Glofish 70 gobies 260–261 breeding 230, 231 suckerlike device 261 goldfish 74, 332–343 breeding 326, 327, 328, 341 designing ponds for 300 diseases 324 feeding 316, 337 hand-stripping 326 indoor tanks 312, 313 origins and ancestry 22, 334 pigmentation and sheen 333 scales 16
Fish are the oldest of all vertebrates (animals with backbones), with an ancestry dating back more than 500 million years. However, the earliest fish to appear in the world’s oceans were very different from those seen today, since they had no jaws or scales. They lacked specialized fins, so they relied solely on tail movements to propel them through the water. Internally, their spine was made of cartilage, rather than bone.
