55 Gallon Tank Need help identify Cichlid

Need help identifying an impulse buy Ciichlid. Tank is a 10+ year mature tank (overstocked) with adult fish. I need to identify what type of Cichlid this is to see if I will have any issues when it grows up (fish very small right now, less than an inch in size). Many of the fish in this tank are 8+ years old. Nobody in the store could identify it and I couldn’t find any matching images on the internet.
Behavior: Fish has been in tank for 2 hours and every fish leaves it alone. In fact they all get out of the way or behave as if it doesn’t exist.




What’s in the tank now:
(1) Redtail Shark (Epalzeorhynchos bicolor)

(6) Spotted Silver Dollar (Metynnis Lippincottianus)

(4) Dwarf Petricola Catfish (Synodontis lucipinnis)

(5) Dwarf Chain Loach (Yasuhikotakia sidthimunki)

(1) Blue Phantom/Spotted Pleco (Hemiancistrus Sp., L-128)

(1) Bulldog/Rubbernose Plecostomus (Chaetostoma formosae, L187b)

(1) Bolivian (German) Ram (Mikrogeophagus altispinosus)

(1) Electric Blue Acara (Andinoacara pulcher)

(1) Rainbow Cichlid (Herotilapia multispinosa)

(5) Red Glass Barb - Fire Barb - Rosy Barb (Puntius conchonius)

 

I want to say juvenile Jack Dempsey - that's the first thing that came to my head when I saw it.

 

I want to say juvenile Jack Dempsey - that's the first thing that came to my head when I saw it.

As I haven't seen one that dark in a while, I had to check with some fotos of clear ID, I'm inclined to say the same. Rocio octofasciata. Clear candidate for a return.

 

I'll say Blue Acara/ Adinoacara Pulcher.

 

That looks like a Jack Dempsey Cichlid to me. Needs to get bigger to determine sex for sure. Hopefully you got a male! Males colour up way more than females and grow bigger. Females usually just have colouration around their face area and remain quite bland everywhere else.

I've seen males grow usually around 7" - 8". You'll get the odd male that grows up to 10" big (very uncommon). Most will grow and stay within the 7" range (females even smaller).

They can be aggressive or can be fairly relaxed. Either can happen.

Also, dark substrate will bring out a Jack Denpsey's colours more!

Good choice! And have fun!

 

Jack Dempsey - thank you for the assistance. I found this photograph online that is similar now that I know what to look for:
https://i.redd.it/q2w7amd8gu381.jpg

Since it is a JD, the only fish in my tank where this could be an issue (that I am aware of) are my small dwarf chain loaches. The rosary barbs are larger in size than the loaches. I’m also going to need to reduce the number of fish in tank over time to make room for JD size. Given the age of my silver dollars, they might be best choice as I’m expecting them one by one will pass on due to age. Tank has enough hiding places and filtration.



However, I just read coralbandit suggestion of Blue Acara and found this image that looks like it as well:

TRUE BLUE ACARA (Andinoacara pulcher)


I have a fully mature Electric Blue Acara in the tank and he/she pays zero attention to the little new fish.

 

The first photo was a bit uncertain and does resemble a blue Acara. However, the second photo clearly shows a young JD, Rocio octofasciata.

 

2 more photos. Fish now has been in tank over 24-hours (these 2 photographs)