Fat Sleeper fish: small odd-ball for planted tanks

pepetj

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NOT A GOOD IDEA (see post #5)

I've been keeping a fascinating fish in my planted tanks and I wanted to share it with you. I only have one but waiting for more to become available locally.

As a juvenile I placed him/her in a 40gal long Community tank (Perfecto); he/she is now, as adult, living in my planted, paired-off Blue Snakeskin throwback Discus tank (Aqueon 26).

I'm talking about the Dormitator maculatus, commonly mislabeled as Fat Sleeper Goby since it's not a Gobiidae but a member of the Eliotridae family (sleepers).

Dormitatormaculatus.jpg


This is a somewhat shy fish that despite being wild caught seems ready to eat commercial fish food although it may pray on small sized fish such as Cardinals and Neon Tetras; what makes this fish special, in my opinion, is that due to its lack of swimming bladder it is prone to use plant structures to stay put or "fall asleep" and the fact that they seem to go around all the tank without claiming a particular territory.

Be it near substrate level on small foreground plants or towards the water surface along the long and sturdy leaves of Vallisnera gigantea, I find this small oddball a truly beautiful fish.

Maximum size of 70.0cm (27 1/2") had been reported but its most usual size goes up to 14.5cm (5 3/4").

My Fat Sleeper has adapted quite well to my soft/acidic tank (pH 5.2 to 5.7, 4 dGH, 0.5 to 1 dKH). It was previously living at a pH 6.5 to 6.8, 5 to 6 dGH and 2 to 2.5dKH.

Pepetj
Santo Domingo
 
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Biollante

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Thar Be Monsters, Monster Fish Keepers Anyway

Hi Pepetj,

Dormitator maculatus are indeed of Class Actinopterygii (ray-finned fishes) Order: Perciformes Family: Eleotridae.

The fish in your photo appears to be a juvenile, gonads will grow and sexual dimorphism will be apparent at around a year old.

These are freshwater/brackish water critters that can even take marine conditions for extended periods of time. They like caves and lots of driftwood.

These fish can reach 70 centimeters (28 inches) and are very territorial when mature at about a year. Along the way they they become accomplished predators.

I gather that most of these fish never reach 70 cm but still can come in easily at 35 cm and they eat anything.

I have never kept these fish, but spoke to an associate that has a couple of breeding pairs and he suggested you might wish to do a little more reading and go to Monster Fish Keepers, http://www.monsterfishkeepers.com/forums/. :)

I hope this helps, I would urge you to consider “re-homing” the little gal/guy. :gw

Nice photo, nice tank... :cool:

Biollante
 

pepetj

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You are right about the pic being of a juvenile. That was him/her at three inches SL, shortly after I got it. I'm waiting for more to come since I do intend to set a species only tank for them. I wish it grew larger but the fish I have have been sitting at the 5" mark for months. Its reaching a year with me next January.

Thanks for the advice. I appreciate it. It has a huge mouth for a fish its size. I'm a member of MonsterFishKeepers too, nice forum. How to tell male from female? Hopefully your friend have some clear idea... This fish seems to inhabit the island I live (Hispaniola) but the specimen I have was imported from the Caribbean basin of Colombia.

Pepetj
Santo Domingo
 

Biollante

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Hi Pepetj,

All I know is that in mature males the second dorsal fin is elongated, I will try to find out if there are any other clear differences. :)

I seem to recall both the males and females are quite colorful.

Biollante
 

pepetj

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Not a good idea

After some time I finally got my hands on a school of this species.

I put them in two different planted tanks.

These guys don't destroy plants in the sense that they don't uproot them, even delicate stems, yet... they munch on them!

The oldest specimen, the one that never touched a plant is still free of that behavior so he/she is staying with me. All others? already banned from my tanks.

My sweet Downoi crowns? gone, all of them; Ludwigia sp? Rotala sp? nice leaves for munch.

I live, I learn. Fat Sleepers are not planted tank safe!

Pepetj
Santo Domingo