Live-Bearers Are Born About 1/4-Inch Long
The optimum temperature for the fastest development of the eggs inside a female is between 77 F and 80 F. Development will take approximately 4 weeks in the average live-bearer. At 68 F, the interval lengthens to some 35 days or more. In dull light, the development lengthens. The eyes of the fish are sometimes visible through the thin walls of the gravid spot. To accommodate the developing eggs, the mother’s body expands, becoming deeper and broader. A few days before delivery, she develops a bulge below the gills. As a result, her outline became fairly square. The majority of live-Bearers are about 1/4-inch long. They are not only much larger than the newly hatched young of egg-layers, but are also capable of swimming and looking for food. Dr. Myron Gordon found 168 embryos in a large wild-caught Platy fish. The swordfish mature at six to eight months old while the guppies deliver their first offspring at only 90 days old. . . .