What are the Willem Heijns guidelines?

[Alden]

Dan Woodland has mentioned these guidelines for cichlid keeping. I'm curious to find out more details about them. Anyone care to shed some light on the matter?

[Willem Heijns]

I might be the one to answer this.

Almost 20 years ago, I developed a system to decide which (Central American) cichlids could be kept in a home aqarium without too much harm to their welfare. In those years legislation seemed to be imminent to regulate pet business and pet keeping. When the legislation didn't materialize, I forgot about the whole thing.

Then, early 2009, I talked with Dan Woodland about it and we decided to try and bring the system to the USA. The project was called: "Responsible Cichlid Keeping", RCK for short. I translated my guidelines into English and Dan and I tried our hand at a few species to see what would come out. The result was (at least to me) devastating. The way cichlids are kept in the USA is so much different than what I propogate in the Netherlands, I would sure run into trouble trying to lay Dutch (or better: my) standards upon USA cichlid keepers. I'll give just one example: in my system Parachromis dovii is unfit as an aqaurium fish. It should not be kept, not even in the biggest tank one can possess. I know that both from using my system as well as from my sad experience with this species. Now try and tell this to people in the USA who keep Parachromis dovii as a pet (solitary) with hardly any room to turn around let alone swim a couple of times its length before reaching the end of the tank. There's famous cichlid keepers among these people. Remember Pablo?

Now, in 2012, this legislation in the Netherlands is yet again on the political agenda. A list on which all species of mammals to be kept at home are to be published is almost ready to go into effect (planned January 1st, 2013). Any mammal not on the list is not allowed to be kept. We even have created our own Animal Cops to enforce this law.
So I am reviving my project. Anyone interested?

[Alden]

Willem,

Thank you for your response. I did not realize that this issue was also a political one. I do understand what you mean in regards to parachromis. I've seen a gigantic dovii in the Denver Zoo. He and his pair are majestic, and I see how it would be hard to raise them in private aquaria.

I think I've seen many tanks especially on the net with extremely dense populations of Central American cichlids. I think they look very colorful, but I do see how some of these fish are pretty beat up.

In terms of my own tank, I have a 125 gallon tall tank. (60" Long x 18" wide x 24" tall). I know foot print is of prime consideration for large central American cichlids. But I do enjoy central Americans big or small. Could you provide some suggestions for stocking a tank such as my own? I think your response could help many American hobbyists be more mindful of their tank stocking.

[Dan Woodland]

Hi Willem,

Even though we met with indifference to your plan here in the US I didn't give up. I was successful in converting several local fish keepers here. I myself opted to procure even larger tanks and have limited my fish numbers and size in those tanks even more. I see much more natural behavior, I'm happier with my set up and I believe my fish are happier as well.

Alden here even changed his stocking level, seemingly overnight, based on my comments born of your system - which I sent to him.

Onward and upward, Woody

[Lisachromis]

Ok, back on to the subject.... guidelines for keeping large Centrals (or others).

[Alden]

Thank you Lisa!

[Willem Heijns]

I knew you would still be interested Alden.

A lot of people seem to think that size is the only criterion to use in deciding if species are fit or not. But in my original formula swimming behaviour and agression also counted. In the upgrade I am building on those criteria to refine the system. In the end we should have something that can be used for cichlids worldwide (and maybe other fish too).

What would you consider important additional criteria?

[Dan Woodland]

Willem,

What about origin? Fish come from different habitats like lakes, bogs, streams and rivers which can very. For example, a fish may live in a river but typically stays in a small tributary instead of using the river proper meaning they require less room to roam and live.

Another might be aggression could be further defined. For example, seek and destroy versus intimidation. Seek and destroy fish would require much more room to chase off intruders while intimidation fishes would stop after only a foot or less. Here you could use Crytpoheros sp. as the example of intimidation and Herichthys sp. as a seek and destroy version.

Lastly, what about the type of feeding or special characteristics? One of your current examples includes Petenia splendida, maybe the fact that they are a pure "predator" built for speed and they feed by gulping could be considered.

