Topic
Pollimyrus
About: Pollimyrus is a research topic. Over the lifetime, 14 publications have been published within this topic receiving 351 citations.
Papers
TL;DR: Simulated standardized courtship encounters with females revealed that males differ markedly in their apparent ability to produce sustained moans and it is suggested that this may be particularly important to females in mate selection.
Abstract: An analysis of the natural bioacoustic signals made by two closely related African fishes (P. adspersus and P. isidori) revealed that these species separated along several acoustic dimensions that are likely to be important for species isolation. Both species produced grunts that were composed of a trains of pulses, but the pulse repetition rates were distinctly different (56±3 s.d. vs 44±4 s.d. pps). Complex tone bursts (moans) were also used, but the species differed substantially in the location of the fundamental peak (240 Hz±12 s.d. vs 332 Hz±34 s.d.). Some P. adspersus males sustained these tones for over a second (812 ms±495 s.d.), whereas P. isidori produced shorter tones (121 ms±35 s.d.). During interactions with females, the two species produced the grunts and moans in distinct species-typical patterns: P. adspersus males alternated grunts with moans and P. isidori produced a single grunt followed by a succession of moans. A detailed analysis of identified individual P. adspersus showed that acoustic features constituted individual signatures which could be used by conspecifics to identify individuals. Grunt spectral peak frequency was shown to be a good predictor of male mass, with peak frequency decreasing at 72 Hz per gram. Simulated standardized courtship encounters with females revealed that males differ markedly in their apparent ability to produce sustained moans and it is suggested that this may be particularly important to females in mate selection.
103 citations
TL;DR: Phylogenetic relationships among mormyrids were determined by comparing cytochrome b sequences of 27 species belonging to 15 genera and confirmed that the lateral ethmoid bone was lost several times within the Mormyrinae.
77 citations
TL;DR: Genomic fingerprinting with ISSR-PCR and Sequence analysis of the cyt b gene confirmed that the three forms or species form a monophyletic clade, with P. castelnaui sister to the other two species.
Abstract: We studied the systematic status of a form of Pollimyrus of the lower Kwando River that is flanked by the Okavango River, inhabited by Pollimyrus castelnaui (Boulenger, 1911), and the Zambezi River, inhabited by Pollimyrus marianne Kramer et al., 2003. In morphology and electric organ discharges (EODs), the Kwando phenotype proved well differentiated from both P. castelnaui and P. marianne. Sequence analysis of the cyt b gene confirmed that the three forms or species form a monophyletic clade, with P. castelnaui sister to the other two species. Genomic fingerprinting with ISSR-PCR confirmed differentiation of the Kwando form, that we recognize as a different species, P. cuandoensis sp. nov., from its sister species, P. marianne. A considerable amount of EOD and morphological variation was revealed among samples of P. cuandoensis sp. nov. from four different locations on the lower Kwando River, possibly due to hybrid introgression. This seems an ideal system for testing theories of parapatric speciation. h...
67 citations
TL;DR: The acoustic pathway from the ear to the diencephalon in a sound‐producing fish (Pollimyrus) is described based on simultaneous neurophysiological recordings from single neurons and injections of biotin pathway tracers at the recording sites.
Abstract: We have described the acoustic pathway from the ear to the diencephalon in a sound-producing fish (Pollimyrus) based on simultaneous neurophysiological recordings from single neurons and injections of biotin pathway tracers at the recording sites. Fundamental transformations of auditory information from highly phase-locked and entrained responses in primary eighth nerve afferents and first-order medullary neurons to more weakly phase-locked responses in the auditory midbrain were revealed by physiological recordings. Anatomical pathway tracing uncovered a bilateral array of both first- and second-order medullary nuclei and a perilemniscal nucleus. Interconnections within the medullary auditory areas were extensive. Medullary nuclei projected to the auditory midbrain by means of the lateral lemniscus. Midbrain auditory areas projected to both ipsilateral and contralateral optic tecta and to an array of three nuclei in the auditory thalamus. The significance of these findings to the elucidation of mechanisms for the analysis of communication sounds and spatial hearing in this vertebrate animal is discussed.
50 citations
TL;DR: The first behavioral measurements of auditory sensitivity for Pollimyrus adspersus, an electric fish that uses both electric and acoustic signals for communication, matched closely the spectral content of the sounds that this species produced during courtship.
Abstract: In this report we present the first behavioral measurements of auditory sensitivity for Pollimyrus adspersus. Pollimyrus is an electric fish (Mormyridae) that uses both electric and acoustic signals for communication. Tone detection was assessed from the fish’s electric organ discharge rate. Suprathreshold tones usually evoked an accelerated rate in naive animals. This response (rate modulation ⩾25%) was maintained in a classical conditioning paradigm by presenting a weak electric current near the offset of 3.5-s tone bursts. An adaptive staircase procedure was used to find detection thresholds at frequencies between 100 and 1700 Hz. The mean audiogram from six individuals revealed high sensitivity in the 200–900 Hz range, with the best thresholds near 500 Hz (66.5±4.2 SE dB re: 1 μPa). Sensitivity declined slowly (about 20 dB/octave) above and below this sensitivity maximum. Sensitivity fell off rapidly above 1 kHz (about 60 dB/octave) and no responses were observed at 5 kHz. This behavioral sensitivity matched closely the spectral content of the sounds that this species produced during courtship. Experiments with click trains showed that sensitivity (about 83-dB peak) was independent of inter-click-interval, within the 10–100 ms range.
13 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2018 | 2 |
| 2017 | 1 |
| 2014 | 1 |
| 2003 | 1 |
| 2000 | 3 |