in all tanks & that helps even if it's not heavily planted. I had a medium planted tank & the N would sometimes drop to 0. I had to either fertilize, feed more or remove some plant mass or I could end up with cyano & some types of algae.Same tank, a big plant trim/removal (say 20% mass) I could see N shoot up over 30ppm :shock: . But a word of caution--there's more than nitrate to needing water changes, it's just easy to measure ( I actually don't test all that often except for suspected problems).

Re: fat fish in aquaria

Posted: Sun Feb 12, 2012 9:26 pm
by glenna
thanks NancyD, I appreciate the advice!
I guess my fish (like me) will sometimes eat beyond being hungry!!! still, none really LOOK too fat :D

all of my tanks are planted and I really see the benefit of that. I even put some wisteria in the Qtank to help balance parameters.

I do not see any compelling evidence to feed differently than I have been doing, so will continue as is, for now.

Re: fat fish in aquaria

Posted: Mon Feb 13, 2012 11:55 am
by Diana
Easier to explain with a dog or cat, but the same applies to fish:
1) What species are they, some a naturally a different shape that you might mistake for fat.
2) What sex are they, in many cases the female of the species will be a bit plumper, especially if she is pregnant (livebearer) or filling up with eggs.

OK, here is where we compare fish to a dog:
Look down at the dog (the fish) from above. Can you see some shape where the skeleton goes from shoulders and ribs (wide) to the end of the ribs (tucked in a bit) then wider again at the hips? This is a healthy dog.
Similarly for fish. Given the species and sex of the fish, they should not bulge out too much from head to tail, but should taper pretty smoothly from a wide head (this is where most of the bones are, in the skull) to a narrow tail. Females will not usually taper as evenly, they may be a bit plump (wider than the head) if they are developing eggs. Fish that are streamlined to stick to rocks (Hillstream Loaches) will still look like this tapering, but it may be harder to see cause the fins overlap and might be mistaken for a fat fish if it is hard to see.
If the fish will not swim away, look through the bottom of a smooth glass that is dipped under the water surface. Much better visibility. You can also look at the fish from the bottom, for example and algae eater that is stuck to the glass.

OK, here is where we compare fish to a cat.
Look at the cat from the side. Is there a smooth line from elbow (That joint next to the body in the front leg) back to the hind leg? Does the skin sag or bulge in this area? An overweight cat or a pregnant cat will sag. A cat of healthy weight will have a pretty smooth line through here.
Similarly with fish, especially bottom dwellers. They are made to rest on the bottom, so will be pretty flat from head to tail. Mid-tank fish will have a smooth curve through this area, and it will be pretty close to a mirror image of their dorsal area. They match top and bottom for the most efficiency in swimming. If they are getting fat, the bottom line will be a lot more curved than the top line.

Another comparison with either dogs or cats is that an overweight animal of any species will have an overall layer of fat under the skin, and will look plump all over. This is also what the very beginnings of dropsy look like, before the scales stand up.
A dead fish can be examined, and may have fat around the internal organs. This is where it does the most harm, and why you want to keep your fish thinner rather than fatter.

Skinny fish: Loaches tend to lose weight right behind the head, where you might call it the back of the neck. Look at some pictures here of Skinny Disease to see this. From head to body should not bulge out through here, but see the sunken areas in those pictures? That is starvation.

How all this relates to food:
Some fish do not know when they are getting full.
Fish will eat and fill up a bit up front, then this swelling goes down as they digest the food. Some species do not seem to show this so much. Dwarf Gouramis are one of the most obvious. Predatory fish may also show a temporary bulge when they have eaten a lot. They are especially well built to handle a very large meal, then not eat for several days (small fish) to several weeks (monster fish)

Fish that are hungry will generally act more aggressive when food hits the tank. A feeding frenzy sort of event. Some species just do not behave this way, so do not assume because they are slower to respond that they are not hungry. Fish that eat insects at the surface will probably show the most action. Many omnivorous fish do this. Predatory fish may not, because they stalk their food (I am thinking of my Bichers right now). When I feed them Guppy culls, there is no feeding frenzy, but all the Bichers go into search mode, scanning the plants to find the Guppies. Vegetarian fish also do not overreact to food. Algae and aquatic plants do not fly away like insects or need to be stalked, so these fish might not respond in an obvious way to some blanched squash, but if they are more hungry a larger piece of squash will disappear overnight as they graze it more often. A smaller piece might be ignored if they are not so hungry. I have also seen my algae eating fish eat all the soft part of cucumber or squash, and leave the rind when they are not quite so hungry. They will eat the rind when they are more hungry.

