Histological analysis of hatchlings of the Australian lungfish, Neoceratodus forsteri, from water impoundments reveals fundamental flaws in development

Anomalies in embryos and hatchlings of the Australian lungfish are now found in many of the environments inhabited by lungfish, such as reservoirs (Lakes) created over natural rivers, and affect many tissues and organs in the body, most obviously the epidermis and related sense organs, but extending to blood vessels and skeletal structures as well. Development of muscular tissues is affected, but only by the lack of nutrition in the eggs as laid by the parents, and by failure of the hatchlings to feed. They are found in embryos collected from the Lakes and reared in the laboratory by standard methods, and are also present in embryos and hatchlings collected directly from the Lakes. They are not found in fish collected from unaltered parts of Rivers below the Lakes. Recently, in the Lakes, the anomalies are so widespread, and so serious, that they affect all the young of one season. The most probable cause of abnormal development is a lack of volatile fatty acids in the diet of adults, resulting in the production of poor quality eggs, as has been found in other species of fish. The results of this study have serious implications for survival of the species, since almost every habitat where lungfish are found, and are still spawning, has now been altered by the building of water impoundments. Restoration of freshwater environments in south-east Queensland should be a priority for the State and Federal Governments and for water authorities.