Caudal luring species and allegedly by two lizards, though other interpretations (e.g., distraction) seem more plausible for the lizards. Caudal luring also occurs in a shark, the tasselled wobbegong, "Eucrossorinus dasypogon" and very likely in the pelican eels, "Eurypharynx", which possess a bioluminescent tail tip. The behavior is associated with sedentary predators whose diets include animals susceptible to a worm-like (or fish-like, in the case of "Eucrossorinus" and perhaps "Eurypharynx") luring appendage. Snakes generally lure small ectotherms (e.g., frogs and lizards), although luring of birds has been demonstrated (Spider-tailed horned viper) and luring of insectivorous mammals is suspected. Caudal luring occurs most
Operculum (gastropod) shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which are not capable of closing the shell aperture. Opercula have sometimes been modified: in the Strombidae the operculum is claw-shaped and is used