Comparative study on sound production in different Holocentridae species

Abstract

BackgroundHolocentrids (squirrelfish and soldierfish) are vocal reef fishes whose calls and sound-producing mechanisms have been studied in some species only. The present study aims to compare sound-producing mechanisms in different Holocentridae genera (Holocentrus, Myripristis, Neoniphon, Sargocentron) from separate regions and, in some cases, at different developmental stages. An accurate comparison was made by recording six species while being hand-held, by observing TEM) the sonic muscles and by dissections of the sound-producing mechanism.ResultsIn all these species, calls presented harmonics, their dominant frequency was between 80 and 130 Hz and they were composed of trains of 4 to 11 pulses with gradual increasing periods towards the end of the call. In each case, the calls did not provide reliable information on fish size. The sounds were produced by homologous fast-contracting sonic muscles that insert on articulated ribs whose proximal heads are integrated into the swimbladder: each pulse is the result of the back and forth movements of the ribs. Small differences in the shape of the oscillograms of the different species could be related to the number of ribs that are involved in the sound-producing mechanism. These fish species are able to make sounds as soon as they settle on the reef, when they are 40 days old. Comparison between Neoniphon from Madagascar and from Rangiroa in French Polynesia showed a new, unexpected kind of dialect involving differences at the level of pulse distribution. Neoniphon calls were characterised by a single pulse that was isolated at the beginning of the remaining train in Madagascar whereas they did not show any isolated single pulses at the beginning of the call in Rangiroa.ConclusionThis family cannot use the acoustic fundamental frequencies (or pulse periods) of grunts to infer the size of partners. Pulse duration and number of pulses are statistically related to fish size. However, these characteristics are poorly informative because the correlation slope values are weak. It remains other features (sound amplitude, resistance to muscle fatigue, calling frequency) could be used to assess the body size. Characteristics of the sound producing mechanisms are conservative. All species possess fast-contracting muscles and have the same kind of sound producing mechanism. They do show some change between clades but these differences are not important enough to deeply modify the waveforms of the calls. In this case, our description of the grunt could be considered as the signature for the holocentrid family and can be used in passive acoustic monitoring.

Vocalisations of the bigeye Pempheris adspersa: characteristics, source level and active space

“…In coral reef habitats, the diversity of fish species is matched by a diversity of soniferous species, especially members from the families Pomacentridae (Myrberg et al, 1993;Parmentier et al, 2009Parmentier et al, , 2006, Holocentridae (Parmentier et al, 2011) and Chaeotodontidae (Boyle and Tricas, 2010;Tricas et al, 2006). The types of vocalisations produced are almost as diverse as the number of species that produce sounds.…”

A superfast muscle in the complex sonic apparatus of Ophidion rochei (Ophidiiformes): histological and physiological approaches

“…Fast contracting sonic muscles were also described in Pygocentrus nattereri (Millot et al, 2011) and several holocentrid species (Gainer A superfast muscle in the complex sonic apparatus of Ophidion rochei (Ophidiiformes): histological and physiological approaches et al, 1965;Parmentier et al, 2011). Again, superfast activity appears to be paralleled by the typical fast fiber morphology (Gainer et al, 1965;Eichelberg, 1977;Parmentier et al, 2011). In O. tau, P. nattereri and Holocentrus rufus, the fundamental frequency of the sound corresponds to the contraction rate of the sonic muscle (Fine et al, 2001;Millot et al, 2011).…”

“…20 μm in diameter) that are not completely tetanized at 500 Hz (Fine et al, 1990;Fine et al, 2001). Fast contracting sonic muscles were also described in Pygocentrus nattereri (Millot et al, 2011) and several holocentrid species (Gainer A superfast muscle in the complex sonic apparatus of Ophidion rochei (Ophidiiformes): histological and physiological approaches et al, 1965;Parmentier et al, 2011). Again, superfast activity appears to be paralleled by the typical fast fiber morphology (Gainer et al, 1965;Eichelberg, 1977;Parmentier et al, 2011).…”

Unusual sound production mechanism in the triggerfishRhinecanthus aculeatus(Balistidae)

“…In most of the fishes that use a swimbladder for sound production, calls result from high-speed muscles whose contraction rate corresponds to the fundamental frequency of the call (Boyle et al, 2015;Fine et al, 2001;Parmentier et al, 2011). Alternatively, swimbladder walls can be stretched before rapid release in order to provoke sound production (Kéver et al, 2014;Parmentier et al, 2003Parmentier et al, , 2010.…”