Switch/new entry in Ageneiosus

[Marc van Arc]

After reading/thinking/using common sense, I'd like to propose the following wrt Ageneiosus:

Ageneiosus sp.blue/sp green stripe = Ageneiosus atronasus (that one could sit in the cf. atronasus entry; I could probably provide pictures).

Ageneiosus cf. atronasus = Ageneiosus brevis (that would be a matter of getting the pictures and info to A. brevis).

As I messed up quite thoroughly the last time I tried to implement such a change, I'd rather see a more experienced person perform this.
I can check/change minor things afterwards.
That is of course, if everyone agrees.

[The.Dark.One, posts: 1438]

As I said on the other thread, I'm not very knowledgeable on this genus. What is the reasoning for thinking the blue/green stripe are the true atronasus?

The ones we have in as cf. atronasus appear different to the image under brevis (apart from the colour) by the steeper arched nape profile on the 'brevis' picture. If you look at a syntype of brevis it also has a very flattened head and arched nape:

http://acsi.acnatsci.org/base/getthumbn ... get=587799

I don't think the cf atronasus are brevis. I think they may be atronasus.

This was pictured at Pier recently. They were imported a few weeks ago:

http://www.scotcat.com/thedarkone/auche ... onasus.jpg

But if that is so, what is green/blue stripe?

[The.Dark.One, posts: 1438]

Have a look at the description and plates of Tympanopleura nigricollis which is currently a synonym of atronasus.

Page 139 and Plates V and VI.

If indeed nigricollis is a synonym of atronasus then the green/blue stripe looks more like atronasus/nigricollis. But if that is correct and cf atronasus isnt brevis, what is it?

[Marc van Arc]

The reasoning behind this is the description of A. atronasus by Walsh' dissertation (page 234). This is a match imo with sp blue/sp green stripe specimens.

Also, the fish currently pictured in the brevis entry looks like an adult male "cf. atronasus" to me (despite the colour). And as I don't have to tell you, adult males have a steeper arched nape profile than females and/or adolescent males.

I've just read that brevis can be distinguished from atronasus by a much longer anal fin. So I'm going to check the pictures again.....

[MatsP]

As I messed up quite thoroughly the last time I tried to implement such a change, I'd rather see a more experienced person perform this.
I can check/change minor things afterwards.

You didn't mess up that badly, you did what you thought was the right steps - it was, largely, mine & Jools fault for implementing admin functions that aren't "bad usage proof" (and I have fixed that particular problem that you ran into).

I'm happy to work through the steps with you, if you'd like to try it for yourself. After all, it's MEANT to be usable by more than me and Jools (and most importantly with less computer experience) - if it isn't, then we need to fix it.

--
Mats

[Marc van Arc]

Thanks Mats, but let's first see if we can come to some kind of agreement about the switch

[MatsP]

Thanks Mats, but let's first see if we can come to some kind of agreement about the switch

Yes, I'm not going to get involved in that one...

--
Mats

[Marc van Arc]

Have a look at the description and plates of Tympanopleura nigricollis which is currently a synonym of atronasus.

Page 139 and Plates V and VI.

If indeed nigricollis is a synonym of atronasus then the green/blue stripe looks more like atronasus/nigricollis. But if that is correct and cf atronasus isnt brevis, what is it?

Being no member of ACSI, I can't see those plates, as I can't log in. And on the "free" ACSI site, I can only find plates of T. piperata.

[The.Dark.One, posts: 1438]

Try this

http://archive.org/download/fishesofwes ... 00eige.pdf

In terms of the brevis syntype I think it is only about 9.6cm SL and at that size the cf .atronasus dont look as depressed and curved as that syntype.

[Marc van Arc]

Wow, this has 526 pages. Which page are you refering to pls?

Meanwhile, I'd like to take things one step back.

Leaving aside the fact whether it is or isn't brevis, do we agree that the fish pictured in brevis is a nuptial male specimen of the species that is pictured in cf. atronasus?
I for one strongly believe so, as usual based on looks. The fact that it is very pale should not interfere with "determination", because only a week ago I received 2 "whitish" Ageneiosus as well, which coloured up nicely after being released from the bag and settling in.

