Temperate eels are well known for partial migration where contingents may remain settled in marine habitats or move between seawater and brackish and freshwater habitats during their sub-adult life. This behaviour is less described in tropical Anguillid eels, particularly as it relates to salinity preference, habitat selection, and growth. In this study, glass eels Anguilla marmorata were collected from an estuary near the Cagayan River, northern Philippines, and observed for their behaviour and growth response in freshwater, brackish water, and seawater. A. marmorata glass eels spent most of their time in freshwater and brackish water and the least amount of time in seawater throughout the 30-min trial. Some individuals showed switching behaviour between salinity choices, but freshwater was the final selection. Growth-in-length was moderately and significantly lower for seawater-reared glass eels than those reared in freshwater and brackish water. Glass eels reared in freshwater had the highest survival, followed by those reared in brackish water and seawater. Habitat choice, growth, and survival trials all indicated that A. marmorata glass eels found in the Cagayan River have a major preference for freshwater and brackish water over seawater. These findings raise concerns with regard to the increased fishing pressure of eels, water pollution, and quarrying which is concentrated in freshwater habitats.

温带鳗鱼因部分迁移而闻名，在这些物种中，特遣队可能在其成年后的生活中仍定居在海洋生境中，或在海水与咸淡水和淡水生境之间移动。这种行为在热带鳗鱼中很少被描述，特别是因为它与盐度偏好，生境选择和生长有关。在这项研究中，玻璃鳗安圭拉marmorata从附近的卡加延河，菲律宾北部河口收集，并为淡水，半咸水，海水和他们的行为和生长反应观察。沙枣在整个30分钟的试验中，玻璃鳗大部分时间都花在淡水和微咸水中，而海水中的时间最少。有些人表现出在盐度选择之间的切换行为，但是淡水是最终的选择。海水饲养的玻璃鳗的生长长度适中，明显低于淡水和微咸水中饲养的鳗鱼。在淡水中饲养的玻璃鳗存活率最高，其次是在微咸水和海水中饲养的玻璃鳗。栖息地的选择，生长和存活试验均表明，A。marmorata卡加延河中发现的玻璃鳗鱼比海水更偏爱淡水和微咸水。这些发现引起了人们对鳗鱼捕捞压力增加，水污染和采石场集中在淡水栖息地的担忧。