摘要:

Abstract.The brown algaScytosiphon lomentariais discussed as a possible indicator of heavy‐metal contamination of marine coastal waters. A comparison with other brown algae shows that a strong development of the specific surface ofS. lomentariathallus increases the ability of accumulating suspended iron and lead from ambient waters. The paper presents the results obtained from several localities in the Sea of Japan.Scytosiphonhas an advantage over other indicator species used in the monitoring of sea heavy‐metal contamination due to its virtually “cosmopolitic” distr

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1985.tb00133.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Marine turtles harbour a variety of epizoa, some of which are specific to these hosts, but shelled gastropod and bivalve mollusks were previously unrecorded on marine turtles. Thousands of turtles of five species from all major oceans were examined. Loggerheads,Caretta caretta, from Greece and the states of Georgia and Florida, USA, were the most remarkable hosts to mollusks. At least 15 species of bivalves and 5 species of gastropods were found on turtles. Many turtles hosting mollusks carried only one species and few individuals. Edible oysters, the most common molluscan epizoan on Grecian Loggerheads, may grow to more than 10cm in diameter, so in some cases the mollusks may survive for several years on the turtle. Large epizoan bivalves may in turn serve themselves as substrates for epizoa, molluscan or otherwise. There are no known obligate relationships between turtles and mollusks, although there may be a parasitic relationship between the Loggerhead turtle, a spirorchid blood fluke, and a gastropod intermediate host. It is unknown if turtles carrying mollusks are at a disadvantage.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1985.tb00134.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Amounts of photosynthate in the rhizomes, in photosynthetically inactive basal parts of the leaves and different old leaf blades were examined. Winter leaf growth was supported by mobilisation of starch in the rhizome. This winter growth enablesPosidonia oceanicato utilize the increased energy influx in early spring via the substantial leaf area already developed and to approach highest productivity in spring. During summer and autumn considerable concentrations of soluble carbohydrates were found in the leaves and rhizomes. Starch was stored in the rhizomes in concentrations of up to 6.8 % of dry weight. Levels of nitrogen and free amino acids were correlated with growth rates. The percentage of total nitrogen present as free amino acid‐nitrogen decreased from November (35 %) to summer (less than 1 %), by which time leaf growth had stopped. In contrast to this, amounts of organic anions were low in winter and spring and reached their maximum in summer.Within a shoot, sites of leaf growth were characterized by high amounts of total nitrogen and free amino acids (innermost leaves), while carbon Fixation was highest in the leaves #2–#4. Particularly high concentrations of soluble carbohydrates were found midway along leaf blades.It is evident that this unusual growth rhythm ofPosidonia oceanicawas only possible because of the ability to store considerable amounts of carbon and nitrogen in the rhizomes.The results of this investigation demonstrate on the one hand that the chemical composition of the plant is strongly correlated with growth and production, and on the other hand that it is dependent on environmental factors, such as energy influx and temperature, which change with sea

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1985.tb00135.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Rhynchozoon larreyi(Audouin, 1826) is a successful competitor for space in sessile reef communities at Port Sudan and Eilat (Red Sea). At these localities it has always been found in association withZancleasp. The relationship between the two species is regarded as mutualistic. The hydroid benefits through association with a successful spatial competitor; the bryozoan gains advantage through protection of its surface from predation and fouling. Morphological modification of the bryozoan colony in response to this association leads to a highly organized reticulate surface pattern, which provides both symbionts with access to feeding currents.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1985.tb00136.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1985.tb00137.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY