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
Operculum (brain) Operculum (brain) In human brain anatomy, an operculum (Latin, meaning "little lid") (pl. opercula), may refer to the frontal, temporal, or parietal operculum, which together cover the insula as the opercula of insula. It can also refer to the occipital operculum, part of the occipital lobe. The insular lobe is a portion of the cerebral cortex that has invaginated to lie deep within the lateral sulcus. It sits like an island (the meaning of "insular") almost surrounded by the groove of the circular sulcus and covered over and obscured by the insular opercula. A part of the parietal lobe, the