Full Description

"Recording the different acoustic behaviors indicated that sounds are divided into two main categories: aggressive sounds produced in conjunction with threat postures (charge and chase), and submissive sounds always emitted when fish exhibited head shaking movements (i.e. a submissive posture). Both types of sounds showed size-related intraspecific variation in dominant frequency and pulse duration: smaller individuals produce higher frequency and shorter duration pulses than larger ones, and inversely."

"Unlike other pomacentrids, sounds are not produced for mate attraction in clownfishes but to reach and to defend the competition for breeding status, which explains why constraints are not important enough for promoting call diversification in this group."

"Additionally, it was reported that clownfishes might produce sounds during courtship. Courtship in clownfishes is generally stereotyped and ritualized, and is typically accompanied by different activities such as nest cleaning, courtship, spawning and nest care [16]. Basically, studies that describe the courtship sounds in clownfishes are limited in number. To date, sound production during reproductive period has been reported in three clownfish species (A. ocellaris, A. frenatus, A. sandaracinos) by Takemura [22]. However, these observations need to be carefully considered since, according to the author, the sounds were hardly heard and sometimes they do not seem to be directly related to spawning behavior [22]."

"Generally speaking, the recorded sounds were composed of a series of sounds being multiple-pulsed."

"Submissive sounds were always associated with head shaking movements (Fig. 1), but fish could sometimes carry out these movements without vocalizing. Submissive sounds (N = 285 sounds analyzed for all individuals of the different groups; see Table 2) were produced when subordinates displayed submissive posture as a reaction to charge and chase by dominants, which means that these sounds were never recorded for the dominant females (rank 1) during this study. Generally speaking, submissive sounds are completely different from aggressive ones. They are always composed of several pulses whereas aggressive sounds are composed of a single pulse unit that can be emitted alone or in series (Fig. 2). They also exhibit shorter pulse periods and shorter pulse durations than aggressive sounds."

"In A. frenatus, submissive sounds can be produced alone or in series (2–9 sounds, 3.0+-0.56), and are multiple-pulsed (2–6 pulses, 3.2+-0.26). Pulse period averaged 11.8+-2.4 ms and pulse duration ranged from 4.7 to 10.3 ms (7.9+-2.15 ms). Sound period averaged 197.0+-26.6 ms and sound duration ranged from 23.5 to 50.6 ms (35.9+-9.59 ms). Pulses had peak frequency of 591+-115 Hz and most sound energy ranged from 454 to 778 Hz. Dominant frequency and pulse duration were highly correlated with SL. Dominant frequency significantly decreased (R = 20.98, p<0.0001; Fig. 3A) whereas pulse duration significantly increased (R = 0.98, p<0.0001; Fig. 3B) with increasing SL. Pulse period was correlated across SL (R = 0.96, p<0.0001; Fig. 3C) and this sonic variable was also significantly correlated with pulse duration (R = 0.95, p = 0.0001). Additionally, sound duration was correlated with increasing SL (R = 0.97, p<0.0001; Fig. 3E); this acoustic feature being also significantly correlated with both pulse duration (R = 0.93, p = 0.0003) and pulse period (r = 0.98, p<0.0001).Likewise, sound period was correlated with increasing SL (R = 0.86, p = 0.0031; Fig. 3F), being significantly correlated with sound duration (R = 0.82, p = 0.0063). The number of pulses per sound did not change significantly (R = 0.10, p = 0.7917; Fig. 3D) across SL, as well as the number of sounds per train (R = 0.06, p = 0.8686; Fig. 3G)."

"In addition, the influence of fish size on acoustic features was enhanced by comparing them between individuals of the same social rank but from different groups. All the acoustic features were significantly different between individuals of the same rank (Table 3), except when these ones had similar SL. In this case, acoustic features did not differ (Dunn’s test, p>0.05)."

"However, our multiple observations highlight that submissive sounds (i.e. chirps, see [23]) are clearly different from aggressive sounds (i.e. pops, see [23]). Aggressive sounds are mainly produced by dominants during chases and threat displays between conspecifics [20], whereas submissive sounds are always emitted when subordinates exhibit head shaking movements in reaction to aggressive displays by higher-ranking individuals. Therefore, both types of sounds seem to be an integral part of the agonistic behavior in clownfishes."

"Clear differences were found among aggressive and submissive sounds attributed to different individuals. All acoustic variables were significantly more variable between than within individuals and thus could all potentially provide cues to identify individuals. Furthermore, the most important variables to allow individual identification were dominant frequency and pulse duration for both types of sounds (Tables 4, 5). Pulse period, in a lesser extent, was also consistently important for discriminating among individuals in the case of submissive sounds (Table 5)."

Observation Environment Quotes

"Three groups being each composed of four individuals of Amphiprion frenatus (Standard Length, SL: 44–112 mm) were collected by scuba diving on the fringing reef around Nakijin village (26u409N – 127u599E; Okinawa, Japan) during May and June 2009. All fish were then brought back with their host (Entacmaea quadricolor) to Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus where they were transferred to a community tank (3.562.061.2 m) filled with running seawater at ambient temperature (28 to 30.5uC)."

