Family No. 227: CONGROGADIDAE
by R. Winterbottom
Snakelets
Siangetjies
Body elongate and eel-like; 1 or 2 dorsal spines (absent in
1 Pacific species); dorsal and anal fins long (32-77 and 26-65
rays respectively); no anal spines; pectoral fin rays 9-14;
pelvic fin varies from 1,4 to absent; branched caudal rays 10.
Teeth conical; gill-rakers poorly developed; gill membranes
united, fused or free from isthmus; 6 branchiostegal rays ; a
single spine on opercle. Scales cycloid, small, covering
body. Head scaled (cheek and opercle) or naked. Lateral
line variable (from short and incomplete to as many as 4
separate lateral-lines on each side).
Snake lets range from intertidal to 140 m; some attain 50
cm in length. Widely distributed in coastal waters of the
Indo-West Pacific area. Ten genera , 17 species; 5 species in
our area. Halimuraenoides isostigma Mauge & Bardach,
1985 from Madagascar may be found in our area and is thus
included in the key.
KEY TO GENERA
la V present ... ... ... ... .... ..... .. .... ...... ....... ...... .... .. ........ ...... .... .. 2
Ib Vabsent .... .. .... .... ...... .. ............................. .. ...... .. ...... .. .... 4
2a LL single, short, ending below anterior part of D ....... Natalichthys
2b LL not a single, short section ............................................... 3
3a LL consisting of a short anterior section and a
longer posterior section along midlateral part
of body; V 1,3; P 12 ...... .. .............................. . Halimuraenoides
3b Three LL on body posterior to anus ; V 1,2; P 10 .......... Halidesmus
4a Gill membranes fused to isthmus ............................ ... Haliophis
(H. guttatus Forsskal, known from the Red Sea , SW Madagascar and
from Mozambique Id.).
4b Gill membranes united but free of isthmus .. ....... ...... Halimuraena
Genus Halidesmus Gunther, 1871
Three species, 1 in South Africa.
227.1 Halidesmus scapularis: 15 em (Algoa Bay).
227: CONGROGADIDAE (SNAKELETS)
Snakelet
227.1 Halidesmus scapularis
Gunther, 1871
PLATE 112
Siangetjie
Halidesmus scapularis Gunther, 1871: 668, PI. 67, Fig. A (Port
Elizabeth , South Africa); Smith , 1952: 97*; SFSA No. 1028*; Smith &
Smith , 1966: 113* . Porogrammus capensis Gilchrist & Thompson, 1916:
57* (False Bay, South Africa).
D 1,58-63; A 48-52; P 8-10; LL variable, but always 3 lines (dorsal,
lateral , ventral) posterior to A origin ; GR 3+6. Depth 6.6-7.6; head
10.3-13.2.
.
Colour variable, usually light to dark brown, sometimes
with dusky crossbars; an ocellated dark spot on shoulder
above opercle. Attains 20 cm. False Bay to Coffee Bay,
Transkei; common in intertidal pools and marginal subtidal
areas.
Genus Halimuraena Smith, 1952
Three species, 1 in our area (the other 2 extralimital, but
may be found here) .
KEY TO SPECIES
1 a Cheek, opercle and nape scaled ;
8 suborbital canal pores .. .... ..... H. lepopareia Winterbottom, 1980
(Comoro Ids. and northern Madagascar)
Ib Cheek, opercle and nape naked;
7 suborbital canal pores ............. ... .................. .. .... ........ ... ... 2
2a Dark ocellated spot on shoulder above opercle;
LL of a single, short, anterior section and a
longer posterior section along midlateral part
of body ............... ... .... .... ...... ... ....... H. hexagonata Smith, 1952
(Extralimital , to about 15°S on Mozambique coast; Madagascar)
2b No dark spot on shoulder above opercle; LL single,
ending below anterior part of D ........ .. .. .. .... .. ...... ...... . H. shakai
Zulu snakelet
227.2 Halimuraena shakai
Winterbottom,.1978
Zoeloe-slangetjie
Halimuraena shakai Winterbottom, 1978: 49, Figs. 1 & 2 (off Sodwana
Bay, Natal).
