Do _____ Jump?!?!?

pcon · Jul 2, 2019

YES

unless it's a seahorse or a starfish, then just maybe. An open top tank is a risk to the fish inside. Some people are okay with that risk some are not, but it is up to the aquarist's equipment not the stocking selection to ultimately prevent fish jumping.

This has been your snarky FSA (fish safety announcement)

Sorry if this offends anyone, not at all targeted at any one in particular, just a popular question today and previously, and I felt like it would be funny way to jump into the topic.

Advanced Discussion:
I myself have been guilty of not protecting my fish from their own stupidity, so I want to be sympathetic to the sentiment behind the question. Let's be honest, lots of aquarists do maintain tanks without a top, being snarky and saying all fish jump is not helpful to the "diehard" topless tank keepers. I know because seeing it dozens of times didn't change my mind. Note the following is not a cart-blanch endorsement to keep your tank uncovered, but a discussion of some of the underlying questions and ethics behind the common, do xyz fish jump posts. Cover your tank and protect your animals!

So if you are one of these keepers what is the appropriate way to answer the core question. It starts with asking the right question: What is the propensity, or likelihood, for ____ to jump?
Now if I post this and still get the form letter, "all fish jump put a cover on you madman" response, how can I still answer this question for myself. Start with a couple quick searches of the big forums, _fish name_ + jump, see how often it comes up. Then look into the natural behavior of the fish. Is it a deepwater fish liable to never have encountered the surface since hatching? Is it a flighty wrasse or darting goby liable to launch off, at speed, in a random direction? Do my fellow aquarists report this fish jumping? Does it jump when caught or handled? For captive breed fish do the breeders keep them in covered tanks? These are all questions that can help give insight to the propensity for a fish to jump.

The core of this question and the range of responses begs at: what is best practice, what is acceptable practice, and what is inappropriate reef-keeping. It is not best practice to allow a tank to remain uncovered and unattended. Is it is inappropriate to allow needless deaths of the animals we keep. We have the technology to virtually eliminate loss of life from fish jumping. If we can prevent such deaths, is it an acceptable practice to allow them by maintaining a tank without a cover? Is such a loss of life acceptable for the aesthetics of a topless tank? Is selective stocking an appropriate alternative method to mitigate such loss of life? These are questions that ethical reef-keepers must ask themselves if maintaining a tank without a top.

At the end of the day all fish can jump, and we as aquarists have a responsibility to mitigate the loss of life in this hobby, there for we really should put covers on our tanks.

But I like the look of my tank so much more without a top! What can I do?
Take it off when you are there directly watching or simply around your tank and put it back when you leave your tank. For me I only take the top off anymore to work in the tank or take pictures, because the likelihood of the fish to jump any moment is not worth the small inconvenience and large ugliness of my home made covers. My friend leaves them off when he is in the same room as his tank, because he has stocked his tank with fish with a low propensity to jump, and he enjoys the unobstructed top down view. When he is in other rooms of his home, is asleep, or simply not paying the tank much attention, he returns the cover to the tank.

Ultimately it is my conclusion that there are no excuses for allowing a fish to die by jumping from an uncovered tank and we should continue to move the hobby towards jump prevention being an essential part of our life support systems. As such, topless reef-keeping should be considered inappropriate. (pardon the pun) That being said it does not eliminate the need to answer the question "what is the propensity for ____ to jump?" as there are reef-keepers who responsibly enjoy an unobstructed top down view.

Thanks for reading my rant, please chime in with your opinions below.

jsker · Jul 2, 2019

I have only had one carpet surfer in 5 years with my current system.

pcon · Jul 2, 2019

jsker said:
I have only had one carpet surfer in 5 years with my current system.

how did it happen? who was the jumper? what is your lid situation like? and what has been your general stocking?

