New Xenotilapia spp. discovered

Thomas Andersen · Post by **Thomas Andersen** » Sun Dec 18, 2005 2:31 pm

Recently Evert van Ammelrooy discovered a potentially undescribed Xenotilapia species while diving in Lake Tanganyika - for more information please see this paper: http://www.cichlidae.info/section.php?n=tsd&id=113

Any comments are highly welcomed

Thomas

PS. Evert: Thank you very much for providing pictures and information

BlackDeep · Post by **BlackDeep** » Tue Dec 20, 2005 1:48 pm

Hello Thomas,

Interesting!
This fish seems really a new xenotilapia species. The head form is diffrently to other xenotilapias.
I hope we will hear more informations in the future about this xenotilapia.

bye
Florian

Thomas Andersen · Post by **Thomas Andersen** » Tue Dec 20, 2005 2:01 pm

Hi Florian,

yes, I can´t see that it should fit any described Xenotilapia species - the protruding upperlip and shape of the mouth could resemble a X. caudafasciata, but the coloration are completely different, and to me it also looks like the shape of the head is different

All the best,

Thomas

Thomas Andersen · Post by **Thomas Andersen** » Mon Jan 02, 2006 5:23 am

I would really like some comments on this mystery Xenotilapia - as stated above I really can´t see that it should fit any known species of Xenotilapia - comments are highly welcomed

All the best,

Thomas

Mark Smith · Post by **Mark Smith** » Mon Jan 02, 2006 10:32 pm

Hi Thomas

Might we obtain some information from the photographer himself regarding its behavior?? Was the photo taken at night or in the day. I realize that at 50 meters depth, it may already be dark?? even during the day, particularly if the water is heavy with sediments.

It is hard to know what else to say about this fish. I agree with you that it doesn't match up to any known/described species. It comes close to X. caudifasciata in overall body shape, but that is all. Professor Poll, back in the 1980's predicted that most new cichlid discoveries from Lake Tanganyika would consist of mouthbrooders. I tend to agree with him. The depths of Lake Tanganyika are likely to contain many new species of mouthbrooders, as is noted with this new Xenotilapia.

The fellow who photographed this cichlid, was he able to collect some bodies for study?

Mark

I would really like some comments on this mystery Xenotilapia - as stated above I really can´t see that it should fit any known species of Xenotilapia - comments are highly welcomed

Thomas Andersen · Post by **Thomas Andersen** » Tue Jan 03, 2006 2:52 am

Hi Mark,

Thanks for your comment

Yes, I hope Evert would come by and make some comments and give some additional information – I think most of the pictures by Evert were taken during evening/night dives

Professor Poll, back in the 1980's predicted that most new cichlid discoveries from Lake Tanganyika would consist of mouthbrooders. I tend to agree with him. The depths of Lake Tanganyika are likely to contain many new species of mouthbrooders, as is noted with this new Xenotilapia.

I also think there’s still many species hidden in the depth waiting to be discovered and that we in the coming years will see some really surprises – it’s so fascinating that a Lake that has been investigated for over a 100 years still haven’t revealed all its secrets

All the best,

Thomas

tanganyikadiver · Post by **tanganyikadiver** » Tue Jan 03, 2006 5:48 am

hello,
well thomas her i am finally.
the picture was taken in the evening/night. but even on the day it would be completely dark on this depth. but on the day and night diving at the same location you will see different species of fish.

the size of the fish was a few cm bigger then adult fluorescent green who were swimming there too.

liuchin · Post by **liuchin** » Tue Jan 03, 2006 10:42 am

Hi Thomas, Evert and all
Evert, your photos are really amazing, thanks.
As Evert said it's dark at that depth even during the day, so the specices such as red princess and fluorescent don't need any light for the tank, right?
I think the Xenotilapia are also territorial specices, I'm curious that how these sand-dweller breed and forage in such dark environment?

best regards
Liuchin

Thomas Andersen · Post by **Thomas Andersen** » Wed Jan 04, 2006 4:42 am

I think the Xenotilapia are also territorial specices, I'm curious that how these sand-dweller breed and forage in such dark environment?

Good question, Liuchin

Even though it for the human eye looks like complete darkness, some light may still penetrate the water down at this depth and the cichlids have adjusted to these living conditions by developing certain features; e.g. Xenotilapia sp. red princess, X. ornatipinnis and to a lesser degree X. sp. “fluorescent green” have very large eyes to catch the little light available at this depth. Xenotilapia (sensu Poll, not Takahashi

) have three lateral lines, where other cichlids normally have only two – this could be seen as an advance both in the depth, for a better registration of the movement of prey, predators and conspecifics, as well as in the shallows particular for the registration of predators.

I have noticed that my X. sp. “fluorescent green” seems to depend much more on their smelling sense than their eyes when searching for food, it actually looks like they smell their way through the tank. This behavior could also be seen as an adoption to living in a habitat with subdued light conditions.

