Interochromis loocki ?

[Adrian Indermaur]

Hy everyone

I`m currently investigating on Interochromis loocki and the more I research the more confused I get!?! Did anyone of you keep this species before and more Importantly do you have pictures. The only three pictures (CrC and Konings) I found all look a lot like juvenile P. fasciolatus to me.
While fishing in the southern part of the lake the most common Tropheini species is a fish that could be Interochromis loocki but could also be P. "orthognathus tricolor" (Konings)

I would love to here some opinions or better experiences on that!

here is the pic of the fish I'm talking of:

Thanks a lot

Greets Adrian

[Mark Smith]

It looks like it could be. However, the body does not appear to be deep enough.

I do know that juvenile I. loocki look very similar in appearance to some juvenile Petrochromis species, with several prominent vertial barring, and it wouldn't surprise me if various collectors are not able to tell them apart. It is possible that I. loocki has come into the hobby this way, but I am not completely sure. I don't think this species has ever been exported properly.

Old editions to the TFH book Lake Malawi and Lake Tanganyikan Cichlids (the one that had several editions), shows adults of this species incorrectly identified as a Petrochromis species. I think the photos were also taken by Glen Axelrod sometime in the 1970s when he had visited the lake and collected enough material to describe Tropheus polli.

[Benoit]

Hello, the photo is very interesting, Interochromis is a difficult species to determine, because we do not see them in aquariums.
If you have other pictures, I'd like to see them, I'm going to spend three weeks at the lake in October and is part of my priorities in order to recognize it later.
If possible, I will be exported.

Benoît.

[Mark Smith]

That's great news, Benoit! Hopefully, you can bring some back and chronicle the life history of this enigmatic species. This species should be very common, at least as juveniles, in very shallow water where plants grows in profusion.

We look forward to hearing how your trip goes!

[Benoit]

It's like Simochromis I think, rigth ?

[Adrian Indermaur]

hey everybody,
we just had a meeting this weekend and I made some research my self, i even BOUGHT the description.

The fish in the picture is for sure Interochromis loocki. I always was confused about the three pictures that are around in the net from Ad Koenings. I think they actually all show juvenile P. fasciolatus. I personally think Interochromis is synonomus to what is named P. sp "orthognathus tricolor" which is supposed to be the southern variant of P. orthognathus. I dived the Lake quite a few times in the southern part and Interochromis is very common there, perhaps the most abundant Tropheini species.

P. fasciolatus and Interochromis are sympatric and look very muck a like... I attached some pictures
Foocus on the orientation of the mouth and compare to the pictures from the net....

[Benoit]

Hi, I feel that you have reversed the names on the last two, no? For me the one with the mouth upward is fasciolatus...?

Regards

[Adrian Indermaur]

Maybe I`m getting something wrong, but the names are below the respective pics and on my screen it is as you say - the upward mouth is P. fasciolatus.

[adkonings]

Hi Adrian,

I think there are a few problems regarding your ID of the "orthognathus tricolor" being I. loocki. The tricolor does feed like a Petrochromis and is part of at least three species that have been grouped around P. orthognathus. The type of I. loocki (photo attached) does indeed resemble the shape of the tricolor but it was collected at Kigoma where there is no tricolor present. The type of I. loocki has bicuspid teeth in the outer row but all Petrochromis have tricuspid teeth. There is P. orthognathus in Kigoma. I agree that my photos probably depict juvenile P. fasciolatus as that was supposed to be the species most resembling I. loocki. The solution is rather simple: examine the teeth of the 'orthognathus tricolor' (I have never done that) and if they are bicuspid in the outer row it probably is I. loocki. In that case I. loocki at Kigoma could be a cryptic species that resembles P. orthognathus. According to Yamaoka (1998) I. loocki is very close to P. orthoganthus and P. fasciolatus. The latter has a thick lower jaw which its juveniles do not have and therefore I thought that they could be I. loocki. It has been an enigmatic species for me and am glad some clearing has been done (or is going to be done soon). Enjoy your cichlids,
Ad

[Adrian Indermaur]

hy Ad,

I'm very happy to here your opinion on the topic. I did not want to say that P. "orthognathus tricolor" in fact is synonomos to I. loocki. From a healthy eye it just seem very likely that they are closely related.
The issue of the bicuspid teeth does not really bother me knowing how plastic, variable or fast changing certain ecological traits are. From my observations I. loocki also feeds like a real Petrochromis.
Unfortunately I don`t have a lot of experiences in the Tanzanian part of the lake and never dived Kigoma so I can not tell anything about that. Further I don`t have any specimens of P. "orthognathus tricolor" so I can`t examine any but I would love to do so since I`m anyway working on the Tropheini.
The type locality being Kigoma also baffled me because I never heard of the species being distributed that far north. Have you seen I. loocki sympatrically but distinguishable with P. "orthognathus tricolor" somewhere between Kigoma and Zambia?

