Aristotle's History of Animals In Ten Books · Aristotle
CHAPTER XII.
1. The oviparous fish have a divided uterus placed on the lower part of the body, as I observed before. All that have scales are viviparous, as the labrax, cestreus, cephalus, etelis,[204] and those called white fish, and all smooth fish except the eel. Their ova resemble sand. This appearance is owing to their uterus being quite full of ova, so that small fish appear to have only two ova; for the small size and thinness of the uterus renders it invisible in these creatures. I have before treated of the sexual intercourse of fish. The sexes are distinct in almost all fish, though there is some doubt about the erythrinus[205] and the channa, for all these are found to be pregnant. [204] Perhaps the Sea-bream, Sparus. [205] Perhaps Perca marina. 2. Ova are found in those fish which have sexual intercourse, though they possess them without intercourse. This is observable in some kinds of river fish; for the phoxini[206] appear to be pregnant as soon as they are born, and when they are quite small. They emit the ova in a stream; and, as I observed before, the males devour great numbers of them, and others perish in the water. Those are preserved which they deposit in their appropriate situations. For, if all were preserved, the numbers that would be found would be immense. Not all those that are preserved are fertile, but only those on which the seminal fluid of the male has been sprinkled. When the female produces her ova, the male follows, and scatters his semen upon them. Young fish are produced from those ova which are thus sprinkled. The remainder turn out as chance may direct.
Text from Project Gutenberg, public domain in the United States.