[Marc van Arc]

Does no-one have an opinion on this?

[wrasse, posts: 729]

Just read this thread.

Its a shame that we only appear to have that one photo to refer to, of A Brevis. Am I right in saying that?

The rise from the head to the dorsal appears steep in that one specimen.

[Marc van Arc]

Its a shame that we only appear to have that one photo to refer to, of A Brevis. Am I right in saying that?
The rise from the head to the dorsal appears steep in that one specimen.

Thanks for your reply, Richard.
The fact that there's just one photo for that species is the reason why I wanted to take one step backwards.
That "rise" you mentioned is imho easily declared by the fact that this one photo shows an adult male specimen.
The question is: does anyone - besides me - believe that the current Ageneiosus brevis and the current Ageneiosus cf_atronasus are one and the same species?
Let's worry about names later on.

[Jools]

The question is: does anyone - besides me - believe that the current Ageneiosus brevis and the current Ageneiosus cf_atronasus are one and the same species?

I don't think so. I am not considering pigmentation or locale at all. The picture of Ageneiosus brevis seems to have a longer snout and the "bare back" distance from the adipose fin to the caudal peduncle appears longer. The dorsal and pectoral fin spines seem longer. That's aside from the hump which Ageneiosus cf_atronasus, IME, doesn't show at the same size.

Jools

[Marc van Arc]

Jools, I don't want to nag, but is there a slight possibility that you had only females when you kept cf. atronasus?

[Jools]

Jools, I don't want to nag, but is there a slight possibility that you had only females when you kept cf. atronasus?

Hi Marc,

That is very possible; it was around 1999 as well - not fresh in the mind or well documented in my photo collection. However, if you're thinking our A. brevis is a nuptial male (which is a very sensible thought) then I would ask "where are the pictures of these guys in captivity"? We have lots of specimens photographed and they are available in the trade in numbers at this size, but I have not seen one developed to show the long fin rays and humped back. We also cannot determine the gender of the photographed presumed male. However, there are other pics that make this a possibility and are male. E.G.

This is close: http://forums.waterwolves.com/uploads/p ... 410795.jpg
This is closer: http://2.bp.blogspot.com/_7PD10If-KW8/S ... G_1378.JPG

I am open to this idea, just think it's premature without more data. It was Lee Finley who, to my knowledge, first made the determination of A. cf. astronatus way back then. It would be interesting to know why it was as such. I have a vague recollection it was because of location.

There's not a lot to go on in the ACSI collection either.

The question, actually, might be are all these fishes actually A. brevis...

Cheers,

Jools

[The.Dark.One, posts: 1438]

If you look at the size of the type specimen of brevis on the link I provided, the specimen looks about 6cm SL. I have seen a tankful of the cf. atronasus, all bigger than this and none have the distinctive shape. Bearing in mind the preserved specimen is one of the types then we have to have high regard to it, rather than to the image in the clog which may not even be brevis.

[Jools]

I tend to agree with Steve, unless the "hump" appears as the fish ages (as opposed to grows) then there is no other explanation I can see. That said, I've not seen either species at longer than around 7cm SL.

Jools

[Marc van Arc]

Alright, let's leave this issue for the time being. I currently have 7 specimens of the cf. atronasus, so should be able to compare properly in due time.

Meanwhile, there's still the issue of the A. sp 3 green stripe, which Walsh clearly determinates as Ageneiosus atronasus. How about that one? Is this one going to be on hold as long as the cf. atronasus is "kept alive"? These two species are rather different in pattern and shape nad I don't think you can have a true atronasus and a cf atronasus that looks quite different, because that would make the "cf" rather silly. Maybe I've answered my own question....

Btw: I wouldn't be surprised if the near future would bring us a split between the large Ageneiosus species and the smaller ones (by which I mean "Tympanopleura-like" species, like for instance the two above mentioned species).

Looking forward to your opinions/views.

[Jools]

Now I've seen a tankful of adult fishes at Pier, I did not see one with the high head and shoulders yet could clearly see males.

I am tempted to leave things as they are for now?

Cheers,

Jools