placoid

英汉释义

• adj.

  1.【动】板状的;有盾状鳞的

• n.

  1.有盾鳞的鱼

英英释义

• adj.

  1.describes fish scales that have a flat base and a sharp projecting spine tipped with enamel. The subclass of fish that includes sharks, rays, and skates have placoid scales.

英汉例句

• 1.enamel A shiny hard material covering the dentine of teeth and the surface of some scales ( cosmoid and placoid scales).

  珐琅有光泽的坚硬物质包覆在牙齿及一些鳞片（圆鳞与盾鳞）表面。这是脊椎动物所产生最坚硬的物质。

• 2.dentine A hard mesodermal material in teeth and some scales (cosmoid, ganoid and placoid scales) produced by odontobasts.

  齿质组成牙齿或某些鳞片（硬鳞与盾鳞）中层的坚硬物质。