Studies on the Underwater Sound―VIII Acoustical behavior of ...

4 downloads 7 Views 3MB Size Report
Acoustical behavior of clownfishes (Amphiprion spp.) Akira TAKEMURA. The acoustical behavior of seven species of clownfishes (Pomacentridae) bred in the  ...

NAOSITE: Nagasaki University's Academic Output SITE

Title

Studies on the Underwater Sound―VIII Acoustical behavior of clownfishes (Amphiprion spp.)

Author(s)

竹村, 暘

Citation

長崎大学水産学部研究報告, v.54, pp.21-27; 1983

Issue Date

1983-02

URL

http://hdl.handle.net/10069/30420

Right This document is downloaded at: 2017-10-06T21:51:10Z

http://naosite.lb.nagasaki-u.ac.jp

Bull. Fac. Fish. Nagasaki

Univ., No. 54, 21-27

Studies Acoustical

(1983)

21

on the Underwater

behavior

Sound—VIll

of clownfishes

Akira

(Amphiprion

TAKEMURA

The acoustical behavior of seven species of clownfishes (Pomacentridae) Hubbs Sea World Research Institute was observed. Each specimen emitted of a pulse or a series of pulse sounds.

spp.)

bred in the tanks at some sounds composed

These sounds were divided into three categories by their

frequency components and, among of these species, some differences were found out. Each sound was relatively vigorous.

The fish was utilizing these sounds for protecting their territory on their

life, especially by some activities related with spawning or threat.

The mutualism centridae)

between the clownfish (Poma-

species among them, namely; Amphiprion clarkii,

and sea anemone is already well known.

A. polymnus, A. biaculeatus, A. ocellaris, A. frena-

A pair of adult clownfish forms a territory around

tus, A. melanopus and A. sandaracinos

the sea anemone and their movements

Observations on acoustical

are limited

in this small area. The adhesive eggs of the fish are

were carried out.

laid on the surface of a rock near the sea anemone. Usually, a pair of fish spawn and take care of eggs

are raised.

behavior of these fishes

These specimens had been reared in glass tanks of two sizes, 45 × 60 × 40 (depth) cm and 100 × 300 ×

in their territory every month, however, the spawn-

100 (depth) cm. The sand is placed 15 cm thick on

ing took place more frequently in the laboratory

the

as

bottom

of small

tanks

for filtration.

A

every two weeks. Female vigorously cleans up the

hydrophone was suspended at the middle depth in

spawning ground just before and after spawning.

the center of the tank. A pair of clownfish was kept

However

in each tank.

after

spawning,

females

of the

most

species of this genus hardly take care of eggs. On

Water and air supply were stopped

during the recording to minimize the noise.

the contrary, males eargerly take care of eggs and

It was very difficult to record the correct fre-

do not go away from the eggs through the incuba-

quency or duration of calls of fishes, because the

tion period.

tanks were small and no measure was adopted to

During a series of those behavior, times emit the sound.

Verwey

they some-

(1930), Schneider

lessen the reflection of sound.

(1964) and Allen (1975) described already in their reports about the calls of some species of the fishes.

their sound and behavior.

Moreover, Verwey and Schneider suggested some

Underwater

assumptions on the sound production

Currently

a total

spp. are known

from

of

World

Hubbs

Sea

and Methods

of 27 species the world. Research

between

Sounds

mechanism. The clownfish

Materials

However, it seems

that it is able to assume the relationship

of Amphiprion

were

kept

times

emitted

were

kept

In the aquarium

emitting

Institute,

fishes.

seven

alone

did not emit any sound in the tank,

some

sounds

in a tank.

increased

however, when

The

in proportion

plural

frequency

when they they

some-

specimens of sound

to the number

of

22

A. Takemura: Acoustical behavior of clownfishes

  All of these sounds were constituted by pulse 4一

sound and had something in common with the main

ψ■

■膨確

σ壷●





Accordingly, the pattern of sound was quite simple.

