00504nas a2200133 4500008004100000245012200041210006900163300001400232490000800246100002600254700002000280700002200300856004800322 2006 eng d00aTime-domain signal divergence and discrimination without receptor modification in sympatric morphs of electric fishes0 aTimedomain signal divergence and discrimination without receptor a2182-21980 v2081 aArnegard, Matthew, E.1 aJackson, B., S.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/4101327nas a2200133 4500008004100000245008100041210006900122300001200191490000600203520085700209100001601066700002801082856008301110 2006 eng d00aA portable bio-amplifier for electric fish research: design and construction0 aportable bioamplifier for electric fish research design and cons a295-2990 v43 a

The weak electric organ discharges (EODs) of gymnotiform knife fishes can be readily amplified with a wideband amplifier connected to submerged electrodes. The output from such an amplifier can then be monitored with audio speakers or digitized for subsequent analysis. Commercially available devices are expensive and usually require mains electrical power. Here we provide design notes and instructions for the construction and calibration of a cheap, portable, battery-powered, AC-coupled wideband bio-amplifier. This device was designed to allow electric fishes to be located in the field, and also to permit the relatively noise-free acquisition of EOD waveforms from specimens held in temporary captivity. This contribution is intended to encourage students of neotropical ichthyology to explore electric signaling in gymnotiform fishes.

1 aWells, J.K.1 aCrampton, William, G.R. uhttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-6225200600020001802498nas a2200157 4500008004100000022001400041245016000055210006900215260001200284300001400296490000700310520193800317100001902255700001802274856004802292 2006 eng d a1432-076200aAllopatric differentiation in the acoustic communication of a weakly electric fish from southern Africa, Marcusenius macrolepidotus (Mormyridae, Teleostei)0 aAllopatric differentiation in the acoustic communication of a we c12/2006 a385 - 3990 v613 a

A few species of the weakly electric snoutfish, the African freshwater family Mormyridae, have been reported to vocalise. However, allopatric populations of a single species were never compared. Members of three allopatric Marcusenius macrolepidotus populations, originating from the Upper Zambezi River in Namibia, the Buzi River (Mozambique), and the Incomati River system in South Africa, vocalised with pulsatile growl- and tonal hoot sounds in dyadic confrontation experiments. A high rate of growling accompanied territorial and agonistic interactions and also non-threatening interactions between males and females, which in one pair appeared to be courtship. Growl sound characteristics of M. macrolepidotus from the Incomati system differed from those of the Upper Zambezi in a significantly higher frequency of the first harmonic (mean, 355 Hz vs 266 Hz). The two vocalising males from the Buzi River generated growls about twice as long as the other fish. Furthermore, the growl pulse period was about 4 ms in M. macrolepidotus from the Upper Zambezi River and from the Incomati system, but 6 ms in M. macro- lepidotus from the Buzi River. Hoots were only observed in agonistic encounters. Hoot oscillograms showed a sinusoi- dal waveform, and the mean duration of this sound was similar in Incomati system fish (mean, 161 ms), Upper Zambezi fish (172 ms) and Buzi fish (103 and 145 ms for the two vocalising individuals). The mean frequency of the first hoot harmonic was higher in Incomati system fish (326 Hz) than in Upper Zambezi fish (245 Hz). Both growl and hoot occurred only in the presence of conspecifics, probably signalling the presence and condition of an opponent, territory owner or potential mate. This is the first evidence for (1) sound production and acoustical commu- nication in another species and genus, M. macrolepidotus, from southern Africa to be (2) geographically differentiated.

1 aLamml, Michael1 aKramer, Bernd uhttps://mormyrids.myspecies.info/en/node/3801681nas a2200169 4500008004100000245017400041210006900215300001200284490000700296520105000303100002701353700002201380700002301402700001701425700002101442856004801463 2006 eng d00aElectrophysiological and molecular genetic evidence for sympatrically occuring cryptic species in African weakly electric fishes (Teleostei: Mormyridae: Campylomormyrus)0 aElectrophysiological and molecular genetic evidence for sympatri a198-2080 v393 a

For two sympatric species of African weakly electric Wsh, Campylomormyrus tamandua and Campylomormyrus numenius, we moni- tored ontogenetic diVerentiation in electric organ discharge (EOD) and established a molecular phylogeny, based on 2222 bp from cyto- chrome b, the S7 ribosomal protein gene, and four Xanking regions of unlinked microsatellite loci. In C. tamandua, there is one common EOD type, regardless of age and sex, whereas in C. numenius we were able to identify three diVerent male adult EOD waveform types, which emerged from a single common EOD observed in juveniles. Two of these EOD types formed well supported clades in our phyloge- netic analysis. In an independent line of evidence, we were able to aYrm the classiWcation into three groups by microsatellite data. The correct assignment and the high pairwise FST values support our hypothesis that these groups are reproductively isolated. We propose that in C. numenius there are cryptic species, hidden behind similar and, at least as juveniles, identical morphs.

1 aFeulner, Philine, G.D.1 aKirschbaum, Frank1 aMamonekene, Victor1 aKetmaier, V.1 aTiedemann, Ralph uhttps://mormyrids.myspecies.info/en/node/39