Subclass HOLOCEPHALI
Order CHIMAERIFORMES
Chimaeras
by L.J.v. Campagna
Chimaeras
Cartilaginous fishes with a single external gill opening on
each side; gills hidden by a soft operculum or gill cover.
Teeth fused into three pairs of continuously growing tooth
plates, two in upper jaw and one in lower. Upper jaw fused
to skull; hyoid arch not involved in suspension of jaws. In
addition to paired intromittent organs or claspers on the
pelvic fins, adult males have a doorknocker-like frontal
tenaculum or head clasper on the forehead and a pair of prepelvic claspers in front of the pelvic fins; the prepelvic and
head claspers are used to grasp the female during copulation. Lateral-line canals superficial on skin, readily visible
on head and body. First dorsal fin erectile, with a strong,
mildly toxic spine. Development oviparous, large eggs enclosed in spindle-shaped egg-cases and deposited on substrate.
Chimaeras are delicate, slow-moving bottom fishes,
mostly found in deep water on upper continental or insular
slopes down to at least 2 600 m; some species occur in shallow water. Chimaeras use their large, fan-like pectoral fins
for propulsion: they feed on small fishes and bottom invertebrates. Found in all oceans except polar seas, but close to
land and not pelagic. Callorhinchids are common in trawl
catches and occasionally landed by anglers.
Three living families, all three occur in our area.
Family No. 32: CHIMAERIDAE
by L.J.V. Campagna
Chimaeras
Chimaeras
Snout short and bluntly pointed. First dorsal fin erectile,
with a strong, curved or nearly straight, serrate or smooth
spine; second dorsal fin long and low, caudal fin with a
horizontal axis; a small, low, long-based anal fin present or
absent. Egg-cases spindle-shaped, with or without narrow
flanges.
Worldwide in temperate to tropical waters, mostly below
200 m, but some species close inshore at high latitudes;
tropical species in deep, cold water. Two genera, both in
our area.
KEY TO GENERA
1a Anal fin present ..................................................... Chimaera
1b Anal fin absent .................................................... Hydrolagus
144
KEY TO FAMILIES
1a Snout with recurved, hoe-shaped projection;
second dorsal fin short, high and falcate;
caudal fin with a raised axis ....... CALLORHINCHIDAE (No. 34)
1b Snout straight, not hoe-like; second dorsal fin long
and low, not falcate; caudal fin with a horizontal axis ................ 2
2a Snout short and bluntly pointed .......... CHIMAERIDAE (No. 32)
2b Snout very long, acutely
pointed .............................. RHINOCHIMAERIDAE (No. 33)
Genus Chimaera Linnaeus, 1758
Six species, 1 in our area.
Chimaera
32.1 Chimaera monstrosa
Linnaeus, 1758
Chimaera
Chimaera monstrosa Linnaeus, 1758: 236 (Atlantic); Dumeril, 1865:
686 (Cape of Good Hope); Smith, SFSA No. 93.
LL wavy; C with long filament.
Body silvery with brownish markings. Attains 152 cm.
Eastern Atlantic and Mediterranean Sea, off Cape Province in 91 - 1 097 m.
Order CHIMAERIFORMES
Chimaeras
by L.J.v. Campagna
Chimaeras
Cartilaginous fishes with a single external gill opening on
each side; gills hidden by a soft operculum or gill cover.
Teeth fused into three pairs of continuously growing tooth
plates, two in upper jaw and one in lower. Upper jaw fused
to skull; hyoid arch not involved in suspension of jaws. In
addition to paired intromittent organs or claspers on the
pelvic fins, adult males have a doorknocker-like frontal
tenaculum or head clasper on the forehead and a pair of prepelvic claspers in front of the pelvic fins; the prepelvic and
head claspers are used to grasp the female during copulation. Lateral-line canals superficial on skin, readily visible
on head and body. First dorsal fin erectile, with a strong,
mildly toxic spine. Development oviparous, large eggs enclosed in spindle-shaped egg-cases and deposited on substrate.
Chimaeras are delicate, slow-moving bottom fishes,
mostly found in deep water on upper continental or insular
slopes down to at least 2 600 m; some species occur in shallow water. Chimaeras use their large, fan-like pectoral fins
for propulsion: they feed on small fishes and bottom invertebrates. Found in all oceans except polar seas, but close to
land and not pelagic. Callorhinchids are common in trawl
catches and occasionally landed by anglers.
Three living families, all three occur in our area.
Family No. 32: CHIMAERIDAE
by L.J.V. Campagna
Chimaeras
Chimaeras
Snout short and bluntly pointed. First dorsal fin erectile,
with a strong, curved or nearly straight, serrate or smooth
spine; second dorsal fin long and low, caudal fin with a
horizontal axis; a small, low, long-based anal fin present or
absent. Egg-cases spindle-shaped, with or without narrow
flanges.
Worldwide in temperate to tropical waters, mostly below
200 m, but some species close inshore at high latitudes;
tropical species in deep, cold water. Two genera, both in
our area.
KEY TO GENERA
1a Anal fin present ..................................................... Chimaera
1b Anal fin absent .................................................... Hydrolagus
144
KEY TO FAMILIES
1a Snout with recurved, hoe-shaped projection;
second dorsal fin short, high and falcate;
caudal fin with a raised axis ....... CALLORHINCHIDAE (No. 34)
1b Snout straight, not hoe-like; second dorsal fin long
and low, not falcate; caudal fin with a horizontal axis ................ 2
2a Snout short and bluntly pointed .......... CHIMAERIDAE (No. 32)
2b Snout very long, acutely
pointed .............................. RHINOCHIMAERIDAE (No. 33)
Genus Chimaera Linnaeus, 1758
Six species, 1 in our area.
Chimaera
32.1 Chimaera monstrosa
Linnaeus, 1758
Chimaera
Chimaera monstrosa Linnaeus, 1758: 236 (Atlantic); Dumeril, 1865:
686 (Cape of Good Hope); Smith, SFSA No. 93.
LL wavy; C with long filament.
Body silvery with brownish markings. Attains 152 cm.
Eastern Atlantic and Mediterranean Sea, off Cape Province in 91 - 1 097 m.