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The following paper is available. Please feel free to contact me
([EMAIL PROTECTED]) for a PDF.
Amorim et al. (2004). Sound production during competitive feeding in the
grey gurnard. Journal of Fish Biology 65, 182-194
abstract
The acoustic repertoire of captive grey gurnard, Eutrigla gurnardus, during
competitive feeding consisted of three types of sounds: knocks, grunts and
growls. Knocks were audible as a single sound, whereas grunts and growls
were perceived as longer, pulsed sounds to the human ear. Typically, knocks
were composed of 1-2 pulses, grunts of 4-8 and growls of more than 10
pulses. Growls were longer and had shorter pulse periods than grunts. All
sound types had peak frequencies around 500 Hz. The sequences of behaviours
observed during feeding interactions suggest that grey gurnards obtain food
both by scramble and contest tactics. Competing fish emitted knocks mainly
while grasping a food item, and also during other non-agonistic behaviour,
suggesting that knock production may reflect a state of feeding arousal but
could also serve as a warning of the forager's presence to nearby
competitors. Grunts were mainly emitted during frontal displays, which were
the most frequent behavioural act preceding grasps, suggesting that they
may play a role in deterring other fish from gaining access to disputed
food items.
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