Swimbladder cross sections and acoustic target strengths of 13 pollack and 2 saithe
Abstract
Data are presented on the swimbladder form and acoustic target strengths of each of 15
surface-adapted gadoids, 13 pollack (POLLACHIUS POLLACHIUS) and 2 saithe (POLLACHIUS VIRENS),
of lengths from 31.5 to 44.5 cm. The swimbladder data consist in sagittal cross sections of the
swimbladder, derived by shock-freezing of the whole fish and slicing with a microtome. The
acoustic data consist in the dependence of the target strength on tilt angle for both dorsal and
ventral aspects for each of four echo sounder frequencies, from 38 to 120 kHz. Possible uses of such
data in acoustic modelling of swimbladder-bearing fish and in systematic studies of swimbladder
morphometry are mentioned.
Publisher
[Fiskeridirektoratets havforskningsinstitutt]Series
Fiskeridirektoratets skrifter, Serie Havundersøkelservol 18 no 1