Aleyev (6 Ergebnisse)

Zustand: Good. 441 pp., hardcover, ex library, else text clean & binding tight. - If you are reading this, this item is actually (physically) in our stock and ready for shipment once ordered. We are not bookjackers. Buyer is responsible for any additional duties, taxes, or fees required by recipient's country. Photos available upon request.…

Zustand: New. In.

Paperback. Zustand: Brand New. 444 pages. 9.02x5.98x1.00 inches. In Stock.

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - 1. Nekton as an ecomorphological type of biont The term nekton was suggested and used for the first time in 1890 by E. Haeckel in his book Plankton-Studien. Etymologically the word nekton derives from the Greek VTJKTTJP, i.e. swimming. As Haeckel defined it, nekton describes collectively all swimming animals that are 'free to choose their path', i.e. can resist a strong current of water and, distinct from planktonic animals, go where they wish. While giving a general idea of the dividing line between plankton and nekton, Haeckel's definition, which has played an important role in shaping our ideas about nekton, today no longer provides a sufficient basis for ecological and functional morphological investigations, since it affords no possibility of quantitatively assessing either the boundary between plankton and nekton or that between nekton and other ecomorphological types of biont. Thus Parin (1968), proceeding from Haeckel's principle, believes that in the epipelagic zone of the ocean the minimum size of nektonic fishes with a well-developed capacity for active swimming may be between 15 and 30 cm, as fishes shorter than 15 cm are unable to counter oceanic currents. Meanwhile young Leucaspius (Leucaspius delineatus) only 1.5 cm long, observed by this writer in ponds near Moscow proved capable of active horizontal migrations across the entire body of water, which, if Haeckel's definition is accepted, brings the border between planktonic and nektonic fish in this case to between 1.5 and 2.0 cm. …

Hardcover. Zustand: Fine. No Jacket. First Edition. Hardcover; 8vo, 435 pages. FIRST EDITION. Blue cloth hardcovers with gilt lettering on cover and spine. The pages are glossy, bright, and clean. Missing the jacket, but the flap was retained and laid in back. Including numerous illustrations. FINE/--. Book. …

392 p., 147 figs, cloth. Library stamps (Zoologisch Museum Amsterdam). Good copy of the scarce original Russian edition. In Russian with English summary.Thorough study of nekton as defined against benthos and plankton.