红耳龟密西西比亚种Trachemys scripta elegans
别名：巴西龟、红耳龟、红耳彩龟
形态特征：头中等大小，成体背甲呈椭圆形，形状较扁平，长150～200mm，雌性较雄性体型大。背面颜色由幼年到成年由浅至深，呈翠绿色、深绿色或墨绿色等，其上杂以黄绿色及黑褐色条纹；缘盾具深褐色同心圆纹；腹面浅黄色，每枚盾片之上具黑色斑块；头部墨绿色、深绿色等，杂以黄绿色条纹，两眼后各有一道醒目的红色条斑；四肢背面、尾墨绿色，其上亦有黄绿色细条纹。雌性尾细，泄殖腔孔位于背甲后缘之内；雄性尾粗且长，泄殖腔孔位于背甲后缘之外。
生活习性：栖于池塘、河流、水库等多种水环境；杂食性，捕食小鱼、小虾等，亦取食水生植物。
地理分布：原产于美国，后被引入世界多地。
环渤海地区分布：均有发现，但未形成自然繁殖种群。
注：该种为著名的观赏及食用龟类，原产于美国密西西比河及格兰德河流域，经由宠物贸易扩散至全球诸多水系，我国南方多个省份已发现入侵种群。该物种适应能力极强，与本地物种竞争食物、栖息地等生存要素，被世界自然保护联盟列为世界最危险的100个入侵物种之一，应严禁将其放生于开放水域。
Testudines Emydidae Trachemys
70.Trachemys scripta elegans
Description Adults' body size up to 150-200mm, females' are bigger than males;head is in medium size; carapace is in oval shape and flattened; color of the carapace is changed depending on the age of the turtle.Carapace's color is usually green, or dark green background with yellow green and dark; highly variable markings; brown concentric circle pattern on the scutes; plastron always in light yellow color with dark, paired, irregular markings in the center of most scutes.Green head has fine, irregular, yellow lines; one distinguishing red stripe is on each side of the head; (external) ears is behind the eyes; dark green legs and tail, with fine yellow green lines.Female's tail is thinner, the cloacal opening at or under the rear edge of the carapace; male's tail is thicker, longer, the cloacal opening beyond the edge of the carapace.
Behaviour Trachemys scripta elegans inhabit those areas with a source of still, warm waters, such as ponds, lakes, creeks, streams, or slow-flowing rivers, and reservoirs.They are omnivores.They normally feed on the small prey, such as small fish, shrimps and aquatic plants.
Distribution Native to America and then are introduced to the world.Distribution around Bohai Sea: found but not form the natural breeding population.
Notes Trachemys scripta elegans provide a famous food source and ornamental value.They originated from the area around the Mississippi River and Rio Grande River Basin,and have been introduced all over the world through the pet trade.They have become an invasive species in many southern provinces of China.With strong adaptability, they outcompete native species and they are included in the list of the world's 100 most invasive species published by the IUCN.Releasing them in open waters should be forbidden and prevent them escape during feeding.