摘要:

Abstract.The distribution of the macrobenthic community, in relation to various physical and chemical characteristics of the sediment, was studied along the coast of Southern Tuscany (Central Tyrrhenian) in an area under the influence of the Ombrone River outflow.The zonation of the benthos was found to be primarily under the control of a gradient of water movement, as is reflected by variations in the sediment structure from the coast to the open sea. This correlation is somehow influenced by secondary gradients such as the degree of mixing of the sediment and the deposition of terrigenous materials along the river plume.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00290.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.The authors demonstrate the probable immigration and stable settling of the pycnogonidAmmothea hilgendorfi(Böhm, 1879) at one station in the lagoon of Venice. The species is widely distributed naturally on both sides of the Pacific Ocean and has probably immigrated on ship hulls through the Suez Canal to the Mediterranean. Two more cases (the pycnogonidAnoplodactylus portusand the amphipodElasmopus pectenicrus) of adventitious species in this sea are compared

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00291.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.P. oceanicaforms broad prairies which completely surround the island of Ischia. This is a histochemical and ultrastructural study of the photosynthetic apparatus of thePosidoniaplant. In the leaf, epidermal cells have a porous region underneath the cuticle and contain most of the chloroplasts. Fiber bundles run hypodermally and phenol storing cells are present in the mesophyll. Chloroplast ontogenesis is characterized by juvenile stages with provesicular bodies. Sea depth apparently affects some morphological features of the photosynthetic apparatus, like leaf blade thickness, phenolic cell and hypodermal fiber frequency.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00292.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.The excited rate of oxygen consumption, and the wet weights of the digestive gland and the gills were studied in relation to overall size. One experiment was made in Roscoff, France, one in Portaferry, N. Ireland, and three in Wicklow, Ireland. Higher levels of oxygen consumption were found in Roscoff together with greater gill weight. Seasonal changes in the level of oxygen consumption in Wicklow may be influenced by the dry wt/wet wt ratio of the gills ‐ probably an index of condition for the crabs as a whole. The power functions for allometric growth were virtually constant for each factor in all five experiments. All levels of factors were reduced in males weighing more than 60 g. Disproportions in the weights of the chelae marked the populations in Roscoff and Portaferry, compared with Wicklow. These suggest a genetic basis for the geographical differences in oxygen consumption and gill weight. The importance of local experiments for local conditions and the possibilities for predicting physiological rates from morphology are discusse

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00293.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Along the Sinai coast of the Red Sea a deep diving survey with the research submersible GEO investigated the depth distribution of stony corals. 47 hermatypic species were identified below 50 m; 9 species extended below 100 m. Their depth distributions are related to light penetration. Observed changes in hermatype growth forms with depth were investigated and interpreted as photo‐adaptations. 10 species of ahermatypic corals were found between 100–205 m. Ahermatype growth forms are adaptations to plankton feeding and do not change with de

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00294.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Book reviewed in this article:Bonner, J. T.: Kultur‐Evolution bei Tieren. Aus dem Amerikanischen von Ingrid Horn. Paul Parey VerlagMayer, GarryF. (Ed.): Ecolocical Stress and the New York Bight: Science and Manageme

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00295.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY