Descriptions of three new species of Marcusenius Gill, 1862 <br />(Teleostei: Mormyridae) from South Africa and Mozambique

Abstract

Morphological and genetic studies of mormyrid fishes belonging to the genus Marcusenius from South Africa and Mozambique revealed four species of which three are described as new. Marcusenius pongolensis is widespread throughout the Incomati, Pongola and Kosi river systems, and sparsely represented in the Limpopo River system in South Africa. Marcusenius krameri sp. nov. is endemic to the Limpopo River system, and is the sister taxon of M. caudisquamatus sp. nov. from the Nseleni and Mhlatuze river systems in the KwaZulu-Natal Province of South Africa. The Ruvuma specimens were well differentiated from all southern and eastern African species of Marcusenius, and are therefore recognised as M. lucombesi sp. nov. Phylogenetic analysis of the mitochondrial cytochrome b gene showed that the three new species and M. altisambesi form a monophyletic lineage that is sister to a group containing M. pongolensis and M. macrolepidotus. Marcusenius krameri and M. lucombesi seems to prefer slow flowing reaches of rivers, whereas M. pongolensis and M. caudisquamatus seems to mainly inhabit rapid flowing sections of rivers with a rocky substrate. A key to the southern African species of Marcusenius is provided.

Electric organ discharges of South African Marcusenius species (Teleostei: Mormyridae) and their effectiveness as indicators of local species diversity

“…Furthermore, M. krameri's EOD waveform was supported as an entity distinctly separate from the EODs of all other South African bulldog fish species in comparisons of the two sexes. This is in agreement with Maake's et al (2014) morpho-genetic study that designated species status for M. krameri. Maake et al (2014) also reported intraspecific morphological differentiation in M. pongolensis: specimens from the independent Kosi System clustered separately from the other South African pongolensis origins, because of significant differences in five morphological characters (Maake et al 2014: Figure 5b, Table 4).…”

“…We studied four geographical samples of M. pongolensis, as re-described by Maake et al (2014). The sample from the Sabie River (35 females, 10 males) matched the one from the Kosi System (13 females, 8 males) in showing statistically significant sex differences in each one of the six EOD characters studied (ANOVA, p< 0.02).…”

“…The taxonomy used follows Maake et al (2014). We studied 136 fish for their electric organ discharges (EODs) from the following rivers and systems ( Fig.…”

“…Kramer et al (2007) reinstated M. pongolensis but also recorded a high level of variability in morphology, molecular genetics, and EOD waveform among samples of bulldog fish from different South African localities, but were unable to establish a clear geographical and taxonomical pattern. A recent study by Maake et al (2014) demonstrated the presence of three Marcusenius species in South Africa: the widespread M. pongolensis, as well as the south-eastern M. caudisquamatus and the northern M. krameri. The present study investigates the question of differentiation in EOD waveform among South African Marcusenius species since Maake et al (2014) did not include EOD analysis in their study.…”

“…A recent study by Maake et al (2014) demonstrated the presence of three Marcusenius species in South Africa: the widespread M. pongolensis, as well as the south-eastern M. caudisquamatus and the northern M. krameri. The present study investigates the question of differentiation in EOD waveform among South African Marcusenius species since Maake et al (2014) did not include EOD analysis in their study.…”