Syno from Nigeria

Erwin · Post by **Erwin** » 10 Mar 2004, 11:50

There is a Synodontis which is frequently imported from Nigeria, and I believe it is always wrong identified. I think it is in the Aqualog Photocollection (1) on p.61 identified as S. eburneensis, and on p.72 as S. punctifer. According to Poll (1971) both species occur more western in Ivory Coast.

I think it is the large greyish dot just above the humeral process, which looks like the sunrise of a black sun, what makes the similarity to the two above mentioned species. Let's look first on four pictures which I have just recently taken on three specimens. The smallest one had 34 mm SL, the medium sized 50 mm SL and the "large" one 62 mm SL, so this is not very large!

Concerning the small steps in size between the different individuals, and thinking about a larger end-size, couldn't it be, that this species is loosing all its dots completely? Wouldn't it be more thinkable that a large Nigerian species, like S. budgetti or S. gambiensis could be the better identification?

What do you think?

Erwin

Post by **Silurus** » 10 Mar 2004, 12:27

I think these are young S. schall (S. gambiensis is a junior synonym).

Erwin · Post by **Erwin** » 10 Mar 2004, 15:02

Hmh

, is it for sure, that S. gambiensis is a synonym of S. schall? I have checked the Catalog of Fishes, and Eschmeyer also lists newer (newer than LÃ©vÃªque et al. 1989:120 and Paugy in LÃ©vÃªque et al. 1992:561, in detail Willoughby 1994:28 ) references which are using S. gambiensis again. I don't speek French, so I have problems to follow their arguments. What do you think?

Willoughby, N. G. (1994): The taxonomy of the genus Synodontis (Pisces: Siluroidea) in Lake Kainji, Nigeria. Afr. J. Trop. Hydrobiol. Fish v. 5 (no. 1): 25-30. [not seen!]

Erwin

Post by **Silurus** » 10 Mar 2004, 16:19

I have a copy of the Willoughby paper and it is not very informative, consisting largely of a key. Both S. schall and S. gambiensis occur in the same couplet and the characters used to distinguish them (relative sizes of upper and lower jaw tooth bands, relative rugosities of the upper and lower surfaces of the pectoral spine and the skin, and the shape of the tip of the supraoccipital) don't seem very convincing.
I think that Paugy tended to lump things, but it seems that his case is more convincing than that of Willoughby.

pturley · Post by **pturley** » 10 Mar 2004, 17:24

Hey I just bought one of these as a contaminant in a batch of S. nigroventris which was such a mixed bag, only three of the thirty or so was actually UD cats. The rest looked like S. nigrita or very similar.

Thanks HH, good to know what it is without having to look for it.

Erwin · Post by **Erwin** » 11 Mar 2004, 15:03

Thank you Heok Hee, your answers were very informative (like always)!

Erwin

Erwin · Post by **Erwin** » 12 Mar 2004, 07:56

I have new informations from somebody who is keeping this species in an aquarium since more than a year, and he told me, that his fish have only grown to a size of about 10 cm, while the S. acanthomias, which he purchased at the same time, are much larger now. S. schall is a species which reaches almost 40 cm, so it would be unusual, if they grow in one year only up to 10 cm. Has anybody else seen the fish at the pictures in bigger size?

Erwin

sidguppy · Post by **sidguppy** » 12 Mar 2004, 10:52

I've kept a single schall at one time in the past; it's a fast grower.
mine took about 8 months to change a 4 cm weeny into a 18 cm tankmonster.

Mine never showed any spots either; just plain brown (nice chocolate color), not evenm up close, it was spotless.
Id dids have those light colored whiskers though, that's why it sort of caught my eye in a shipment of robbianus/nigrita-mix.
And that huge tell-tale adipose too.

Post by **Silurus** » 12 Mar 2004, 12:20

Interestingly, Willoughby (1994) hypothesized that S. schall and S. robbianus are the conspecific, although Paugy (1992) maintains that they are distinct species.
Synodontis robbianus only grows to 10 cm or so, so maybe there's another angle to this.

sidguppy · Post by **sidguppy** » 02 Apr 2004, 20:15

Then obviously mine did read books, bent on reaching those 40+ cm they state for that species.
Although I have seen "nigrita's' (the dark brown variety with many close clustered slightlydarker spots, not the pale variety with the few spreadout black spots) bigger than my schall, they were less highbuild and less sturdy.

he had all the makings of a giant in him, but it was his behaviour that made me booting him out.....tearing up 2 Batrachoglanis (didn't kill, but ripped them up and made them miserable), chasing the crap out of two adult flavitaeniatus and buggering two anaspido/paraucheno's in there.....

Man, schall is ONE MEAN son of a .....fish!

Post by **corybreed** » 02 Apr 2004, 20:59

Erwin
Over the last few months I have picked up abuot a dozen of these Synodontis mixed in with Nigerian imports. I also thought they were eburneensis. I hope they are not S. schall because I do not have the room for them. Looking at photos in the Aqualog Collection, the adipose fin looks much larger on S. schall. The fish I have look more like the photos of eburneensis.
Mark

Post by **Dinyar** » 03 Apr 2004, 01:12

I have kept what I am confident was S. schall, and IMO there is no way these fish of Erwin's are S. schall.

Dinyar