Need help identifying my fish species.

[CanukAimara]

Hello! I recently obtained a fish from Craig's list. The guy was not sure what type of fish it was and I am new to fish keeping.
He is 4" long with a narrow body and extremely mean. I have him in my 150G with my 6" Ted devil whom he recently killed. I want tk at-home this evil little fish but first need to know what species he is.
I want to tell his next owner as much about him.as I can. Any help.ide tidying him wpdbe greatly appreciated! Ty in advance!

 

[kno4te]

Loisellei perhaps. Maybe duanes and Gourami Swami may know.

 

[Kelly_Aquatics]

Agree with kno4te just with stressed colors

 

[duanes]

It is very hard to tell Parachromis freidrichstalii from P multifasciatus (loisellei).
Males of either have assorted small spots on the gill plate, so in he OPs pic (although hard to see) it looks female, because of the solid color on the lower jaw and gill plate. I edited the 2nd clearer shot to get a better look.

Below is a video taken in Cenote Aktun Ha (the carwash Cenote) near Tulum Mexico of Parachromis multifasciatus, at about the 1 minute 8 second mark, there are a few others that show up for a few brief seconds throughout.
Aktun Ha

 

[Zex Marquis]

Loiselli...although I think the scientific name has changed recently. Had a breeding pair once almost 20 years ago. They can achieve gorgeous coloring. Very underrated cichlid

 

[duanes]

They are now considered P multifasciatus.
The reason....
in 1905 Regan scientifically described them P multifasciatus.
In 1989 Bussing described what he thought was a new species (maybe a color variant) calling it P loisellei
But it seems instead of a new species loisellei turned out to be the already described multifasciatus, so the oldest name takes precedence.
This is a similar sort of problem occurrence as with Vieja melanura/synspilla.
In 1862 Gunther described melanurus.
In 1935 Hubbs described the same fish (although a color variant) as synspilla.
Recent DNA sequencing has determined they are both the same species, so the oldest name is considered valid, synspilla is not.

 

[CanukAimara]

Ty everyone for your help! What ever this fish species is, he us violent beyond simple territory. He killed my red devil yesterday who was twice is his size. My red devil was territorial and coukd hold his own against a Dovii but not this fish. I do not understand...
I saw the fight happen; my Red devil grabbed this fish by the mouth and when they released this little fish swimmed down to the bottom came up charging and rammed by devils stomach area. My devilwas floating sideways all evening then I found him dead this morning. The other fish ( this one in my pics ) did not even take one bite out of my devil. So it was not for food. It's a 150g tank can't be for territory can it?

 

[duanes]

In nature a 150 gallon area is about half the size of a territory this fish would hold.
I have watched JDs in Mexco defend territories of at least 250 to 300 gallons from all other cichlids
Some of the larger Parachromis, an area of at lest 1,000 gallons.
I believe our human perception of what is adequate space, is far from what some of these territorial species instinctually consider enough.

 

[CanukAimara]

In nature a 150 gallon area is about half the size of a territory this fish would hold.
I have watched JDs in Mexco defend territories of at least 250 to 300 gallons from all other cichlids
Some of the larger Parachromis, an area of at lest 1,000 gallons.
I believe our human perception of what is adequate space, is far from what some of these territorial species instinctually consider enough.

Wow! I never looked at it that way before. I see this tiny little 4" fish in this fairy large tank and think hes happpy. I even went out of my way to to make his aqyaavape as realistic as cas possible. I.e. riverbed standish rocks driftwood even a little current .
I guess I made it soooo realiticgefeels at gone in there and killed my devil. I wish Icould go back two days, I lived my devil he was the best fish ever! He loved me and I loved in. I NEVER Imagimed in my Wildest dreams a 4 inch Central American Cichlid would kill my devil. Sp I put them together in this 150G tank. Now my devil is dead and this wierd little fish keeps starring at me. He doesn't even swim much. I appreciate your advice and thank you! I think k Iwu at-home him as he obviously is not happpy with me.

 

[CanukAimara]

In nature a 150 gallon area is about half the size of a territory this fish would hold.
I have watched JDs in Mexco defend territories of at least 250 to 300 gallons from all other cichlids
Some of the larger Parachromis, an area of at lest 1,000 gallons.
I believe our human perception of what is adequate space, is far from what some of these territorial species instinctually consider enough.

I see this fish following my crayfish now. Should I get my crayfish out of the tank? He keeps stalking my crayfish but not biting him yet.

P.S. my crayfish is twice his size. So was my red devil Cichlid though.