Retention of the second polar body for the production of triploid Arctic charr (Salvelinus alpinus) was induced by 65 MPa (650 bar) pressure shocks applied 30, 40 or 50 min after fertilization, each shock lasting 5 min. Triploid yield (percentage of relative survival to control × percent triploidy) varied from 55 to 100 % and it was generally superior to 80. Despite increased mortality and decreased growth in diploid charrs during the spawning period, growth and survival did not differ between diploid and triploid Arctic charr up to and during their third year of life. Most of the triploid males had developed testis, but they did not render milt; few triploid females had developed ovaries. Fecundity of triploid females was low and fertilized eggs from triploid females did not hatch.