244: ZANCLIDAE (MOORISH IDOL)
wide distribution is probably due to its long planktonic
larval/postlarval stage. Juveniles have been found as far as
Mossel Bay on our south coast.
Family No. 245: SIGANIDAE
by D.J. Woodland
Rabbitfishes
Konynvisse
Body compressed, ovate, covered with very small scales.
Pelvic fins with an inner and outer spine separated by 3 softrays, a character unique to the family. Dorsal fin almost
invariably with 13 spines and 10 soft-rays and preceded by
an embedded, procumbent spine. Anal spines 7, soft-rays 9.
Jaws with a row of small, close-set, incisiform teeth.
As implied by the name, rabbitfishes feed mainly on sea
weeds and grasses, but will readily take a small animal bait.
Schooling species often abundant around estuarine flats,
rock and coral reefs; adults of pairing species restricted to
coral reefs though juveniles may occur in estuarine areas.
Rabbitfishes constitute up to 60 percent of the standing crop
of marketable-sized fishes of shallow reef flats. Some
species used in aquaculture; flesh excellent to slightly
weedy. Spines venomous; stab wounds very painful, but
pain seldom lasts more than half an hour. Venom can be
destroyed by immersing wound in hot (55°C) water. Live
fish are easy to identify because of characteristic, complex
colour patterns. Dying, dead and preserved specimens can
be difficult to identify, since many species have similar
proportions and counts, and distinct species, when
threatened, can adopt similar obliterating colour patterns
of irregular brown blotching. Tropical Indo-Pacific, ranging
from Tuamotus to east Africa. A single genus, Siganus,
divided into 2 subgenera, La (5 spp.) and Siganus (22 spp.);
La, characterised by a tubular snout, is not found in our
area.
Genus Siganus Forsskal, 1775
Only 2 species definitely occurring in our area. S. luridus
(Ruppell, 1829) may occur south ofBeira, and is included in
the key. S. rivulatus Forssklll, 1775 has been reported from
our area, but the records are unconfirmed and apparently
based on misidentifications of S. sutor. Another extralimital species, S. canaliculatus (Park, 1797), is also included in the key.
KEY TO SPECIES
1a C deeply forked (except in juveniles < 10 em);
body depth about ~ SL; head, sides and C covered
with a regular pattern of dark spots. equal to
or larger than interspaces ........................................ S. stellatus
1 b C moderately forked to truncate; body depth less than
~ SL; sides without a regular pattern of dark spots.................... 2
824
2a C truncate or barely emarginate; snout blunt,
equal to or shorter than eye diameter; front nostril
with a long flap extending past rear nostril; sides
dark brown to olive, either plain or marked with
paler vermiculations; complete bars on C ..................... S. luridus
(Not known south of Beira)
2b C emarginate in juveniles to forked in adults; snout
longer than eye diameter; front nostril flap reaching
at most to rear nostril; only outer rays of C noticeably
barred ............................................................................ 3
3a Body depth 2.7-3.4 in SL; horizontal golden lines
on lower sides, fading at death ................................ S. rivulatus
(Known only from Red Sea and Mediterranean)
3b Body depth 2.2-2.8 in SL; pearly spots on sides,
often fading at death .......................................................... 4
4a Scale rows between LL and base of 3rd D spine
21-27; a few hundred small pearly spots, often
elongated, on body .......................................... S. canaliculatus
(Not known west of Arabian Sea)
4b Scale rows between LL and base of 3rd D spine 24-32;
about 30-50 large round pearly spots on body .................. S. sutor
245.1 Siganus stellatus
Forsskal,1775
PLATE 128
Starspotted rabbitfish
Sterspikkel-konynvis
Siganus stellatus Forsskal, 1775: 26 (Jeddah, Red Sea); Smith, SFSA
No. 902a*; Blaber, 1978: 41.
Depth 2.0-2.3; 23-28 scale rows between LL and base of 3rd D spine; P
17. Cheeks covered with strong scales. Lobes of C usually broadly
rounded at tips, but upper lobe occasionally acutely pointed.
Body greyish green with small brown spots. In Red Sea
specimens, the spots decrease in size towards the nape,
producing an oval green patch about procumbent spine.
Diffuse, eye-sized, dark blotch at LL origin, very prominent in juveniles. Attains 40 cm. Adults in pairs about coral
reefs; juveniles in schools, entering estuaries in weedy
areas. Kosi Bay northwards. Found on coral reefs throughout Red Sea, west and central Indian Ocean, and Andaman
Sea.
245.2 Siganus sutor
(Valenciennes, 1835)
PLATE 128
Whitespotted rabbitfish
Witspikkel-konynvis
Amphacanthus sutor Valenciennes, in Cuv. & Val., 1835: 148 (Seychelles; Reunion; ?Malabar, specimens from Malabar probably the closely
related S. canaliculatus). Siganus oramin (non Bloch & Schneider):
Barnard, 1927: 785 (figure, copied from Day, is not S. sutor); Smith,
SFSA No. 901*; 1964: 297. Siganus rivulatus: Smith, SFSA No. 902*(?)
(colour pattern in figure vaguely resembles "fright" pattern of this
species). Siganus canaliculatus (non Mungo Park): Smith, 1975: 65.
Depth 2.2-2.6; P 16-18. Last A spine 1.3-1.5 times in longest A spine.
