Using a comparative anatomy study and recent DNA samples, deep sea ichthyology researchers have determined that what was once thought to be three separate fish species is actually one species, at different growth stages and genders. The larval stage of the Cetomimidae, a species colloquially known as "flabby whalefish," was once called Mirapinnidae, or tapetails. Tapetails are so called because they have long, streamer-like tails which dangle out behind them. The larval stage lives relatively near the surface, where food is plentiful. The male larval Cetomimidae gorges itself during this stage, much like a caterpillar gorges itself before becoming a butterfly. And like butterflies, male adult Cetomimidae do not eat. Adult Cetomimidae, formerly classified as Megalomycteridae and called "bignose fish" have a mouth which is fused shut. They live off the fat stored in their liver as they search the ocean depths for a mate. The female adult Cetomimidae has a huge mouth, and also sports teeth inside her gills, which can serve as a separate mouth. This type of extreme sexual dimorphism is not unusual in deep sea fishes, presumably because resources are so scarce. The anglerfish is probably the most famous example of deep sea dimorphism. The female anglerfish is relatively large, with a gaping mouth, and a luminescent "fishing lure" which she dangles over her mouth. Meanwhile the male anglerfish is a tiny fraction of her size, and lives as a parasite, embedding himself in her skin and feeding off her own blood system. A female anglerfish will typically have several parasitic males embedded in her skin.