How long do fish live?

[Sk8r]

1. on the small fishes that are caught and sold as adults, they may take 1 year reaching their adult size, and may live ten years or more---but you never know how old they were when caught---unless you get a juvie and know it.

2. The larger fish that are caught and sold as juvies, figure about 10 years. Or more. Koi, for instance, can live 235 years. Clams can live 500 years, so be respectful. 10 years is a respectable figure, and can run further. One thing our tanks lack is sharks and giant groupers and such. So many, many individual fish just might live longer in our tanks than on the reef. Mortality in the hatching is huge, mortality by being eaten as hatching fry is huge. Mortality from being a food source for a larger fish is quite large. And then there are the lucky ones that claim a hole in the reef, come out when it's safe, and depend on sharp senses and quick reactions to retreat. They survive hurricanes and boat collisions, and 10 years is a fairly long and eventful life on the reef.

3. Inverts, not so much, but I've got some scarlet hermits that have been with me five years, and if Peanut survived the tank change (but could have changed her shell) she could be going at more than 10. I lately saw a fighting conch I bought five years ago surface and dive again under the sand. Maybe I'll see him again in 2025....

 

[Zionas]

I wonder if anyone’s kept a blenny close to or more than 10 years. I’ve heard a number of Watchmen Gobies living for 10+ years and Clowns, Tangs, angels making it past 10 or even 20 isn’t anything new to me.

In my part of the world LFS will often tell us the size of their fish or get fish in at certain sizes / we have different sizes to choose from. Is it the same in the US / UK?

For example, we get YWGs in the 1.5-2” range as a standard for the species. Blennies like the Bicolor I think around the same.

 

[Sk8r]

Blennies are somewhat more fragile---some only eat one type of thing and if you run out, it may not (particularly the comb-tooths) be able to handle pellet, and pretty well needs film algae. I suspect part of the failure to thrive is dietary.

 

[Zionas]

Which belmnies are particularly prone to starving? Does this include Blennies like the Ecsenius genus and the Starry, or are you mainly referring to the Lawnmower, Atrosalarias, Meiacanthus sp.?

If you think they’re more fragile I’ll just stick to a goby as my bottom dweller.

Also would any of these blennies be good for controlling algae?

 

[Sk8r]

The toughest and most general feeder (eats almost anything) ime is the tiny tailspot. The lawnmower can starve after it runs out of algae. The larger combtooths, partly possibly because of their mouth structure, are dependent on film algae and what grows on rocks. Maintain enough phosphate to encourage a little algae and you can keep them. But fish such as dragonets that depend on copepod reproduction IN the tank (which also relies on algae) and a raft of species such as the combtoothed blennies, the linckia sea stars, and others that depend on that film (on the glass) algae that people work so hard to get rid of---you just have to set up your tank so that it maintains a little algae for them, and have enough rockwork to spread it out so it has a lot of surface to work with. Fish food generally doesn't have what the film-feeders need. You also need stable chemistry, so that some spike or low doesn't blitz the food supply. This, for one thing, is why it's best to build your fish-population slowly, adding species as your tank matures and after your obligatory new-to-this mistakes have given way to experience. The habit of keeping a logbook and testing at least once a week will help you gain knowledge as to how to 'read' your tank and what's going on with the general ecosystem.

 

[Zionas]

I’ll definitely be keeping a logbook and recording my observations.

Since the Bicolor’s in the same family as the Tailspot is it also a very generalized feeder? How long have you had your Tailspot for?

Thanks for all the info once again.

 

[Sk8r]

My fish population dates from the Great Blackout about 2 years ago, so that's what I know on this one: most of my fish did survive it, including an 8" humbug or golden domino damsel, but they all had to go to other homes, because an 8" humbug is not going to let anything into the tank that they weren't already accustomed to.