Order MYXINIFORMES
Hagfishes
The hagfish order comprises a single family that is
represented in the temperate waters of all oceans.
Family No.1: MYXINIDAE
by Bo Fernholm
Hagfishes
Slymslange
Usually classified with the lampreys (Order
Petromyzoniformes, not represented in South Africa) and
extinct palaeozoic fishes in the Superclass Agnatha (jawless
fishes); therefore often studied by zoologists interested in
the evolution of vertebrates. Body eel-shaped, with cartilaginous skeleton. No paired fins, but usually a low ventral
finfold. Two pairs of barbels around the single nostril above
the mouth, and one barbel on either side of mouth. Mouth
with laterally biting, protrusible, orange-yellow, horny
teeth. Eyes rudimentary under the skin. One to several
pairs of gill openings, leading from the internal gill pouches,
restricted to the ventral anterior region. Body usually dark
brown, grey or purple, sometimes with lighter ventral coloration and light eye-patches .
(When irritated , hagfishes secrete an abundant amount
of sticky slime from the two rows of slime pores along the
lower part of the body, quickly turning the water around the
fish into slime which acts as a defensive mechanism. Exclusively marine and locally common on muddy bottoms into
which they burrow. Of no significant commercial interest.
Harmless to man, but loathed by fishermen for biting on
hooks or preying on caught fish . All tackle touched by these
creatures has to be cut away otherwise no fish will come
near the bait. - M.M. Smith.) Occasionally caught in bottom trawls, but most efficiently collected in baited traps.
Two genera, with a total of 4 species in our region.
KEY TO GENERA
1a Five to eight pairs of gill openings ..... .. ... .......... .... ...... Eptatretus
1b One pair of gill openings ...... .. .... ........ .. ..... ........ .... .... .. Myxine
Genus Eptatretu5 Cloquet, 1819
Fourteen species; 3 in our area.
KEY TO SPECIES '
1a Five pairs of gill openings .... .... ..... ......... ... ............ E. profundus
1b Six or more pairs of gill openings ... ...... .. ... ...... ...... .......... ... ... 2
Slymslange
2a Six pairs of gill openings .. .................. ........... ... .... E. hexatrema
2b Eight pairs of gill openings ..... .......... .... .... ... .. ...... . E. octatrema
1.1 Eptatretus hexatrema
(Muller, 1834)
Sixgill hagfish
Seskief -slymslang
Bdellostoma hexatrema Miiller, 1834: 79 (Table Bay, Cape of Good
Hope) ; Adam & Strahan, 1963: 6. Heptatretus hexatrema: Smith , SFSA:
25*; Barnard, 1950: 1. Eptatretus hexatrema: Smith, 1975: 9; Strahan,
1975: 144; Hardisty, 1979: 19. Eptatretus cirrhatus (non Schneider): Rass,
1971: 18.
Total cusp count of teeth 40-48 with the anterior 3 in outer row, and
anterior 2 in inner row fused at bases. Prebranchiallength about 30% of
total length; 90-103 pairs of slime pores.
Attains 80 cm. A common hagfish known only from
Walvis Bay to Durban, in 20 - 400 m.
N
. . .... - .. .
1.1 Eptatretus hexatrema: ventral view of 40 cm specimen (Cape south coast).
C = cloacal slit; E = egg capsule; GA = gill apertures; H = hook of egg
capsule; N = the single nostril; SGP = slime gland pores; T = teeth in open
mouth.
35
Hagfishes
The hagfish order comprises a single family that is
represented in the temperate waters of all oceans.
Family No.1: MYXINIDAE
by Bo Fernholm
Hagfishes
Slymslange
Usually classified with the lampreys (Order
Petromyzoniformes, not represented in South Africa) and
extinct palaeozoic fishes in the Superclass Agnatha (jawless
fishes); therefore often studied by zoologists interested in
the evolution of vertebrates. Body eel-shaped, with cartilaginous skeleton. No paired fins, but usually a low ventral
finfold. Two pairs of barbels around the single nostril above
the mouth, and one barbel on either side of mouth. Mouth
with laterally biting, protrusible, orange-yellow, horny
teeth. Eyes rudimentary under the skin. One to several
pairs of gill openings, leading from the internal gill pouches,
restricted to the ventral anterior region. Body usually dark
brown, grey or purple, sometimes with lighter ventral coloration and light eye-patches .
(When irritated , hagfishes secrete an abundant amount
of sticky slime from the two rows of slime pores along the
lower part of the body, quickly turning the water around the
fish into slime which acts as a defensive mechanism. Exclusively marine and locally common on muddy bottoms into
which they burrow. Of no significant commercial interest.
Harmless to man, but loathed by fishermen for biting on
hooks or preying on caught fish . All tackle touched by these
creatures has to be cut away otherwise no fish will come
near the bait. - M.M. Smith.) Occasionally caught in bottom trawls, but most efficiently collected in baited traps.
Two genera, with a total of 4 species in our region.
KEY TO GENERA
1a Five to eight pairs of gill openings ..... .. ... .......... .... ...... Eptatretus
1b One pair of gill openings ...... .. .... ........ .. ..... ........ .... .... .. Myxine
Genus Eptatretu5 Cloquet, 1819
Fourteen species; 3 in our area.
KEY TO SPECIES '
1a Five pairs of gill openings .... .... ..... ......... ... ............ E. profundus
1b Six or more pairs of gill openings ... ...... .. ... ...... ...... .......... ... ... 2
Slymslange
2a Six pairs of gill openings .. .................. ........... ... .... E. hexatrema
2b Eight pairs of gill openings ..... .......... .... .... ... .. ...... . E. octatrema
1.1 Eptatretus hexatrema
(Muller, 1834)
Sixgill hagfish
Seskief -slymslang
Bdellostoma hexatrema Miiller, 1834: 79 (Table Bay, Cape of Good
Hope) ; Adam & Strahan, 1963: 6. Heptatretus hexatrema: Smith , SFSA:
25*; Barnard, 1950: 1. Eptatretus hexatrema: Smith, 1975: 9; Strahan,
1975: 144; Hardisty, 1979: 19. Eptatretus cirrhatus (non Schneider): Rass,
1971: 18.
Total cusp count of teeth 40-48 with the anterior 3 in outer row, and
anterior 2 in inner row fused at bases. Prebranchiallength about 30% of
total length; 90-103 pairs of slime pores.
Attains 80 cm. A common hagfish known only from
Walvis Bay to Durban, in 20 - 400 m.
N
. . .... - .. .
1.1 Eptatretus hexatrema: ventral view of 40 cm specimen (Cape south coast).
C = cloacal slit; E = egg capsule; GA = gill apertures; H = hook of egg
capsule; N = the single nostril; SGP = slime gland pores; T = teeth in open
mouth.
35