01343nas a2200109 4500008004100000245015100041210006900192520086600261100001901127700001501146856007201161 2000 eng d00aA morphological description of the sagittal otoliths of two mormyrids, Marcusenius macrolepidotus and Petrocephalus catostoma (Family: Mormyridae)0 amorphological description of the sagittal otoliths of two mormyr3 a

The morphology of the sagittal otoliths of two South African mormyrid fish, Marcusenius macrolepidotus and Petrocephalus catostoma, were studied to determine possible morphological significance. The sagittae of M. macrolepidotus and P. catostoma are kidney-shaped and oblong, respectively. The ventral margin is slightly indented in the former and slightly flattened in the latter. The sulcus acusticus of both species is archaesulcoid but mesial in M. macrolepidotus and ostio-caudal in P. catostoma. The crista inferior in M. macrolepidotus is ridge-like and well defined posteriorly and anteriorly, whereas in P. catostoma it is clearly defined posteriorly and disappears anteriorly. The otoliths of both species do not have a rostrum, antirostrum or an excisura. The differences in sagittal morphology between the two mormyrid species are distinct.

1 aNicolaai, N.N.1 aJooste, A. uhttps://www.tandfonline.com/doi/full/10.1080/15627020.2000.1140719102363nas a2200109 4500008004100000245017900041210006900220520188000289100001502169700001802184856005102202 2000 eng d00aElectrosensory prey detection in the African sharptooth catfish, Clarias gariepinus (Clariidae), of a weakly electric mormyrid fish, the bulldog (Marcusenius macrolepidotus )0 aElectrosensory prey detection in the African sharptooth catfish 3 a

During their seasonal runs in the Okavango and other freshwater bodies in southern Africa, the sharptooth catfish, Clarias gariepinus, specialises on the bulldog, Marcusenius macrolepidotus, as its main prey. We examined whether the catfish can locate bulldogs by detecting their pulse-type electric organ discharges (EODs). The electrosensory threshold for single-cycle, monopolar square-wave pulses was exceedingly low (down to 13 µVp–p/cm for 4-ms pulses) in trained, food-rewarded sharptooth catfish (n=4), confirming the results of Lissmann and Machin who were, however, unable to identify a biological function. Other stimulus pulse waveforms (single-cycle, monopolar as well as bipolar sine-wave pulses) were also effective stimuli according to their spectral low-frequency energy contents (0– 30 Hz). Male bulldogs display an EOD pulse approximately 10× the duration of female EODs (≈0.5 ms). The C. gariepinus threshold for field-recorded playbacks of a male bulldog EOD (of long duration) was 103 µVp–p/cm, whereas the brief female and juvenile EODs were not detected (using intensities of natural EODs). EODs of other mormyrids were detected when either monopolar or of long duration. Signal source amplitude increased linearly with standard length (SL) in bulldogs. Signal reach, as calculated from signal source amplitude and receiver sensitivity, is up to 150 cm for a large male bulldog (SL 27.5 cm), and 83 cm for a male that has just turned sexually mature (SL 12.6 cm). Therefore, most bulldogs eaten by catfish are probably male, in agreement with the size distribution of bulldogs found in catfish stomachs. These results suggest that sharptooth catfish rely heavily on their acute electrical sense during hunting, and an important function for electroreception in an African catfish has been identified.

1 aHanika, S.1 aKramer, Bernd uhttp://link.springer.com/10.1007/s00265000023200405nas a2200109 4500008004100000245004300041210004300084260008400127653001400211100001800225856005200243 2000 eng d00aProtocol for building field electrodes0 aProtocol for building field electrodes aIthaca, NYbHopkins Lab, Dept. of Neurobiology and Behavior, Cornell University10aelectrode1 aHarned, Garry uhttps://mormyrids.efishgenomics.com/fr/node/47000515nas a2200121 4500008004100000245016600041210006900207300001200276490000700288100001800295700002900313856005100342 2000 eng d00aThe southern churchill, Petrocephalus wesselsi, a new species of mormyrid from South Africa defined by electric organ discharges, genetics, and morphology0 asouthern churchill iPetrocephalus wesselsii a new species of mor a393-4130 v591 aKramer, Bernd1 avan der Bank, F., Herman uhttps://mormyrids.efishgenomics.com/fr/node/6100547nas a2200145 4500008004100000245013800041210006900179300001200248490000800260653001500268100002200283700002400305700002100329856005100350 2000 eng d00aMolecular systematics of the African electric fishes (Mormyroidea: Teleostei) and a model for the evolution of their electric organs.0 aMolecular systematics of the African electric fishes Mormyroidea a665-6830 v20310aMormyridae1 aSullivan, John, P1 aLavoué, Sébastien1 aHopkins, Carl, D uhttps://mormyrids.efishgenomics.com/fr/node/5900456nam a2200121 4500008004100000022002300041245005600064210004900120260004200169490000900211100001500220856009900235 2000 eng d aHyb: 3-540-14811-600aThe Mormyridae and other Osteoglossomorpha (CD-ROM)0 aMormyridae and other Osteoglossomorpha CDROM aNew YorkbSpringer Verlag, ETI-UNESCO0 v20001 aHarder, W. uhttps://www.amazon.com/Mormyridae-Osteoglossomorpha-Biodiversity-Database-CD-ROM/dp/3540148116