Quantitative Studies Upon Some Blood Constituents of Helix Pomatia

Abstract

The living activities of Helix pomal'm are in many ways dependent upon the weather conditions. During the cold months, from about October or November to March or April, the snails hibernate, closing their shells by secretion of the calcareous epiphragma, and receiving their energy from stored reserve substances. During the warm months the intensity of their activity depends largely upon the amount of rain falling in any particular year, the snails feeding and being active only in moist surroundings with the period of reproduction lasting usually from June to August. In a previous investigation (v. Brand, 1031) it was shown that the chemical composition of the body of Helix shows characteristic differences at various times during the annual cycle. It seemed of interest to study some of the blood constituents, in order to test whether similar regular changes occur here. Material and MethodsThe animals, Helix poinatla, were purchased from a dealer in Fran-423-431.

Carbohydrate levels inPatella

“…Seasonal analyses of molluscan blood sugar levels have been restricted to the terrestrial Helix pomatia L. From monthly analyses, Schwarz (1935) could not detect any definite seasonal variation, beyond a possible increase before and at the end of hibernation. Wolf-Heidegger (1935) obtained higher mean blood sugar values (22 mg %) for summer as compared with hibernating Helix (11 mg %), but this seasonal difference was not confirmed by the investigations of Lustig, Ernst & Reuss (1937) and Holtz & von Brand (1940). It was desirable to extend these seasonal investigations to other Mollusca, using a method particularly suitable for small blood samples and low concentrations of glucose.…”

“…Wolf-Heidegger (1935) obtained higher mean blood sugar values (22 mg %) for summer as compared with hibernating Helix (II mg %), but this seasonal difference was not confirmed by the investigations of Lustig, Ernst & Reuss (1937) and Holtz & von Brand (1940). It was desirable to extend these seasonal investigations to other Mollusca, using a method particularly suitable for small blood samples and low concentrations of glucose.…”

Calcium regulation in the freshwater snail indoplanorbis exustus during shell repair

“…The latter increase in size and form calcified layers. The initial covering of the defect is frequently accomplished within a few hours (Durning, I957;Abolins-Krogis, 1958;Wagge, I95i), although complete repair requires a much longer period (Holtz & von Brand, 1940). In I. exustus the complete shell repair requires about a week.…”

Variations in the Water and Mineral Contents of Some Organs of the Snail, Helix Pomatia L.

“…Such variations in water content are of interest in relation to the water economy of the snail and also because they could be accompanied by important physiological changes. In Helix pomatia, the blood likewise varies considerably in dilution, whether this be measured in terms of concentrations of sodium or chloride, or in terms of freezing point depression, the latter, for instance, varying from 0.24 to 0.62 O C (Duval 1930;Kamada 1933;Lustig, Ernst, and Reuss 1937;Holtz and von Brand 1940;Vonvohl 1961;Burton 1964). Moreover, the more concentrated blood tends to be found in hibernating and aestivating individuals of low water content.…”