The physiology of earthworms

Abstract

1956; Watson, 1958), but there is at least one important diflference compared with vertebrate collagen : there is no periodicity of the fibrils at 640 A intervals in either L. terrestrts (Watson and Silvester, 1959), or A. longa (Reed and Rudall, 1948) (Fig. 5). The cuticle is highly proteinaceous in character, some 80% of the total being composed of protein whilst the remaining 20% is made up of polysaccharides, galactose, pentoses and hexosamines (Watson, 1958). Nitrogen accounts for 14-6% of the cuticle weight and at least 16 amino-acids are represented in the protein. The amino-acids of the cuticle of two species, L. terrestrts and A. longa are Hsted in Table 3 where they are compared with a typical vertebrate collagen, that of ox-hide (Watson and Smith, 1956; Watson, 1958; and Singleton, 1957). Amines with non-polar side chains e.g. glycine, are present in quantities similar to those in vertebrate collagen, but arginine, histidine, and lysine with basic side chains are less abundant than in vertebrate material, whilst aspartic acid, glutamic acid and serine (D-serine?) with acidic side chains are present in greater quantities than in the vertebrate counterpart. There is no trace of hydroxylysine in earthworm cuticle. The gizzard of L. terrestrts is lined with a cuticle. This can be removed and Rudall (1955) subjected this material to X-ray analysis, obtaining patterns similar to those of chaetae (see p. 15). Cuticle from this situation is not stable in hot dilute alkali, does not crystallize, and though chitin-like is not in the a-chitin form. The presence of a chitin would be shown by a fibrillar structure, but van Gansen (1959b, 1960) using similar material finds no evidence for the belief that the gizzard lining is fibrillar. Chemical tests with orcein, resorcin, van Gieson stain, benzidine and Gomori stain

The effect of the anterior ganglia on forward movements in the earthworm

“…1953). Very little is known of the chemical nature of the products of these secreting cells (Laverack, 1963). After this initial period of decline, however, regeneration of neural tissue begins (Stephenson, 1930) and gradualIy the anterior ganglia regain control of movements.…”

Survival, Weight, and Prolificacy of Eisenia fetida (Savigny 1826) in Relation to Food Type and Several Soil Parameters

“…(2010) [23] reported a decrease by 50% of water content of the body for the species Apporectodea caliginosa (Savigny 1826) during its estivation. However, losing weight in soil is a faster process than gaining weight in water [21].…”

“…Richardson et al (2009) [20] found that the species Amynthas agrestis (Goto and Hatai 1899) survived with more success in higher temperatures of soil when the moisture of soil was appropriate, which increased the survival of the species and decreased the weight loss, and the maintenance of the fresh body weight depends on moisture degree of soil. When earthworms were taken from soil and placed in water they usually gained weight [21]. (2010) [23] reported a decrease by 50% of water content of the body for the species Apporectodea caliginosa (Savigny 1826) during its estivation.…”

Dew-worms in white nights: High-latitude light constrains earthworm (Lumbricus terrestris) behaviour at the soil surface

“…While the nocturnal activity pattern relates to the prevalence of suitable moisture and temperature, avoidance of harmful daylight UV-radiation and the risks imposed by dayactive predators are also likely to have affected the evolution of this behaviour (Edwards and Bohlen, 1996). The diurnal activity patterns of L. terrestris can also have an endogenous physiological component as the rhythms can persist under continuous darkness (Laverack, 1963).…”