While on a tour of the new Aquarium here in Cleveland, Ohio I asked the tour guide about feeding the sharks in the largest tank so they didn't eat the other fish... she simply said we make sure we keep them very well fed. Maybe feeding styles or requirements would be another thing to consider.

Just a few random thoughts, I’ve got to get back to work.

Woody

PS. After seeing fish the their natural habitat I realized they need more room so I increased tank sizes while decreasing the size of fish kept in those larger tanks. I’m now seeing more of the natural behavior in the tank as I did in the wild. I’m sure they appreciate the space and I too enjoy this “combination” much more as a hobbyist and fish keeper.

[Bas Pels]

While on a tour of the new Aquarium here in Cleveland, Ohio I asked the tour guide about feeding the sharks in the largest tank so they didn't eat the other fish... she simply said we make sure we keep them very well fed. Maybe feeding styles or requirements would be another thing to consider.

Problem with keeping fish very well fed all year around is thay will eat a lot more than in nature - especially fish in rivers might have lean times

Talking of differences between ivers and lakes brings me on water chemistry (being a chemist might help too )

A 30 cm black water fish can be kept in a certain tank, a 30 cm Tanganjica fish can be kept in that same tank - but not together

Many people don't appreciate water chemistry, or other problems with combining fish which don't meet in nature

problems which do influence fish well being largely

[Dan Woodland]

Sorry Bas, I should have said I don't practice the "well fed" method nor do I condone/promote it. I was merely pointing out some "options".

While on a tour of the new Aquarium here in Cleveland, Ohio I asked the tour guide about feeding the sharks in the largest tank so they didn't eat the other fish... she simply said we make sure we keep them very well fed. Maybe feeding styles or requirements would be another thing to consider.

Problem with keeping fish very well fed all year around is thay will eat a lot more than in nature - especially fish in rivers might have lean times

Talking of differences between ivers and lakes brings me on water chemistry (being a chemist might help too )

A 30 cm black water fish can be kept in a certain tank, a 30 cm Tanganjica fish can be kept in that same tank - but not together

Many people don't appreciate water chemistry, or other problems with combining fish which don't meet in nature

problems which do influence fish well being largely

[Bas Pels]

Dan

If I remember correctly, you once stated that before

Still, it is a matter which is often discussed. In fact, I'm quite certain that if I were to starve my fish for a month or so - being the lean time of year I would be critisized

In fact. I have been critisized (not on this forum) for keeping my Uruguayan cichlids and others cold in winter (10-12 C, that is 52-55 F). Values one sees in their home country

[Dan Woodland]

Dan

... Values one sees in their home country

Precisely what I try doing as well... you can'y go wrong when you duplicate their natural habitat parameters.

People think I'm nouts keeping my fish at 76 but they breed and look great so I'm guessing the river knows best.

[Alden]

Willem,

What about origin? Fish come from different habitats like lakes, bogs, streams and rivers which can very. For example, a fish may live in a river but typically stays in a small tributary instead of using the river proper meaning they require less room to roam and live.

Another might be aggression could be further defined. For example, seek and destroy versus intimidation. Seek and destroy fish would require much more room to chase off intruders while intimidation fishes would stop after only a foot or less. Here you could use Crytpoheros sp. as the example of intimidation and Herichthys sp. as a seek and destroy version.

Lastly, what about the type of feeding or special characteristics? One of your current examples includes Petenia splendida, maybe the fact that they are a pure "predator" built for speed and they feed by gulping could be considered.

While on a tour of the new Aquarium here in Cleveland, Ohio I asked the tour guide about feeding the sharks in the largest tank so they didn't eat the other fish... she simply said we make sure we keep them very well fed. Maybe feeding styles or requirements would be another thing to consider.

Just a few random thoughts, I’ve got to get back to work.

Woody

PS. After seeing fish the their natural habitat I realized they need more room so I increased tank sizes while decreasing the size of fish kept in those larger tanks. I’m now seeing more of the natural behavior in the tank as I did in the wild. I’m sure they appreciate the space and I too enjoy this “combination” much more as a hobbyist and fish keeper.

I think Dan brings up great points in terms of other things to consider.

