cadee (75 risultati)

Condizione: New.

No Binding. Condizione: Very Good. ORIGINAL 1989 Article, disbound from journal; no covers; in very good condition. Journal.

No Binding. Condizione: Very Good. ORIGINAL 1994 Article, disbound from journal; no covers; in very good condition. Journal.

Soft cover. Condizione: Good. Text is chiefly in English. "Dup" written in small, faint letters in top corner of cover, near spine; pages at back half of volume and back cover have small creasing; tight, text clean. Paginated 145-200, illustrated. Includes nicely illustrated 6-page article about the rare 2nd German ed. of Knorr's Vergnugen (1768-1784). Oversize [br bx].

Condizione: New. In.

Paperback. Condizione: New.

Netherlands Journal Of Sea Research 10: 440-460, 9 figs 8vo, offprint.

10pp, 4 figs, Printed Card Cover, VGC,

Bull. Soc. Sci. Nat. Ouest Fr. 1991: 71-79, 5 figs, 1 pl 8vo, offprint.

22pp, 13 figs, 1 b-w pls, Printed Card Cover, VGC,

E. J. Brill, Leiden - 1968, 16x24 cm, broché, 122 pages, 6 planches hors texte Excellent état - Pour les envois hors de France, la tafication «livre & brochure» pour les frais de port a disparue.Les frais de port annoncés correspondent à une moyenne. Ils seront calculés au plus juste en fonction du poids de votre article.

Paperback. Condizione: Very Good. there is wear on the corners and edges; the spine of the book is unbroken and uncreased;

8vo. Pp. viii,121, 6 plates, 52 figs., tabs., bibliogr. Orig. wrappers. - Doctoral thesis.

Condizione: Good. Originele bedrukte hardcover, veel illustraties in kleur en z/w (waaronder foto's), 4to.

PAP. Condizione: New. New Book. Shipped from UK. THIS BOOK IS PRINTED ON DEMAND. Established seller since 2000.

12 pp., 2 figs, br. 4.

Kartoniert / Broschiert. Condizione: New.

PAP. Condizione: New. New Book. Delivered from our UK warehouse in 4 to 14 business days. THIS BOOK IS PRINTED ON DEMAND. Established seller since 2000.

Assemblages of fossil brachiopods are often characterized by the absence af juvenile specimens. This absence may be due for instance to method of collection, transport by currents, mechanical destruction, diagenetic solution, predation, factors that all may work selectively on small specimens. In some instances, where it was assumed from a taxonomic analysis that these factors could be excluded, low or even absence of juvenile mortality was given as an explanation. These cases are reviewed and alternative explanations are proposed. So, the assemblage could be the result of mass-mortality (census-assemblage) of a population without juveniles due to the fact that this "census" was taken some time after the last successful recruitment. Another explanation is that adults and juveniles live spatially separated, the assemblage of shells accumulating at localities where the adults live then contains no juvenile specimens. Recent examples of spatial separation of adults and juveniles are given for different groups of marine organisms which shows this phenomenon to be widespread and not only occurring in vagile animals. As long as other explanations are available, low juvenile mortality should be used with great reservation to explain the absence of juveniles in fossil assemblages, as such mortalities are rarely observed in present-day marine animals. Although juvenile mortality is usually high in the planktonic larval stage it is by no means restricted to this stage as stated sometimes. Also just settled benthic organisms are highly vulnerable to predation and other causes of mortality. 29 pp., br. gr. 8.

Condizione: Très bon. J.L.G se sert de Zelliseller Evolution pour gérer ses Market Places.

Leiden, E.J. Brill, 1968. 121 pp. 52 figs. & 6 b./w.plts. Softcover.Text in English & small summary in Dutch.

