Sound production in the Ponto-Caspian gobyNeogobius fluviatilisand acoustic affinities within theGobiuslineage: implications for phylogeny

Abstract

The aim of this study was to describe the vocal repertoire of the Ponto-Caspian goby Neogobius fluviatilis and to compare the acoustic properties of this species with those of other soniferous Mediterranean gobies belonging to the Gobius lineage. Vocalizations and associated behaviours were recorded under controlled aquarium conditions in female and male N. fluviatilis. Sound emission was elicited by means of 'intruder tests', using an individual of the same or opposite sex as an intruder, and recording sounds using a hydrophone placed 20 cm from the shelter used as a nest for the resident fish. Five acoustic properties, including spectral and temporal properties, were measured from 13 individuals. The vocal repertoire of the species consisted of sequences of short vocalizations during both agonistic and reproductive intraspecific interactions. The wave form of each sound resolved in a pure sine wave composed of rapidly repeated pulses. Sounds lasted about 200 ms, showing an average fundamental frequency of about 80 Hz. Sound properties did not differ between reproductive and the aggressive contexts, and the general structure of sounds was highly stereotyped. The individual means of three acoustic independent traits characterizing the sounds of seven species of the Gobius lineage, including N. fluviatilis, were then entered in a discriminant function analysis to assess how well species could be differentiated on the basis of acoustics, and their degree of affinities. The results suggested that the pulse repetition rate of the sounds, i.e. the relative tonal/pulsatile nature of the sounds, was the most important property in differentiating the species, and that this trait may contain a high level of phylogenetic signal, as the species producing tonal sounds clustered together, in line with the results of recent molecular phylogenic studies. The results were discussed in light of the geological and phylogeographical events believed to have driven the diversification of European gobies.

Interspecific variation of warning calls in piranhas: a comparative analysis

“…Few studies have discussed call diversity and evolution in closely related fish species. In some Gobiidae, Batrachoididae and Pomacentridae, characteristics of the acoustic signals and similarities between the sound-producing mechanisms support affinities between different groups of species16192021. However, calls of the different taxa provide different kinds of information and are not necessarily produced in the same behavioural context.…”

“…However, calls in clownfish are not used during courtship periods but only during agonistic interactions15 meaning there is no sexual selection based on call features. In the Mediterranean gobies, call diversification is more important since related species show less overlap of their call features and have even developed different kinds of calls, i.e., pulsatile, tonal and complex sounds2021. Sounds are used in reproductive contexts meaning the selective forces driving the diversification are more important.…”

Acoustic communication during reproduction in the basal gobioid Amur sleeper and the putative sound production mechanism

“…Experiments were set up according to the protocol provided by Horvatić et al . () to record reproductive (male–female) or aggressive interactions (male–male). We used an acoustic intruder test, during which the fish was left in the observational tank for acclimatization (10–15 days) to establish territoriality.…”

“…Gobioid fishes (phylogeny according to Thacker, ) form one of the most investigated Teleost groups in terms of vocal repertoire. Within this group, acoustic communication has been documented in 23 species (Horvatić et al ., ; Zeyl et al ., ). In general, gobioid sound emission occurs during agonistic and reproductive contexts.…”

“…Lastly, thump sounds are short low‐frequency pulsed signals with sound energy under 1 kHz (Amorim & Neves, ; Malavasi, Collatuzzo & Torricelli, ; Zeyl et al ., ). Briefly, in the most investigated species, pulse trains dominate during both agonistic and reproductive (pre‐spawning) interactions, while thumps and tonal sounds are involved in courtship activities in many gobioids (Ladich & Kratochvil, ; Lugli et al ., ; Lindström & Lugli, ; Amorim & Neves, , ; Malavasi et al ., , ; Horvatić et al ., ; Zeyl et al ., ). Complex sounds, reported in only three gobioids to date, were recorded during aggressive circumstances ( Gobius cruentatus and Periophthalmodon septemradiatus ) or as a part of spawning acoustic repertoire in Padogobius bonelli (Lugli et al ., , ; Sebastianutto et al ., ; Polgar et al ., ; Zeyl et al ., ).…”