41. Reproduction in the Tasmanian numbfish is viviparous, with the developing embryos nourished to term via their yolk sacs . 42. This species is ovoviviparous, meaning that the young hatch inside the uterus and are nourished by a yolk sac . 43. One to four, but usually two pups are retained in the uterus, where they feed from a yolk sac . 44. The placenta structure is derived from the wall of the embryonic yolk sac that has fused with the uterine wall. 45. When the rearing habitat is reached, the larvae typically take around 25 days for the yolk sac to be absorbed. 46. PGCs come from the epiblast and migrate subsequently into the mesoderm, the endoderm and the posterior of the yolk sac . 47. Inside the embryo, the dorsal aorta forms and eventually connect the heart to the capillary plexus of the yolk sac . 48. The larvae are long at hatching, with a small yolk sac that is absorbed by the time the larva reaches. 49. Depending on the species, froglets hatch with or without the tail fully absorbed but with the yolk sac still visible. 50. Specialized primordial germ cells are forming and migrating from the yolk sac to the embryonic gonads during week eight and nine.
