Abstract
The reproductive cycles and fertilities of seven species of barnacles (Balanus improvisus DARWIN, Balanus amphitrite DARWIN, Balanus eburneus GOULD, Balanus albicostatus PILSBRY, Balanus kondakovi TARASOV & ZEVINA, Balanus reticulatus UTINOMI and Chthamalus challengeri HOEK) have been determined by periodic sampling from the raft or intertidal piles and by examination of their gonads and retained embryos.
The breeding of the first three species was characteristically seen as extreme or rather strong eurythermy. However the last four species could breed only at a limited range of temperature. The number of broods per year of each species was estimated as follows; B. improvisus is 32 times, B. amphitrite 21∼26, B. eburneus 20, B. albicostatus 22, B. kondakovi 15∼22, B. reticulatus 13 and C. challengeri 2∼3.
The above-mentioned results and other breeding habits of these species were compared with those of different species of barnacles studied by previous workers.
