Archocentrus myrnae

Loiselle, 1997

Common Name: Topaz Cichlid

Family: Cichlidae (Cichlids)

Synonyms: none that I could find

 Distribution: Río Cocolis, a tributary of Río Sixaola, 3.5 km southeast of Shiroles, on Bratsí-Shiroles road, Limón, Costa Rica

Max. size: 5"

 Sex differences: Males are larger, females will have a black spot in the dorsal and get some spangling on the belly much like convict females.  When the female is guarding eggs and fry the bottom front half of her turns black.

Breeding: Cave spawner

Gestation Period: 48 hours

Number of Fry: 100-200

 Requirements: pH 7.0-8.4 (the fish was seen in waters of 8.4 and rather hard) (personal communication); temperature 70-80°F (21-26°C)

A. myrnae lives in a clean, shallow, fairly fast flowing river.  The river has a sandy bottom. The temperature at the time of the sighting was 25°C (77°F).  The other cichlid it lives with is Astatheros bussingi.  Other species it is found with include: Astyanax aeneus (Central tetra or Sardina), Pomadasys crocro (Roncador or Burro Grunt), Poecilia gilli (Costa Rica Molly or Olomina), Alfaro cultratus (Knife-edged livebearer),  Awaous banana (Lamearena or River Goby)  and Sycidium altum (Chupapiedra  -a goby)

I got these fish as really small F1 fry from Juan Miguel Artigas Azaz.  I placed them in a 20 gallon tank on their own until they grew up to a few inches long.  At that time I placed them into a 33 gallon tank.  This tank is filtered with an Aquaclear filter.  There is large gravel on the bottom along with a few rocks and a nice clay pot.  There are a few plants as well in the tank.  They get a 30% water change weekly.  The pH runs 7.8 and the temperature was 78°F. They ended up crowded along with a ton of Africans that I was holding to send out to a friend.  When they were on their own in the tank they were always hiding and skittish.  When the Africans were in the tank they came out and you saw them.

The tank was getting pretty crowded with all the Africans and the myrnae in it before I was able to send the Africans to their new home.  However, after the Africans were gone the myrnae reverted back to their original hiding behaviour.  I received some M. affinis (rainbowfish) from a fellow club member and I placed them into this tank.  The myrnae still hid but were more visible after this.  The two largest myrnae, which happened to be male and female, took over a pot that I had in the far end of the tank.  They spawned in there a few days before I was going away on a 2 week trip.  The fry were free-swimming the day I left.  Some were placed into a 10 gallon plastic container with a Hydrosponge.  I asked for the fish-sitter to feed them as well.  They all seemed alright when I returned from my trip.  The fry were started off on baby brine shrimp and graduated to finely crushed flake food.  I enjoyed having these fish (when I could see them).  I just love the blue eyes on this fish!!

© Copyright 2000-2003 Lisa Boorman
All Rights Reserved

Suggested Reading:

The Cichlid Aquarium by Dr. Paul Loiselle

To see more references on cichlids:

Cichlid Book List

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