So, the idea that fish that are hungry will eat the food faster is true, but you have to remember what is normal for your fish. A generally slow eater might take overnight to eat something, and that is fast for him. A top feeder may strike and gobble all the food before it sinks below the water. Is that 'eating all the food in a minute'? Should you then add more 'cause they are supposed to eat for 2 minutes?
Anyway, this is too varied an answer to really set a hard and fast rule about how long the fish have to eat.

Anyway, here is how I feed:
Twice a day, 6 days a week.
Rotate through many types of food, including dry flakes and freeze dried, frozen, fresh and lightly cooked vegetables.
Put more of some foods in tanks where there are fish to eat them- the tanks with the larger Plecos get the largest slices of vegetables. The tank with Endlers fry gets fed more often, but not very much at each time. (Depends on how old the fry are, but there are so often new litters that this tank gets a lot of food, spread out in little pinches through the day). The tank with predators gets culls, then no more food for 48 hours.

Re: fat fish in aquaria

Posted: Mon Feb 13, 2012 4:51 pm
by starsplitter7
Diana's response got me to thinking about food. I have found myself fortunate enough to be working in a fish store that serves the local fish farm community. Many people don't know that in about a 50 miles radius from Tampa is the largest concentration of fish farmers outside of the far east. Chances are if you buy an American ornamental fish at a store (especially a box store), it came from one of the farms that I provide feed for.

One thing I should have known, but never really considered, is that many foods are "crumbles". A piece of food that is nutritionally complete is broken apart into pieces small enough for fish to eat -- like flake. So when a fish eats a mouthful of food, they may get a bite of protein, a bite of fat, of carbs, of ash, blood meal, . . . This is usually only the case for small foods. There's new technology called Microencapsulation that puts the entire nutritional value into a pellet. It is like Hikari's micro pellets/wafers that have three pieces -- a protein, a vitamin and a fat, I think. If the fish eats one of each, they get the entire nutritional value. If they eat part of a crumble or several pieces they might only get a piece of fat and a piece of protein for example.

I wonder if this could be why they are so hungry sometimes. Maybe they didn't get a bote of protein. I try to feed my fish about 15 types of food so that I can cover their nutritional needs. I have lots of different food and the fish have different requirements. That also makes a difference. Extra food goes into the fridge, since it will lose its nutritional value. Vitamin C deficiency is a major problem for fish, and I am pretty sure (could be 100% wrong) that vitamin C is water soluable, so it is unstable in water. One reason to encapsulate the food.

Just a thought.

Re: fat fish in aquaria

Posted: Tue Feb 14, 2012 1:54 pm
by Diana
Good point about how crumbles or flakes might deprive fish of some nutrients at any one meal. But over time, wouldn't it balance out? Today the grabbed a green flake, tomorrow they gobbled 2 red flakes and so on.

Anyway, by feeding a wide range of food I think the diet is most like a fish in the wild. Some days there might be a big mosquito hatch, so all the fish stuff themselves on mosquito larvae. Another day there are some schools of egg scattering fish breeding, so the fish get a meal or two of fish eggs. Another day the algae get a boost from fertilizer in the run off from the land, so all the fish get their vegies. Some days there is so little to eat the fish are picking the bacteria and algae off the rocks and logs.
Sounds a lot like how I feed.

Re: fat fish in aquaria

Posted: Tue Feb 14, 2012 2:13 pm
by starsplitter7
I agree. I just think in the wild the food is more nutritious. I am appalled when I read the food lables -- bone meal, feather meal and blood meal. I don't think the fish eat feathers in the wild. :)

I think often people just feed one type of food, and if the food is old, the vitamins are deficient.

I am just surprised I never knew these things before.

Re: fat fish in aquaria

Posted: Wed Feb 15, 2012 3:34 pm
by UVvis
I watched an alligator gar eat swan feathers on day... :D Dumb fish...

Most animals in nature have a seasonal diet. Even the predators that primarily eat one or two prey end up with gut loadings that vary. Much of the fish meal is just ground up everything leftover from filleting the meat off of wild or farm raised fish. Lots of fish on fish recycling, in the wild and captivity.

Fish are generally pretty good at covering up illnesses/injuries and other issues, else they become a target. Normally if you are worried about a fish not eating, something else is wrong.

Re: fat fish in aquaria

Posted: Thu Feb 16, 2012 1:53 pm
by starsplitter7
Maybe the gar through there was a swan attached to the feathers? :)