Stunning new Synodontis found

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A stunning new species of Synodontis catfish has just been described from the Ogooue River system in Gabon, Africa.

The new mochokid catfish has just been named Synodontis acanthoperca in a paper in the systematics journal Zootaxa, and was described by John Friel and Thomas Vigliotta from Cornell University Museum of Vertebrates.

The attractively marked catfish was found at fast-flowing rapids at two separate sites in the Ogooue River system in Gabon. The first specimens were caught in the Rapids of Massoukou, on the Ogooue River near Franceville, while the second batch were caught more than 300 miles (500 km) away in the Louetsi River near Bongolo.

Friel and Vigliotta say that the distance between the two populations suggests that Synodontis acanthoperca is likely to be widely distributed through the upper Ogooue and may occur wherever similar rapid water habitats occur.

One of the smallest knownThe new species is one of the smallest known members of the Synodontis genus, with most specimens used in the type series measuring around 4cm and the largest known specimen measuring 5cm/2".

Male Synodontis acanthoperca have spiny ornamentation previously unrecorded in mochokid catfishes.

The fish also has a colour pattern that is so distinctive it is relatively easily distinguished from other species of Synodontis.

Said Friel and Vigliotta: "We initially considered that these specimens might be conspecific with Synodontis marmoratus Lonnberg 1895 described from the Meme River and later illustrated by Poll in 1971. This is another small Synodontis species with body pigmentation consisting of contrasting dark patches on a light background.

"However, S. marmoratus does not possess a distinctive pair of spots on the caudal fin, lacks any evidence of opercular spines in similar sized specimens and also differs in head, barbel and body proportions from S. acanthoperca."

The name "acanthoperca" is a combination of the Greek acanthi, which means thorn, and the Latin opercul, meaning cover or lid, and refers to the opercular spines that become highly developed in sexually mature males of this species.

Friel and Vigliotti say that the hypertrophied opercular spines in acanthoperca are one of the species' most distinctive features and are not only unique among Synodontis, but also previously unrecorded in other members of the Mochokidae family.

The presence of a link between "spiny ornamentation" and sexual dimorphism in mochokids in also unique.

The genus SynodontisThe Synodontis genus currently contains around 120 valid species, but a number of undescribed fish have been discovered and currently await formal description.

John Friel told Practical Fishkeeping that he was aware of some other synos from Gabon that were yet to be named.

"I am aware of at least two other undescribed species of Synodontis from Gabon. I'm currently working on the description of another species and some European scientists are also describing another Synodontis species. Like many Synodontis species, both of these new taxa have distinctive pigmentation that distinguish them from other described species."

Friel says that there many mochokids in general are awaiting formal description, too.

Says Friel: "I've been doing a lot of research on mochokids as part of the All Catfish Species Inventory and have been making

new collections from several places in Africa (Cameroon, Tanzania and Zambia thus far).

"On every trip, I have collected one or more species of mochokids that not have not previously been described. This is especially true for smaller mochokids such as those of the genus Chiloglanis.""What really excited me was the sexual dimorphism displayed in this species..."

"This is not the first new species I have described, so finding a new

species is not so surprising or unusual for me. What really excited me about this species was the sexual dimorphism displayed in this species. An opercular spine is very unusual feature in catfishes and

the degree to which it is developed in males of this species is quite

remarkable."

A large number of Synodontis species are popular with fishkeepers, both because of their attractive colour patterns and their tendency to swim upside down.

For more information see the paper: Friel, JP and TR Vigliotta (2006) - Synodontis acanthoperca, a new species from the Ogooue River system, Gabon with comments on spiny ornamentation and sexual dimorphism in mochokid catfishes (Siluriformes: Mochokidae). Zootaxa 1125: 45-56 (2006).

Fact file - Synodontis acanthopercaScientific name: Synodontis acanthoperca Friel and Vigliotta 2006

Family: Mochokidae

Origin: Ogooue River, Gabon, Africa.

Size: One of the smallest known species, fully grown at 4-5cm.

Diet: Not known, but probably aquatic invertebrates.

Habitat: A rheophilic species that lives among rapids.

Identification: Smaller than most Synodontis and similar in colouration to S. marmoratus. However, acanthoperca has two spots on the caudal fin and males have large opercular spines that are not seen in marmoratus.

Availability: As far as we are aware, this species has not yet been imported for the aquarium trade. It looks as if the fish could have significant aquarium potential.