Suitability of hybrid mackerel (Scomber australasicus × S. japonicus) with germ cell-less sterile gonads as a recipient for transplantation of bluefin tuna germ cells.

•Hybrid mackerel showed germ cell-less sterility.•Germ cell-less gonads retained Sertoli and Leydig cells for nursing donor germ cells.•Gonads of hybrid mackerel attracted and incorporated intraperitoneally transplanted bluefin tuna germ cells.•Hybrid mackerel are promising recipients for production of bluefin tuna gametes.