Statistical Studies of the Whale Foetuses
| Autor: | Yoshio Matsuura |
|---|---|
| Rok vydání: | 1936 |
| Předmět: | |
| Zdroj: | NIPPON SUISAN GAKKAISHI. 5:25-32 |
| ISSN: | 1349-998X 0021-5392 |
| DOI: | 10.2331/suisan.5.25 |
| Popis: | The present account is chiefly based on “International Whaling Statistics, Vol. III (1932), Vol. V (1934) and Vol. VI (1935), edited by the Committee for Whaling Statistics appointed by the Norwegian Government. Oslo.” 1. The rate of pregnacy in blue whale females does not fall at least in the range from 2 to 7 years old, while in fin whale females it falls already in the ages of 6 to 7. 2. The percentage of the twin-pregnancies (possibly including both single-ovum and double-ovum twin pregnancies). to the normal ones is as follows: blue whale 0•.5%, fin whale 0•8%, sei whale 0•6%. These percentage values are more or less smaller than those of man, horse or cow (about 1•0%). Litter sizes varying from 5 to 7 are also reported in blue whale, but they are very rare. 3. The rate of foetal growth from 2 to 9 solar months of pregnancy can be expressed by the equation l=ktnwhere, l is the body length of foetuses in cm, t age of foetus in months, and n and k are constants, of which n=1•9 with blue whale, and n=1•7 with fin whale. |
| Databáze: | OpenAIRE |
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