Also the different colors in the light don’t penetrate the water equally, illustrated by this graph borrowed from a post made by Seveland in the CA cichlid section:

One color penetrates water better than others, namely blue, which penetrates farther than any other color. The deepwater Xenotilapia often have a blue upper lip; it’s very pronounced in X. sp. red princess and X. bathyphila (not the Isanga/Kekese variants), and to a lesser degree in e.g. X. ornatipinnis and X. sp. “fluorescent green” – the blue lips possibly play a role in recognition of conspecifics and mating (or at least that’s what I think

)

Other deep-water species also have blue on them, e.g. the males of Benthochromis tricoti, C. frontosa and maybe the best example, Paracyprichromis nigripinnis with its blue neon bands.

Other species like Trematocara have special sensory pores on the head, that register even very small movements and are thus able to detect moving prey in the dark - but that´s another story

I hope this made some kind of sense

All the best,

Thomas

liuchin · Post by **liuchin** » Wed Jan 04, 2006 7:14 am

Hi, Thomas,
Very thanks for your thorough demonstration to my curiousity, These xenotilapia species live in darkness area and have such beautiful color, that's amazing.

I'm trying to simulate the natural habitat for my X.red princess and fluorescent green as possible as I can. Can you tell me how the water current condition in this deeper area? strong, weak or still?

best regards
Liuchin

Thomas Andersen · Post by **Thomas Andersen** » Wed Jan 04, 2006 7:25 am

Yes, it is amazing that such fantastic creatures can be found in such depth - it has in fact puzzled me that X. sp. red princess are colored in yellow and red, colors that are not seen well in this depth

As for the current, I don´t know, but I don´t think it´s much - Evert could proberly better answer this question

All the best,

Thomas

tanganyikadiver · Post by **tanganyikadiver** » Wed Jan 04, 2006 12:04 pm

hi,

the current can be different everyday.
it can be really still till not able to swim against the current. we could never tell in advance by looking at the weather what kind of current there would be.

Thomas Andersen · Post by **Thomas Andersen** » Wed Jan 04, 2006 12:25 pm

Amazing that there is so much variation in the current at such a depth - thanks Evert for the info

All the best,

Thomas

liuchin · Post by **liuchin** » Thu Jan 05, 2006 10:54 pm

hi, Evert
Thanks for your information. It's really surprising me too.

Thomas Andersen · Post by **Thomas Andersen** » Fri Jan 06, 2006 9:48 am

An addition to how color changes with increased depth – Fishbase has a “view fish at depth” feature, here with a Paracyprichromis nigripinnis as example: http://filaman.ifm-geomar.de/photos/dep ... nig_uc.jpg

It’s really distinct how all other colors than blue is being absorbed by the water

Thomas

Mark Smith · Post by **Mark Smith** » Fri Jan 06, 2006 11:26 am

Hey Guys

I was following the thread on how colors are filtered out with depth. Ordinarily that is true. However, while I was diving off the coast of southern California at Catalina Island, I dove to a depth of 100 feet off of the Casino at Avalon to observed the sunken boat called the SueJack. At 100 feet, the Catalina Goby or Blue Banded Goby, Lythrypnus dalli, still showed the bright red coloration that it is famous for. I'm not sure why the red color was still visible at that depth, as a nearby red sea star looked completely brown.

Any thoughts on this?

Mark

Michael.NEGRINI · Post by **Michael.NEGRINI** » Wed Jan 11, 2006 5:47 am

Hello all,

why not a new species of Grammatotria rather than Xenotilapia ?
For me, the head shape is closer to the former genus. No spot on the caudal peduncle...it's just a guess.

Best regards, Michael

Thomas Andersen · Post by **Thomas Andersen** » Wed Jan 11, 2006 4:11 pm

Hi Michael, thank you very much for your comment

Yes, you got a point, and it’s an interesting thought indeed – of course no one can be certain, that it indeed is a Xenotilapia species or a Grammatotria or even a species that needs its own new genus, before a proper examination has been done.

It has some similarities with Grammatotria lemairii in the shape of the head and mouth, but I still think that the species it resembles the most in body- and head-shape, is Xenotilapia caudafasciata – but I guess it all depends on the eyes of the beholder

All the best,

Thomas

Picture from http://www.fishbase.org

Benoit · Post by **Benoit** » Tue Jan 24, 2006 4:12 am

Hello

What about Xenotilapia nasus ?
Don't you think this fish looks like it ?

Thomas Andersen · Post by **Thomas Andersen** » Tue Jan 24, 2006 8:43 am

Salut Benoit, good to see you here

(you should drop by more often; and Estelle too

)

What about Xenotilapia nasus ?
Don't you think this fish looks like it ?

Not really, I think the shape of the body, head and the coloration differs a lot. Also the characteristic protruding little nose of X. nasus is absent and the new Xeno has a protruding upper lip instead

X. nasus:

Picture from http://www.fishbase.org