Family No. 205: CHAETODONTIDAE
by P.C. Heemstra
Butterflyfishes
Vlindervisse
Body ovate, strongly compressed. Dorsal fin continuous,
more or less covered with scales; anal fin also scaly. Pelvic
fins well developed, with a spine and five rays. Caudal fin
truncate or rounded, usually with 15 branched rays. Scales
ctenoid, covering head and body. Preopercle without a
large spine at the angle; no spines on head. Vertebrae
11 + 13. Mouth small; teeth long and slender, none on
vomer and palatines. "Chaetodon" means bristle tooth and
aptly describes the dentition of butterflyfishes. Branchiostegal membranes separate, with 6 or 7 rays. Gill-rakers
short, not numerous.
Butterflyfishes occur in tropical/subtropical waters of all
oceans. They live in depths of 1 - 200 m, and are not found
far from shore except as post-larvae in the peculiar
"tholichthys" stage. Most species are associated with coral
reefs, and coral polyps are a common item in their diet.
They also feed on a variety of small invertebrates (including
benthic and planktonic forms) and algae. Juveniles of several species are facultative "cleaners" (i.e. they pick small
parasites from the skin of other fishes), and even adults are
occasionally observed picking parasites.
This family was recently revised by Burgess (1978). Ten
genera with about 120 species; 4 genera and 24 species in
our area. The species are most readily identified by looking
at the illustrations, but keys to species are provided to aid in
determination of small juveniles.
KEY TO GENERA
la Snout greatly prolonged, tubular, its length 1.1-2.1
in body depth; P reaching past A origin ....................... Forcipiger
1 b Snout not greatly prolonged or tubular, its
length 3-5 in body depth; P not reaching past
Aorigin .......................................................................... 2
2a 4th D spine elongated, filamentous ........................... Heniochus
2b 4th D spine not elongated ................................................... 3
3a LL complete, extending to C, with 68-73
scales .......................................................... Hemitaurichthys
3b LL incomplete, ending below D rays, with
22-25 scales .......................................................... Chaetodon
Genus Chaetodon Linnaeus, 1758
D spines 10-17; snout short or moderately produced. The
largest genus, with more than 90 species; 20 species in our
area. C. hoefleri Steindachner, 1882 occurs from the
Mediterranean to southern Angola, and is closely related to
C. marleyi.
205: CHAETODONTIDAE (BUTTERFL YFiSHES)
KEY TO SPECIES
la D spines 16 or 17 ............................................ C. blackburnii
Ib Dspines 11-14 ................................................................. 2
2a D spines 11 ..................................................................... 3
2b D spines 12-14 ................................. ................................ 4
3a D XI,21-23; A 111,16-18; LL 39-44; snout 3.8-4.1
in head; juveniles without ocellus at front of
soft D ................................................................ C. hoefleri
3b D XI,22-25; A 111,18-19; LL 36-42; snout
3.2-3.5 in head; juveniles with prominent,
white-ringed ocellus at front of soft D ....................... C. marleyi
4a A IV,14-15; D XIII-XIV,14-16 ............................ C. trifascialis
4b A 111,15-23; D XII-XIV,15-28 ............................................ 5
5a D soft-rays 15-18; black blotch or ocellus on LL below
posterior D spines ............................................................ 6
5b D soft-rays 18-28 ............................................................. 7
6a Two blue lines curving down and back from origin
of LL; white-ringed black ocellus on sides ................. C. bennetti
6b No blue lines on body; black blotch on body
not white-ringed ........................................... C. zanzibarensis
7a Large round black spot on LL below rear D
spines; black stripe along rear margin of D
across peduncle and along rear edge of A ........... C. unimaculatus
7b No black spot on LL below rear D spines .............................. 8
8a D XII,18-20; body with lines of dark spots
ascending posteriorly ....................................... C. melanno/us
8b D XII-XIV ,20-28; colour pattern not as above........................ 9
9a A 111,16-18 .................................................................... 10
9b A 111,18-23; (A 111,17-19 in C. lunula) ................................ 11
lOa Body with subvertical dark chevrons; soft D,
C, rear part of body and A yellow; dark eye
band not continuous dorsally; no black bar
on C .................................................... C. madagaskariensis
lOb Body with black spots; black bar on C ................ C. guttatissimus
11a Snout length (minus upper jaw) greater than eye
diameter ............................................................. C. falcula
11b Colour pattern not as in C. falcula ...................................... 12
12a Anterior D rays of adults prolonged into a filament;
dark eye band much wider below eye than above;
snout length (minus upper jaw) subequal to eye
diameter; body pale grey or white, with series
of oblique dark lines ............................................... C. auriga
12b No D rays prolonged into a filament; colour pattern
not as above .................................................................. 13
13a D XII,23-28; snout length (minus upper jaw)
distinctly greater than eye diameter..................................... 14
13b XII-XIV,20-26; snout length subequal to or less
than eye diameter ........................................................... 15
14a Body with narrow vertical black lines; LL 28-32 ........ C. lineolatus
14b Body with curving black lines; LL 38-45 ..................... C. meyeri
15a D XIII-XIV,20-22; A 111,18-20; body with several
dark subhorizontallines .................................... C. trifasciatus
15b D XII-XIV,20-26; A 1II,18-23; colour not as in
C. trifasciatus ................................................................. 16
16a A 111,19-23 .................................................................... 17
16b A 111,17-19 .................................................................... 18
627
by P.C. Heemstra
Butterflyfishes
Vlindervisse
Body ovate, strongly compressed. Dorsal fin continuous,
more or less covered with scales; anal fin also scaly. Pelvic
fins well developed, with a spine and five rays. Caudal fin
truncate or rounded, usually with 15 branched rays. Scales
ctenoid, covering head and body. Preopercle without a
large spine at the angle; no spines on head. Vertebrae
11 + 13. Mouth small; teeth long and slender, none on
vomer and palatines. "Chaetodon" means bristle tooth and
aptly describes the dentition of butterflyfishes. Branchiostegal membranes separate, with 6 or 7 rays. Gill-rakers
short, not numerous.
