AN ULTRASTRUCTURAL STUDY OF SPERMATOZOA OF HELIX ASPERSA AND HELIX POMATIA (GASTROPODA, PULMONATA)
نویسندگان
چکیده
منابع مشابه
The Mucoproteins of the Snails, Helix Aspersa and Helix Pomatia
The problem of the structure of complex proteins containing carbohydrates in their molecule is still a subject of discussion. The fundamental questions which have been debated during the last decades and which have been the subject of many controversies are concerned with the nature of the carbohydrate group present in the molecule of these substances. Since the discovery of mucoproteins or muc...
متن کاملThe hydrolysis of glucosaminides by an enzyme in Helix pomatia.
IT has long been known that the polysaccharide chitin when completely hydrolysed yields glucosamine and acetic acid; in recent years it has indeed been shown conclusively that the basic unit of the polysaccharide is N-acetylglucosamine. The evidence for the latter statement rests, firstly, on the discovery by Karrer & Hofmann [1929] ofan enzyme in Helixpomatiawhich is able to hydrolyse chitin t...
متن کاملThe Evaporation of Water from Helix Aspersa
It is known that the activity of terrestrial pulmonates is connected in some way to the extensive and often rapid fluctuations in water content which are characteristic of these animals (Howes & Wells, 1934; Wells, 1944). The work of Hughes & Kerkut (1956) and Kerkut & Taylor (1956) has further shown that the activity of the pedal ganglion of slugs changes with the osmotic pressure of the bathi...
متن کاملInfluence of egg cannibalism on growth, survival and feeding in hatchlings of the land snail Helix aspersa Müller (Gastropoda, Pulmonata, Stylommatophora).
Under controlled conditions, growth, survivorship and several nutritional parameters (ingestion, egestion and assimilation) were measured weekly in hatchlings that either ate a conspecific egg after birth (cannibalistic) or not (non-cannibalistic) and in food-deprived individuals (control group). Subsequently, the snails were fed on Taraxacum officinale. After 4 days, cannibalistic snails were ...
متن کاملAn Electron Microscope Study of the Cells Lining the Small Blood Vessels of Helix pomatia Linn
identified between neighbouring Schwann cells at nodes of Ranvier (Robertson, 1957; Uzman and Nogueira-Graf, 1957), in the latter situation there is no multiplicity of cytoplasmic layers, as is the case in the former. Since the cells of the inner core bear some resemblance to both fibrocytes and Schwann cells, i t might be supposed that they would best be provisionally classified as "neural fib...
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ژورنال
عنوان ژورنال: Journal of Molluscan Studies
سال: 1989
ISSN: 0260-1230,1464-3766
DOI: 10.1093/mollus/55.3.389