They are among the most widespread of the anglerfishes, found in all oceans from the tropics to the Antarctic. They are large and elongated: females of the largest species, Krøyer's deep sea angler fish, Ceratias holboelli, reach 1.2 m (3.9 ft) in length. Males, by contrast, are much smaller, reaching 14 cm (5.5 in), and, like other anglerfish males, spend much of their lives attached to a female after a free-living adolescent stage in which they are very small – at most 1.3 cm (0.51 in) – and have sharp, beak-like, toothless jaws.[2] One or more males attach themselves permanently to a female, eventually merging circulatory systems. As this genetic chimera matures, the male grows large testicles, while the rest of its bodyatrophies. Ceratiidae are the only creatures known to become chimeras as a normal part of their lifecycle.
