Twait shad destruction. Conservation of this species is covered by Appendix III of the Bern Convention and Appendix II and V of the European Community Habitats Directive. The twait shad is a typical herring-type fish and much resembles the allis shad. It has no lateral line and the belly is more rounded than that of the sprat and Baltic herring. The gill cover is ridged and the caudal peduncle has large, plate-like scales. This fish is more colourful than the Baltic herring. The back is a bluish green colour and the head brownish with a golden tinge on the operculum. The flanks
Caudal luring are a number of other behavioural interpretations for a wiggling appendage, and luring-like motions are associated with several other behavioural contexts (e.g., defence, stress, etc.). Caudal luring is thought to have evolved from a caudally localised intention movement (a behaviour derived from locomotor movements). Essentially, the act of remaining stationary while sensing prey produces general nervous system excitation that gets released in the form of tail movements. Caudal luring is not merely tail undulations, but must specifically be attractive to prey. Caudal distraction is another behaviour used by snakes, and the tail motions are very similar to caudal luring. The