@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 {879, title = {Evidence for parapatric speciation in the mormyrid fish, Pollimyrus castelnaui (Boulenger, 1911) from the Okavango-Upper Zambezi River systems: P. marianne sp. nov., defined by electric organ discharges, morphology and genetics}, journal = {Environmental Biology of Fishes}, volume = {67}, year = {2003}, pages = {47 - 70}, abstract = {

We report on parapatric speciation in the mormyrid fish,Pollimyrus castelnaui (Boulenger, 1911), from the Okavango and the Upper Zambezi River systems. We recognise samples from the Zambezi River as a distinct species, P. marianne, displaying an eastern phenotype of electric organ discharge (EOD) waveform (Type 3) that is distinct from the western EOD phenotype (Type 1) observed in P. castelnaui samples from the neighbouring Okavango. Samples from the geographically intermediate Kwando/Linyanti River (a tributary of the Zambezi that is also intermittently connected to the Okavango) presented a more variable third EOD phenotype (Type 2). In 13 out of 14 morphological characters studied, the Zambezi River samples differed significantly from P. castelnaui. Morphologically and in EOD characters, the Kwando/Linyanti fish are distinct from both P. castelnaui and P. marianne. Sequence analysis of the mitochondrial cytochrome b gene unambiguously reveals that specimens from the Zambezi River System form a well supported taxon which clearly differs from P. castelnaui from the Okavango (1.5\–2.5\% sequence divergence).Within specimens from theKwando\–Zambezi System some geographic differentiation can be detected (nucleotide substitutions up to 0.6\%); but groups cannot be resolved with certainty. Significant allozyme differences were found between the Okavango and all other EOD types from the Upper Zambezi System, and, within the Zambezi System, between the Kwando (Type 2) and Zambezi (Type 3) individuals. The low Wright\’s fixation index values, the lack of fixed allele differences, and small genetic distances provide little evidence for speciation between groups within the Zambezi System, but moderate to great fixation index values and significant allele frequency differences were observed between the Okavango and the other fishes. It is concluded that within the Zambezi System, differentiation between Kwando/Linyanti and Zambezi populations (as revealed by morphology and EOD waveform comparisons) is so recent that substantial genetic (allozyme and mitochondrial sequence) differences could not have evolved, or were not detected.

}, issn = {03781909}, doi = {10.1023/A:1024448918070}, author = {Bernd Kramer and F. Herman van der Bank and Flint, Nicolette and Sauer-G{\"u}rth, Hedi and Michael Wink} } @article {425, title = {The southern churchill, Petrocephalus wesselsi, a new species of mormyrid from South Africa defined by electric organ discharges, genetics, and morphology}, journal = {Environmental Biology of Fishes}, volume = {59}, year = {2000}, pages = {393-413}, author = {Bernd Kramer and F. Herman van der Bank} } @article {905, title = {Tube-snouted gymnotiform and mormyriform fishes: convergence of a specialized foraging mode in teleosts}, journal = {Environmental Biology of Fishes}, volume = {38}, year = {1993}, month = {12/1993}, pages = {299{\textendash}309}, chapter = {299}, url = {http://aquaticecology.tamu.edu/files/2012/07/MarreroW-EBF93.pdf}, author = {Marrero, Crispulo and Winemiller, Kirk O.} } @article {134, title = {Electric signal variation among seven blunt-snouted Brienomyrus species (Teleostei: Mormyridae) from a riverine species flock in Gabon, Central Africa}, journal = {Environmental Biology of Fishes}, volume = {67}, year = {2003}, pages = {321-339}, author = {Matthew E Arnegard and Carl D Hopkins} } @article {287, title = {Permanent and seasonal expressions of sexual dimorphisms in a weakly electric fish, Mormyrus rume proboscirostris Boulenger 1898 (Mormyridae, Teleostei)}, journal = {Environmental Biology of Fishes}, volume = {70}, year = {2004}, pages = {175{\textendash}184}, author = {Moller, P. and Schugardt, C. and Frank Kirschbaum} }