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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" Synodontis notatus.

 

Synodontis notatus

 

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.

 

 

Synodontis notatus - head view & barbel arangement

Synodontis notatus - mouth & uninterupted palatine teeth

 

Synodontis congicus (note the short maxillary barbels)

 

Synodontis notatus

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.

 

One-spot Synodontis

Synodontis maculatus

Mochocinae

Africa: Congo basin. Type locality: Riv. Oubangui à Bangui.

23.0cm (9ins)

22-26°C (71-79°F)

6.5-7.2.

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 and bloodworm.

Adipose fin: Fleshy finlike projection without rays, behind the rayed dorsal fin.
Caudal fin: The tail.
Dorsal fin: The primary rayed fin(s) on top of the body.
Operculum: The bony covering of the gills of fishes.
Dorsum: The upper (dorsal) surface of the head or body.
Maxillary barbels: Pertaining to the upper jaw (maxillary barbels).
Pectoral fin: The paired fins just behind the head.

Synodontis: From the Greek syn, meaning together, and odontos, meaning tooth; in reference to the closely-spaced lower jaw teeth.
notatus: Marked, ( with a spot, usually).

Seegers, L. 2008 The catfishes of Africa. A handbook for identification and maintenance. Aqualog Verlag A.C.S. GmbH, Germany. 604 p.

Photo Credits

© Danny Blundell
Drawings from Poll, Max; Revision Des Synodontis Africains (Famille Mochokidae) 1971.