2.0

t.o

3.0

Tkne in sec.

   The sound with a long duration such as O.056

−O.065sec was emitted rarely under the special

蓬 ξ。



ッ       の       の

seldom exceptions of being emitted in a series.

N蚕蕊診§ρ¢

over, most of the sounds were emitted singly with

3    2    i

frequency component of less than 1 kHz. More−

Fig. 1. Underwater sound of A. clarkii

behavior, however, the duration of pulse sound was usually O.02−O.03 sec.

   Moreover, those pulse sound emitted by this

   The components of frequency of sound were

species was rarely emitted before special move−

very various and all of sounds were divided into

ments as mentioned later and was usually emitted

following three categories;

during or after the violent and special movement.

1. Sound containing the frequency component

Explanations of pulse sound of each species are

  from very low frequency such as D. C. to several

given below:

  kilohertz, sometimes more than 8 kHz.

  1..4〃ψ吻η●onぬ痴ゴ

2. Frequency components limited between 200   −300 Hz and a few kilohertz.

3. Sound composed of the frequency component

   Almost all sounds of this species were contained

in the second category. Especially the frequency component were concentrated into 1−2 kHz (Fig.

  of more than 1 kHz.

1). The variety of sound of this species was very

   Moreover, each category was divided into 5−9

poor, however, the sound was emitted most fre−

subcategories by fundamental frequency, harmonic

quently among the seven species described before.

and so on. H owever, the frequency of emitted

The both sounds of single and a series of pulse were

sound was quite low under the normal behavior and

emitted, and, in generally, single pulse sound was

most of all the frequency components were limited

higher than a series of sound by about 300 Hz.

in low frequency less than 2 kHz and main fre−

   Those sounds were heard from the fish not only

quency was about 500 Hz. The clownfish emitted

when they were eating the food either suspending in

the sound composed of single pulse or of a series of

water or floating at the surface of water but also

pulses. The latter sound was emitted by plural

when they were bathing in the sea anemone.

specimens that were staying close to each other and

   In addition to this, the single pulse sound with

the sound of series of pulse was not heard when

the frequency component of more than 2 kHz was

each specimen swam or stayed separately.

also recorded.

   The clownfishes are taxonomically classified

  2. A. Polpmnus

into two groups by the number of stripes of fish’s

   This species is large−sized one among the clown−

body and the third category of sound were heard

fish. The sound emitting of this species is very rare

from the group of fish with more than two stripes

and the sound of the second category was not heard

on their body and were not heard from the group of

(Fig. 2). Those rare sounds were cl assified into

fish with less than one stripe. Moreover, the high

three pattem Namely;

frequency and weak pulse sound such as popping

1. Pulse sound with the frequency component of

were heard from every tank, however, it seems that

  2.5−4kHz and, sometimes, composed of 4−5

those sounds were caused by nonbiological factor.

  pulses.

Namely, the tank was divided into two parts (a part with fish and the other part with no fish) by

styropone plate and same sound was heard from each part of tank.

2. Single pulse and frequency component of D. C.   一4 kHz.

3. Single pulse and frequency component of D. C.

  一more than 8 kHz.

23

Bull. Fac. Fish. Nagasaki Univ., No. 54 (1983)

  All of these sounds had a strong component at 轟{

鑑嘉監罫ぴ

female, however, this sound was not special sound

障葦‘二り璽皆鍵

sound from their behavior, was emitted from

1

..暇..... 曹  ...舶

  The sound which was judging as the threatening

3   a    曝

low frequency.

and was of the same pattern with the other sound



3P

2.0

γ㎞彰納 5娼.¢.

and was emitted more strongly.   3. A. biaculeatus

.墾.寮罵灘.・灘饗

e一 ・..・..

