Chapter XVI.

1. The reproductive function is not active in all fish at the same time or the same manner, nor are they pregnant during the same length of time. Before the season of sexual intercourse the males and females begin to assemble, and at the period of intercourse and the production of their ova they pair together. Some of them do not remain pregnant more than thirty days, and others not so long; but all of them remain so for a number of days, which can be distributed into seven. Those which some persons call marini remain pregnant for the longest period. The sargus becomes pregnant in the month of December, and remains so for thirty days. The kind of cestreus which some persons call the chelon and the myxon are pregnant at the same time as the sargus. All these suffer in their pregnancy, wherefore they are driven to the shore at this season; for in the vehemence of their desire they are carried towards the land, and always continue in motion during this period till they have produced their ova. The cestreus is more remarkable for this than any other fish. As soon as they have deposited their ova, they become quiet.

2. In many fish there is a limit to their reproductive powers, when worms make their appearance in their abdomen. These worms are small living creatures, which expel the reproductive substance. The small fry of the rhyas makes its appearance in the spring, and that of many others about the vernal equinox. Other fish do not produce at this season of the year, but in the summer or near the autumnal equinox.

3. The atherina produces its young first of all, near the land. The cephalus is the last. This is evident from the small fry of the former appearing first, and that of the latter last of all. The cestreus also produces among the first. The salpa in most places deposits its ova during the summer, and sometimes in the autumn. The aulopias, which they call anthias, produces its ova in the summer season. After these the chrysophrys, labrax, mormyrus, and all those which are called dromades; the trigla and cocarinus are the latest of all the gregarious fish. These oviposit in the autumn. The trigla deposits her ova in the mud, which causes her to be late, for the mud continues cold for a long while. The coracimus is next to the trigla, and goes among the sea weed to deposit her ova: consequently they frequent rocky places. It continues pregnant for a long while. The mænides oviposit at the winter solstice. Many other marine fish oviposit in the summer, for they are not captured at this period. The mænis is the most productive of all fish, and the batrachus the most so among the selache. They are, however, rare, for they perish very readily; they oviposit in shoals and near the land.

4. The selache, as being viviparous, are less productive. These are particularly preserved by their large size. The belone is late in producing its young, and many of them are burst by their ova in the act of parturition; for these ova are not so numerous as they are large. They surround the parent as if they were phalangia; for she produces them attached to herself, and if any one touches them they make their escape. The atherina deposits her ova by rubbing her abdomen against the sand. The thynni burst with fat. They live two years. The fishermen argue thus: when the thynnides fail one year, the thynni fail the year after. They appear to be a year older than the pelamus.

5. The thynni and scombri copulate at the end of February, and produce their young at the beginning of June. They produce their ova, as it were, in a purse. The growth of the thynnides is rapid; for when these fish produce their young in the Pontus, they produce from the ovum creatures which some persons call scordylæ, and the Byzantines call auxidæ, because they grow in a few days. They go out in the autumn with the thynnus, and return in the spring as pelamides. Nearly all other fish grow rapidly, but those in the Pontus more rapidly than in other places; for the amiæ there increase visibly every day. It is necessary to remember that the same fish have not in the same place the identical time of coition and gestation, nor the same period of reproduction and completion of their offspring. For those which are called coracini produce their ova at the time of wheat harvest, though, generally speaking, the order of their reproduction is that which I have mentioned.

6. The conger also becomes pregnant, though this circumstance is not equally distinct everywhere on account of its fat; for the organ of reproduction is long, like that of serpents. It becomes distinct, however, when laid upon the fire; for the fat smokes and consumes away, and the ova, when pressed, jump out with a cracking noise. If any person will feel and rub them with the finger, the fat will appear smooth and the ova rough to the touch. Some congers have fat but no ova; and others, on the contrary, have no fat but such ova as I have described. We have now treated of nearly all the oviparous animals, whether furnished with fins, or wings, or feet, and of their sexual intercourse, gestation, development, and such like subjects.