PlanetCatfish.com

If you look back to what my comment refers to, is that scientists that research captive bred species for food do not have a need to know how long they live. The point of this is that there is very little useful information AVAILABLE as to how long any particular fish lives. Salmon was used as an exampl of fish that is commonly kept in commercial settings, which is more likely to have money thrown at it for reasearch - but there is little value in figuring out what the lifespan is for these fish. As a consequence, there is also not much research done to figure out lifespan for other fish.

And whatever source we have for this, it's a big task to fill in 3000 species worth of data. But that still assumes there is a valid, reliable source for the information, which is what most of this thread refers to.

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Mats

Just my two cents.

I don't think ichthyologist are wasting time, everything always sounds easier than it is. Just like adding this info to the cat-elog.

Scientist have budgets, space allocations, and specific goals just like everyone else. Can you imagine the fish warehouse they would have to have to keep all these different species of cats for 10, 20, 50+ years. Really. Think about it for a minute or two if you tried to do it on your own. The amount of money, space, tanks, and effort for scientist to do that type of research is not worth the investment by any means. I don't know how you could expect them to do that just to find out how long they may live?

Jools wrote:One question I'd ask is why do you need to know this. What difference does it make?

I do think some general information related to life span could be very important. People looking at these TSN's, RTC's, and other big cats might think twice if they see how long they can live. Just like people who think they are interested in buying a tortoise until you tell them they can live for up to 100 years then they think twice about it.

Anytime we add a new data item that needs to be populated manually, that's, say 90 seconds per species.

90 seconds times 3000 odd species is 75 hours solid work. Given I put in 5 hours solid a week on this, that would take 15 weeks to complete. So, the opportunity cost alone is very high even if you had some data and it is mostly unavailable except for a very few species.

We cannot know what the lifespan is in the wild for all 3000 odd species. The short answer to this question is that it will be provided from statistical information from the "my cats" - however that needs some data cleansing before it's used in anger. That way you will be able to see average and longest living in captivity - which gives a guide rather than empirical data.

Jools

If there are specific species that this can be usefully applied to, then it would be much easier to add the data to those specific species - e.g. RTC, TSN, etc. This could be entered into the data sheet as "General information".

The problem with doing it for ALL species (or all genera) is the amount of work involved, and if it's just guesswork, it's questionable as to the value of it. More data in the Cat-eLog is only really doing something good if it's reliable _AND_ useful. And if it's widely available - it's no point having "age data" for about 2% of the species - that just raises new questions ("Why haven't you got age data for <X> - mine is 10 years old, how about you enter that?").

I'm not saying we can't edit specific data sheets that have "unexpected" (annual species?) or "important" lifespans (very long, for example).

But I see this thread to be about a wholesale "have information on every datasheet as to the expected lifespan".

[Jools also provided some good insight - I've been writing this as well as trying to fix a rather obscure bug that occurs when a user has a "&"-sign in their name in the "My Aquarai" - almost there, just need to make sure I've caught ALL of the places, and fix the "My cats" and "My blogs" as well.]

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Mats

Lots of good points in this thread and I like Mats' suggestions immediately above. As any kind of accurate life span information is very hard to come by, we can add notes to the "general" data sheet field if the specie's lifespan is unusual, or we get some solid data.

I have actually been doing some research on this topic, unrelated to this thread, and I can tell you that life expectancy information is very scant. 99% of what is out there is for farmed food fishes and is focused only on getting the fish species in question to market size. These fish do not die of old age however.

People looking at these TSN's, RTC's, and other big cats might think twice if they see how long they can live.

Milton, I wish this were the case but no warning seems to help on this front. In most of these cases we are dealing with Tapfish aquarists. They want a RTC, a clownfish like Nemo with an anenome, and a school of pink-dyed oscars in their 30 gallon. Anyone that suggests this combination might not work is clearly an idiot. Do a quick google of "PC and idiot" and you will find a score of people saying that PC is full of idiots because we told someone that a 20 gallon tank was not a good choice for their new TSN.

The key is to try to get people to evolve from owning a fishtank, which exists to make them happy, to an aquarist who is actually concerned about how to make their fish happy.

-Shane

Shane wrote:Milton, I wish this were the case but no warning seems to help on this front.

I think you got your names crossed!

I think it's a case of mistaken avatar identity!

Jools

I think it's a case of mistaken avatar identity!

Yeap, you both have coma-canoa as your avatar. May bad.
-Shane

Thanks all. Nice new input.

PlecoCrazy wrote:Scientist have budgets, space allocations, and specific goals just like everyone else. Can you imagine the fish warehouse they would have to have to keep all these different species of cats for 10, 20, 50+ years. Really. Think about it for a minute or two if you tried to do it on your own. The amount of money, space, tanks, and effort for scientist to do that type of research is not worth the investment by any means. I don't know how you could expect them to do that just to find out how long they may live?

