194: GERRElDAE (PURSEMOUTHS)
Family No. 194: GERREIDAE
by D.J. Woodland
Pursemouths
Plooibekke
Body compressed, slender or deep . Scales large, deciduous. Dorsal fin more or less notched; with 9 or 10 spines and
9-11 rays. Anal fin III,7 (for species in our area). First dor~
sal and first anal spines very short; bases of dorsal and anal
fins sheathed by a row of scales. Mouth very protrusible,
arching downward when protracted; teeth minute .
Live in schools about sandy shallows of tidal creeks,
lagoons, coral reefs and beaches subject to moderate wave
action; enter freshwater . Feed by picking at bottom invertebrates or by taking in mouthfuls of sand which they sieve
through the gill-rakers. Overall coloration brilliant silver.
Some species with upper sides variously marked with dusky
spots, bars or stripes; juveniles of most species have dusky
bars on their sides; dead specimens often develop a dusky
stripe along each scale row. Seldom exceed 15 cm, a few
species attain 30 cm. Flesh excellent, but spoils very rapidly.
For these reasons of little interest to anglers, except that
they may be netted in large numbers in tidal creeks to provide an excellent bait. Occurring in all warm seas; a few
species prefer more temperate waters. Perhaps as many as
40 species; 5 or 6 genera, but only 1 in our area.
Genus Gerres Quoy & Gaimard, 1824
Perhaps as many as 30 species, but only 5 in our area.
KEY TO SPECIES
la Second D spine much longer than head (in specimens
4-6 cm SL, 2nd D spine not longer than head, but
its tip reaches past base of last D spine); 3rd D
spine equal to or longer than distance from tip
of snout to rear edge of preopercle .... ..... ..... ........ G. Jilam entasus
Ib Second D spine shorter than head (in specimens 4-6 cm
SL, 2nd D spine not reaching last D spine) ... .. .................. .. ..... 2
2a Last two D spines longer than eye diameter .................. G. rappi
2b Last two D spines not longer than eye diameter ............. ... ....... 3
3a Body depth 2.S-2.9 in SL ... ............. ....... ................ G. acinaces
3b Body depth 3.0-3.4 in SL ....... ........... ..... .. ... .............. .. ....... . 4
4a 3Yz scale rows between LL and base of Sth D spine;
LL 3S-39 (+ 3-4 on C) .... .. ........................................ G. ayena
4b 4Yz-SYz scale rows between LL and base of Sth
D spine; LL 44-4S (+ 4-S on C) ........ .............. ........ G. ablangus
194.1 Gerres acinaces
Bleeker, 1854
PLATE 68
Smaliscale pursemouth
Kleinskub-plooibek
Gerres acinaces Bleeker, 18S4: 194 (Jakarta, Java); Smith, SFSA No.
631; Blaber, 1978: 33. Gerres linealatus: Regan , 1908: 24S . Gerres ayena
Smith, SFSA No. 629* (figure only).
608
D IX-X ,9-11; A III}; LL 42-44 (+ 3-S on C); 4Yz-SYz scale rows between LL and base of Sth D spine . Depth 2.S-2.9. Longest C rays longer
than either P or head. Second A spine longer than eye diameter.
Sides olive above to silvery below; in young, 7 or 8 dusky
bars on sides of body; in older fish, several vertical series of
ovoid spots below LL and rows of dark spots following scale
rows above LL. Trailing margin of C black. Attains 25 cm.
Tropical Indo-Pacific, south to Algoa Bay.
194.1 Gerres acinaces: 23 em (Inhaea Id.).
194.2 Gerres filamentosus
Cuvier, 1829
Threadfin pursemouth
Sweepvin-plooibek
Gerres Jilamentasus Cuvier, 1829: 188 (Vizagapatam, India). Gerres
punctatus: Smith, SFSA No. 628*; Blaber, 1978: 33.
D IX,1O; A III}; LL 43-47 (+ 2-3 on C); 4Yz-S scale rows between LL
and base of Sth D spine. Depth 2.0-2.S in fish longer than 9 em SL, 2.S-3.0
in smaller fish .
Silvery, with 8-10 vertical series of ovoid bluish spots on
sides, coalesced as bars in juveniles. Attains 25 cm. IndoPacific, common in northern part of our area; strays as far
south as Algoa Bay; to 50 m.
