Condition-dependent auditory processing in the round goby (Neogobius melanostomus): links to sex, reproductive condition, and female estrogen levels.

Abstract

SUMMARYNeural responses to sensory stimuli often differ between sexes, vary seasonally, and can be regulated by endocrine activity, but the ecological and physiological mechanisms driving such patterns are not well understood. The current study examined how auditory function in the round goby (Neogobius melanostomus), a vocal teleost, co-varied with sex, reproductive condition and female plasma 17β-estradiol level. Auditory evoked potentials were collected in response to tone pips (100-600Hz) and a natural round goby pulse vocalization. Additionally, saccule hair cell densities were compared across reproductive groups. Auditory threshold was evaluated in terms of pressure and particle acceleration, and response amplitude and onset latency were measured at 10dB above threshold. Relative to males, females displayed lower auditory thresholds in response to the natural vocalization and to tones at 300-600Hz, and had a higher density of saccule hair cells. The 17β-estradiol level was positively associated with amplitude and latency for the pulse stimulus and with both threshold and amplitude for tones at 100-200Hz in females. Relative to non-reproductive males, reproductive males exhibited longer response latencies at 100-200Hz. The results demonstrate sexual dimorphism in auditory function in a teleost fish as well as intra-sexual variation, partially based on hormone levels. The current research further identifies links between auditory function and reproductive behaviors in fishes and provides a finer-scaled analysis of how this behavior is reflected at the level of the sensory systems facilitating signal reception.

Acoustic communication in marine shallow waters: testing the acoustic adaptive hypothesis in sand gobies

“…Hearing sensitivity in the studied species is comparable to that of other fish species living in near-shore marine habitats, including other gobies (see figure 5 in Lugli, 2010). For example, Gobius cruentatus and Gobius melanostomus have best hearing sensitivities at frequencies below 300 Hz, also matching the main conspecific sound frequencies (Rollo and Higgs, 2008;Codarin et al, 2009;Zeyl et al, 2013). Nevertheless, regardless of being vocal or mute, fish inhabiting noisy environments typically lack hearing specialisations, have low hearing sensitivities and are thus less affected by noise, suggesting that hearing sensitivities may have been shaped mainly by AN regimes (Ladich, 2013).…”

Sexual dimorphism in the sonic system and otolith morphology of Neobythites gilli (Ophidiiformes)

“…Otoliths have been described from many different species and they are usually regarded as species specific, but without differences between males and females – meaning that the morphological dimorphism of sagittal otoliths in Neobythtites is exceptional. In other teleosts, studies have reported better hearing abilities during spawning season, but this was related to sensitive cells and concentrations in hormones (Maruska, Ung & Fernald, ; Zeyl, Love & Higgs, ), not to otolith shape or size. Many species whose sexes have different calling abilities do not show differences in the otolith.…”

Passive acoustic monitoring shows no effect of anthropogenic noise on acoustic communication in the invasive round goby (Neogobius melanostomus)

“…Reproductive female round goby respond preferentially to the grunt call (Isabella-Valenzi & Higgs, 2013;Rollo & Higgs, 2008;Rollo et al, 2007) and show a high degree of directionality to this call (Rollo & Higgs, 2008) while reproductive males respond better to the drum vocalisation (Isabella-Valenzi & Higgs, 2013). Round goby hearing is solely low frequency (Belanger, Bobeica, & Higgs, 2010)-with perhaps better tuning to the call itself than to other sound types (Belanger et al, 2010;Zeyl, Love, & Higgs, 2013). Responsiveness to sensory signalling is dependent on reproductive state, with reproductive females showing higher responsiveness to acoustic as well as multisensory stimuli, perhaps in association with circulating hormone levels (Kasurak, Zielinski, & Higgs, 2012;Zeyl et al, 2013).…”

“…Round goby hearing is solely low frequency (Belanger, Bobeica, & Higgs, 2010)-with perhaps better tuning to the call itself than to other sound types (Belanger et al, 2010;Zeyl, Love, & Higgs, 2013). Responsiveness to sensory signalling is dependent on reproductive state, with reproductive females showing higher responsiveness to acoustic as well as multisensory stimuli, perhaps in association with circulating hormone levels (Kasurak, Zielinski, & Higgs, 2012;Zeyl et al, 2013).…”