MESH SELECTIVITY CURVES FOR FLOUNDER PARALICHTHYS-OLIVACEUS TRAMMELNET

To obtain mesh selectivity curves for trammelnets for the flounder Paralichthys olivaceus, probabilities of truncations by interior meshes were calculated on the basis of a lengthgirth relationship of the fish. For the calculation, girths at the end of the operculum and the anus (Ga) were measured with specimens from commercial catches. As a twine was tangled at the pterygiophore of the anal fin and fish tended to be enmeshed obliquely, the Ga-truncation curves calculated were revised by substituting a mesh perimeter phi with 0.8 phi which was obtained from girths along net marks on fish bodies. The mesh selectivity curves closely fitted the length frequency distribution of the catches from commercial nets of respective mesh sizes.