synodontis multipunctatus photo - identification is ok???

[boubou]

synodontis multipunctatus...
identification is ok???

[MatsP]

With the very distinct caveat that I'm not a Synodontis expert, I'd say yes, these are

Synodontis multipunctata

.

I think the eyes are too small for

Synodontis grandiops

.

--
Mats

[Richard B]

Multipunctata based on the eye as a % of snout length is 55% in pic 4

44-62% is multipunctata, grandiops is 64-81%

[Scleropages]

Richard, is this true in small specimens (under 1" TL) as well?

[Birger]

I tried my best to do a pectoral-fin ray count off your pictures but they are not clear enough for me.

If you can manage a picture of a pectoral fin spread open, that is another way to tell which species, but Richard has a good eye for these (pun intended)

Birger

[Silurus]

I counted 7 branched pectoral-fin rays from the photos. Should be grandiops?

From the Cat-eLog:

...having 7 unbranched elements in S. grandiops vs. 8 in S. multipunctata.

This isn't correct, though, as the soft pectoral-fin elements (i.e. the rays) are almost always branched (the only exception being the last one or two rays, which are sometimes unbranched in some catfishes).

[Birger]

Okay, thanks HH I will look at it and reword it for the Cat-eLog, good for you your eyes are sharper than mine

Birger

[nvcichlids]

Multipunctata based on the eye as a % of snout length is 55% in pic 4

44-62% is multipunctata, grandiops is 64-81%

And what if its 63%?

[Birger]

Multipunctata based on the eye as a % of snout length is 55% in pic 4

44-62% is multipunctata, grandiops is 64-81%

And what if its 63%?

Hybrid

[nvcichlids]

i'm glad we got that all cleared up.

I do find it interesting how the % of eye to snout ratio can be used to ID.

[MatsP]

i'm glad we got that all cleared up.

I do find it interesting how the % of eye to snout ratio can be used to ID.

It is quite common to use various proportions of one part of body to another part, often several in combination, to differentiate species. Of course, it is harder when they overlap, and sometimes the statistical value in the measuring of, say, 4 juvenile fish may not reflect well on ALL specimens of the new species.

But if you read the official new description of a species, you often see "eye-size 22-33% of head-length, vs. 28-45% for <some other species>".

Whether the choice is head-length or snouth-length is pretty arbitrary, of course. There are a number of descriptions of what different measurements to make, and sometimes published in the description itself [because you need to make sure that you are ACTUALLY measuring the same thing - e.g. where does the head "end" and the body "start"].

--
Mats

[boubou]

wow... maybe i need some time befoire i better know this species...
all my group (6) are between 2" to 2.5"... too small to identify???
you have some pic to help to see the difference???

[MatsP]

At 2", they should be big enough. A photo showing the pectoral fin [that's the ones on the side just by the head] with the rays ("bones") shown clearly would help a whole lot, since the number of rays in this particular fin is different for the two species that this may be.

Unfortunately, none of your pictures so far show this fin very clearly, although Silurus appear to have counted them to 8 - which makes it S. grandiops. Note that you need to count at the base of the ray, not at the end, where they split into several branches [3 by the looks of things].

--
Mats

[Richard B]

Richard, is this true in small specimens (under 1" TL) as well?

A good point - i would suspect like a lot of animals that head & body proportions vary at different stages throughout lifetimes & this snout length % is a key for ID for adults. (look at humans - a baby has a head a quarter of the total body size but in adults it is far smaller). My intial thought was grandiops as the body looks a little "squatter" than i would expect to see in multipunctata when i initailly looked at the photos - if specimens are immature, pectoral ray counts are key.

If i was to play devil's advocate i would further point out this doesn't help us if such things as grandiops/multi hybrids exist (which could be debated another day) or any undescribed similar species (this is speculation based on seeing odd-looking grandiops that are not multis, like "species goldeneye" & the fish that i have seen over here a few times called commercially "dhonti small spot"

[Birger]

I counted 7 branched pectoral-fin rays from the photos. Should be grandiops?

From the Cat-eLog:

...having 7 unbranched elements in S. grandiops vs. 8 in S. multipunctata.

This isn't correct, though, as the soft pectoral-fin elements (i.e. the rays) are almost always branched (the only exception being the last one or two rays, which are sometimes unbranched in some catfishes).

Change has been submitted for both S.grandiops and S.multipunctata.

Birger

[Oliver D.]

Hi,

you have some pic to help to see the difference???

I have only Synodontis grandiops, with a size of 4-5 cm:








Perhaps someone can make pictures from S. multipunctata pectoral fin?

[Scleropages]

Oliver, those pics are awesome. Looks like that syno is swimming right out of my monitor--and I haven't sniffed any glue yet this morning.

[Birger]

Oliver...they are good images!


If you choose to allow them for the Cat-eLog send them to me at [email protected] or Jools at [email protected]

Birger

[andywoolloo]

dang..yeah what scleropages said (drooling) real beauties.

Oliver, those pics are awesome. Looks like that syno is swimming right out of my monitor--and I haven't sniffed any glue yet this morning.

[boubou]

i take to take a pic with another angle for help... not an easy thing...
well done oliver... very good photo... if you have more share it please...

[Scleropages]

Boubou, best bet is to take the fish out of the tank and hold it as per the sexing instructions on the Syno pages in the Cat-eLog (belly up in your hand with the dorsal fin held between your middle and ring fingers). Then, take a picture of the ventral (belly) aspect of the fish. Use the flash. You should be able to get an excellent pic of the pectoral fins that way.