Cheeks with few to many fine scattered scales.
wide distribution is probably due to its long planktonic
larval/postlarval stage. Juveniles have been found as far as
Mossel Bay on our south coast.
Family No. 245: SIGANIDAE
by D.J. Woodland
Rabbitfishes
Konynvisse
Body compressed, ovate, covered with very small scales.
Pelvic fins with an inner and outer spine separated by 3 softrays, a character unique to the family. Dorsal fin almost
invariably with 13 spines and 10 soft-rays and preceded by
an embedded, procumbent spine. Anal spines 7, soft-rays 9.
Jaws with a row of small, close-set, incisiform teeth.
As implied by the name, rabbitfishes feed mainly on sea
weeds and grasses, but will readily take a small animal bait.
Schooling species often abundant around estuarine flats,
rock and coral reefs; adults of pairing species restricted to
coral reefs though juveniles may occur in estuarine areas.
Rabbitfishes constitute up to 60 percent of the standing crop
of marketable-sized fishes of shallow reef flats. Some
species used in aquaculture; flesh excellent to slightly
weedy. Spines venomous; stab wounds very painful, but
pain seldom lasts more than half an hour. Venom can be
destroyed by immersing wound in hot (55°C) water. Live
fish are easy to identify because of characteristic, complex
colour patterns. Dying, dead and preserved specimens can
be difficult to identify, since many species have similar
proportions and counts, and distinct species, when
threatened, can adopt similar obliterating colour patterns
of irregular brown blotching. Tropical Indo-Pacific, ranging
from Tuamotus to east Africa. A single genus, Siganus,
divided into 2 subgenera, La (5 spp.) and Siganus (22 spp.);
La, characterised by a tubular snout, is not found in our
area.
Genus Siganus Forsskal, 1775
Only 2 species definitely occurring in our area. S. luridus
(Ruppell, 1829) may occur south ofBeira, and is included in
the key. S. rivulatus Forssklll, 1775 has been reported from
our area, but the records are unconfirmed and apparently
based on misidentifications of S. sutor. Another extralimital species, S. canaliculatus (Park, 1797), is also included in the key.
KEY TO SPECIES
1a C deeply forked (except in juveniles < 10 em);
body depth about ~ SL; head, sides and C covered
with a regular pattern of dark spots. equal to
or larger than interspaces ........................................ S. stellatus
1 b C moderately forked to truncate; body depth less than
~ SL; sides without a regular pattern of dark spots.................... 2
824
2a C truncate or barely emarginate; snout blunt,
equal to or shorter than eye diameter; front nostril
with a long flap extending past rear nostril; sides
dark brown to olive, either plain or marked with
paler vermiculations; complete bars on C ..................... S. luridus
(Not known south of Beira)
2b C emarginate in juveniles to forked in adults; snout
longer than eye diameter; front nostril flap reaching
at most to rear nostril; only outer rays of C noticeably
barred ............................................................................ 3
3a Body depth 2.7-3.4 in SL; horizontal golden lines
on lower sides, fading at death ................................ S. rivulatus
(Known only from Red Sea and Mediterranean)
3b Body depth 2.2-2.8 in SL; pearly spots on sides,
often fading at death .......................................................... 4
4a Scale rows between LL and base of 3rd D spine
21-27; a few hundred small pearly spots, often
elongated, on body .......................................... S. canaliculatus
(Not known west of Arabian Sea)
4b Scale rows between LL and base of 3rd D spine 24-32;
about 30-50 large round pearly spots on body .................. S. sutor
245.1 Siganus stellatus
Forsskal,1775
PLATE 128
Starspotted rabbitfish
Sterspikkel-konynvis
Siganus stellatus Forsskal, 1775: 26 (Jeddah, Red Sea); Smith, SFSA
No. 902a*; Blaber, 1978: 41.
Depth 2.0-2.3; 23-28 scale rows between LL and base of 3rd D spine; P
17. Cheeks covered with strong scales. Lobes of C usually broadly
rounded at tips, but upper lobe occasionally acutely pointed.
Body greyish green with small brown spots. In Red Sea
specimens, the spots decrease in size towards the nape,
producing an oval green patch about procumbent spine.
Diffuse, eye-sized, dark blotch at LL origin, very prominent in juveniles. Attains 40 cm. Adults in pairs about coral
reefs; juveniles in schools, entering estuaries in weedy
areas. Kosi Bay northwards. Found on coral reefs throughout Red Sea, west and central Indian Ocean, and Andaman
Sea.
245.2 Siganus sutor
(Valenciennes, 1835)
PLATE 128
Whitespotted rabbitfish
Witspikkel-konynvis
Amphacanthus sutor Valenciennes, in Cuv. & Val., 1835: 148 (Seychelles; Reunion; ?Malabar, specimens from Malabar probably the closely
related S. canaliculatus). Siganus oramin (non Bloch & Schneider):
Barnard, 1927: 785 (figure, copied from Day, is not S. sutor); Smith,
SFSA No. 901*; 1964: 297. Siganus rivulatus: Smith, SFSA No. 902*(?)
(colour pattern in figure vaguely resembles "fright" pattern of this
species). Siganus canaliculatus (non Mungo Park): Smith, 1975: 65.
Depth 2.2-2.6; P 16-18. Last A spine 1.3-1.5 times in longest A spine.
Cheeks with few to many fine scattered scales.