[Willem Heijns]

Maybe we should try and sharpen our focus here. The guidelines I'm working on are aimed at giving advice on the "responsible keeping of cichlids" on the species level. This implies that for every cichlid species a statement must be possible as to how fit or unfit this species is for keeping as an aquariumfish. Wellbeing of our fish is the leading criterion. How can we achieve this?

Here's the logic:
1. determine the natural environment of the species
2. define the degree of dependence of the species on this environment
3. find out how much effort (knowledge, space, money, etc) is needed to create the necessary invironment
4. classify each species based on the results of the first three steps, taking into account the characteristics of the species itself.

What to look for? The requirements can be split into a few categories. They are:
a. size of the tank (based on size and behaviour of the species at hand)
b. setup of the tank (substrate, watercurrent, plants, etc)
c. water chemistry
d. food (including predation)
e. shelter (fleeing distance)
f. reproduction (substrate, caves, mating)
g. social behaviour (tolerance against conspecifics and other fish, picking order)
h. communication.
As soon as I have all the criteria defined and set the measures, I can start weighing all species against the criteria. That will be a hell of a job. Anyone willing to assist?

I have one very compelling question in this respect. Assuming that we try to keep our cichlids in such a way that they will show as much of their natural behaviour as possible and also assuming that reproduction is part of that natural behaviour, is a species that has never been bred in the aquarium fit as an aquariumfish?

[Bas Pels]

I have one very compelling question in this respect. Assuming that we try to keep our cichlids in such a way that they will show as much of their natural behaviour as possible and also assuming that reproduction is part of that natural behaviour, is a species that has never been bred in the aquarium fit as an aquariumfish?

Although cichlids do - as far as I know - not migrate in order to reproduce, many species do. Others burrow, for instance

I'm quite certain my Pterogoblichthys gibbiceps will never reproduce, but I do feel I'm keeping them well enough (1 for 1000 liters in a tank).

So in general: no
for cichlids - perhaps

[Don Hiatt]

Maybe we should try and sharpen our focus here. The guidelines I'm working on are aimed at giving advice on the "responsible keeping of cichlids" on the species level. This implies that for every cichlid species a statement must be possible as to how fit or unfit this species is for keeping as an aquariumfish. Wellbeing of our fish is the leading criterion. How can we achieve this?

Here's the logic:
1. determine the natural environment of the species
2. define the degree of dependence of the species on this environment
3. find out how much effort (knowledge, space, money, etc) is needed to create the necessary invironment
4. classify each species based on the results of the first three steps, taking into account the characteristics of the species itself.

What to look for? The requirements can be split into a few categories. They are:
a. size of the tank (based on size and behaviour of the species at hand)
b. setup of the tank (substrate, watercurrent, plants, etc)
c. water chemistry
d. food (including predation)
e. shelter (fleeing distance)
f. reproduction (substrate, caves, mating)
g. social behaviour (tolerance against conspecifics and other fish, picking order)
h. communication.
As soon as I have all the criteria defined and set the measures, I can start weighing all species against the criteria. That will be a hell of a job. Anyone willing to assist?

I have one very compelling question in this respect. Assuming that we try to keep our cichlids in such a way that they will show as much of their natural behaviour as possible and also assuming that reproduction is part of that natural behaviour, is a species that has never been bred in the aquarium fit as an aquariumfish?

I feel the only way to adequately answer these questions would be to gather data. Something along the line of an ongoing survey (Perhaps a section of this site?)

I admit, the main problem I see with such an endeavor would be how to deal with all the variability in aquarium size, maintenance schedules and husbandry practices.

If we could determine that 9 out of 10 people were successful in keeping "X Cichlid" in "Y size aquarium", we could pretty much assume that the aquarium in question is suitable for maintaining that species.

Like I said, there are is that variability issue to take into consideration, what did the 9 keepers do to be successful and what caused keeper # 10 to be unsuccessful?

If this information could be gathered and processed, it could help in determining what works and what does not in the long run for many species.

[Willem Heijns]

I'm afraid it's not that simple Don. The variability you mention in how cichlids are kept is not the issue here. It's the requirements as seen from "the fish's point of view". I could easily find 10 people who will state that they keep Parachromis dovii "successfully", even in a 125g tank. By successfully they would probably mean that the fish didn't die. If we want to change the way cichlids are kept, we should not start with common practice. That is why it is such a hell of a job.

