Order SILURIFORMES
Catfishes
Skin naked; first dorsal and pectoral fins with a long
serrated spine; no pelvic fin spine; 3 or 4 pairs of barbels
around the mouth. Anterior five vertebrae and their ribs
modified to form a bony connection between the swimbladder
and the ear; this specialised structure (called the "Weberian
apparatus") is a unique characteristic of all ostariophysan
fishes and substantially improves the hearing of these
fishes.
The siluriforms are the only ostariophysans to have
adapted to life in the sea, but most siluriforms occur in
freshwaters of South America.
KEY TO FAMILIES
1a Caudal fin continuous with the long soft-rayed
second dorsal and anal fins .. ... .. ...... .. ... ... .... .... .. PLOTOSIDAE
(j
1b Caudal fin forked, separate from dorsal adipose
fin and anal fins ................... ............... .... .... ... ....... ARIIDAE
Family No. 59: ARIIDAE
by W.R. Taylor
Sea catfishes
Seebabers
Medium to large fishes. Body elongate; snout and head
rounded to depressed; mouth terminal to inferior. Gill
membranes fused with each other and attached to isthmus.
Teeth in jaws fine or granular; those on palate when
present, fine, granular or molariform, arranged in bands or
patches. One pair of maxillary and two pairs of mental
(mandibular) barbels. Head with dorsal rugose bony shield
covered with thin skin in some species or by thick skin and
muscles in others; the supraoccipital process or posterior
portion of this shield extends backward to the pre dorsal
plate at the base of the dorsal fin. Front and rear nostrils
Babers
close together; rear nostrils partly covered by a flap of skin.
Gill-rakers 10-20 on first arch, present on anterior faces of
all arches and on posterior faces of third and fourth arches,
but present or absent from rear faces of first and second
arches. Five to 7 vertebrae fused into a "complex vertebra"
that is rigidly fused to skull. Dorsal fin with a very short
spine followed by a long serrated spine and 7 soft-rays;
pectoral fins with a serrated spine, 9-13 soft-rays; an
adipose fin opposite anal fin; anal fin with 16-22 soft-rays;
pelvic fins with 6 soft-rays, variously modified in the female
at maturity; caudal fin forked, with 13 branched rays (6 in
upper and 7 in lower lobe). Scales absent. Lateral line complete, branching posteriorly onto upper and lower lobes of
caudal fin. Swimbladder present.
The South African species of Ariidae were previously
known under the generic names Tachysurus Lacepede and
Arius Valenciennes. Tachysurus is not an ariid catfish as it
was illustrated and described as having a rayed adipose fin.
The genus Arius differs from our species as follows: epiotic
lamina broadly fused with transverse processes of 4th fused
vertebra but epiotic not entering skull roof; 7 anterior fused
vertebrae, 2 of which bear ribs; moderate size gill-rakers
along rear (inner) margin of first 2 gill arches.
Found in marine, brackish and freshwater of warm-temperate and tropical continental coasts. Many genera and
species.
Dangerous fishes, as the hard fin spines that are covered
by a venomous mucus inflict painful lacerated wounds. The
venom is destroyed at 50°C so immersion of the wound in
water between 50 and 55°C relieves the pain immediately.
The flesh is wholesome and tasty. The eggs are about as big
as peas or small marbles, and carried in the mouth of the
male until they hatch; for some time after that, the young
occupy this shelter. Two genera and 3 species in our area.
KEY TO GENERA
1a Teeth on palate villiform; 2 transverse patches of
teeth meeting at midline behind premaxillary tooth
band; GR 11-18 on rear or inner surface of 1st and
2nd gill arches; top of head smooth, covered with
thick muscle layers; posterior process of cleithrum
broadly fan-shaped ... . ...... . ...... . ..... Galeichthys
Gafeichthys tooth pattern.
211
Catfishes
Skin naked; first dorsal and pectoral fins with a long
serrated spine; no pelvic fin spine; 3 or 4 pairs of barbels
around the mouth. Anterior five vertebrae and their ribs
modified to form a bony connection between the swimbladder
and the ear; this specialised structure (called the "Weberian
apparatus") is a unique characteristic of all ostariophysan
fishes and substantially improves the hearing of these
fishes.
The siluriforms are the only ostariophysans to have
adapted to life in the sea, but most siluriforms occur in
freshwaters of South America.
KEY TO FAMILIES
1a Caudal fin continuous with the long soft-rayed
second dorsal and anal fins .. ... .. ...... .. ... ... .... .... .. PLOTOSIDAE
(j
1b Caudal fin forked, separate from dorsal adipose
fin and anal fins ................... ............... .... .... ... ....... ARIIDAE
Family No. 59: ARIIDAE
by W.R. Taylor
Sea catfishes
Seebabers
Medium to large fishes. Body elongate; snout and head
rounded to depressed; mouth terminal to inferior. Gill
membranes fused with each other and attached to isthmus.
Teeth in jaws fine or granular; those on palate when
present, fine, granular or molariform, arranged in bands or
patches. One pair of maxillary and two pairs of mental
(mandibular) barbels. Head with dorsal rugose bony shield
covered with thin skin in some species or by thick skin and
muscles in others; the supraoccipital process or posterior
portion of this shield extends backward to the pre dorsal
plate at the base of the dorsal fin. Front and rear nostrils
Babers
close together; rear nostrils partly covered by a flap of skin.
Gill-rakers 10-20 on first arch, present on anterior faces of
all arches and on posterior faces of third and fourth arches,
but present or absent from rear faces of first and second
arches. Five to 7 vertebrae fused into a "complex vertebra"
that is rigidly fused to skull. Dorsal fin with a very short
spine followed by a long serrated spine and 7 soft-rays;
pectoral fins with a serrated spine, 9-13 soft-rays; an
adipose fin opposite anal fin; anal fin with 16-22 soft-rays;
pelvic fins with 6 soft-rays, variously modified in the female
at maturity; caudal fin forked, with 13 branched rays (6 in
upper and 7 in lower lobe). Scales absent. Lateral line complete, branching posteriorly onto upper and lower lobes of
caudal fin. Swimbladder present.
The South African species of Ariidae were previously
known under the generic names Tachysurus Lacepede and
Arius Valenciennes. Tachysurus is not an ariid catfish as it
was illustrated and described as having a rayed adipose fin.
The genus Arius differs from our species as follows: epiotic
lamina broadly fused with transverse processes of 4th fused
vertebra but epiotic not entering skull roof; 7 anterior fused
vertebrae, 2 of which bear ribs; moderate size gill-rakers
along rear (inner) margin of first 2 gill arches.
Found in marine, brackish and freshwater of warm-temperate and tropical continental coasts. Many genera and
species.
Dangerous fishes, as the hard fin spines that are covered
by a venomous mucus inflict painful lacerated wounds. The
venom is destroyed at 50°C so immersion of the wound in
water between 50 and 55°C relieves the pain immediately.
The flesh is wholesome and tasty. The eggs are about as big
as peas or small marbles, and carried in the mouth of the
male until they hatch; for some time after that, the young
occupy this shelter. Two genera and 3 species in our area.
KEY TO GENERA
1a Teeth on palate villiform; 2 transverse patches of
teeth meeting at midline behind premaxillary tooth
band; GR 11-18 on rear or inner surface of 1st and
2nd gill arches; top of head smooth, covered with
thick muscle layers; posterior process of cleithrum
broadly fan-shaped ... . ...... . ...... . ..... Galeichthys
Gafeichthys tooth pattern.
211