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Ageneiosus sp. ????

Posted: 16 Jan 2005, 08:32
by amiidae
Hi guys,

they were sold to me as Ageneiosus sp. (currently abt 1ft)

some suggested that this is A. Brevifilis any second opinion?

thks

pic link here

http://www.arofanatics.com/members/amii ... neiosussp/

Posted: 16 Jan 2005, 09:42
by Marc van Arc
Hi,
It might also be A. spec. cf. guianensis. There's a pic in the Burgess Altas of a juvenile. Yours may be more mature and/or better fed. Great fish.
Mind you: my source is a book from 1989; perhaps this name is no longer valid or a synonym these days.

Posted: 16 Jan 2005, 10:13
by sidguppy
what happened to him?
the first two pix he has a perfect nose; the third a pink spot and on the fourth it looks like he's been in a too mall tank for a long time.....

Posted: 16 Jan 2005, 10:30
by amiidae
sidguppy wrote:what happened to him?
the first two pix he has a perfect nose; the third a pink spot and on the fourth it looks like he's been in a too mall tank for a long time.....
i've got a pair and both got some sketches while netting.

Posted: 16 Jan 2005, 11:09
by Marc van Arc
Never mind. That will heal very quickly.
As I should have read before, when yours are 1 foot tall, they are no longer juveniles. Do you have the Burgess book?

Posted: 16 Jan 2005, 11:11
by Marc van Arc
BTW: pair as in 2 or pair as in 1 male/1 female?

Posted: 16 Jan 2005, 11:25
by amiidae
Marc van Arc wrote:BTW: pair as in 2 or pair as in 1 male/1 female?
got 2 of them but don't know how to sex them. do you Marc ?

nope.. i don't have the "Burgess book"

Posted: 16 Jan 2005, 13:46
by Marc van Arc
The analfin of the female is normal, whereas the beginning of the analfin of the male is thickened. This thickened part is used in the mating proces to put the sperm inside the female body (what's new -)) ). Also the males caudal spine will thicken and grow, as will his barbels. But that may have to come yet. The analfin differences must be visible with fish the size like yours.
Keep me posted pls.

Posted: 16 Jan 2005, 20:49
by Silurus
I think your fish is A. atronasus. The snout seems too short to be A. ucayalensis (of which A. guianensis is questionably a synonym).

Ageneiosus sp.

Posted: 21 Jan 2005, 22:48
by lfinley58
Hi all.

Nice fish! Taking both the body form and the color pattern into consideration, I personally feel that the fish is Ageneiosus polystictus.

Lee

Re: Ageneiosus sp.

Posted: 22 Jan 2005, 05:18
by amiidae
lfinley58 wrote:Hi all.

Nice fish! Taking both the body form and the color pattern into consideration, I personally feel that the fish is Ageneiosus polystictus.

Lee
Hi Lee,

any site or link or pic that i may refers ?

thks

Ageneiosus sp.

Posted: 23 Jan 2005, 15:26
by lfinley58
Hi again,

I could find no sites with pics that would relate to A. polystictus. But, I have modified (read changed) my thoughts regarding the fish in question. After some reading (plenty of time for that...we are burried in a blizzard)I am of the thought that the fish is more closely allied with A. inermis (most references that you will find relating to this species will be noted as A. brevifilis). My change of heart is based on body form and particularly the shape of the caudal fin. The "classical" color/pattern of A. inermis does not match the fish in question, but Steve Walsh (in his unpublished revision of Ageneiosus) does note that some specimens from "...dark waters..." do have a pattern that has similarities to that of A. polystictus.

So for now, I would personally consider the fish as A. cf. inermis. Assuming that the locality for the fish given on the site (Guyana) is correct this would present no distributional problems. A. polystictus is apparently limited to black waters of the Rio Negro and lower Rio Branco (Brazil). Walsh questions whether it may also be found in southern Venezuela.

A. inermis has the largest distribution of any Ageneiosus species and consequently a very long list of synonyms (see CLOFFSCA). It may well be that in the future some of these synonyms will be again raised to species status.

Hope the above helps.

Lee

Posted: 23 Jan 2005, 15:33
by Mika
Steve Walsh (in his unpublished revision of Ageneiosus)
From where can this be purchased?

Ageneiosus sp.

Posted: 23 Jan 2005, 15:46
by lfinley58
Hi again,

The Steven J. Walsh unpublished 1990 PhD thesis - A systematic revision of the neotropical catfish family Ageneiosidae - can be obtained in hard copy through University Microfilms International, 300 N. Zeb Road, Ann Arbor, MI 48106, U.S.A. The order number is 9116062.

Steven's thesis does provide in one source a great amount of information on "Ageneiosidae". From a taxonomic perspective this must, of course, be considered in relation to the latest treatment of the family eg. Ferraris in CLOFFSCA.

Lee