Butterflyfishes occur in tropical/subtropical waters of all
oceans. They live in depths of 1 - 200 m, and are not found
far from shore except as post-larvae in the peculiar
"tholichthys" stage. Most species are associated with coral
reefs, and coral polyps are a common item in their diet.
They also feed on a variety of small invertebrates (including
benthic and planktonic forms) and algae. Juveniles of several species are facultative "cleaners" (i.e. they pick small
parasites from the skin of other fishes), and even adults are
occasionally observed picking parasites.
This family was recently revised by Burgess (1978). Ten
genera with about 120 species; 4 genera and 24 species in
our area. The species are most readily identified by looking
at the illustrations, but keys to species are provided to aid in
determination of small juveniles.
KEY TO GENERA
la Snout greatly prolonged, tubular, its length 1.1-2.1
in body depth; P reaching past A origin ....................... Forcipiger
1 b Snout not greatly prolonged or tubular, its
length 3-5 in body depth; P not reaching past
Aorigin .......................................................................... 2
2a 4th D spine elongated, filamentous ........................... Heniochus
2b 4th D spine not elongated ................................................... 3
3a LL complete, extending to C, with 68-73
scales .......................................................... Hemitaurichthys
3b LL incomplete, ending below D rays, with
22-25 scales .......................................................... Chaetodon
Genus Chaetodon Linnaeus, 1758
D spines 10-17; snout short or moderately produced. The
largest genus, with more than 90 species; 20 species in our
area. C. hoefleri Steindachner, 1882 occurs from the
Mediterranean to southern Angola, and is closely related to
C. marleyi.
205: CHAETODONTIDAE (BUTTERFL YFiSHES)
KEY TO SPECIES
la D spines 16 or 17 ............................................ C. blackburnii
Ib Dspines 11-14 ................................................................. 2
2a D spines 11 ..................................................................... 3
2b D spines 12-14 ................................. ................................ 4
3a D XI,21-23; A 111,16-18; LL 39-44; snout 3.8-4.1
in head; juveniles without ocellus at front of
soft D ................................................................ C. hoefleri
3b D XI,22-25; A 111,18-19; LL 36-42; snout
3.2-3.5 in head; juveniles with prominent,
white-ringed ocellus at front of soft D ....................... C. marleyi
4a A IV,14-15; D XIII-XIV,14-16 ............................ C. trifascialis
4b A 111,15-23; D XII-XIV,15-28 ............................................ 5
5a D soft-rays 15-18; black blotch or ocellus on LL below
posterior D spines ............................................................ 6
5b D soft-rays 18-28 ............................................................. 7
6a Two blue lines curving down and back from origin
of LL; white-ringed black ocellus on sides ................. C. bennetti
6b No blue lines on body; black blotch on body
not white-ringed ........................................... C. zanzibarensis
7a Large round black spot on LL below rear D
spines; black stripe along rear margin of D
across peduncle and along rear edge of A ........... C. unimaculatus
7b No black spot on LL below rear D spines .............................. 8
8a D XII,18-20; body with lines of dark spots
ascending posteriorly ....................................... C. melanno/us
8b D XII-XIV ,20-28; colour pattern not as above........................ 9
9a A 111,16-18 .................................................................... 10
9b A 111,18-23; (A 111,17-19 in C. lunula) ................................ 11
lOa Body with subvertical dark chevrons; soft D,
C, rear part of body and A yellow; dark eye
band not continuous dorsally; no black bar
on C .................................................... C. madagaskariensis
lOb Body with black spots; black bar on C ................ C. guttatissimus
11a Snout length (minus upper jaw) greater than eye
diameter ............................................................. C. falcula
11b Colour pattern not as in C. falcula ...................................... 12
12a Anterior D rays of adults prolonged into a filament;
dark eye band much wider below eye than above;
snout length (minus upper jaw) subequal to eye
diameter; body pale grey or white, with series
of oblique dark lines ............................................... C. auriga
12b No D rays prolonged into a filament; colour pattern
not as above .................................................................. 13
13a D XII,23-28; snout length (minus upper jaw)
distinctly greater than eye diameter..................................... 14
13b XII-XIV,20-26; snout length subequal to or less
than eye diameter ........................................................... 15
14a Body with narrow vertical black lines; LL 28-32 ........ C. lineolatus
14b Body with curving black lines; LL 38-45 ..................... C. meyeri
15a D XIII-XIV,20-22; A 111,18-20; body with several
dark subhorizontallines .................................... C. trifasciatus
15b D XII-XIV,20-26; A 1II,18-23; colour not as in
C. trifasciatus ................................................................. 16
16a A 111,19-23 .................................................................... 17
16b A 111,17-19 .................................................................... 18
627