OUT OF NATURE’S CURIOSITY SHOP

Dominion, Volume 21, Issue 291, 8 September 1928, Page 24

OUT OF NATURE’S CURIOSITY SHOP

THE LUNG FISH

At a recent meeting of the Llnnean Society of New South Wales, an extremely interesting paper was contributed by Dr.T. L. Bancroft, the wellknown Queensland naturalist, qpoit the life history of the Australian, lung fish (Ceratodus foster!), says the » Sydney “Morning Herald.” For the last seventeen years, Dr. Bancroft has been investigating the habits and life history of this fish, which is so remarkable that some zoologists claim that it is not a tish but an amphibian. For seventeen years Dr. . Bancroft.has been trying to breed the fish from the eggs under most natural conditions at his home on the Mary River; but up to the last year all these experiments have failed, for though he could develop them up to six weeks, they invariably died. Now he finds he has been all this time killing them witli kindness. In his anxiety to give Ihcm abundance of water lie had been overdoing it. When tie reverted to shallow pans with a sandbank on the side, he found the baby fish revelled in the warmer water, and rested at times on the wet sand. They passed the critical age. are now healthy little fish, and the problem is solved. This wonderful air-breathing fish is only found in the Mary and Burnett Rivers in Queensland, and in old days the settlers called them the Burnet River salmon. Though a large number of museum specimens were obtained by Rhe Australian . Museum authorities about fifty years ago. it Is only of late years that these fish have been exhibited in aquariums. There is a pair at the Zoological Gardens at Taronga Park, and also two quite at home in the aquarium at the London Zoo at Regent’s Park. With blunt head, a body of uniform thickness from the back of the head to the flattened tail, short pectoral fins, and the whole body encased in large rounded scales, it is certainly quite unique in the firsh world, while the possession of a large lung further separates, it from all other fish. There

are similar fossil fish in our rock beds, and two other surviving lung fish are found in West Africa and the Amazon River. Now, Dr. Bancroft makes the alarming statement that unless the young fry is artificially reared in hatcheries the ceratodus is doomed, and will be extinct in another decade. He bases his assertion on the fact that for some years no small fish have been seen on the rivers, and that all the existing fish are from twenty to thirty years old. This he considers due to the small number of eggs each female deposits (about 300) and the number of carnivorous aquatic insects which swarm in these waters, and which devour the freshly-laid eggs and tiny fry before they can fend for themselves. Some of the members present at the meeting asked if this be so how did the young ceratodus develop among its enemies in old days, but this, I think, can be explained in several ways. There may have been more small fish of other kinds which devoured the dragon fly larvae, water bugs, and other predators. Wiki fowl, now absent on account of settlement, may have frequented the rivers, or other simple changes may have altered the balance of nature on these rivers. If this danger of extinction is correct it is a matter for the consideration of the Curator of the National Museum of Australian Zoology at . Canberra. Not counting the world- wide interest of the scientific world in the preservation of the ceratodus, from an economic point of view an up-to-date hatchery should be established on the Mary River. Even if it is a slow-growing creature, as some authorities state, a regular supply of healthy young ceratodus, which could be used to stock other rivers, and be sent all over the world for aquarium specimens, should be a good investment.