9: CARCHARHINIDAE (REQUIEM SHARKS)
13a Teeth with single, large, oblique cusp and some smaller
cusplets along lateral (posterior) edge; teeth in 2 or 3
functional series; front edge of 2nd D shorter than that
of ventral C lobe ............................................................ 14
13b Teeth with a low bluntly rounded cusp or with narrow,
erect cusp (juveniles of Triakis with a short cusplet on
each side of main cusp); teeth in 4 or more functional
series; front edge of 2nd D longer than that of ventral
C lobe .......................................................................... 15
14a Second D height about 1\-2 x A height and more than
V2length of C tip; 1st D origin behind inner corner
of P ................................................................. Hypogaleus
14b Second D height subequal to A height and less than
1/2 length of C tip; 1st D origin over inner corner of P . Galeorhinus
15a Teeth bluntly rounded, arranged in a quincunx forming a
pavement-like crushing dentition, the tooth rows oblique
to jaw axis; distance from A base to lower C lobe greater
than 2nd D height .................................................. Mustelus
15b Teeth with a narrow, erect cusp (juveniles with a
short cusplet on each side of main cusp), the tooth rows
perpendicular to jaw axis; distance from A base to lower
C lobe less than 2nd D height ...................................... Triakis
Genus Carcharhinus Blainvilie, 1816
Body cylindrical; no spiracles. Lip folds short to rudimentary. Teeth blade-like, unicuspid; upper teeth serrated (at
least in adults), lower serrated or smooth. First D closer to P
than to V; at least twice as high as 2nd D; 2nd D origin in
front of middle of A base. No keels on caudal peduncle.
Viviparous. Of the 25 species recognised by Garrick (1982),
17 occur in our area. C. macloti is included because it is
known from Kenya and likely to be found in our area. Identification is difficult and it is often necessary to see the teeth
and, in some cases, to obtain vertebral counts. The following key to the southern African species is based on those of
Bass et al. (1973) and Garrick (1982); any identification
made via the key should be checked by referring to the individual species accounts. Fin markings (if any), the presence
or absence of an interdorsal ridge, and tooth shapes are vital
to accurate identification. Because of intraspecific variation
in some characters, three species are entered twice in the
key.
KEY TO SPECIES
la First D slightly tapered with broadly rounded
apex; fins mottled with white (fins of juveniles may be
black-tipped but these also have a black saddle on
caudal peduncle) ............................................ C. longimanus
Ib First D obviously tapered to a pointed or sharply
rounded apex; fins not mottled with white; no black
saddle on caudal peduncle ................................................. 2
2a Second D with black tip, all otherfins plain .................. C. sealei
2b Second D plain, white-tipped or, if black-tipped,
then with dark markings on some of the other fins................... 3
68
3a C with conspicuous, wide, black trailing edge;
1st D without any dark markings......................................... 4
3b C without conspicuous, wide, black trailing edge or,
if so, 1st D also has dark markings ....................................... 5
4a First D with distinct white tip and trailing edge .......... C. wheeleri
4b First D without distinct white tip and trailing
edge ....................................................... C. amblyrhynchos
5a Interdorsal ridge present ................................................... 6
5b Interdorsal ridge absent ................................................... 15
6a First D, P, V and C with white tips and
trailing edges ............................................. C. albimarginatus
6b First D, P, V and C plain or with dark markings ..................... 7
7a Second D, P and lower C lobe with black tips; 1st D with
thin black trailing edge near apex; A usually plain ......... C. sorrah
7b Fins usually without any distinctive markings;
if any fins are dark-tipped then A has a dark tip ...................... 8
8a Anal fin lobe more than twice 2nd D height ........................... 9
8b Anal fin lobe less than twice 2nd D height ............................ 10
9a First D origin behind P inner corner..................... C. falciformis
9b First D origin over P inner corner ........................... C. obscurus
lOa Snout to 1st D origin less than 2.2 x 1st D height ....... C. plumbeus
lOb Snout to 1st D origin more than 2.2 x 1st D height .................. 11
