Celestial Eye have deeper bodies and shorter fins, and have selectively bred for these features as required by the British standard. In recent decades, the Chinese have crossed Celestials with several other breeds, most commonly Lionheads, Ranchus and Pompoms, producing much larger fish with short ranchu-like fins and very deep, blocky bodies, often with nasal 'bouquets' (pompoms) and rudimentary headgrowths. Some of these crosses tend to be less animated swimmers, especially those that possess a short, sharply downturned, ranchu-like caudal peduncle with flared and short caudal fins, traits which are otherwise uncharacteristic for the breed. Such fish can be quite sedentary, spending
Caudal luring often in juvenile snakes and is most prevalent in vipers and pitvipers, but it also occurs in boas, pythons, tropidophiids, colubrids, and elapids of the genus Acanthophis. Caudal luring has been used as an experimental paradigm to investigate stimulus control and visual perception in viperid snakes. It has been suggested that caudal luring was involved in the evolution of the rattlesnake rattle. Attempts have been made to test this hypothesis, however, the evidence is contentious. There have been dubious reports of caudal luring and concomitant speculations. Prey luring in general is confounded by false interpretation. The difficulty is that there