Behaviour Description Quotes

"Additionally, it was reported that clownfishes might produce sounds during courtship. Courtship in clownfishes is generally stereotyped and ritualized, and is typically accompanied by different activities such as nest cleaning, courtship, spawning and nest care [16]. Basically, studies that describe the courtship sounds in clownfishes are limited in number. To date, sound production during reproductive period has been reported in three clownfish species (A. ocellaris, A. frenatus, A. sandaracinos) by Takemura [22]. However, these observations need to be carefully considered since, according to the author, the sounds were hardly heard and sometimes they do not seem to be directly related to spawning behavior [22]."

"Submissive sounds were always associated with head shaking movements (Fig. 1), but fish could sometimes carry out these movements without vocalizing. Submissive sounds (N = 285 sounds analyzed for all individuals of the different groups; see Table 2) were produced when subordinates displayed submissive posture as a reaction to charge and chase by dominants, which means that these sounds were never recorded for the dominant females (rank 1) during this study. Generally speaking, submissive sounds are completely different from aggressive ones. They are always composed of several pulses whereas aggressive sounds are composed of a single pulse unit that can be emitted alone or in series (Fig. 2). They also exhibit shorter pulse periods and shorter pulse durations than aggressive sounds."

" Example of agonistic sounds produced by Amphiprion frenatus during interactions."

"However, our multiple observations highlight that submissive sounds (i.e. chirps, see [23]) are clearly different from aggressive sounds (i.e. pops, see [23]). Aggressive sounds are mainly produced by dominants during chases and threat displays between conspecifics [20], whereas submissive sounds are always emitted when subordinates exhibit head shaking movements in reaction to aggressive displays by higher-ranking individuals. Therefore, both types of sounds seem to be an integral part of the agonistic behavior in clownfishes."

Sound Name Quotes

"Generally speaking, the recorded sounds were composed of a series of sounds being multiple-pulsed. "

"Submissive sounds were always associated with head shaking movements (Fig. 1), but fish could sometimes carry out these movements without vocalizing. Submissive sounds (N = 285 sounds analyzed for all individuals of the different groups; see Table 2) were produced when subordinates displayed submissive posture as a reaction to charge and chase by dominants, which means that these sounds were never recorded for the dominant females (rank 1) during this study. Generally speaking, submissive sounds are completely different from aggressive ones. They are always composed of several pulses whereas aggressive sounds are composed of a single pulse unit that can be emitted alone or in series (Fig. 2). They also exhibit shorter pulse periods and shorter pulse durations than aggressive sounds."

"However, our multiple observations highlight that submissive sounds (i.e. chirps, see [23]) are clearly different from aggressive sounds (i.e. pops, see [23]). Aggressive sounds are mainly produced by dominants during chases and threat displays between conspecifics [20], whereas submissive sounds are always emitted when subordinates exhibit head shaking movements in reaction to aggressive displays by higher-ranking individuals. Therefore, both types of sounds seem to be an integral part of the agonistic behavior in clownfishes."

Full Description

"In the clownfish A. akallopisos, the most aggressive males were characterized by a higher number of pulses per sound and a shorter pulse period (pers. obs.)."

Behaviour Description Quotes

"In the clownfish A. akallopisos, aggressive sounds emitted by non-breeders, males and females differ in dominant frequency by >10% [20]."

Sound Name Quotes

"In the clownfish A. akallopisos, the most aggressive males were characterized by a higher number of pulses per sound and a shorter pulse period (pers. obs.). "

Full Description

"Recording the different acoustic behaviors indicated that sounds are divided into two main categories: aggressive sounds produced in conjunction with threat postures (charge and chase), and submissive sounds always emitted when fish exhibited head shaking movements (i.e. a submissive posture). Both types of sounds showed size-related intraspecific variation in dominant frequency and pulse duration: smaller individuals produce higher frequency and shorter duration pulses than larger ones, and inversely."

"Unlike other pomacentrids, sounds are not produced for mate attraction in clownfishes but to reach and to defend the competition for breeding status, which explains why constraints are not important enough for promoting call diversification in this group."

"2) spawning was witnessed in the field for A. perideraion, and no sound was produced by the mating pair during the reproductive event. Yet, recording of aggressive sounds during the same session supports the fact that the recording material worked well."

Observation Environment Quotes

"2) spawning was witnessed in the field for A. perideraion, and no sound was produced by the mating pair during the reproductive event. Yet, recording of aggressive sounds during the same session supports the fact that the recording material worked well."

Behaviour Description Quotes

"2) spawning was witnessed in the field for A. perideraion, and no sound was produced by the mating pair during the reproductive event. Yet, recording of aggressive sounds during the same session supports the fact that the recording material worked well."