尼罗尖吻鲈(Lates niloticus L．)的形态和生物学特性

Morphological and Biological Characteristics of Nile Perch(Lates niloticus L.)

解剖观察自埃及引进的尼罗尖吻鲈（Lates niloticus L．），对其形态特征做了详细记录，并在养殖过程中对生物学特性做了观察。尼罗尖吻鲈体延长，侧扁；DⅦ-Ⅷ，10—14。前鳃盖下缘有强棘；鳃盖后缘呈锯齿状，有一硬棘。被鳞为栉鳞，中等大小，侧线清晰与体背缘平行，具侧线鳞60—80枚。尾鳍圆滑不分叉。成鱼鱼体银白色，并有暗色条纹，幼鱼背部大多有青黑色斑块，下半部银色。消化道粗短，与体长之比约为0．66。尼罗尖吻鲈是热带种类，肉食性，适宜生长温度为26～32℃，生长速度快，一般2—3年性成熟。

The Nile perch（ Lates niloticus L. ）was introduced from Egypt in 2003. The morphological and biological characteristics of Nile perch were studied and recorded in the paper. The fish body is long and compressed. The dorsal fin has 7 -8 spines and 10 - 14 soft rays. Caudal fin is rounded. Pre-orbital and pre-opercular bones armed with spines and a large spine is on the free edge of the operculum. Scale is ctenoid scale with middle size. Lateral line has 60 - 80 scales. The length of intestine is 0. 66 of the body length. Color of body is dark greyish-blue dorsally and greyish-silver on flank and ventrally. Nile perch is a tropical and carnivorous species. The growth rate is faster and the suitable temperature for growth is 26 - 32 ℃. The gonad maturation usually takes 2 - 3 years for the fish.