lIa First D origin closer to P axil than to P inner corner ................ 12
lib First D origin closer to P inner corner than to P axil ................ 13
12a Mouth width less than 2.4 x distance from inner end
of nostrils to mouth ............................................... C. altimus
12b Mouth width more than 2.4 x distance from inner end
of nostrils to mouth ........................................ C. ga/apagensis
13a First D origin over P inner corner ....................................... 14
13b First D origin in front of inner P corner .............. C. ga/apagensis
14a Upper teeth narrow, their lateral margins deeply
concave or notched .......................................... C. brachyurus
14b Upper teeth broad, their lateral margins slightly
concave but not notched ...................................... C. obscurus
15a Body pale brown, all fins with dark tips ............ C. melanopterus
15b Some or all fins without dark tips ....................................... 16
16a Upper teeth broad, their lateral margins not notched .............. 17
16b Upper teeth narrow or, if of moderate breadth, with
clearly notched lateral margins .......................................... 18
17a First D height more than 3.2 x 2nd D height ........ C. amboinensis
17b First D height less than 3.2 x 2nd D height ................... C. /eucas
18a Upper teeth with large side cusps (cusplets); rear tip of
1st D elongated, about 2/J of fin base; 2nd D origin
well behind A origin, about opposite its midbase ......... C. mac/oti
18b Upper teeth without side cusps; rear tip of 1st D short,
less than 1/2 fin base; 2nd D origin about opposite A
origin ........................................................................... 19
19a Distance between D bases less than 2.2 x 1st D
height .............................................................. C. limbatus
19b Distance between D bases more than 2.2 x 1st D
height .......................................................................... 20
20a Snout bluntly rounded; upper jaw teeth with
oblique cusps .................................................. C. brachyurus
20b Snout sharply pointed; upper jaw teeth with narrow,
erect cusps on broad bases ................................. C. brevipinna
13a Teeth with single, large, oblique cusp and some smaller
cusplets along lateral (posterior) edge; teeth in 2 or 3
functional series; front edge of 2nd D shorter than that
of ventral C lobe ............................................................ 14
13b Teeth with a low bluntly rounded cusp or with narrow,
erect cusp (juveniles of Triakis with a short cusplet on
each side of main cusp); teeth in 4 or more functional
series; front edge of 2nd D longer than that of ventral
C lobe .......................................................................... 15
14a Second D height about 1\-2 x A height and more than
V2length of C tip; 1st D origin behind inner corner
of P ................................................................. Hypogaleus
14b Second D height subequal to A height and less than
1/2 length of C tip; 1st D origin over inner corner of P . Galeorhinus
15a Teeth bluntly rounded, arranged in a quincunx forming a
pavement-like crushing dentition, the tooth rows oblique
to jaw axis; distance from A base to lower C lobe greater
than 2nd D height .................................................. Mustelus
15b Teeth with a narrow, erect cusp (juveniles with a
short cusplet on each side of main cusp), the tooth rows
perpendicular to jaw axis; distance from A base to lower
C lobe less than 2nd D height ...................................... Triakis
Genus Carcharhinus Blainvilie, 1816
Body cylindrical; no spiracles. Lip folds short to rudimentary. Teeth blade-like, unicuspid; upper teeth serrated (at
least in adults), lower serrated or smooth. First D closer to P
than to V; at least twice as high as 2nd D; 2nd D origin in
front of middle of A base. No keels on caudal peduncle.
Viviparous. Of the 25 species recognised by Garrick (1982),
17 occur in our area. C. macloti is included because it is
known from Kenya and likely to be found in our area. Identification is difficult and it is often necessary to see the teeth
and, in some cases, to obtain vertebral counts. The following key to the southern African species is based on those of
Bass et al. (1973) and Garrick (1982); any identification
made via the key should be checked by referring to the individual species accounts. Fin markings (if any), the presence
or absence of an interdorsal ridge, and tooth shapes are vital
to accurate identification. Because of intraspecific variation
in some characters, three species are entered twice in the
key.