During the last few decades nutrient concentrations in the Dutch coastal waters have increased significantly. Values observed for rates of primary production as well as for concentrations of chlorophyll and for particulate organic matter have been higher during recent years than estimates from earlier periods. Thus more food will have been available for herbivorous benthos during recent years. Both biomass and annual production of the macrozoobenthos living on the tidal flats in the western part of the Wadden Sea doubled during the 1970 to 1984 period. More than half of the species contributed to this increase. In the species studied in most detail, Macoma balthica, both reproductive success and growth rate increased significantly during the 15-year period. Though a causal relationship between simultaneous increases of nutrient levels, primary production and secondary production cannot be proved, such a relationship seems to be natural. So far, obvious detrimental effects such as mass mortalities from lack of oxygen appear to be rare in the well-mixed Wadden Sea. 10 pp., 4 figs, gr. 8.

6 pp., 1 pl., 4.

10 pp., 1 fig., 1 pl., 4.

A large sample rich in empty Bithynia tentaculata (Linnaeus, 1758) was collected in a drift-line along Lake IJssel, The Netherlands. Of 400 adult Bithynia shells 62 (15.5%) showed repair of a damaged outer lip, most probably due to failed attacks by predators. The roach Rutilus rutilus (Linnaeus, 1758) was probably its main shell-crushing predator here. However, repair after physical damage by waves breaking on the stones of the dike cannot be excluded completely. 4 pp., 2 figs, 4.

10 pp., 4 figs, gr. 8.

Bivalves and gastropods dropped by hooded crows (Corvus corone cornix) show - not surprisingly - a similar fragmentation as those dropped by herring gulls (Larus argentatus). Both bird species drop the shells from some height to crack them. Bivalves have one or both valves fragmented, but the valves still hold together by the ligament. Gastropods have either the spire broken off or a large hole in the body-whorl, sometimes also in the penultimate whorl. This hole is often opposite the aperture leaving the outer lip undamaged. Such large holes seem characteristic for shells dropped by birds. Stomatopods also make holes in shells but these are usually smaller. 5 pp., 2 pls, gr. 8.

Rissoa membranacea disappeared from the Dutch Wadden Sea together with the large subtidal stands of eelgrass Zostera marina L. in the early 1930s, due to a still not completely understood 'Wasting disease' in Zostera. A small population of R. membranacea survived together with Zostera marina in an inland brackish water 'de Bol' on Texel until 1981. Empty shells of R. membranacea can still be found at these localities. The relatively large size of the top-whorl of Wadden Sea R. membranacea indicates that the larvae were lecithotrophic. In this respect they are comparable to R. membranacea type B from the Roskilde Fjord of Rehfeldt (1968) and Waren (1996) and to R. membranacea s.s. as described by Verduin (1982b). It is, however, questionable whether R. membranacea Type A of Rehfeldt and R. labiosa sensu Verduin can be separated from R. membranacea s.s. They differ only in the smaller size of the embryonic whorl indicating planktothrophic pelagic larvae. This might as well indicate two different types of larval development, lecithotrophic and planktotrophic in one and the same species R. membranacea s.l. Apical dimensions in samples from the Ria de Arosa (Spain) and from Dutch Eemian deposits show a gradual change from small 'R. labiosa' to larger 'R. membranacea' values, which supports the merging of both nominal species and corroborates Waren's suggestion of a continuum in larval development in R. membranacea between lecithotrophy and planktotrophy as well as newer ideas of a gradually and easily crossed transition between lecithotrophy and planktotrophy of McEdward (1997). 10 pp., 2 figs, gr. 8.

13 pp., 6 figs, 2 pls, 4.

A mass stranding of hundreds of cuttlebones of Sepia orbignyana occurred on the coast of Texel, the Netherlands, in July 2002. Up to now usually only low numbers were found on the Dutch coast. S. orbignyana does not live in the North Sea. Accompanying drift material such as thong weed Himanthalia elongata indicates a SW origin from the Channel and skeletons of the By-the-wind-sailor Velella velella (Cnidaria, Hydrozoa, Chondrophora) may even indicate an origin from as far as the Bay of Biscay. Drift-bottle experiments in the past have indicated that it takes at least one to two months to drift from the entrance of the Channel near Plymouth to the Dutch coast. A large proportion of the cuttlebones (65%) showed peck marks by fulmars and 55% had scratch marks probably also made by birds supporting a drifting time of this length. 8 pp., 5 figs, gr. 8.