Sigwart j d (6 resultados)

Epibiotic foraminifers selectively settle on the most food-rich area of the host substrate, even when the species acts as a facultative ectoparasite in later life stages. In 398 specimens examined of the deep-sea chiton Leptochiton arcticus from Iceland, 46% show evidence of infestation by foraminifers, with many showing extensive shell damage from present and past bioeroding epibionts. Disturbances to the inner layer of the host shell are indicative of parasitism, as evidenced both by wound healing calcification and protrusions of the foraminiferan tubules. The epibionts employ different feeding strategies at different stages of their life cycle, taking advantage of nutrient availability from the posterior respiration currents and excrement of the chitons as juveniles, and feeding parasitically as adults. Epibiont persistence on individual hosts ? through successive generations, or long-term continuous bioerosion by epibionts ? allow larger adult parasitic foraminifers of Hyrrokkin sarcophaga to penetrate the thick tail valve of a chiton and feed parasitically on the host tissue. The proportion of chitons infested increases with host size, indicating that epibionts are accumulated through a chiton s life, seemingly without major detriment to host survivorship. 7 pp., 5 figs, 4.…

We report observations from a very short survey of micromolluscs collected on the seaweed Caulerpa from several sites near Cebu, in the Philippines. We recovered 159 morphospecies of bivalves and gastropods on Caulerpa spp. from point sampling of seaweed from across four markedly different habitats: active aquaculture, disused aquaculture sites, mangrove, and coral rubble. The contribution of Caulerpa spp. to local molluscan biodiversity varied at a larger scale among habitats, ranging from a maximum of 108 morphospecies per site in coral rubble adjacent to reef areas, to only 5 species of molluscs found on commercially grown Caulerpa. But there was a substantial fine scale variation, as two adjacent sites in coral rubble had 41 or 76 morphospecies. The limited nature of the sampling yet high species richness highlights known patterns of extremely high marine biodiversity in Southeast Asia and the Philippines in particular. The level of variability reflects the dynamic nature of these habitats and high local-scale variability. The seaweed Caulerpa has commercial importance and is cultured locally in pond aquaculture, but in the wild Caulerpa provides important habitat for molluscan biodiversity. 7 pp., 5 figs, 4. …

Kl.-4to. 28 S., 1 mehrfach gefaltete Kupfertafel. Rücken-Broschur (angestaubt, etwas knickspurig, Stempel auf Titelrückseite). Abhandlung über siamesische Zwillinge, in diesem Falle wohl verfasst von dem Sohn des Praeses, dem Respondenten Aug. Joh. David Sigwart, der bereits die Stellung eines Prosectors innehatte. Die Kupfertafel mit Darstellungen eines am Bauch zusammengewachsenen Zwillingspaares. la.…

Softcover/Paperback. Condición: Gut. 1. 192 S. Gutes Exemplar, geringe Gebrauchsspuren, Cover/SU berieben/bestoßen, Schnitt/Papier nachgedunkelt, innen alles in Ordnung. D260911axm66 ISBN: 9783777446820 Sprache: Deutsch Gewicht in Gramm: 863.

LeatherBound. Condición: NEW. LeatherBound edition. Condition: New. Reprinted from 1759 edition. Leather Binding on Spine and Corners with Golden leaf printing on spine. Bound in genuine leather with Satin ribbon page markers and Spine with raised gilt bands. A perfect gift for your loved ones. NO changes have been made to the original text. This is NOT a retyped or an ocr'd reprint. Illustrations, Index, if any, are included in black and white. Each page is checked manually before printing. As this print on demand book is reprinted from a very old book, there could be some missing or flawed pages, but we always try to make the book as complete as possible. Fold-outs, if any, are not part of the book. If the original book was published in multiple volumes then this reprint is of only one volume, not the whole set. Sewing binding for longer life, where the book block is actually sewn (smythe sewn/section sewn) with thread before binding which results in a more durable type of binding. Pages: 36.…