Trent, you make a good sense but science has many more sophisticated ways apart from the blunt frontal attack as you are imagining. For example, in that recent episode of River Monsters, an ichthyologist was shown estimating the age of a caught long-finned eel using a small bone extracted from its head that has layers/rings on it like the rings on a tree trunk. This tells the age. If I am not mistaken, he thought that 3'-4' eel was 20 or 40 years old - I just don't remember well.

There are other ways with statistical polls of fish keepers, fishermen, fish-breeders, etc. being not the least of them. For example, most people agree that for an alligator garpike to reach 7'-8' length would require at least half a century.

And finally, trustworthy sources: for example, I'm sure we can trust Taksan when he says his two RTCs lived 27 years in his pond.

Don't know if carbon-14 radioactivity analysis can be applied to living and short-living things. Probably not, but anyway, these are just a few examples.

also, if we only knew of all the superficially silly ways the governments spent our tax money

i saw once the US paid quarter million $ to send a scientist study some procreational habits of some obscure squirrels somewhere in central america or SA... nobody could explain in plain terms why that was important for our country...

I have no idea what the value of researching squirrel's reproductive life is - but it can be quite expensive to do research, if it's over a long period of time for example. Someone obviously approved the research grant, and I don't think they are usually given on "I'd like a nice trip to a warm country, so I'll make you think I'm studying squirrels, while sipping Margeritas on the beach..." - researchers have to explain what they are going to achieve, and why it's "important". Given that there are HUNDREDS of undescribed species in just Loricariidae, I think finding out how long the fish live take a lower priority of the money available for catfish research. And I guarantee you that no one can explain in simple terms why/how, for exampple, Jon Armbruster's, Nathan Lujan's or Mark Sabaj's work is good for the US either. But these people do work on describing new species for us - some of them catfish, but they work on what they can get grants for. Someone interested in squirrels, parrots or spiders can probably quite easily say "The US government spent $X [where X is some large number compared to most people's personal budgets] on studying tropical (cat-)fish for no apparent reason...".

The problem with "polling people". If you ask the average (non-expert) aquarist how long goldfish live, you will PROBABLY get an answer of "1-2 years", yet if you ask someone who actually knows how to care for goldfish, they can live as long as 30 years, and 15-20 is common. Same thing if you ask "how long does a common pleco live?", you will probably not get the "properly cared for" answer that I think is what we want in the Cat-eLog.

We are, however, planning to harvest data from the "My Cats" to get some sort of idea of the lifespan of the fish (we could then draw curves showing that for this particular species, most people keep them for about 5 years, but some live to 25...)

In the case of analyzing bones, scales or something like that, it a) relies on seasonal changes, which may be less pronounced in tropical regions (New Zeeland is not a tropical climate), and how do you know you've found the typical/longest lifespan of a fish - it's the same problem [but a bit harder to analyze] as "max size" of a fish. Until someone catches a bigger one, we only know the size of the biggest one recorded so far...

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Mats

While an expertise led guess of a lifespan banding for 400+ genera might be of some use, I think it limited and prone to error - as well as perceived versus actual data.

Data regarding lifespan in nature is pretty much unavailable and, I would argue, of less use to an aquarist.

So, my solution to this old chestnut will be to use My Cats data. Over the next week we will introduce email notifications to ask users to update the species they are keeping. If no reply after a year, the species will be marked as no longer kept.

This will build a view of how long people keep their fishes for. Now, I know this isn't an entire longevity picture, particularly lifespan in nature, but I do not think this is the useful thing. I think what we want are two things. To know how long a fish can be expected to live for in captivity (on average and the longest on record) and also to try to beat that record. I appreciate that hard to keep fish will likely have a low average - but that is important to know.

We will introduce a new field onto the catelog for this, I think, around mid 2012 once more data has been accumulated.

Jools

@ Victor

I think it is not important yet, but it could get more important in the future

For instance, this study might reveal new insights in other squirrels, taxonomic or perhaps even conservationally. The problem with pure science is, it has proven to result in many usable knowledge, but one can not predict what will help and what not

Take the NASA for instance. Why would anyone want to walk on the moon? I would not. But this madness did result in the communication sattellite, for instance, which is worth a dozen times whatever has been spend on spacefright - and now I'm being conservative.

The quest for the mating behaviour of this squirrel might pop up with information about medicinal plants, it could result in new techniques or new equipment worth a fortune

Mind you. I'm not saying I care about the results which are sought, after all, I'm not a aquirrel so why would I want to know how squirrels mate? I could not care less.

But any rediculous project such as this one has a good change of interesting spin offs.