Of cartilaginous fishes, the rhina or angelfish is the only one
that breeds twice; for it breeds at the beginning of autumn, and at
the setting of the Pleiads: and, of the two seasons, it is in better
condition in the autumn. It engenders at a birth seven or eight young.
Certain of the dog-fishes, for example the spotted dog, seem to
breed twice a month, and this results from the circumstance that the
eggs do not all reach maturity at the same time.