Aequidens Diadema quickly passing species max size?

[Omrit]

Everywhere I read has aequidens diadema (sometimes called the royal acara I think) listed as reaching a little under 4 inches with fishbase saying a dominant male can be half an inch bigger so 4.5 inches or so.

I have two that were about an inch long when I got them, and they have grown a little under an inch a month for 4 months. This surprised me given their small max size, but I am starting to suspect I either have something else or most of the online info is wrong?

One is bigger than the other. The larger one is a rather fat 4.5 inches.

Pic #2 and #3 were taken today. The last pic of the acara pic #7 was taken 20 days ago, a noticeable increase in over-all body thickness has occurred in that short time as you can see.

http://imgur.com/a/04CuDxy

I take terrible pictures sorry.


I like them a lot and the tank is 300 gallons so them getting larger is no issue. Just curious really.

 

[Sinister-Kisses]

4" is definitely not the max size. I've only kept one personally but it was about 6-7".

 

[duanes]

While 4.5 inches may be normal size in nature, which may have to do predation, food supply, or that large specimens head for depths where they are seldom seen, or caught.
I have heard of them growing to 8" in aquariums.

Where I catch their distant cousin, Andinoacara coerleopuntatus in Panama, I seldom land any individuals larger than 3 or 4" in nature, but in my tanks, I have had alpha males easily hit 7".

 

[ryansmith83]

Those sizes are very off. Big males will end up 7 - 8” or so. My females were maybe 5” or so.

Cichlid Room Companion concurs.

 

[Hybridfish7]

Everywhere I read has aequidens diadema (sometimes called the royal acara I think) listed as reaching a little under 4 inches with fishbase saying a dominant male can be half an inch bigger so 4.5 inches or so.

I have two that were about an inch long when I got them, and they have grown a little under an inch a month for 4 months. This surprised me given their small max size, but I am starting to suspect I either have something else or most of the online info is wrong?

One is bigger than the other. The larger one is a rather fat 4.5 inches.

Pic #2 and #3 were taken today. The last pic of the acara pic #7 was taken 20 days ago, a noticeable increase in over-all body thickness has occurred in that short time as you can see.

http://imgur.com/a/04CuDxy

I take terrible pictures sorry.


I like them a lot and the tank is 300 gallons so them getting larger is no issue. Just curious really.

Essentually every size on fishbase is based on wild lengths. It is pretty much common aquarium knowledge at this point that the big 3 acara genera (cichlasoma, aequidens, andinoacara) regularly hit the 6-10" mark.

 

[neutrino]

I've seen a number of sources list them small, 4 or 5 inches. The fishbase reference I see lists max size as 11.8 cm standard length, which would be nearer 5 inches not counting the caudal fin, so 6 or so inches total length. This is still on the small side-- Is it a matter of wild fish vs well fed aquarium fish? I'm not so sure, in some species it's the opposite, aquarium specimens rarely reach wild sizes. Also, as many anglers know, it's not uncommon for the same species to be smaller in some locations, larger in others due to habitat differences. My guess is, since both diadema and metae cover a wide range, this may have been based on early wild specimens, perhaps from a population/location where they were smaller.

From what I've seen (and personal experience) 7 inch males is pretty average, maybe on the small side, and larger is not unusual. Several times I've seen someone think they were getting a peaceful 5 inch fish that turned out to be 9 inches and boisterous, lol.

From what I've seen "royal acara" usually refers to A. sp. jenaro herrera, though who knows with common names. In any case, while undescribed and typically listed as A. diadema sp. jenaro herrera, diadema are mouthbrooders and jenaro herrera are substrate spawners (reportedly, I haven't had them yet), so I'm not the only one who suspects they're not the same species.

 

[Hybridfish7]

I've seen a number of sources list them small, 4 or 5 inches. The fishbase reference I see lists max size as 11.8 cm standard length, which would be nearer 5 inches not counting the caudal fin, so 6 or so inches total length. This is still on the small side-- Is it a matter of wild fish vs well fed aquarium fish? I'm not so sure, in some species it's the opposite, aquarium specimens rarely reach wild sizes. Also, as many anglers know, it's not uncommon for the same species to be smaller in some locations, larger in others due to habitat differences. My guess is, since both diadema and metae cover a wide range, this may have been based on early wild specimens, perhaps from a population/location where they were smaller.

From what I've seen (and personal experience) 7 inch males is pretty average, maybe on the small side, and larger is not unusual. Several times I've seen someone think they were getting a peaceful 5 inch fish that turned out to be 9 inches and boisterous, lol.

From what I've seen "royal acara" usually refers to A. sp. jenaro herrera, though who knows with common names. In any case, while undescribed and typically listed as A. diadema sp. jenaro herrera, diadema are mouthbrooders and jenaro herrera are substrate spawners (reportedly, I haven't had them yet), so I'm not the only one who suspects they're not the same species.

Duanes is probably on his way to say this, but small cichlids that fill that niche (acaras, jack dempsies, convicts, cryptoheros, etc) tend to get eaten by things once they hit the 5" mark give or take an inch. Space to themselves, food, clean water, and protection from predators is what allows cichlids of this niche to get nearly twice (or sometimes even three times) their size limit in the wild. Most rocio in the wild are in the 5-6" mark. I've seen some in some more secluded Florida canals hit 7-8. The biggest in an aquarium was 16".

 

[neutrino]

Predation is a constant, not just "once they hit the 5" mark." There are a number of factors affecting wild vs captive fish size, not just predation, and a number of reasons the same species may vary in size from one location to another-- or, for that matter, from one tank to another.

 

[Hybridfish7]

Predation is a constant, not just "once they hit the 5" mark." There are a number of factors affecting wild vs captive fish size, not just predation, and a number of reasons the same species may vary in size from one location to another-- or, for that matter, from one tank to another.

I know, I meant that as in, getting to that size usually means they're probably not making it past that size, since being that size makes them more of a (rewarding) target

 

[duanes]

And lets not forget about that common and efficient apex predator, us.
Here in Panama, cichlids are commonly on the menu, from endemic Vieja to Parachromis, to feral Tilapines and Cichla.
Below are P-Bass fillets, from Cichla caught in Lake Gatun