Microsynodontis batesi

by Dr. Paul Loiselle

The upsidedown catfishes of the genus Synodontis are justly popular aquarium residents. These hardy, colorful catfishes have much to recommend them, but as they are decidedly on the robust side, they require sizeable tanks to prosper in captivity. Happily there are a number of mochokid catfishes whose modest adult size makes them ideal candidates for smaller aquaria. Microsynodontis is the most speciose genus of these miniature mochokids, comprising a dozen described species, hailing - with the unique exception of Microsynodontis polli Lambert 1958, native to the upper Niger River - from the coastal rivers of Cameroon, Rio Muni, Gabon and the Republic of Congo as well as the vast Congo basin. As their name implies, these fish look like a

Synodontis seen through the wrong end of a very powerful telescope. While the two genera differ with regard to several skeletal characteristics, they only differ superficially with regard to one feature. Synodontis have a deeply forked caudal fin, whereas in Microsynodontis the shape of this fin can be moderately emarginate, truncate or rounded. A Microsynodontis species was imported into the Netherlands in the 1950ʼs (Baensch, 1997). Whether that species was actually M. batesi is open to question. At that time only a single species of Microsynodontis, M. batesi, was thought to occur in the waters of the Lower Guinean region of West Central Africa. A major revision of the genus (Ng, 2004) has increased the species count for this region from one to nine. Microsynodontis batesi is native to the basins of the Sanaga, Nyong, Lobé, Ivindo and Campo Rivers in central and southern Cameroon as well as the Ntem River drainage of southern Cameroon and northern Gabon. With the exception of M. hirsuta Ng 2004, which also occurs in the Ntem drainage, all the other Lower Guinean species have been described from material collected in Equatorial Guinea and Gabon. If the fish in this initial importation came from Cameroon, they probably were M.batesi. However, absent precise data on the fishes’ provenance, preserved voucher specimens or a good color photo, the identity of this Microsynodontis will always remain in doubt.

The subject of this month’s article made its appearance on Wet Spot’s price list as “Microsynodontis sp. - African Bumblebee Catfish” early in 2015. I have always felt that Microsynodontis were potentially very desirable aquarium residents and as the price of these African Bumblebee Cats was certainly right, I took the plunge and ordered half a dozen. Thanks to Wet Spot’s customary competent packing, the fish arrived in superb condition. After slow-drip acclimation, they quickly settled into their new quarters. They proved surprisingly photogenic and the resulting images made it possible to establish their identity using the key in Ng’s revision. My African Bumblebee Catfish keyed out to Microsynodontis batesi. The fishes’ Cameroonian provenance, confirmed by a quick phone call to Wet Spot, provided additional confirmation of this identification - M. batesi is the only species of the genus found in that country.

This is an easily maintained catfish. As Microsynodontis batesi is a tropical lowland species, it would be unwise to expose it to temperatures lower than 72̊ F. (24̊ C.). Like other fish hailing from Cameroon, this species prefers soft, slightly acidic water, but it will tolerate neutral to slightly alkaline pH values and hardness values up to 10̊ DH. Like their larger cousins, Microsynodontis are solitary, largely nocturnal catfish. Each individual seeks out a sheltered area to spend the day. Offered a choice of shelters, my fish have displayed a marked preference for the nooks and crannies offered by pieces of waterlogged wood. The appearance of food immediately brings these diminutive catfish into the open and triggers a bout of frenetic activity. I have never regarded catfish as the sharpest pencils in the piscine box, but the rapidity with which this group of M. batesi has learned to associate my appearance with the arrival of food has obliged a reassessment of my views regarding siluroid learning ability! This fish will readily consume flake and pelletized foods of appropriate size, but frozen bloodworms and live black worms are devoured with particular enthusiasm. My fish share their tank with a group of Puntigrus anchisporus and several pairs of Pachypanchax sakaramyi. As these fish occupy the middle and upper third of the water column, opportunities for interaction with the catfish are restricted to the daily feeding time scrum. I thus cannot say whether M. batesi would display comparable indifference to bottom-living fishes such other catfishes, loaches or as dwarf cichlids. That said, in light of its small adult size - a large M. batesi measures a tad over 2" (5.0 cm) TL - prudence would dictate choosing tankmates of roughly the same size.

Miniature fishes typically compensate for the reduced fecundity consequent upon reduced body size in two ways. The first is to produce small numbers of eggs or live young on a more or less continuous basis. White clouds, the smaller Corydoras species and Heterandria formosa are familiar practitioners of this strategy. The second is to invest significant effort in protecting a reduced clutch of eggs. Dwarf cichlids, licorice and sparkling gouramis and Phylonemus typus, the Lake Tanganyika mustache catfish deal with size-constrained fecundity in this manner. Which path Microsynodontis follow remains to be determined, for nothing is known of their reproductive behavior. What is known of the reproductive biology of their larger cousins is not particularly helpful to aquarists seeking some insight into how these miniature catfish conjugate the amatory verbs. The genus Synodontis includes egg scatterers, species that care for their eggs and one species that parasitizes mouthbrooding cichlids!

Determining the sex of their fish should not be a problem for prospective breeders of M. batesi. Males of this species, like those of their larger cousins, have a welldeveloped, somewhat penis-shaped genital papilla that can be easily seen using a hand lens. Females are also somewhat larger and markedly plumper in appearance than males. As previously noted, this species is typically solitary in its behavior. However, the largest female of my group and a smaller male consistently share a shelter. I plan on moving this compatible couple into a well planted five gallon tank and feeding them generously. Time will tell whether this approach to breeding, which has proven successful when applied to miniature Yunnanilus loaches and the moth catfishes of the genus Hara, will also work with M. batesi.

Small, rather secretive species like M. batesi do not show themselves to best advantage in retailers’ tanks and are thus rarely to be found in such a venue. Thus finding this delightful little catfish is likely to prove something of a chal- lenge. For the moment, hobbyists wishing to work with this species are most likely to find it offered for sale by on -line dealers. Regardless of how much effort must be expended in the search, M. batesi will repay it in full!

Literature Cited

Baensch, H. A. 1997. Aquarien Atlas. Band 5. Mergus-Verlag, Melle, pp. 1 - 1148.

Ng, H. H. 2004. The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1 - 52.