Most vertebrae in an eel

Most eels have 100–200 vertebrae as adults, but the exceptionally attenuated, elongate bodies of the snipe eels (family Nemichthyidae – "thread fishes", appertaining to their slender form), which measure 1–2 m long, contain as many as 500 vertebrae. Yet their bodies only weigh 80–400 g. They also have very long, slender jaws – hence their common name.

Snipe eels, of which nine species are presently recognized, are found in every ocean and generally occupy depths of 300–600 m, but their larvae (leptocephali) occur in much shallower waters. Although many specimens of snipe eel have been procured, the only food items found inside their stomachs have been shrimp-like crustaceans, even though ichthyologists assume that they should be capable of catching and ingesting small fishes and cephalopods too, especially given the size of their jaws.