Can fish mourn?

[nomzombie]

Recently I decided to donate my common pleco, Behema, to my LFS. She was 15.5 inches long and my tank is only 16 inches wide. Mind you it is a 75 gallon tank but it was becoming a bit of a task for her to turn around, and over the last month she has developed more aggressive eating behavior and started rearranging my decorations. She would flip things over, remove the weights from my bubble bars, and overturn any hiding places for my Goby. I figured she was only going to get bigger and more aggressive so it was time for her to move on to somewhere bigger. But ever since she's been gone my Violet Dragon Goby, Falkor, has really changed. He is no longer the life of the party at night. He hardly ever swims around the tank. Honestly, it's kind of like he's moping. They've been together for around 6 years and the only other fish left in the tank since all of the goldfish died 8 months ago (old age) is a tiny clown pleco that I never see. Could it be that he's lonely? I never considered that unmated fish could be attached to one another.

Falkor is a 13 in violet dragon Goby and is about 6 years old. My aquarium is a 75 gallon setup. The water parameters haven't changed at all. Nor the temperature. I do a 15% water change 1-2 times a week with gravel vacuuming to combat the bio load of the large pleco I just donated and also the green water. It's a never ending battle since I don't have a darker area for the tank. He shows no other signs of illness. Is there something else I should be keeping an eye out for?

Sent from my 0PJA2 using Aquarium Advice mobile app

 

[Autumnsky]

They can be most definitely be sad at losing a tank mate. They can lose self confidence and behave differently; as in there is no one to stand by me now. Don't feel to bad as that is too big a fish for the tank. Those guys get ginormous, as you know.

Is it a brakish tank?

What is your goal for this tank now? Sometimes a change like rehoming a very large fish changes what you might want the tank to become for you. Which can change which type of fish you might want to keep.

Also then just consider the type of fish which will be compatible with eachother and get some new tank mates or tank mate for the existing fish if that one is still what you wish to keep and build around. Another nocturnal type maybe

Maybe a few more BN Plecos, or something else.

If it is brakish there are some fish that would do well like Mollies, and Guppies can adapt to brakish water. I believe the Mollies will eat some algae.

 

[PB_Smith]

They can be most definitely be sad at losing a tank mate. They can lose self confidence and behave differently; as in there is no one to stand by me now.

that sure is assigning a lot of human emotions to an animal that doesn't posses the nervous system to "think" in those terms.

Consider another possibility, the goby isn't swimming all over the place because it is now more relaxed and at ease with the large pleco gone.
Pleco's become very territorial and can be rather nasty, relentlessly harassing other fish. As fish grow and their relative sizes change, so do the dynamics of territory and aggression.
I suspect your goldies may have died from more than old age, considering they can outlive humans.
Plecos and goldfish/koi ideally should NEVER be kept together, they have very different needs concerning water parameters and the slime coating on goldfish is tasty vittles to plecos.

The only time I have ever seen any type of "sadness" at the loss of a fish is with bonded mating pairs that will mate for life.

In every other instance the only change in behavior I see when losing a fish is always related to the pecking order of the fish.

Currently I have a magenta dottyback in my salt tank. For months all has been fine. But now he has grown to be more or less the third largest fish in the tank, and the most territorial. As a result, my damsel, eiblie angel and goldenhead goby rarely swim around in the open and I almost never see the angel anymore.
But I know as soon as I take the dottyback out, the other fish will be swimming all around again.

I suspect that is what is going on much more so than the goby mourning the loss of a friend. He's probably more relieved it's gone and is more relaxed.

a fish swimming back and forth incessantly and almost constantly is showing signs of stress more than signs of happiness.

 

[nomzombie]

Well his behavior wasn't constant. It was just at night after the lights had been out for awhile he would just dance around the tank. It didn't seem erratic or stressed to me. But I could also be overlooking something. (Which is why I'm here!)

As most people who rescue fish from Walmart, we weren't quite educated properly on the care for the violet Goby. So he's lived in a freshwater tank his entire life. And according to my research before I took over this tank, the freshwater would have killed him by now but I'm guessing since he grew up in it his body is just acclimated to it. So I think switching to brackish water might be too much for him at this point. So the plan NOW is to plant the tank since I no longer have to worry about a large pleco ripping up all my hard work! I'll keep the tank a cool water freshwater tank. We haven't used the heater since the last goldfish died. I want to stock it with some dojo loaches, panda corycats, and a couple schools of cool water minnows like white cloud mountain and rosy red. And I was thinking of building a planted cave covered in Java moss and a little extra substrate so I can have a small colony of ghost shrimp. And I think having some more bottom dwelling nocturnal fish and a new place to hide might cheer him up.

Also I worded my post a little weird that made it seem like all the goldfish died at one time. They died over the course of a few years. We had 3 humpback goldfish. Ugly things. We had those a very long time before we got the pleco and Falkor. I don't Remember when the first one died but the second one was about 5 years ago and the last one was about 8 months ago. The last one was completely blind and just sort of lumbered around. I'm not sure why they died. I just assumed. They all died before I took on responsibility for the tank and moved it to my house.

Sent from my 0PJA2 using Aquarium Advice mobile app

 

[PB_Smith]

Ok, yeah the more "fancy" goldfish are not as hardy.
But I have seen plecos latch on to large goldfish or ram them in the side.
As I said, big plecos can get nasty.

 

[Autumnsky]

Using human words for behaviors. Not assigning emotions to the fish. For example how a fish behaves differently with a dither fish. Fact is they can and often do behave differently when a [large] companion fish is removed.

 

[keegster803]

With the goby, the loss of the pleco might have made him feel like their is a predator lurking, and he might just feel scared.


Sent via echolocation