@article {645, title = {Reproduction and development in some species of the weakly electric genus Campylomormyrus (Mormyridae, Teleostei)}, journal = {Environmental Biology of Fishes}, volume = {100}, year = {2016}, month = {Dec-07-2016}, pages = {49-68}, chapter = {49}, abstract = {

Reproduction in captivity of four species of the mormyrid genus Campylomormyrus was investigated. Cyclical reproduction was provoked by changing water conductivity (C) alone: decreasing C led to gonadal recrudescence, an increase induced gonad regression. Data on the reproduction and development of three species are presented. All three species are indeterminate fractional spawners. Spawning intervals ranged from 6 to 66 days in C. rhynchophorus, 10\–75 days in C. tshokwe, and 18 days in C. compressirostris (calculated values). Fecundities (eggs per fractional spawning) ranged from 70 to 1570 eggs in C. rhynchophorus, 100\–1192 in C. tshokwe, and 38\–246 in C. compressirostris. Spawnings/ovipositions occurred during the second half of the night; no parental care was observed; no special spawning substrates were necessary. C. compressirostris successfully spawned in breeding groups, C. rhynchophorus as pair. Agonistic behavior in the C. tshokwe pair forced us to divide the breeding tank; therefore, only ovipositions occurred. However, injection of an artificial GnRH hormone allowed us to obtain ripe eggs and sperm and to perform successful artificial reproduction. All three species produce yolky, slightly sticky eggs. Egg diameter ranges from 2.3\–3.0 mm. Hatching occurred on day 3, feeding started on day 11. Transition from larval to juvenile stage occurred at around 20 mm total length (TL). At this size C. rhynchophorus developed a higher body than the two other species and differences between the species in the melanin pigmentation of the unpaired fins occurred. Between 32 and 35 mm TL the upper and lower jaws started to elongate.

}, keywords = {Artificial reproduction, Behavior, Campylomormyrus, Cyclical reproduction, Environmental factors, Ontogeny}, issn = {0378-1909, 1573-5133}, doi = {10.1007/s10641-016-0554-1}, url = {http://dx.doi.org/10.1007/s10641-016-0554-1}, author = {Nguyen, Linh and Paul, Christiane and Victor Mamonekene and Bartsch, Peter and Ralph Tiedemann and Kirschbaum, Frank} } @article {499, title = {Species delimitation and phylogenetic relationships in a genus of African weakly-electric fishes (Osteoglossiformes, Mormyridae, Campylomormyrus)}, journal = {Molecular Phylogenetics and Evolution}, year = {2016}, month = {Jan-04-2016}, abstract = {

African weakly-electric fishes (Mormyridae) are able to communicate through species-specific electric signals; this feature might have favoured the evolutionary radiation observed in this family (over 200 species) by acting as an effective pre-zygotic isolation mechanism. In the present study we used mitochondrial (cytb) and nuclear (rps7, scn4aa) markers in order to reconstruct a species-phylogeny and identify species boundaries for the genus Campylomormyrus, by applying inference methods based on the multispecies coalescent model. Additionally, we employed 16 microsatellite markers, landmark-based morphometric measurements, and electro-physiological analyses as independent lines of evidence to the results obtained from the sequence data. The results show that groups that are morphologically different are also significantly divergent at the genetic level, whereas morphologically similar groups, displaying dissimilar electric signals, do not show enough genetic diversity to be considered separate species. Furthermore, the data confirm the presence of a yet undescribed species within the genus Campylomormyrus.

