263: BALISTIDAE (TRIGGERFISHES)
Durban are doubtful, as there are no specimens of this
species from South Africa in the J.L.B. Smith Institute or in
the South African Museum . Rare; specimens wanted.
Genus Balistoides Fraser-Brunner, 1935
Mouth terminal; teeth uneven, notched; enlarged bony
scales behind gill slit; deep groove before eye below nostrils; 2-4 longitudinal rows of large tubercles on C peduncle
and forward slightly onto body; C rounded . Two species,
both in our area.
KEY TO SPECIES
la Ventral part of body with large round white
blotches; cheek entirely covered with scales;
body scales small, LS 39-50 ........ .... ............ .. ... .. B. conspicillum
Ib No white blotches on ventral part of body ;
naked longitudinal groove behind corner
of mouth ; body scales large, LS 29-32 .... .... .. .. ...... .. B. viridescens
263.4 Balistoides conspicillum
(Bloch & Schneider, 1801)
PLATE 136
Clown triggerfish
Nar-snellervis
Balistes conspicillum Bloch & Schneider, 1801: 474 (Indian Ocean) .
Balistoides conspicillum: Smith , SFSA No. 1161*; Smith, 1979: 44* ; Matsuura, 1980: 44*'
o III+25-27; A 21-22; P 14; LS 39-50, head scale rows 33-37.
A very striking fish , sometimes called B. niger Bonnaterre , 1788; but this name was preoccupied by Batistes
niger Bloch, 1786 (now known as Metichthys niger). Attains
50 cm. Found on outer reef terraces with surge channels.
Indo-West Pacific south to Durban; not in Red Sea.
263.5 Balistoides viridescens
(Bloch & Schneider, 1801)
PLATE 136
Dotty triggerfish
Gestippelde snellervis
Balistes viridescens Bloch & Schneider, 1801: 477 (Mauritius) . Balisto ides viridescens: Smith , SFSA No. 1160*; Matsuura , 1980: 46* ; Tyler,
1980: 122*.
263.5 Balistoides viridescens: 30 em (Seychelles).
878
o III + 24-26; A 23-24; P 14; LS 29-32.
A plump, ovate fish. Attains 70 cm . Red Sea and IndoWest Pacific south to Delagoa Bay, rare .
Genus Canthidermis Swainson, 1839
Mouth terminal, teeth uneven, notched; deep groove
before eye, below nostils; no grooves on cheeks. Two
species; C. sufflamen (Mitchill, 1815) from the western
Atlantic has more D, A and Prays.
263.6 Canthidermis maculatus
(Bloch, 1786)
PLATE 136
Rough triggerfish
Ruwe snellervis
Balistes maculatus Bloch, 1786: 25, PI. 151 (American waters). Canthidermis maculatus: Smith, SFSA No. 1166*; 1965: 35* ; Matsuura, 1980:
66*; Tyler, 1980: 117* , 127* .
o III + 23-25; A 20-22; P 14-15; LS 37-46; head scale rows 28-32.
Small juveniles with spots not confined to ventral surface,
adult body and head dark, lighter below with elongated
white spots that can disappear with growth; fins dark.
Attains over 50 cm. All warm and temperate oceans; in our
area found from the Cape to Natal; often well offshore.
263.6 Canthidermis maculatus: top: 34 em (Mossel Bay); bottom: 8 em
juvenile (Transkei).
Genus Me/ichthys Swainson, 1839
Body dark brown to black; mouth slightly supraterminal;
teeth notched, except median pair in each jaw, which are
truncate; depressed circular zone of bony plates behind gill
slit; a groove below nostrils from eye; cheeks wholly scaly;
no enlarged tubercles or spinules on scales, but those on
Durban are doubtful, as there are no specimens of this
species from South Africa in the J.L.B. Smith Institute or in
the South African Museum . Rare; specimens wanted.
Genus Balistoides Fraser-Brunner, 1935
Mouth terminal; teeth uneven, notched; enlarged bony
scales behind gill slit; deep groove before eye below nostrils; 2-4 longitudinal rows of large tubercles on C peduncle
and forward slightly onto body; C rounded . Two species,
both in our area.
KEY TO SPECIES
la Ventral part of body with large round white
blotches; cheek entirely covered with scales;
body scales small, LS 39-50 ........ .... ............ .. ... .. B. conspicillum
Ib No white blotches on ventral part of body ;
naked longitudinal groove behind corner
of mouth ; body scales large, LS 29-32 .... .... .. .. ...... .. B. viridescens
263.4 Balistoides conspicillum
(Bloch & Schneider, 1801)
PLATE 136
Clown triggerfish
Nar-snellervis
Balistes conspicillum Bloch & Schneider, 1801: 474 (Indian Ocean) .
Balistoides conspicillum: Smith , SFSA No. 1161*; Smith, 1979: 44* ; Matsuura, 1980: 44*'
o III+25-27; A 21-22; P 14; LS 39-50, head scale rows 33-37.
A very striking fish , sometimes called B. niger Bonnaterre , 1788; but this name was preoccupied by Batistes
niger Bloch, 1786 (now known as Metichthys niger). Attains
50 cm. Found on outer reef terraces with surge channels.
Indo-West Pacific south to Durban; not in Red Sea.
263.5 Balistoides viridescens
(Bloch & Schneider, 1801)
PLATE 136
Dotty triggerfish
Gestippelde snellervis
Balistes viridescens Bloch & Schneider, 1801: 477 (Mauritius) . Balisto ides viridescens: Smith , SFSA No. 1160*; Matsuura , 1980: 46* ; Tyler,
1980: 122*.
263.5 Balistoides viridescens: 30 em (Seychelles).
878
o III + 24-26; A 23-24; P 14; LS 29-32.
A plump, ovate fish. Attains 70 cm . Red Sea and IndoWest Pacific south to Delagoa Bay, rare .
Genus Canthidermis Swainson, 1839
Mouth terminal, teeth uneven, notched; deep groove
before eye, below nostils; no grooves on cheeks. Two
species; C. sufflamen (Mitchill, 1815) from the western
Atlantic has more D, A and Prays.
263.6 Canthidermis maculatus
(Bloch, 1786)
PLATE 136
Rough triggerfish
Ruwe snellervis
Balistes maculatus Bloch, 1786: 25, PI. 151 (American waters). Canthidermis maculatus: Smith, SFSA No. 1166*; 1965: 35* ; Matsuura, 1980:
66*; Tyler, 1980: 117* , 127* .
o III + 23-25; A 20-22; P 14-15; LS 37-46; head scale rows 28-32.
Small juveniles with spots not confined to ventral surface,
adult body and head dark, lighter below with elongated
white spots that can disappear with growth; fins dark.
Attains over 50 cm. All warm and temperate oceans; in our
area found from the Cape to Natal; often well offshore.
263.6 Canthidermis maculatus: top: 34 em (Mossel Bay); bottom: 8 em
juvenile (Transkei).
Genus Me/ichthys Swainson, 1839
Body dark brown to black; mouth slightly supraterminal;
teeth notched, except median pair in each jaw, which are
truncate; depressed circular zone of bony plates behind gill
slit; a groove below nostrils from eye; cheeks wholly scaly;
no enlarged tubercles or spinules on scales, but those on