KEY TO FAMILIES OF SHARKS IN SOUTHERN AFRICA
la One dorsal fin; 6 or 7 gill slits .................. ..................... ...... 2
1 b Two dorsal fins; 5 or 6 gill slits ............................................ 3
2a Lower ends of 1st gill slits meeting under
throat; mouth terminal .... CHLAMYDOSELACHIDAE (No.3)
2b First gill slits not joined under throat;
mouth ventral ...... .......................... HEXANCHIDAE (No.2)
3a Snout produced into a long flat blade with
distinct awl-like "teeth" along each side;
6 gill slits ............................... PRISTIOPHORIDAE (No. 20)
3b Snout not as above; 5 gill slits ............ .. ............ .. ...... .. .. .. ..... 4
4a Head and body greatly depressed; P
expanded anteriorly to form triangular
lobes extending over gill slits; mouth
terminal ....................................... SQUATINIDAE (No. 21)
.0:' ...... .......... . .
"
. . ..
21
4b Head and body not so depressed; P not
expanded over gill slits ........................ ... .. .... ........ ....... .... .. 5
5a A strong spine at front of each D; anal fin
present; median teeth in jaws with single
sharp cusp, lateral teeth molariform ..................................... HETERODONTIDAE (No.4)
SQUALOMORPHEA (SHARKS)
5b D spines and anal fin not both present;
teeth not as described in 5a ................................................ 6
6a Anal fin present (but not distinct from lower
margin of C in Chiloscyllium); nictitans
well developed, rudimentary or absent ...... ........................... 8
6b Anal fin absent; nictitans absent ......................................... 7
7a Denticles conspicuously enlarged (up to
15 mm wide at their base) and sparsely
scattered over naked skin; dorsal fins
situated over V ......................... ECHINORHINIDAE (No.6)
7b Denticles not conspicuously enlarged and
densely covering skin; D not both situated
over V ...................................... .. ...... SQUALIDAE (No.5)
8a Snout flattened, produced into a long
pointed blade-like rostrum; jaws very
protrusile, wi~h needle-like teeth .. MITSUKURINIDAE (No. 17)
8b Snout not produced into a long blade-like pointed rostrum ..... .. 9
9a Mouth terminal (no definite snout); eye
behind corner of mouth; teeth very
small ..................................... RHINCODONTIDAE (No.8)
43
la One dorsal fin; 6 or 7 gill slits .................. ..................... ...... 2
1 b Two dorsal fins; 5 or 6 gill slits ............................................ 3
2a Lower ends of 1st gill slits meeting under
throat; mouth terminal .... CHLAMYDOSELACHIDAE (No.3)
2b First gill slits not joined under throat;
mouth ventral ...... .......................... HEXANCHIDAE (No.2)
3a Snout produced into a long flat blade with
distinct awl-like "teeth" along each side;
6 gill slits ............................... PRISTIOPHORIDAE (No. 20)
3b Snout not as above; 5 gill slits ............ .. ............ .. ...... .. .. .. ..... 4
4a Head and body greatly depressed; P
expanded anteriorly to form triangular
lobes extending over gill slits; mouth
terminal ....................................... SQUATINIDAE (No. 21)
.0:' ...... .......... . .
"
. . ..
21
4b Head and body not so depressed; P not
expanded over gill slits ........................ ... .. .... ........ ....... .... .. 5
5a A strong spine at front of each D; anal fin
present; median teeth in jaws with single
sharp cusp, lateral teeth molariform ..................................... HETERODONTIDAE (No.4)
SQUALOMORPHEA (SHARKS)
5b D spines and anal fin not both present;
teeth not as described in 5a ................................................ 6
6a Anal fin present (but not distinct from lower
margin of C in Chiloscyllium); nictitans
well developed, rudimentary or absent ...... ........................... 8
6b Anal fin absent; nictitans absent ......................................... 7
7a Denticles conspicuously enlarged (up to
15 mm wide at their base) and sparsely
scattered over naked skin; dorsal fins
situated over V ......................... ECHINORHINIDAE (No.6)
7b Denticles not conspicuously enlarged and
densely covering skin; D not both situated
over V ...................................... .. ...... SQUALIDAE (No.5)
8a Snout flattened, produced into a long
pointed blade-like rostrum; jaws very
protrusile, wi~h needle-like teeth .. MITSUKURINIDAE (No. 17)
8b Snout not produced into a long blade-like pointed rostrum ..... .. 9
9a Mouth terminal (no definite snout); eye
behind corner of mouth; teeth very
small ..................................... RHINCODONTIDAE (No.8)
43