Beitrag
On the problem of aggregations of planktonic crustaceans
[Polyphemus pediculus (L.), Cladocera]
Butorina, L. G.
Archiv für Hydrobiologie Volume 105 Number 3 (1986), p. 355 - 386
24 Literaturangaben
veröffentlicht: Jan 24, 1986
DOI: 10.1127/archiv-hydrobiol/105/1986/355
ArtNo. ESP141010503007, Preis: 29.00 €
Abstract
Aggregations of Polyphemus pediculus, the mass representative of the freshwater Cladocera, are schools without dominance. In a water-body they stay in permanent places and have distinctly contoured mushroom-like shape. The density and size of the schools, as well as the shape, size and density of their surface patches, depends on the water-body type, time of the day, meteorological conditions, composition and number of the crustaceans in them. There is no hierarchy in the schools. Their composition is marked out for its inconstancy. It quickly and repeatedly renews during the day as a result of horizontal and vertical migrations, and it also changes during the vegetation season. One-type individuals in the school are always in one phase of the life cycle. The school has a chaotic structure. The crustaceans in it see well the biotope, individuals of their own species and come into active contacts with each other. The crustaceans are able to transmit information from individual to individual and owing to this coordinated actions of the whole school are performed. Visual channel prevails in the communication of Polyphems. The crustaceans possess colour vision. The school is, primarily, a feeding union of crustaceans, facilitating spotting of sexual partners and preservation of the young.
Schlagworte
crustaceans • plankton • Polyphemus pediculus