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The Duration of Larval Life in Ammoccetes and an attempt to accelerate Metamorphosis by Injections of an Anterior‐Pituitary Extract.
Author(s) -
Knowles F. G. W.
Publication year - 1941
Publication title -
proceedings of the zoological society of london
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0370-2774
DOI - 10.1111/j.1469-7998.1941.tb08475.x
Subject(s) - lampetra , metamorphosis , larva , lamprey , biology , population , zoology , anatomy , fishery , ecology , demography , sociology
Summary. (1) The injection of a thyreotropic fraction of the mammalian pituitary in ammoccete larvse of Lampetra planeri produces a rapid and marked decrease in body‐length, and also histological changes in the endostyle. These changes were found to be reversed if further injections were given. (2) No other signs of metamorphosis were observed in the injected animals. (3) Monthly samples of the ammoccete population in the river Sarno, Naples, Italy, indicate that the larval life of lampreys in that region may extend for not less than two years and not more than three years approximately. I should like to thank Dr. R. Dohrn for the facilities afforded me at the Stazione Zoologica, Naples. The pituitary extracts used in the experiments were kindly supplied by Dr. A. S. Parkes and the British Medical Research Council. I am grateful to Professor Goodrich, F.R.S., and J. Z. Young, M.A., for reading the paper and for helpful criticism. I am also grateful to Angelo Sessa for his help in making the lamprey samples in the river Sarno.