Sperm whales, Whitehead, Hal

Автор: Todd K. Shackelford; Nicholas Pound
Название: Sperm Competition in Humans
ISBN: 1441939172 ISBN-13(EAN): 9781441939173
Издательство: Springer
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Цена: 19589.00 р.
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Описание: In species with internal fertilization, sperm competition occurs when the sperm of two or more males simultaneously occupy the reproductive tract of a female and compete to fertilize an egg (Parker, 1970).

Автор: Yuri Mikhalev
Название: Whales of the Southern Ocean
ISBN: 3030292517 ISBN-13(EAN): 9783030292515
Издательство: Springer
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Цена: 25155.00 р.
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Описание: Based on actual data of Soviet whaling, and reliable methodologies that existed at the time when this monograph was written, it examines the distribution and migration patterns of whales of the Southern Ocean. It defines distinct populations on the basis of phenes, as well as whale breeding zones, which are located in the adjacent to the Southern Ocean waters at lower latitudes. The book records the presence of a new species of killer whale in the Southern Ocean - Orcinus nana. Prenatal growth patterns, pregnancy and lactation duration, mean sizes of new-born whales are determined. Methods for the graphic recording of registering structures are described, and an original method for their decoding is proposed to determine animal age. The age of sexual and physical maturity, life expectancy is determined. Earlier unknown “pair formations” on the lower jaw of baleen whales and sperm whales are described, together with their macro, histological and electronic microscopic structure. The impact of the extermination of whales on the Southern Ocean ecosystem is examined, recommendations for control of the current state of whale populations are given, and perspectives of whale population recovery are estimated. Regions that could be used as testing areas for whale registration method are defined. The book is intended for biologist-cytologists, ecologists and other specialists interested in cetaceans, and for biology students.

Автор: J.G.M. Thewissen
Название: The Emergence of Whales
ISBN: 1489901612 ISBN-13(EAN): 9781489901613
Издательство: Springer
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Цена: 28734.00 р.
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Описание: Research in whale origins is now in an explosive phase, with a cascade of discoveries adding to our understanding of the evolutionary pattern and a suite of new techniques being applied to address new questions.