Five species of acanthocephalans of the family Centrorhynchidae are recorded from birds in Bulgaria: Centrorhynchus amphihius Das, 1950 from Buteo buteo (L.) (new host record), C. glohocaudatus (Zeder. 1800) Luhe, 1911 from Falco tin-nunculus L. and F. vespertinus L, (new host record), Sphaerimstris picae (Rudolphi, 1819) Golvan, 1960 from Pica pica (L.) and Lanius excuhitor L. (new host record), S. lancea (Westrumb, 1821) Golvan, 1960 from Vanellus vanellus (L.), and S. turili (Yamaguti, 1939) Golvan, 1960 from Turdus merula L„ Cinclus cinclus (L.) (new host record) and Stumus vulgaris L. (new host record). New geographical record for Europe is this of C. amphihius, and for Bulgaria - this of S. lurdi. The species are described and figured on the basis of Bulgarian specimens. Sphaerimstris picae is recognized as a valid species and S. teres is considered its synonym. A male of S. picae with a copulatory cap is reported.
The effect of ultraviolet B radiation (UV-B) on cellular ultrastructure, chlorophyll (Chl), carotenoids, and total phenolics of Acrostichum danaeifolium gametophytes was analyzed. The control group of spores was germinated under standard conditions, while the test group of spores was germinated with additional UV-B for 30 min every day for 34 d. The cell characteristics were preserved in gametophytes irradiated with UV-B, but the number of starch grains increased in the chloroplasts and the more developed grana organization in contrast to the chloroplasts of the control group. Chl a content decreased, while Chl b content increased in the gametophytes cultivated with UV-B for 34 d. Contents of lutein and zeaxanthin decreased and trans-β-carotene concentration was enhanced in the gametophytes irradiated with UV-B. The content of total phenolic compounds increased in the gametophytes cultivated with UV-B. Therefore our data suggest that the gametophytes of A. danaeifolium, a fern endemic to the mangrove biome, were sensitive to enhancement of UV-B radiation at the beginning of their development and they exhibited alterations in their ultrastructure, pigment contents, and protective mechanisms of the photosynthetic apparatus, when exposed to this radiation., A. M. Randi, M. C. A. Freitas, A. C. Rodrigues, M. Maraschin, M. A. Torres., and Obsahuje bibliografii
Acclimation of the photosynthesis of C3 plants to elevated atmospheric CO2 concentrations is ffequently observed. Some hypotheses ffequently proposed to explain this phenomenon are: (7) stomatal closure; (2) inhibition of photosynthesis by starch accumulation, and (5) reduced activity or concentration of ribulose-1,5- bisphosphate carboxylase/oxygenase. These hypotheses are compared with experimental evidence ffom the literature.