KEY TO SPECIES
la First D slightly tapered with broadly rounded
apex; fins mottled with white (fins of juveniles may be
black-tipped but these also have a black saddle on
caudal peduncle) ............................................ C. longimanus
Ib First D obviously tapered to a pointed or sharply
rounded apex; fins not mottled with white; no black
saddle on caudal peduncle ................................................. 2
2a Second D with black tip, all otherfins plain .................. C. sealei
2b Second D plain, white-tipped or, if black-tipped,
then with dark markings on some of the other fins................... 3
68
3a C with conspicuous, wide, black trailing edge;
1st D without any dark markings......................................... 4
3b C without conspicuous, wide, black trailing edge or,
if so, 1st D also has dark markings ....................................... 5
4a First D with distinct white tip and trailing edge .......... C. wheeleri
4b First D without distinct white tip and trailing
edge ....................................................... C. amblyrhynchos
5a Interdorsal ridge present ................................................... 6
5b Interdorsal ridge absent ................................................... 15
6a First D, P, V and C with white tips and
trailing edges ............................................. C. albimarginatus
6b First D, P, V and C plain or with dark markings ..................... 7
7a Second D, P and lower C lobe with black tips; 1st D with
thin black trailing edge near apex; A usually plain ......... C. sorrah
7b Fins usually without any distinctive markings;
if any fins are dark-tipped then A has a dark tip ...................... 8
8a Anal fin lobe more than twice 2nd D height ........................... 9
8b Anal fin lobe less than twice 2nd D height ............................ 10
9a First D origin behind P inner corner..................... C. falciformis
9b First D origin over P inner corner ........................... C. obscurus
lOa Snout to 1st D origin less than 2.2 x 1st D height ....... C. plumbeus
lOb Snout to 1st D origin more than 2.2 x 1st D height .................. 11
lIa First D origin closer to P axil than to P inner corner ................ 12
lib First D origin closer to P inner corner than to P axil ................ 13
12a Mouth width less than 2.4 x distance from inner end
of nostrils to mouth ............................................... C. altimus
12b Mouth width more than 2.4 x distance from inner end
of nostrils to mouth ........................................ C. ga/apagensis
13a First D origin over P inner corner ....................................... 14
13b First D origin in front of inner P corner .............. C. ga/apagensis
14a Upper teeth narrow, their lateral margins deeply
concave or notched .......................................... C. brachyurus
14b Upper teeth broad, their lateral margins slightly
concave but not notched ...................................... C. obscurus
15a Body pale brown, all fins with dark tips ............ C. melanopterus
15b Some or all fins without dark tips ....................................... 16
16a Upper teeth broad, their lateral margins not notched .............. 17
16b Upper teeth narrow or, if of moderate breadth, with
clearly notched lateral margins .......................................... 18
17a First D height more than 3.2 x 2nd D height ........ C. amboinensis
17b First D height less than 3.2 x 2nd D height ................... C. /eucas
18a Upper teeth with large side cusps (cusplets); rear tip of
1st D elongated, about 2/J of fin base; 2nd D origin
well behind A origin, about opposite its midbase ......... C. mac/oti
18b Upper teeth without side cusps; rear tip of 1st D short,
less than 1/2 fin base; 2nd D origin about opposite A
origin ........................................................................... 19
19a Distance between D bases less than 2.2 x 1st D
height .............................................................. C. limbatus
19b Distance between D bases more than 2.2 x 1st D
height .......................................................................... 20
20a Snout bluntly rounded; upper jaw teeth with
oblique cusps .................................................. C. brachyurus
20b Snout sharply pointed; upper jaw teeth with narrow,
erect cusps on broad bases ................................. C. brevipinna