Redescription of Dolichallabes microphthalmus (Poll, 1942) (Siluriformes, Clariidae)
As a part of the general revision of anguilliform clariid genera and species, the status of Dolichallabes microphthalmus Poll, 1942, is reviewed, based on morphology and osteology of all available museum specimens. Dolichallabes microphthalmus, the most elongate species within the Clariidae, has been redescribed. Compared to Channallabes apus and Gymnallabes typus, D. microphthalmus is characterized by, in addition to some meristic differences, an elongate body, reduced skull ossification, with (1) one elongate fontanel, (2) antorbital and infraorbital IV the only circumorbital bones present, (3) only one or two suprapreopercular bones on each side, and (4) a sphenotic bearing only one process. Osteological evidence suggests that D. microphthalmus could be considered a paedomorphic clariid.Abstract
(A) Histogram of the number of vertebrae. (B) Histogram of the number of ribs. □: Channallabes apus; ▪: Gymnallabes typus; ▪: Dolichallabes microphthalmus
(A) Holotype of Dolichallabes microphthalmus (MRAC 44655); (B) lateral side, (C) dorsal side, and (D) ventral side of head. (Photographs: S. Devaere)
Comparison of the dorsal view of the skull of (A) Channallabes apus (175247–270; after Devaere et al., 2001) and (B) Dolichallabes microphthalmus (229 mm SL; MRAC 62407). eph: epiphysial bridge, fa: anterior fontanel, fp: posterior fontanel, fr: frontal, io-II: infraorbital II, io-III: infraorbital III, io-IV: infraorbital IV, lac: lacrimal, sph: sphenotic, spop: suprapreopercular
Geographical distribution of Dolichallabes microphthalmus (dotted lines: state borders). 1: Kunungu; 2: Bolobo; 3: Boende; 4: Bokuma (Tshuapa); 5: Ingonge; 6: Maylimbe
Contributor Notes
(SD, DA, FH, WV) Vertebrate Morphology, University of Ghent, K.L. Ledeganckstraat 35, 9000 Gent, Belgium; and (GGT) Section for Ecology and Systematics, Kuleuven, Belgium. (SD)stijn.devaere@Ugent.be Send reprint request to SD.