Stay Interested

Greetings
Adrian

[adkonings]

The issue of the bicuspid teeth does not really bother me knowing how plastic, variable or fast changing certain ecological traits are.

Hi Adrian,

the morphology of teeth (or anything) is not an ecological trait; and in my opinion ecological traits are much less variable than the morphology or coloration of a cichlid. Unfortunately the diagnosis of Petrochromis is mainly based on the shape of the teeth (tricupid). Unless you are supplying another diagnosis you will have to abide to the diagnostic characters that have been established. You will be on dangerous grounds if you ignore the shape of the teeth. In my experience, the shape of the teeth in the outer row of the oral jaws is very consistent throughout the various populations of a cichlid species. In the case of "orthognathus tricolor" the possession of bicuspid teeth in the outer row of the oral jaws would for me be a very strong indication that it is certainly not a member of Petrochromis (and likely be I. loocki).
Enjoy your cichlids!
Ad

[Adrian Indermaur]

Hy Ad,

first just a remark: It is anyway just a definiton issue. I consider all morphological traits with a role in any ecologically relevant behavior (which feeding for sure is) as eco-morphological.
Although I come from a molecular phylogenetics background (and I`m very keen on finding out more about the complex in this respect), I would not dare (:)) to synonymize populations (species) with different dentition.
Especially since most Tropheini are characterized mainly on morphology anyway.
This whole story is just very interesting and I would be happy to investigate further....

I will let everybody now

Greets Adrian

[MGSNK]

Maybe i've got something to add to this story.
I've bought a group of Petrochromis orthognathus sp. Tricolor from Zambia (Chimba).
One specimen, a female died, so I did a teeth check.

If I follow Ad's 'classic' identification method I come to the conclusion that this specific animal is not a Petrochromis, hence, an Interochromis loocki?
Hopefully, future DNA research might give some clarification.

[adkonings]

Maybe i've got something to add to this story.
I've bought a group of Petrochromis orthognathus sp. Tricolor from Zambia (Chimba).
One specimen, a female died, so I did a teeth check.

If I follow Ad's 'classic' identification method I come to the conclusion that this specific animal is not a Petrochromis, hence, an Interochromis loocki?
Hopefully, future DNA research might give some clarification.

This is great. Thank you for taking the trouble examining the teeth of your Tricolor. For me, this is enough "proof" that the fish I referred to as Petrochromis sp. 'orthognathus tricolor' is in fact Interochromis loocki. I was hesitant at first when Adrian brought up this possibility because the type locality of I. loocki is Kigoma and I was of the opinion that the Tricolor was a member of the P. orthognathus complex which I had seen in Kigoma. Recently I found the Tricolor (=I. loocki) at Mboko Island in northern Congo together with P. orthognathus. It is nice to have this puzzle solved. Thank you.

[Benoit]

Interochromis loocki ?

[MGSNK]

Yes, most likely. I guess its pretty much set with this classic identification that P. orthognathus sp. Tricolor is synonymous to Interochromis loocki.

This picturr was taken in the northern part of the lake?

[Benoit]

This pic is made at Mamalesa island, I encountered this species only from the islands of Kipili and south, before that, to the north, there is that of P. orthognathus and P. aff. orthognathus 'Ikola' ...

This would mean that the North would be called orthognathus, but would Interochromis, and the southern one is the real orthognathus ?

[MGSNK]

From my point of view, these are Interochromis loocki, just as the specimens seen in the southern area of the lake. The only difference is in the dorsal fin, from my experience the northern variants (Tanzania) have a more blueish colouring in the dorsal fin, the Zambia specimen have a more reddish colouring.
The golden-copper colouring at the head area is very typical.

[Benoit]

So you up Interochromis loockii and Petrochromis orthognathus in synonymy, if I understand well?

[MGSNK]

Hi Benoit,

No, only the P. orthognathus sp. Tricolor is synonymous to Interochromis loocki. I think that Koblmuller also did some research in this field.