   This species is also larger one among the clown−

膨.

most of sounds emitted by this species was low

 e.s

卍ひ



矯 娯 験 φ 陶 齢 串 ﹁

 曝   

蕊む毒書⑪鉱

             奪.≒



 o,恩

1.o

LS



↑拠鴇 襯 騰《;、

pt・・ ”銑  t

3

\悪/≒蚤べ1趨}懇∵一

..ザ 中

、ノ㌦¶溶㌔﹁

.・で...蜘

・1∴.・:脳.轡.〆・

.、 ご.噸.ぎ:・㌔1一 鳥∴饗監..

F1





@lr.111 ”/,.,/ i’f,i.i. ,,},/ “:t.’Nl

﹁ ” .軸  騨. 一 .陣  鵤 鱗 咽  噛  . 馴  σ  β .擢

”’



弧 ゆ 息.賦

 描瓢潔

” 一“ ;一’

    餓工X蓬露§﹂﹄

⇔ κ 辱

2

                 霊

   ■     r  ,       .㌦            で

B   S   4   建

Hz for D. C.一1 kHz sound. 400−800 Hz for D. C.一7

1.5

1.cr

T納憩 議 sec.

frequency less than 1 kHz (200−800 Hz: 200−600                       ’

=“⋮

.ψ

, “ 略 擢 惣 帥 岬 昂 擢

sound emitting was also low (Fig. 3). The funda−

mental or stronger frequency component of the

▼   4   a

fish such as A. Polpmnus and the frequency of

四董渥費§σo鉱

6悼.     ,.

ポ i    躍    ’ t

       播

辱ρ

O,5

Fig. 4. Underwater sound of A. ocellan’s

Tlpme in sec.

2



3  2  奪 岡葦滋3手差畠 ..

D..........嘱 ﹄.....臨



ponent from 5−8 kHz and has strong component at

奪.   ’ を



一噸

kHz sound).    Moreover, the sound which has frequency com−

.で

鰍・ぽ 鵡畿姥ρ

il一

6 kHz was very rarely heard, but, the source of this

sound was not clear. 2ρ         3,¢

  4. A. ocellan’s

  When the pair form their tenitory and live in a

口li淘豪.魂1妊.角器溺翻3

sea anemone, this species assume a conservative attitude and are always bathing in a sea anemone

1:ll一...唱..ぴ四一.二

and hardly go away from it. Moreover, the sound emitting of this species is also not so frequent (Fig.

    麟、㍉噛ぜへ感_.嫁、......、.鷺.幣属..旨.端..ド..、..:.白油.j

4).

            q5      1.e      恥            鞠鷺 恥 薯㏄,

  These sounds were classified into three patterns

   Fig. 2. Underwater sound of A. Polpmnus

by frequency range and pattern. Namely; 1 . Single pulse sound with very narrow frequency

9齢

  range (1.25−2.8 kHz).

闇       Ψ       鱒

3    2    婁

望盤聯ぎ器尋置

2. Low frequency sound composed of the fre−   quency component of less than 2.5 kHz.    要

9

φ

α贈



町⇒

頃サ



養.



    な      ト

@§ ”

3 . Sound with high frequency component of more   than 3 kHz and, sometimes, make a series of

          Ire ” ’ ” ’ 21e ’ 3LQ            T㎞6 1貸 鷲C.

Fig. 3. Underwater sound of A. biaculeatzts

  pulse continued for about a second. Frequently,

  those sounds are heard during they are pecking

w・﹂毒.馨

D7㌦

 e.s

了㎞e勧 sec,



.F

。.

﹂..

       

O.5

甑 . 、  此.



灘讐  ▼

蝿 岬

ひ.

㍉弧卸.〆一

κ

ぴ ざ  ゆコ コ



1

Dが.騨4.、ゴ..、

サ、





ド勢

 . 髄垂蕊♂§﹄

辱7



 繭

 撫

  メ

  か、 駈



  ︷

魯脇 κ 避

の4甑掌一





t?

郁G

同︵

q  曜  冒  騨  騨  鴨  刷  O  り  軸  胴

N工菖蕊套ロ詮﹄



砂営



雑.

