Algal symbiont

According to this equation an 0 increase of 0.26%c in carbonate represents a 1°C temperature decrease. Bemis et al. (1998) have re-evaluated the different temperature equations and demonstrated that they can differ as much as 2°C in the temperature range between 5 and 25°C. The reason for these differences is that in addition to temperature and water isotopic composition, the 5 0 of a shell may be affected by the carbonate ion concentration in sea water and by photosynthetic activity of algal symbionts. 

Three cytotoxic peptides, patellamide D (31) and lissoclinamides 4-5 (32-33) were isolated from a Great Barrier Reef specimen of L. patella and identified by interpretation of spectral data. The peptides were found within the obligate algal symbiont of the genus Prochloron [65]. Another study of the same Australian L. patella reported lissoclinamide 6 (34), in addition to lissoclinamides 4-5 (32-33) and patellamide D (31). The structure of patellamide D (31) was obtained by X-ray crystallography and its conformation compared with those obtained by molecular modelling [66]. Patellamide D (31) has been reported to be a... 

Fig. 1 Evolutionary tree of Eukarya and Bacteria domains. The third domain (Ar-chaea) is omitted here since no organisms belonging to this group show photosynthetic ability. The tree is further annotated to indicate the distribution of photosynthesis among the major groups photosynthetic organisms, organisms with relict plastid but no photosynthetic genes, A some species with algal symbionts or sequestered plastids, organisms with no plastids but potentially photosynthetic genes in nucleus.

Ahermatypic coral a coral which lacks algal symbionts. 

A.T. Banaszak, R.K. Trench (1995). Effects of ultraviolet (UV) radiation on marine microalgal-invertebrate symbioses. I. Response of the algal symbionts in culture and in hospite. J. Exp. Mar. Biol. Ecol, 194, 213-232. 

Most of the paleotemperature equations appear to be similar to the one stated above (Eq. 10.6), but temperature reconstructions can differ as much as 2°C when ambient temperature varies between 5°C and 25°C (Fig. 10.2 Bemis et al. 1998 for a recent review see Mulitza et al. 2003). The reason is that, in addition to in-situ temperature and water isotopic composition, the shell 5 0 may be affected by the photosynthetic activity of algal symbionts and by the carbonate ion concentration in seawater. Wafer and Berger... 

Lichens are very sensitive indicators of sulphur dioxide pollution and their absence has been reported in many parts of the world. The primary target for the action of sulphur dioxide seems to be the algal symbiont, but the fungal symbiont is also negatively affected. 

In most lichens with two algal symbionts the blue-green algae are not distributed within the thallus but lie in special, delimited, swollen parts of the thallus. These structures, sited either in the medulla or on the upper or lower surfaces of the thallus according to the species, are called cephalodia. 

Studies on the algal symbionts of animals showed two ways of inducing the algae to release carbohydrate to the host. Cernichiari et al. (1969) de-... 

In the foregoing section several theories have been advanced to explain carbohydrate release by lichen algae. None of these theories is satisfactory for all lichens and work is needed to determine if there is one mechanism for all lichens or several mechanisms dependent on the type of algal symbiont. The fact that some lichens contain more than one type of alga indicates that there is still value in searching for a single mechanism. 

In a series of experiments, Richardson et al. (1967) showed that it was the alga rather than the fungus which controlled the rate of movement between the symbionts. The authors examined several species of Lobaria. In this genus the fungal components of the lichens are closely related but the algal symbionts are different. Lobaria scrobiculata contained Lobaria... 

Fruiting of the fungus occurred independently of the algal symbiont as well as the substratum. Low pH stimulated development of the fruits of C. cristatella. Drying also is a stimulatory factor in ascocarp development but it is more important for pycnidial development. Formation of juvenile apothecia was not as frequent as pycnidia and occurred on colonies that were not subjected to drying. Endocarpon developed perithecia and... 

Attempts to synthesize an Endocarpon fungus and the algal symbiont =Stichococcus mimbilis) of Staurothele clopima and vice versa were not successful. This indicates a specificity among the symbionts. 

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