}, keywords = {Campylomormyrus, Geometric morphometrics, Microsatellites, Mormyridae, Multispecies-coalescent, Species-delimitation}, issn = {10557903}, doi = {10.1016/j.ympev.2016.04.035}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1055790316300781}, author = {Lamanna, Francesco and Frank Kirschbaum and Ernst, Anja R.R. and Philine G.D. Feulner and Victor Mamonekene and Paul, Christiane and Ralph Tiedemann} } @article {478, title = {Cross-tissue and cross-species analysis of gene expression in skeletal muscle and electric organ of African weakly-electric fish (Teleostei; Mormyridae)}, journal = {BMC Genomics}, volume = {16}, year = {2015}, month = {Jan-12-2015}, abstract = {

Background: African weakly-electric fishes of the family Mormyridae are able to produce and perceive weak electric signals (typically less than one volt in amplitude) owing to the presence of a specialized, muscle-derived electric organ (EO) in their tail region. Such electric signals, also known as Electric Organ Discharges (EODs), are used for objects/prey localization, for the identification of conspecifics, and in social and reproductive behaviour. This feature might have promoted the adaptive radiation of this family by acting as an effective pre-zygotic isolation mechanism. Despite the physiological and evolutionary importance of this trait, the investigation of the genetic basis of its function and modification has so far remained limited. In this study, we aim at: i) identifying constitutive differences in terms of gene expression between electric organ and skeletal muscle (SM) in two mormyrid species of the genus Campylomormyrus: C. compressirostris and C. tshokwe, and ii) exploring cross-specific patterns of gene expression within the two tissues among C. compressirostris, C. tshokwe, and the outgroup species Gnathonemus petersii.
Results: Twelve paired-end (100 bp) strand-specific RNA-seq Illumina libraries were sequenced, producing circa 330 M quality-filtered short read pairs. The obtained reads were assembled de novo into four reference transcriptomes. In silico cross-tissue DE-analysis allowed us to identify 271 shared differentially expressed genes between EO and SM in C. compressirostris and C.tshokwe. Many of these genes correspond to myogenic factors, ion channels and pumps, and genes involved in several metabolic pathways. Cross-species analysis has revealed that the electric organ transcriptome is more variable in terms of gene expression levels across species than the skeletal muscle transcriptome.
Conclusions: The data obtained indicate that: i) the loss of contractile activity and the decoupling of the excitation-contraction processes are reflected by the down-regulation of the corresponding genes in the electric organ\’s transcriptome; ii) the metabolic activity of the EO might be specialized towards the production and turn-over of membrane structures; iii) several ion channels are highly expressed in the EO in order to increase excitability; iv) several myogenic factors might be down-regulated by transcription repressors in the EO.

}, doi = {10.1186/s12864-015-1858-9}, url = {http://www.biomedcentral.com/1471-2164/16/668}, author = {Lamanna, Francesco and Frank Kirschbaum and Waurick, Isabelle and Dieterich, Christoph and Ralph Tiedemann} } @article {214, title = {An ecological and systematics survey of fishes in the rapids of the Lower Za{\"\i}re or Congo River}, journal = {Bulletin of the Museum of Comparative Zoology}, volume = {147}, number = {6}, year = {1976}, month = {02/1976}, pages = {239{\textendash}317}, url = {http://biodiversitylibrary.org/page/4276443}, author = {Roberts, T.R. and Stewart, D.J.} } @book {213, title = {Contribution {\`a} la Faune Ichthyologique de l{\textquoteright}Angola}, series = {Publica{\c c}{\~o}es Culturais}, number = {75}, year = {1967}, pages = {381}, publisher = {Companhia de Diamantes de Angola (DIAMANG)}, organization = {Companhia de Diamantes de Angola (DIAMANG)}, address = {Lisbon}, keywords = {Angola}, author = {Poll, M.} } @article {267, title = {Le genre Campylomormyrus Bleeker, 1874, {\'e}tude systematique et description d{\textquoteright}une espece nouvelle (Pisces, Mormyridae)}, journal = {Bulletin de l{\textquoteright}Institut Royal des Sciences de Belgique Biologie}, volume = {54}, number = {5}, year = {1982}, month = {08/1982}, pages = {1{\textendash}34, Pls. 1{\textendash}13}, author = {Poll, M. and Gosse, J.-P. and Orts, S.} } @book {159, title = {The Mormyridae and other Osteoglossomorpha (CD-ROM)}, series = {World Biodiversity Database, CD-ROM Series}, volume = {2000}, year = {2000}, publisher = {Springer Verlag, ETI-UNESCO}, organization = {Springer Verlag, ETI-UNESCO}, address = {New York}, issn = {Hyb: 3-540-14811-6}, url = {https://www.amazon.com/Mormyridae-Osteoglossomorpha-Biodiversity-Database-CD-ROM/dp/3540148116}, author = {Harder, W.} } @article {889, title = {Adaptive radiation in African weakly electric fish (Teleostei: Mormyridae: Campylomormyrus): a combined molecular and morphological approach}, journal = {Journal of Evolutionary Biology}, volume = {20}, year = {2007}, month = {01/2007}, pages = {403 - 414}, abstract = {

