Fishing from the earliest times - Blog

DO FISH HEAR ?—EXPERIMENTS T13whether the undoubted effect of their being disturbed by certainnoises is attained by hearing proper, or by vibration actingon the surface part of the fish and communicating instantlywith the internal ear.Day's summary of the question, still regarded after thirtyyears as fair and conclusive, even if attaching undue importanceto the fontanelles, is as follows, " Hearing is developed infish, and it is very remarkable how any diversity of opinioncan exist as to their possessing this sense. The internalauditory apparatus is placed within the cranial cavity : itschief constituent parts are the labyrinth, which is composedof three semi-circular canals, and a vestibule, which latterexpands into one or more sacs, where the ear bones or otolithsare lodged. A tympanum and tympanic cavity are absent.They possess fontanelles between the bones, forming the roofof the skull, which being closed by very thin bones or skinBut the chief mode inpermit sounds from the surrounding water to be readily transmittedto the contiguous internal ears.which hearing is carried on must be due to the surface of thefish being affected by vibration of the water, and the sounds aretransmitted directly to the internal ear, or else by means ofthe air-bladder acting as a sounding drum." 1It goes against the grain to differ with such a charmfuland theme-ful author as Sir Herbert Maxwell. But hisconclusion 2 that fish in Loch Ken were disturbed every timea shooting party half to three-quarters of a mile away dischargedtheir guns cannot be reconciled with the experimentsmade by me in July 191 8 to test the behaviour of trout,when guns were fired, not half a mile away, but quite closeto them.Three of us, all accustomed to watching fish, selected anarrow shallow burn in which the trout ran from fingerlingsup to fish three or four years old. Each in turn fired the gun(an ordinary 12 bore C.F,), with the usual shooting charge ofpowder and No. 5 shot. At the first two trials only was theshot extracted, so as to ehminate any vibration set up by its^ British Fish: Salmonidcs (London, 1887), p. 19.* Memories of the Months, Fourth Series (London, 1914), pp. 232-3.