his factsheet for February 2014 centres on one of my favourite
catfish families, Mochokidae, and of course the Synodontis
genera. They are very interesting catfishes and one of the more
impressive and long known species is the "One-Spot Synodontis"
This is one of three similar species which
include S. congicus
and S. nummifer.
What are the differences between these three?. To start
of with, the number of spots on the two species of S. congicus
and S. notatus does not warrant any attention as they
do vary with my 4 species of S. congicus showing 4 spots
and 3 spots although the common name of "One-spot Synodontis"
for S. notatus does point to the vast majority of specimens.
The main criteria for the 2 species is the length of their maxillary
barbels (pertaining to the upper jaw). S. congicus has
short maxillary barbels reaching back to just after the insertion
of the pectoral fin whereas S. notatus has them longer,
reaching to nearly the end of the pectoral fins, which can be
seen in the accompanying line drawings. S.
congicus has also a shorter
and blunter snout. Another very important feature is the adipose
fin, S. notatus being very small and S. congicus
being the larger of the two. S. congicus tends also to
have a larger eye much as in the vain of S. pleurops
but not as large.
The other species, Synodontis
nummifer has short barbels like S. congicus but
has a spotted head and pigment in the caudal fin. The thing about
all three of these species is that their humeral process (Bony
extension of the pectoral girdle) are quite alike in that they
are all blunt with S. congicus being a little bit shorter
and the head shield being heavier, but this is not a good way
to identify these 3 species in that you may be looking at juveniles
and this method may not be fool proof.
notatus - head
view & barbel arangement
notatus - mouth & uninterupted palatine teeth
congicus (note the short maxillary barbels)
The juveniles of this species have very
large spots (either one or two on each side) but with maturity
the spots do not grow with the body so are smaller in adults.
Snout pointed and straight. The upper
head profile is straight in lateral view. Maxillary
barbels long and extending to far behind the operculum, adipose
fin small and set far back.
Ground colour is grey/brown to olive on
the dorsum with a gold sheen to the operculum area in healthy
specimens. The underside is whitish. There is usually one black
spot, eye sized and posterier to the dorsal, but sometimes they
are two in some specimens.
Best suited to the larger aquarium. A quite
well behaved Synodontis if given the room to grow and will
not molest tankmates if they are not too small.
No reports on the breeding of this species.
No discernable differences.
Will eat a variety of foods and as in most
members of this genus they are not a problem to feed. Tablet and
pellet foods with a good quality flake, frozen mosquito larvae
Ancient name for an undetermined fish from the Nile (Cuvier
notatus : Marked, ( with
a spot, usually).
2008 The catfishes of Africa. A handbook for identification
and maintenance. Aqualog Verlag A.C.S. GmbH, Germany. 604
The primary rayed fin(s) on top of the body
Caudal fin: The
Pectoral fin : The paired fins just behind the
Adipose fin : Fleshy finlike projection
without rays, behind the rayed dorsal fin.
Maxillary barbels : Pertaining
to the upper jaw (maxillary barbels).
Operculum : The bony covering of the gills
Dorsum : The upper (dorsal) surface of
the head or body.
Blundell @ The
Danny Blundell Photo Gallery
Max; Revision Des Synodontis
Africains (Famille Mochokidae) 1971.