6   4   2

耀零

A. Takemura: Acoustical behavior of clownfishes

り ρ 咽

8

欝.

24

1.5

毒ρ

了㎞e 酌 鱒。,

2



        奪ρ       2.0       3,0           Tkue in sec,

         1.e 2.Q s.o           マ醗騰 軌 彩●c,

Fig.5. Underwater sound of/1.ノ地πα伽s

Fig. 6. Underwater sound of A. melanoPus

6



丁9苓

餐一

source of sound because several kinds of these fishes are living in the same tank.



    2

6  ”  ▼  噛  0

ご&諏g鑑

一 齢

4

・勘

師工鰯



・順 .

,  7  醒

juvenile tank. But, we can not distinguish the

 ’i

O ﹁

8

   In addition to this, the neutral sounds among

騨 7

  up on the surface of spawning ground.

the above−mentioned sound are heard from the



縛      ・      ﹂

登番

儲エ鱗忌恥り§σ働慮

 こ

 毒. ソ罫∵岬.鞠轡讐:「騨.警軍.’// 2

3   2    婁

−      精      ,

N釜召二り奉&塞

3   2    −

 }

:.,....,....,,,“....“’L.S,S.L.!L,!,,jLev...,....“ii!“itl

4

.飾

4



          o.5      te      婁.5           Tkne in sec.

  5. A. frenatzcs

Fig. 7. Underwater sound of A. sandaracinos

   The frequency of sound emitting of this species is also not so high but following two types of sound

anemone, swims towards a male and stop just in

were heard (Fig. 5). Namely;

front of the latter. Although this kind of movement

1. Sound with stronger frequency component at 5   −6kHz.

2. Sound with stronger frequency component at

was observed rather frequently, sound emitting was not recorded very often. And, sometimes, this type of sound was observed when a female bite a male at

  300−600 Hz.

throat or abdomen to cause the latter cramping all

   This sound was, sometimes, composed of some

over. After being bitten by a female, the male

  pulses.

usually started to peck madly up the surface of a

  6. A. melanoPus

rock and emitted the sound.

   The following two kinds of sound were heard

   While a vigorous sound during eating the feed

from this species (Fig. 6). Namely;

was heard in other species, this species did not emit

1. Sound composed of a very wide frequency

such sounds.

  range (D. C.一8kHz) without any stressed fre−

  7. A. sandaracinos

  quency components.

   The sound of this species was composed of

2. Sound composed of low frequency less than 1

single or a series of pulse sound with stressed

  kHz with stressed frequency component at 250

frequency component at 300−600 H z and were

  −500 Hz.

composed of less than three pulses with wide fre−

   It is very doubtfull whether the former sound is

quency range (200−3500 Hz) with two or three

caused by this species. On the other hand, the latter

stressed frequency components (Fig. 7)

sound was often emitted in a series and a female

  A fish daShed toward the other fish floated in

used to emit this sound when it get out of a sea

water and the sound was, sometimes, recorded j ust

Bull. Fac. Fish. Nagasaki Univ., No. 54 (1983)

bef6re passing each other.

  Moreover, this sound was also recorded when

25

rested in the sea anemone as before.        の

   On the other hand, a male pecked the surface of

two fishes were floating in water in parallel in such

rock and emitted a high frequency pulse sound

a species as A. melanoPus. The same sound was not

sometimes. The pecking behavior was observed in

always recorded at the same behavior on each

afemale as well. However, female pecked more

specles.

frequently in earlier time, while male began to peck

more frequently later. This movement was some.

