Effects of hook size on the catches of undersized snapper Pagrus auratus

Demersal longl~nes balted w ~t h uniformly-sized pleces of squld were used to test the selective nature of 3 'Mustad' tuna hooks (#12, # l 0 and #8) on the catches of unders~zed and legal-sued snapper Pagrus auratus Increas~ng the absolute slze of the hook by 26 5 ' V0 (1 e # l 2 to #10) resulted in s~gnificantly fewer snapper under the legal slze (250 mm fork length) belng caught Increas~ng the absolute slze of the hook by 64 "/o ( I e # l 2 to #8) d ~d not result In a further decrease in the number of unders~zed snapper caught but i t dld result in s~gniflcantly larger ~n d ~v i d u a l s being caught on the #8 hook These results i n d ~c a t e that predlctlons of hook-select~vlty based on the normal and log~stic curves are not dlrectly applicable An examination of other hook dimensions showed that the length of the b ~l l was inversely correlated wlth the number of under legal-s~ze snapper These results suggest that other hook dlmenslons warrant further investigation O Inter-Research 1993