Nagel k o (6 risultati)

hardcover. Condizione: Wie neu. 299 Seiten; 9780230246348.1 Gewicht in Gramm: 1.

Microcondylaea bonellii is a freshwater mussel with a restricted distribution area that faces a serious decline. Presently, little is known about its biology and ecology. Data on reproduction, growth and habitat of a population living in a stream in northeastern Italy were collected in the years 1990-2003. The species is a short-time breeder with eggs and larvae present in its marsupia from April to June; it is capable of consecutive brooding. It releases infectious larvae in the form of conglutinates, i.e. distinct worm-like objects with glochidia embedded in a fi lamentous matrix. The host fish range is supposedly narrow but direct observations are lacking. The preferred bottom substratum are stable banks of fine to coarse-grained sand, eventually overgrown by higher water plants. The growth pattern of the study population appears to be unchanged for over a century. Identification of host fishes and preservation of favourable substratum conditions are the main factors for the conservation of the species. 9 pp., 6 figs, 4.…

6 pp., 3 figs, gr. 8.

Treated taxa: Bulinus senegalensis, Caelatura aegyptiaca, Mutela ovata, Sierraia whitei, Saulea vitrea, Sierraia leonensis, Ethria elliptica 6 pp., 1 map, 1 plate, gr. 8.

10 pp., 16 figs, gr. 8.

Komitee der Kunstausstellung, Dresden, 1962. 13 S. mit zahlr. Tafeln im Anhang, kart.--- 750 Gramm.