318
J. H. S. BLAXTER AND F. 0. T. HOLLIDAY
time reviewing the earlier work of Maier and Scheuring (1923) on
herring and Wohlfahrt (1936) on Sardina pilchardus. There seem to be
few essential differences between the species (see Fig. 10). The anterior
end of the swim bladder bifurcates into two tubes which widen out into
vesicles within the pterotic and pro-otic bullae. The pro-otio vesicles
are applied to perilymph cavities which have contwt with the utricular
part of the labyrinth through a pro-otic fenestra. The suggestion here is
that the utriculus plays a part in hearing (Wohlfahrt, 1936 ; Verheijen,
1953), which is probably not true, for instance, of the Ostariophysi,
where the swim bladder is associated with the sacculus-lagena part of
the labyrinth (Lowenstein, 1957). Usually the utriculus has been
considered to have an equilibrium function due to its connection with
the semicircular canals as the pars superior of the labyrinth. According
to Ridewood (1891) the utriculi in the herring are joined to one another
by a canal which passes through the membranes of the brain just
behind the pituitary fossa.
Wohlfahrt (1936) discussed in detail the possible auditory function
of the utricular maculae. He considered that the lapillus also retained
a residual equilibrium function. The pterotio and pro-0th bullae acted
as resonators. O'Connell (1955), extending this hypothesis, saw the
utriculus-swim bladder complex as widening the frequency range of the
species, and perhaps their overall sensitivity, with at least a basic
auditory response resting in the sacculus-lagena part of the labyrinth.
2. Response to auditory and vibrating stimuli
Little is known of this, though Verheijen (1953) considered that
herring kept in aquaria could perceive up to 400 clsec at medium
intensity. Blaxter and Holliday (1958), using juvenile herring in
aquaria, observed the effect of sounds of different frequency played
through an underwater loudspeaker on feeding behaviour. At frequencies from 10-100 clsec feeding temporarily stopped, the. fish reacting
strongly to the starting or stopping of the stimuli. From 600-5000
clsec a " startle '' reaction waa observed but feeding was not interrupted.
It appears that commercial echo-sounders have no observable. effects
on herring. Dow (quoted by Moulton and Baokhus, 1956) found no
effect with a 50 kc/sec sounder, and Skoglund (1953) and Blaxfer and
Holliday (1958) none with a 30 kclsec sounder. Bull (1961), however,
has reported a response by some other teleosts to echo-sounders aa
shown by training techniques. If this is confirmed it points to the
need to distinguish between sensitivity and response.
Rumyantsev (1960) reported serious lesions of the body wall and
J. H. S. BLAXTER AND F. 0. T. HOLLIDAY
time reviewing the earlier work of Maier and Scheuring (1923) on
herring and Wohlfahrt (1936) on Sardina pilchardus. There seem to be
few essential differences between the species (see Fig. 10). The anterior
end of the swim bladder bifurcates into two tubes which widen out into
vesicles within the pterotic and pro-otic bullae. The pro-otio vesicles
are applied to perilymph cavities which have contwt with the utricular
part of the labyrinth through a pro-otic fenestra. The suggestion here is
that the utriculus plays a part in hearing (Wohlfahrt, 1936 ; Verheijen,
1953), which is probably not true, for instance, of the Ostariophysi,
where the swim bladder is associated with the sacculus-lagena part of
the labyrinth (Lowenstein, 1957). Usually the utriculus has been
considered to have an equilibrium function due to its connection with
the semicircular canals as the pars superior of the labyrinth. According
to Ridewood (1891) the utriculi in the herring are joined to one another
by a canal which passes through the membranes of the brain just
behind the pituitary fossa.
Wohlfahrt (1936) discussed in detail the possible auditory function
of the utricular maculae. He considered that the lapillus also retained
a residual equilibrium function. The pterotio and pro-0th bullae acted
as resonators. O'Connell (1955), extending this hypothesis, saw the
utriculus-swim bladder complex as widening the frequency range of the
species, and perhaps their overall sensitivity, with at least a basic
auditory response resting in the sacculus-lagena part of the labyrinth.
2. Response to auditory and vibrating stimuli
Little is known of this, though Verheijen (1953) considered that
herring kept in aquaria could perceive up to 400 clsec at medium
intensity. Blaxter and Holliday (1958), using juvenile herring in
aquaria, observed the effect of sounds of different frequency played
through an underwater loudspeaker on feeding behaviour. At frequencies from 10-100 clsec feeding temporarily stopped, the. fish reacting
strongly to the starting or stopping of the stimuli. From 600-5000
clsec a " startle '' reaction waa observed but feeding was not interrupted.
It appears that commercial echo-sounders have no observable. effects
on herring. Dow (quoted by Moulton and Baokhus, 1956) found no
effect with a 50 kc/sec sounder, and Skoglund (1953) and Blaxfer and
Holliday (1958) none with a 30 kclsec sounder. Bull (1961), however,
has reported a response by some other teleosts to echo-sounders aa
shown by training techniques. If this is confirmed it points to the
need to distinguish between sensitivity and response.
Rumyantsev (1960) reported serious lesions of the body wall and