of oceanodromy (seasonal migration) is seen in some species. The fertilized eggs (and later the larvae) are planktonic, floating with the currents until the larvae develop the strength to determine their own way. Only the economically important species have had their reproduction studied in any detail; the larvae and juveniles of Darwin's slimehead are pelagic and frequent rather shallow waters near the coast, whereas in orange roughy, the early life stages are apparently confined to deeper water (around 200 m). Slimeheads are very slow-growing and long-lived fish; the orange roughy ranks among the longest-lived animals known, with a maximum reported age of 149 years (however, this age is disputed). Predators of slimeheads are not well known, but include large deep-roving sharks, cutthroat eels, merluccid hakes, and snake mackerels. References "Habitat, behaviour and colour patterns of orange roughy Hoplostethus atlanticus (Pisces: Trachichthyidae) in the Bay of Biscay" Journal of the Marine Biological Association of the UK (2002), 82:321–331. Pascal Lorance, Franz Uiblein, and Daniel Latrouite. Retrieved March 2, 2005. Fishes: An introduction to ichthyology. Peter B. Moyle and Joseph J. Cech, Jr; p. 365. Printed in 2004. Prentice-Hall, Inc; Upper Saddle River, NJ. Trachichthyidae Taxa named by Pieter Bleeker