Acoustical Behavior during Reproductive Period

times observed up to five hours before spawning

but the remarkable change in behavior was not    Acoustical behavior during reproductive period was observed on A. ocellan’s, A. frenatzrs and A.

observed.    About five hours before spawning, female move−

sandaracinos. The behavior of these fishes resem−

ment became dull and low frequency pulse sound

bled each other. lt was necessary to observe on

which may be emitted by the female was heard

every species, however, it seemed that the other

frequently and gradually.  H:igh pitched sound

species behaved as almost the same as above−

which may be emitted by male were also heard

mentioned three species judging from some brief

sometimes. Pecking movement of a male on the

observation.

su㎡ace of rock became vigorous from aboI覧f two

   It was easy to recognize the anival of spawning

hours before spawning. This movement was con−

period from the degree of fatness of abdomen and

tinued until just before spawning. In case of∠L.

the projection of spawning duct of a female and

sandaracinos this movement was carried out either

these characteristic features became distinct three

simultaneously or altemately with the staying fish

or four days before spawning.

on the lookout for the disturbance. If they were

   They did not go away from a sea anemone and

disturbed, they stopped this movement and started

were bathing in it almost always. And the move−

to take a lookout in the sea anemone. Most of the

ment like “tail digging” was observed sometimes.

disturbance had no effect on this behavior in case of

From about 30 hours before spawning, this move−

/Locellari’s.

ment wa$ executed vigorously and they became

   Just before spawning, the cleaning of spawning

rubbing their side of belly against the rock near the

ground by pecking was more rigorously carried out

sea anemone. This behavior, however, was not

by the female than the male. The female used to

continued for so long a time and theY began to

rub the tip of her spawning duct against the rock

behave like before. Moreover, they sometimes

and pecked the surface of rock for 15minutes

behaved in unusual manners, namely, going away

before spawning, as if she was making sure of the

from the sea anemone, pecking up the surface of the

completion of spawning ground. In case of、4.

rock and going around as if they were looking for

sandaracinos this movement was not observed.

the spawning ground. A series of high frequency

Moreover, the male and female of A.0661彪廊

pulse sound became to be heard more frequently at

emitted individually the low or high frequency

28 hours before spawning, but, it was not clear

pulse sound just before spawning, then she began to

whether these pulses were emitted by this fish or

spawn. However, these sounds were not so closely

not.

connected with spawning, because these sound were

   Female began to rub her abdomen against the

not always heard and were the same as usual sound.

rock (spawning ground) and cramp her body, and

These sound were not heard from∠4. sandaracinos.

emitted a strong and low frequency pulse sound

   The spawning was carried out in the following

sometimes. This behavior lasted for 20 minutes.

manner:The female spawned and sticked the eggs

followed by a 10−minutes interruption. After re−

in a queue,3−4cm in length, on the surface of rock;

peating these movements two or three times, they

after a short rest she reversed and began to lay eggs

26

A. Takemura: Acoustical behavior of clownfishe$

parallel and close to the first queue; this was re−

same attacks by female when male was madly

peated until the spawning ground, 4−5 cm in diam−

pecking on the surface of the rock. The same sound

eter, were filled with egg mass leaving a marginal

was sometimes used for threat, although the degree

space of O.5−1cm wide. After the spawning,’

??│

of threat of A. polymnus was more vigorous.

male and male take care bf eggs. Female became

   A. clarleii emitted the vigorous threatening

gradually less eager to take care of eggs. On the

sound against the angelfish Holacanthus sp., which

other hand, male and female of A. sandaracinos

was put into the same tank. This sound was also a

continued to take care of eggs.

single pulse sound and had very wide frequency

  From beginning to end of spawning, sound were

component (D. C.一8 kHzS) and moreover some of

hardly heard and A. ocellan’s did not emit any

frequency component was lasting for morethan one

sound for a long time after spawnlng. On the other

second depending on the resonance of tank.

hand, A. sandaracinos emitted continuously and

   Threatening sound was mainly emitted after the

constantly a weak and low frequency sound from

fish found the invader in near place, but threat was

the beginning of cleaning of spawning ground.

frequently canied out by some kind of sound.