Angel_Anthias lover · Jul 2, 2019

I agree with everything in the post. My Flasher wrasse always attempts at jumping from my tank and has landed on the floor twice when the lid has been opened just slightly to feed. I cant imagine how many fish would be needlessly dead without it in my tank. Only one time has a fish died from jumping out and that was when my scissortail dartfish darted out of the tank as i opened the lid and placed in a new bag of crabs and i didnt realise until i found the body unfortunately

Haydn · Jul 2, 2019

In the 19 years I have had my current opened topped tank I have only lost one fish to jumping, a Sohal tang. My tank is slightly over a metre deep and I think by the time the fish have got to the surface they are too knackered to jump

The Sohal? he jumped in the middle of a thunderstorm and I think the flashes in the pitch darkness caused it, I now leave 1% blue on my LEDs.
But I do agree with the OP - our fish are our responsibility.

Daniel@R2R · Jul 2, 2019

Great write up! Yes! Any fish can jump!

EmilyXLC · Jul 2, 2019

I can't 'like' this enough.

mattzang · Jul 2, 2019

i get the desire to keep tanks without tops, when i take mine off to do stuff i always start thinking.. maybe i could just leave it off while i'm home.. but would i really hear a fish jump out? do i really check the tank that often even when home? i like my fish too much to risk it

doesn't help that my top was quickly and poorly made (by me) so it's extra unsightly lol

Kyl · Jul 2, 2019

The newer generation of sunken / flush tops really makes using one pretty aesthetically pleasing. They even have black 1/4" mesh now.

I use the DD jumpguard series on both of my tanks, worth every penny.

dd_jumpguard3 by Kyl Aquaria, on Flickr

Waters · Jul 3, 2019

I have lost many fish to jumping.....therefore I no longer keep a lidless tank.

ScottR · Jul 3, 2019

I’ve had only one jumper, a DW goby. And that was when it was immediately introduced to my DT. No other jumpers.

Adventures In Reefing · Jul 3, 2019

Adventures In Reefing · Jul 3, 2019

pcon · Jul 3, 2019

Thanks for the compliments guys I am glad some people liked my ramblings.

mattzang said:
i get the desire to keep tanks without tops, when i take mine off to do stuff i always start thinking.. maybe i could just leave it off while i'm home.. but would i really hear a fish jump out? do i really check the tank that often even when home? i like my fish too much to risk it

doesn't help that my top was quickly and poorly made (by me) so it's extra unsightly lol

I am in the same boat here, I have an extra unsightly cover that I put together in a rush because I was clinging to that gorgeous top down view until it was too late. So I am sympathetic to the desire to address the problem in a way that is both safe for the fish and safe for my eyes.

Haydn said:
In the 19 years I have had my current opened topped tank I have only lost one fish to jumping, a Sohal tang. My tank is slightly over a metre deep and I think by the time the fish have got to the surface they are too knackered to jump
The Sohal? he jumped in the middle of a thunderstorm and I think the flashes in the pitch darkness caused it, I now leave 1% blue on my LEDs.
But I do agree with the OP - our fish are our responsibility.

Thanks for pointing out. A Sohal Tang, is not one I would have expected to jump. You illustrate some different strategies for jump mitigation, tall tanks, soft light transitions, and moonlights, all can help mitigate the likelihood of having a jumper. As we are all saying, none of these things, including a lid completely eliminate the possibility of having a jumper. Often there are gaps in the lid, lightning, spooky people hands and other events out of our control which may result in a jumper.

It probably is important to consider, jump mitigation as the result of a system, not lids as a one size fits all band aid to keeping fish in our tanks. Just like, there is no one answer to filtration in a reef tank there is no one answer to jump mitigation. Stocking, lids, lights, height, and vigilance, form some base factors which can go into our jump mitigation life support subsystem. The combined contribution of these factors need to add to a reasonable degree of safety for each reefer.

Thinking in this framework we can compare say lids and fences, some prefer the aesthetics of a fence to a lid, at the expense of the small reduction in safety factor. This can be combined with stocking to make up for that loss of safety factor.

There is always some degree of risk, we don't all keep seahorses in octopus grade sealed tanks to prevent jumping, nor do I think we should go toward that. But between it being acceptable to, just sort of kinda avoid fish that may be more likely to jump, as I have been guilty of in the past. Even if with keeping stocking generally appropriate we can reduce jump deaths to one every few years is this acceptable? There is some middle ground somewhere.