Thorichthys affinis or meeki

[John Heaton]

The behaviour of my latest collection of T affinis is becoming more like firemouths, every day. Many of them inflate their gular pouches without any real reason, apart to show off.
The colour of their pouches is still not the bright red of the firemouth but they are getting close.

[Alex Odesit]

Hi John,
They do look Thorichtys Meeki to me.

Alex

[John Heaton]

Alex, here are some photos of Firemouths that we collected last year from the San Pedro Martir drainage system, which is to the North of Lake Peten. T. affinis are not found there. They certainly look very similar. If my latest captures are T. meeki this will be a first for Lake Peten.
Yellow T. affinis have been caught very close to the lagoon where we found the newest additions. See Sat photo.

[John Heaton]

Looking back through my records at a previous expedition to the Southern Arm of the Lake I made a surprising discovery.
Some of the fish we caught here I assumed to be T.affinis but they were not yellow and I put them up for question. There were no suggestions.
Here are the photos:-

[Alex Odesit]

John,
Did you noticed that later pictures shows all fish without or possibly very light prominent spot on the gills that characterize most of the Thorichthys species?
My guess these are Affinis, not Meeki.
Alex

[John Heaton]

Alex, I hadn’t noticed the missing ocular blotch on the gill plates. I had commented on this when I first started collecting T affinis from the main Lake. According to descriptions of the Thorichthys genus they occur on all species except one, and that is not affinis.
So I searched my records for photos of my early captures from the main Lake and here are the results, no ocular blotches.
This new revelation makes a strong case for the fish captured from the Lily Lagoon being T. meeki.
Looking at photos of T.affinis captured by a French expedition to Laguna Salpeten, a saline lake near the Eastern end of Lake Peten with its own unique drainage, the ocular blotches were sometimes present and in other photos missing.

[John Heaton]

http://www.cichlidae.com/article.php?id=7

I have now reread Juan's in depth article on Thorichthys. meeki. The comments about colour variation and habitat, shallow lily covered lagoons fit perfectly.
Also, having watched their behaviour I am convinced that these fish are T.meeki.