However, it seemed that this sound was also not

When we snap the wall of tank by a finger nail, we

connected directly with spawning behavior.

can make a strong pulse sound such as white noise resembling the sound of this fish. A. frenatus took

Threat, Attack a皿d Acoustical Behavior

a threatening behavior against this sound. Namely,

they dashed, looked around and cramped their body    There was relatively clear relationship between

and frequently emitted the threatening sound.

the sound and threatening behavior. The clownfish

When this stimulus was frequently given to this

would drive away any invaders from their territory.

fish, the reaction became weak. However, when

It was observed in the tank of A. ocellaris that,

this stimulus was given after an interval, their

cramping their body, they attacked and killed an

threatening movement was provoked again. lt

invader. In case of・4.ノ’renatzcs, male and female,

seemed that this phenomenon was especially re−

especially male, dashed and bit the invader and

markable during a reproductive period and same

                                    ノ

then, sometimes, cramped their body and emitted

phenomenon was observed also in A. sandaracinos.

sound. All of sound were pulse sound, however, the

   In case of threat, it was most common to bite

sound that looked like threatening sound with

the invader, but the threat was sometimes carried

cramping had a long duration(0.056 sec), a very

out by means of the gesture (including the sound).

narrow frequency range of about 500 Hz and with

These threatening movement was limited in their

some harmonic.

territory, but the sphere of these movement was

   These behaviors were continued until the.in−

reduced in case of a bigger invader.

vader got out of sight. At this time, female also

   Observing the behavior and each sound emitted

behaved the same action, but not so actively. It

by clownfish, it seemed that the pattern of sound

was observed that female tried to bite male to get

was not so important and the meaning included in

him back to spawning ground. Very high frequency

sound was variable by the circumstance when the

sound was also rarely heard at that time, but the

sound was emitted and the way of sound proj ection

source of sound was not clear..4, melanopus also

(intensity, duration, repetition rate and etc.).

emitted the same threatening sound with a long duration(0.064 sec)and the sound had sometimes

Mechanism of Sound Production

some harmonics. In this case, female bit the male at throat or abdomen and male emitted a series of

  lt seemed that the mechanism of sound produc−

pulse while male was cramping his body. The same

tion among clownfishes was similar, because the

sound were heard from male which was done the

difference among sounds emitted was very little

Bull. Fac. Fish. Nagasaki

Univ., No. 54 (1983)

and the movement during emitting sound was also

William

similar.

of Hubbs

When we observed the movement of fish

carefully during they were emitting sound, we could sometimes find out the special movement.

E. Evans,

suggestions

and kind

director,

Research

and the stuff

Institute

for their

advices.

This References

of mouth or oper-

cle. Frequently, bubble was projected from opercle.

1) Allen, G. G.

Teeth, air bladder and so on may be taken into consideration

executive

Sea World

movement was mainly connected with taking food, consisting of a quick movement

27

(1975) .

The

Anemonefishes,

second ed., T. F. H. Publications Inc. Ltd., N. J.,

as source of sound, but it seems that

199—239.

these are not closely connected with sound projec-

2) Schneider, H. (1964) . Z. Morphol. Okol. Tiere, 53, 454—474.

tion as mentioned by Verwey (1930) and Schneider

3) Verwey, J. (1930). Treubia, 12(3-4),

(1964) .

305-366.

Acknowledgements

The

author

wishes to express

his thanks

to Dr.

水 中音 の 研 究―Ⅷ ク マ ノ ミ属 魚 類 の 音 響 生 態 につ い て 竹





Hubbs  Sea World  Research  Instituteで 飼 育 中 の クマ ノ ミ属の魚類7種 類 の音 響 生態 を調 査 した.各 種 と もパ ル ス 音 又 は一 連 のパ ル ス音 を発 す る が,こ れ らの発 生音 は周 波 数 成分 に よ って大 き く3つ の カテ ゴ リー に分類 され,種 に よ り幾 分 相違 点 が 観 察 され た.発 生 音 は か な り強 い音 で あ り,主 に テ リ トリー を守 るた め威 嚇や 産 卵 時 の行 動 中に 聞 か れ る.

28

Suggest Documents