[Don Hiatt]

I'm afraid it's not that simple Don. The variability you mention in how cichlids are kept is not the issue here. It's the requirements as seen from "the fish's point of view". I could easily find 10 people who will state that they keep Parachromis dovii "successfully", even in a 125g tank. By successfully they would probably mean that the fish didn't die. If we want to change the way cichlids are kept, we should not start with common practice. That is why it is such a hell of a job.

That is a very valid point Willem. You are right, simply keeping the animal alive is not the same thing as successfully maintaining them.

Unfortunately, for us Cichlid keepers, we would never, ever be able to provide suitable conditions for our pet fish based on their views or actual needs.

The confines of an aquarium no matter how large it is, compared to be vast expanse of nature? Where do you think the fish would rather be? Even when the constant threat of predation is present, Cichlids would continue to do what they do in the wild and be "happy" doing it. Forgive my anthropomorphic use of the word happy. lol

Could we ever provide a truly natural diet or really suitable water conditions? No. We maintain the fish in a closed system.
Example: It is well documented that many fish have a well developed sense of smell. Imagine what it must be like for them to eat and produce excrement in the same small volume of water that is reliant to a relatively small filtration system to maintain their water quality. This could be negligible in a planted tank with smaller fish, but imagine a tank containing some tankbusters like P.dovii?

Some people may retort that the filtration systems they have keep their aquarium water in pristine condition.
But does it really? Are you sure? Would you drink water that had been filtered by your aquarium filter. Probably not.

This may sound like I am bashing the aquarium hobby in general. Not at all. In many cases, we are the last line of defense against extinction for many species of Cichlids.

I feel common sense needs to be used when selecting fish for our tanks. P.dovii is a very large fish. They maintain a very large territory in the wild and consume a diet of mostly other Cichlids. Do we really want to keep a fish like this in a little glass box?

The fact of the matter is Willem, large Cichlids (and fish) are going to be kept if we like it or not. The best thing we can do is to provide information on how to best accomplish this and hope these people will eventually come to their senses.

I myself, have sold off or given away most of my tanks and have abandoned the keeping of large Cichilds feeling they are better off in the wild.

I have a sole empty 125 gallon tank that I plan to under-populate with some dwarf Cichlids when I have time to set it up again.

[Lee Nuttall]

When we talk about space, behaviour and feeding requirements does this also apply to captive raised fish, as many points in Don's post are referring to wild caught specimens. Is there an distinction between the two??

I believe it is important to make this distinction when keeping either wild caught or aquarium raised specimens. I would think that space and feeding requirements at least maybe different when giving guidelines for wild caught fish??

[Dan Woodland]

When we talk about space, behavior and feeding requirements does this also apply to captive raised fish, as many points in Don's post are referring to wild caught specimens. Is there an distinction between the two??

I believe it is important to make this distinction when keeping either wild caught or aquarium raised specimens. I would think that space and feeding requirements at least maybe different when giving guidelines for wild caught fish??

Good question, I don't think there should be Lee. I think both should be treated as they were removed from a natural or wild environment or at a minimum their wild counterparts environmental needs provided. Look at dogs as an example (more people can relate to dogs than fish), no matter if it's raised in your back yard or in the wild it's needs are/should be looked at the same.

A friend has a wolf, yes a 100% wolf, he has it caged up in his back yard. It paces constantly and looks like it's stressed ALL THE TIME!! It's a hard thing to watch as it trys to climb the fence to escape and franticly paces back and forth when it can't. I know dogs are supposed to be more intelligent than fish but that should not matter - I liken his situation to that of our fish captives. As a matter of fact we call our fish "captive bred" which to me intimates they belong in nature not our tanks. No I'm not an advocate of turning all our captive animals/fish loose but we should provide the best most responsible care we can for them.

As Willem's first and second system designs show some animals, fish (dovii) in this discussion, should not be caged/kept at all while others deserve a shot at having a normal/natural existence. Dan