Adipose body on pectoral fins of sexually mature Dianema and Hoplosternum?

[bekateen]

Hello all,

I just read in the literature something about an "adipose body" on the pectoral fins of sexually mature male

Dianema

and

Hoplosternum

. I've never heard of this before. Does anyone have any info on this?

Thanks, Eric

[Bas Pels]

I think you intent us to guess what adipose would mean.

In Dutch the adipose fin is called vetvin, which would translate as 'fat fin'. This would make me translate adipose as thikened, fatty - and in Hoplosternum the first finray in the pectoral fin is thickened.

Problem is, in Dianema I neve saw this. Or did I only see females? I would be very surprized if that was the case. But then, perhaps the Dianema males I was never ripened to full maturity. I have to admit, I never saw a Dianema male which has bred.

But his is only my two cents.

[bekateen]

Hello Bas,

I didn't mean to be vague, except that I'm not familiar with any "adipose body" on the pectoral fins of some male Callichthyids. But given that the scientific article mentioned that hobbyists call the object ( a lump on the male's pectoral fin membrane,, between the pectoral spine and first ray) an adipose body, I was hoping that one or more hobbyists here would know about it.

Cheers, Eric

[MissNoodle]

Could it mean this....

My male hoplosternum punctatum

[bekateen]

Thanks for the photo. I think it's bigger than that, and closer to the base.

Cheers Eric

[MissNoodle]

Okay got another look at my male hoplosternum punctatum 's fins. Perhaps this is what it references? My two females do not have this

[bekateen]

That could be! Thanks!

[MissNoodle]

I can provide a photo unmarked too, its like the rays are thickened and form a mass.

[bekateen]

[Jools]

I think I know - but going to be cryptic and see if any Whovians can figure it out...

Adipose[1].jpg (34.91 KiB) Viewed 5914 times

This picture of a mighty male

Megalechis picta

I collected in the Amazon should also help illustrate the point I think.

Jools

[bekateen]

Thanks, Jools and MissNoodle. Yes those are it. The original publication I saw had a b&w photo , but being b&w, it was difficult for me to know what I was seeing.

Now I do.

Cheers, Eric

[bekateen]

Here's the original photo, in which I struggled to imagine the pad was so large. I was expecting from an older paper a focused, nodular structure in the membrane between the first ray and the spine, or first ray and second ray, rather than a sheet covering so much of the fin's underside. And since the pectoral fins in this photo are somewhat compressed/folded on the large male, it was difficult for me to determine how much of the opaque (whitish) density visible on the large male's pectoral fins was due to the pad, vs. due to the folding of the fin. Jools, your photo clears that up.

Picture from Winemiller, K.O. 1987. Feeding and reproduciton of the currito,

Hoplosternum littorale

. Env. Biol. Fishes, 20(3)_219-227

@MissNoodle, your man definitely has the beginnings of pads. But clearly, he's got some growing to do. . Good luck with your group.

Cheers, Eric

P.S.... I must brush up on my Dr. Who.

[MissNoodle]

He is hoplosternum punctatum, shouldn't he be about almost full grown? He is about 3 inches now

[bekateen]

He is hoplosternum punctatum, shouldn't he be about almost full grown? He is about 3 inches now

Ah yes, if you mean 3" not counting tail. I didn't mean to say "grow longer to match the size of the H. littorale," but rather to grow in maleness.

That said, I don't assume that the two species will have the equivalent growth of such an adipose pad on the pectoral. I've never seen H. punctatum, so maybe what you have on your male is all he will develop.

Sorry for the confusion - and if it does develop further, time will tell.

Cheers, Eric

[MissNoodle]

He is hoplosternum punctatum, shouldn't he be about almost full grown? He is about 3 inches now

Ah yes, if you mean 3" not counting tail. I didn't mean to say "grow longer to match the size of the H. littorale," but rather to grow in maleness.

That said, I don't assume that the two species will have the equivalent growth of such an adipose pad on the pectoral. I've never seen H. punctatum, so maybe what you have on your male is all he will develop.

Sorry for the confusion - and if it does develop further, time will tell.

Cheers, Eric

Lol was a touch worried haha there isn't a whole heck of a lot of information on this species aside from here and one or two other places, so got a little concerned theyd get much larger. Theyre in a 55 gallon but still with other fish haha

Well if those pads get bigger, I'll post photos here. Honestly these are the best catfish species I've owned, which says a lot because all are awesome but these guys are so active and friendly and not shy whatsoever.

There needs to be more info on them

[Jools]

There needs to be more info on them

They were quite often mistaken with

Dianema longibarbis

in the past, but it is a shame there is not more on them. Perhaps you'd consider writing up your experiences and why you like them so much for a Catfish of the Month article? Be happy to run it / assist with writing if that would help.

Cheers,

Jools

[MissNoodle]

There needs to be more info on them

They were quite often mistaken with

Dianema longibarbis

in the past, but it is a shame there is not more on them. Perhaps you'd consider writing up your experiences and why you like them so much for a Catfish of the Month article? Be happy to run it / assist with writing if that would help.

Cheers,

Jools

Id love to! I adore these catfish a lot, its a shame they're not more popular because these have easily become my favourite fish I have.

Where would I submit it?

[Jools]

Email sent.

Jools

[Birger]

Id love to! I adore these catfish a lot, its a shame they're not more popular because these have easily become my favourite fish I have.

Nice, you can do it!!

[Jools]

It shall happen soon....

Jools

[Fishmandavew]

Ok so just to clarify
We are all in agreement that “adipose body” means the bony plates on the underside between the pectoral fins which forms part of the bony structure infront of the adipose fin which on females and immature males do not meet In the middle but on mature males they continue to grow and often overlap in the middle and also forms part of the pectoral first ray?

[Jools]

No, adipose body means fatty patches on the underside of the pectoral fins in mature males.

Jools

[bekateen]

@fishmandavew, here:

Cheers, Eric

[Fishmandavew]

Hi, thanks for clarifying as this is something I have never seen on any of my old male thoracata throughout the years. Although cant check now as my females have all outlived their male counterparts.