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The performance of the muscles involved in spitting by the Archerfish Toxotes
Author(s) -
Milburn Oliver,
Alexander R. McN.
Publication year - 1976
Publication title -
journal of zoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0952-8369
DOI - 10.1111/j.1469-7998.1976.tb04676.x
Subject(s) - biology , muzzle , anatomy , adductor muscles , dissection (medical) , zoology , materials science , composite material , barrel (horology)
The Archerfish Toxotes knocks aerial insects into the water by spitting at them. Spitting has been filmed and the excess pressure in the orobranchial cavity is estimated from the muzzle velocity as 7.2 kN m −2 . A dissection of the head shows that the adductor arcus palatini and geniohyoideus are most likely to be involved in spitting. From measurements made of these muscles, it is calculated that stresses up to at least 210 kN m −2 must act in them during spitting. Further, it appears from the calculations that these muscles must shorten at rates of 2.4‐3.0 muscle lengths sec −1 , which seems unlikely at such high stresses. It is possible that a catapult mechanism may be involved.