_----a']~'IfYfn'YUfA~
227.2 Halimuraena shakai: 5 em SL holotype (Natal).
729
by R. Winterbottom
Snakelets
Siangetjies
Body elongate and eel-like; 1 or 2 dorsal spines (absent in
1 Pacific species); dorsal and anal fins long (32-77 and 26-65
rays respectively); no anal spines; pectoral fin rays 9-14;
pelvic fin varies from 1,4 to absent; branched caudal rays 10.
Teeth conical; gill-rakers poorly developed; gill membranes
united, fused or free from isthmus; 6 branchiostegal rays ; a
single spine on opercle. Scales cycloid, small, covering
body. Head scaled (cheek and opercle) or naked. Lateral
line variable (from short and incomplete to as many as 4
separate lateral-lines on each side).
Snake lets range from intertidal to 140 m; some attain 50
cm in length. Widely distributed in coastal waters of the
Indo-West Pacific area. Ten genera , 17 species; 5 species in
our area. Halimuraenoides isostigma Mauge & Bardach,
1985 from Madagascar may be found in our area and is thus
included in the key.
KEY TO GENERA
la V present ... ... ... ... .... ..... .. .... ...... ....... ...... .... .. ........ ...... .... .. 2
Ib Vabsent .... .. .... .... ...... .. ............................. .. ...... .. ...... .. .... 4
2a LL single, short, ending below anterior part of D ....... Natalichthys
2b LL not a single, short section ............................................... 3
3a LL consisting of a short anterior section and a
longer posterior section along midlateral part
of body; V 1,3; P 12 ...... .. .............................. . Halimuraenoides
3b Three LL on body posterior to anus ; V 1,2; P 10 .......... Halidesmus
4a Gill membranes fused to isthmus ............................ ... Haliophis
(H. guttatus Forsskal, known from the Red Sea , SW Madagascar and
from Mozambique Id.).
4b Gill membranes united but free of isthmus .. ....... ...... Halimuraena
Genus Halidesmus Gunther, 1871
Three species, 1 in South Africa.
227.1 Halidesmus scapularis: 15 em (Algoa Bay).
227: CONGROGADIDAE (SNAKELETS)
Snakelet
227.1 Halidesmus scapularis
Gunther, 1871
PLATE 112
Siangetjie
Halidesmus scapularis Gunther, 1871: 668, PI. 67, Fig. A (Port
Elizabeth , South Africa); Smith , 1952: 97*; SFSA No. 1028*; Smith &
Smith , 1966: 113* . Porogrammus capensis Gilchrist & Thompson, 1916:
57* (False Bay, South Africa).
D 1,58-63; A 48-52; P 8-10; LL variable, but always 3 lines (dorsal,
lateral , ventral) posterior to A origin ; GR 3+6. Depth 6.6-7.6; head
10.3-13.2.
.
Colour variable, usually light to dark brown, sometimes
with dusky crossbars; an ocellated dark spot on shoulder
above opercle. Attains 20 cm. False Bay to Coffee Bay,
Transkei; common in intertidal pools and marginal subtidal
areas.
Genus Halimuraena Smith, 1952
Three species, 1 in our area (the other 2 extralimital, but
may be found here) .
KEY TO SPECIES
1 a Cheek, opercle and nape scaled ;
8 suborbital canal pores .. .... ..... H. lepopareia Winterbottom, 1980
(Comoro Ids. and northern Madagascar)
Ib Cheek, opercle and nape naked;
7 suborbital canal pores ............. ... .................. .. .... ........ ... ... 2
2a Dark ocellated spot on shoulder above opercle;
LL of a single, short, anterior section and a
longer posterior section along midlateral part
of body ............... ... .... .... ...... ... ....... H. hexagonata Smith, 1952
(Extralimital , to about 15°S on Mozambique coast; Madagascar)
2b No dark spot on shoulder above opercle; LL single,
ending below anterior part of D ........ .. .. .. .... .. ...... ...... . H. shakai
Zulu snakelet
227.2 Halimuraena shakai
Winterbottom,.1978
Zoeloe-slangetjie
Halimuraena shakai Winterbottom, 1978: 49, Figs. 1 & 2 (off Sodwana
Bay, Natal).
_----a']~'IfYfn'YUfA~
227.2 Halimuraena shakai: 5 em SL holotype (Natal).
729