194.2 Gerres filamentosus: 15 em (Durban).
Family No. 194: GERREIDAE
by D.J. Woodland
Pursemouths
Plooibekke
Body compressed, slender or deep . Scales large, deciduous. Dorsal fin more or less notched; with 9 or 10 spines and
9-11 rays. Anal fin III,7 (for species in our area). First dor~
sal and first anal spines very short; bases of dorsal and anal
fins sheathed by a row of scales. Mouth very protrusible,
arching downward when protracted; teeth minute .
Live in schools about sandy shallows of tidal creeks,
lagoons, coral reefs and beaches subject to moderate wave
action; enter freshwater . Feed by picking at bottom invertebrates or by taking in mouthfuls of sand which they sieve
through the gill-rakers. Overall coloration brilliant silver.
Some species with upper sides variously marked with dusky
spots, bars or stripes; juveniles of most species have dusky
bars on their sides; dead specimens often develop a dusky
stripe along each scale row. Seldom exceed 15 cm, a few
species attain 30 cm. Flesh excellent, but spoils very rapidly.
For these reasons of little interest to anglers, except that
they may be netted in large numbers in tidal creeks to provide an excellent bait. Occurring in all warm seas; a few
species prefer more temperate waters. Perhaps as many as
40 species; 5 or 6 genera, but only 1 in our area.
Genus Gerres Quoy & Gaimard, 1824
Perhaps as many as 30 species, but only 5 in our area.
KEY TO SPECIES
la Second D spine much longer than head (in specimens
4-6 cm SL, 2nd D spine not longer than head, but
its tip reaches past base of last D spine); 3rd D
spine equal to or longer than distance from tip
of snout to rear edge of preopercle .... ..... ..... ........ G. Jilam entasus
Ib Second D spine shorter than head (in specimens 4-6 cm
SL, 2nd D spine not reaching last D spine) ... .. .................. .. ..... 2
2a Last two D spines longer than eye diameter .................. G. rappi
2b Last two D spines not longer than eye diameter ............. ... ....... 3
3a Body depth 2.S-2.9 in SL ... ............. ....... ................ G. acinaces
3b Body depth 3.0-3.4 in SL ....... ........... ..... .. ... .............. .. ....... . 4
4a 3Yz scale rows between LL and base of Sth D spine;
LL 3S-39 (+ 3-4 on C) .... .. ........................................ G. ayena
4b 4Yz-SYz scale rows between LL and base of Sth
D spine; LL 44-4S (+ 4-S on C) ........ .............. ........ G. ablangus
194.1 Gerres acinaces
Bleeker, 1854
PLATE 68
Smaliscale pursemouth
Kleinskub-plooibek
Gerres acinaces Bleeker, 18S4: 194 (Jakarta, Java); Smith, SFSA No.
631; Blaber, 1978: 33. Gerres linealatus: Regan , 1908: 24S . Gerres ayena
Smith, SFSA No. 629* (figure only).
608
D IX-X ,9-11; A III}; LL 42-44 (+ 3-S on C); 4Yz-SYz scale rows between LL and base of Sth D spine . Depth 2.S-2.9. Longest C rays longer
than either P or head. Second A spine longer than eye diameter.
Sides olive above to silvery below; in young, 7 or 8 dusky
bars on sides of body; in older fish, several vertical series of
ovoid spots below LL and rows of dark spots following scale
rows above LL. Trailing margin of C black. Attains 25 cm.
Tropical Indo-Pacific, south to Algoa Bay.
194.1 Gerres acinaces: 23 em (Inhaea Id.).
194.2 Gerres filamentosus
Cuvier, 1829
Threadfin pursemouth
Sweepvin-plooibek
Gerres Jilamentasus Cuvier, 1829: 188 (Vizagapatam, India). Gerres
punctatus: Smith, SFSA No. 628*; Blaber, 1978: 33.
D IX,1O; A III}; LL 43-47 (+ 2-3 on C); 4Yz-S scale rows between LL
and base of Sth D spine. Depth 2.0-2.S in fish longer than 9 em SL, 2.S-3.0
in smaller fish .
Silvery, with 8-10 vertical series of ovoid bluish spots on
sides, coalesced as bars in juveniles. Attains 25 cm. IndoPacific, common in northern part of our area; strays as far
south as Algoa Bay; to 50 m.
194.2 Gerres filamentosus: 15 em (Durban).