颗粒犁头鳐

颗粒犁头鳐俗称六件鲨.属鳐A形目犁头鳐亚目犁头鳐科.吻长平扁，呈三角形突出.眼小而圆.喷水孔卵圆形，后缘外侧具一细小皮褶.鼻孔狭长，前鼻瓣具一扁须状突出，不转入鼻间隔区域；后鼻瓣发达，转入鼻腔内.口横裂，略呈弧形.牙细小而多，呈铺石状排列.鳃裂５个，狭小.体背面和鳍上密生颗状鳞片.沿背面正中线上有一行粗大结刺.眼上方和肩区亦有小结剌.背鳍２个，大小约相等，第一背鳍位于腹鳍后方.尾平扁，尾侧皮褶发达，尾椎轴平直.尾鳍狭长，上叶发达，下叶不突出.生活时背面赤褐或紫褐色，吻侧淡赤色，腹面白色.为暖水性中小型犁头鳐类.一般体长１—２米.栖息于近岸浅海，常把身体半埋于泥沙中.以其他鱼类为食.卵胎生.分布于印度洋和太平洋西部.我国东海南部和南海均产.Commonly known as the six sharks. Is a skate A-shaped mesh guitarfish suborder Rhinobatidae. Snout length flat flat, triangular prominence. Eyes small and round. Spiracle oval, posterior margin with a small lateral skin-fold . nostrils, long and narrow, the former nose-shaped petals with a prominent bian must not turn into the nose interval region; post-nasal valve developed into the nasal cavity. mouth horizontal crack, slightly curved. teeth small and more, showing stone pavement-like arrangement of . gill slits 5, narrow. body back and fin-like scales dense stars. along the back of the middle line, there are line of thick guitar stab. eye summary of the top and shoulder area is also pierced. dorsal fins 2, the size is about equal to first dorsal fin is located in the rear ventral fin. Odaira bian, tail lateral skin-fold well-developed caudal axis straight. caudal fin long and narrow, the upper lobe developed, under the leaves, not prominent. lives on the back of red brown or purple-brown, light red rostral, ventral white. for the warm Water-based small and medium guitarfish class. generally 1-2 meters in length. inhabit shallow coastal waters, often half-buried in sand in the body. with other fish for food. ovoviviparous. found in the Indian Ocean and western Pacific. China the southern East China Sea and South China Sea are produced.