We combined multiple molecular markers and geometric morphometrics to revise the current taxonomy and to build a phylogenetic hypothesis for the African weakly electric fish genus Campylomormyrus. Genetic data (2039 bp DNA sequence of mitochondrial cytochrome b and nuclear S7 genes) on 106 specimens support the existence of at least six species occurring in sympatry. We were able to further confirm these species by microsatellite analysis at 16 unlinked nuclear loci and landmark-based morphometrics. We assigned them to nominal taxa by comparisons to type specimens of all Campylomormyrus species recognized so far. Additionally, we showed that the shape of the elongated trunk-like snout is the major source of morphological differentiation among them. This finding suggests that the radiation of this speciose genus might have been driven by adaptation to different food sources.

}, issn = {1420-9101}, doi = {10.1111/j.1420-9101.2006.01181.x}, author = {Philine G.D. Feulner and Frank Kirschbaum and Victor Mamonekene and Ketmaier, V. and Ralph Tiedemann} } @article {891, title = {Electrifying love: electric fish use species-specific discharge for mate recognition}, journal = {Biology Letters}, volume = {520927419392041142915996351451455587020220191}, year = {2009}, month = {04/2009}, pages = {225 - 228}, abstract = {

A unique evolutionary specialization of African weakly electric fish (Mormyridae) is their ability to produce and perceive electric signals. Mormyrids use their electric organs discharge (EOD) for electrolocation and electrocommunication. Here we discuss the adaptive significance of the EOD in foraging (electric prey detec- tion) in light of recent results demonstrating that mormyrid fish mate assortatively according to EOD waveform characteristics (electric mate choice). Therefore the EOD as a single trait pleio- tropically combines natural divergent selection and reproductive isolation. Consequently we postulate the EOD as a \“magic trait\” promoting the diversification of African weakly electric fish.

}, issn = {0179-1613}, doi = {10.1098/rsbl.2008.0566}, author = {Philine G.D. Feulner and Plath, M. and Engelmann, J. and Frank Kirschbaum and Ralph Tiedemann} } @article {890, title = {Adaptive radiation in the Congo River: An ecological speciation scenario for African weakly electric fish (Teleostei; Mormyridae; Campylomormyrus)}, journal = {Journal of Physiology-Paris}, volume = {102}, year = {2008}, month = {7/2008}, pages = {340 - 346}, abstract = {

he ultimate aim of this study is to better understand the diversification of African weakly electric fish in the Congo River. Based on a robust phylogenetic hypothesis we examined the radiation within the mor- myrid genus Campylomormyrus. Morphological traits relevant for the divergence between the identified species were detected. Among them, the variation in the shape of the trunk-like elongated snout sug- gested the presence of different trophic specializations. Furthermore, the chosen model taxon, the genus Campylomormyrus, exhibits a wide diversity of electric organ discharge (EOD) waveforms. A comparison of EOD waveform types and phylogenetic relationships showed major differences in EOD between closely related species. This indicates that the EOD might function as a reproductive isolation mechanism. In con- clusion, we provide a plausible scenario of an adaptive radiation triggered by sexual selection and assor- tative mating based on EOD characteristics, but caused by a divergent selection on the feeding apparatus. These findings point towards an adaptive radiation of at least some Campylomormyrus species occurring in the Lower Congo River.

}, issn = {09284257}, doi = {10.1016/j.jphysparis.2008.10.002}, author = {Philine G.D. Feulner and Frank Kirschbaum and Ralph Tiedemann} }