Cytochemical studies on the cuticle and epidermis of Tubifex tubifex M�ll. with special regard to the localization of polysaccharides, heavy metals and the DAB-reactivity

Abstract

The cuticle consits of collagenous fibres and of two types of mucopolysaccharides. The whole cuticle contain PAS-positive polysaccharides, but the acid ones are localized only in the surface zone, both in the epicuticle and in the supracuticular mucoid coat. On the surface-damaged region of the cuticle bacterial infection was observed, those intact mucoid coat may be essential in protection against bacterial infection. Microvilli of the supporting cells play significant role in repairing of cuticular injuries. Acid mucopolysaccharides of the cuticle and epidermis may function as traps for heavy metals, proved by their significant heavy metal content. The cytosol of the epidermal cells possess considerable DAB-reactivity. The enzyme, responsible for the DAB-reaction, may be transported by the microvilli towards the cuticular surface and can play central role in the detoxication of organic foreign compounds.

Morphometry of the epidermis of an invasive megascoelecid earthworm (Amynthas gracilis, Kinberg 1867) inhabiting actively volcanic soils in the Azores archipelago

“…To counter this, the worms may upregulate continuous mucus production for cation trapping and shedding; to this extent, increasing goblet cell counts would be beneficial. This notion is consistent with the observations that secreted mucopolysaccharides on the dermal surface trap heavy metals (Fischer and Horvá th, 1977;Back, 1990), whilst the amount of surface-adsorbed Cd and Zn at any given time is minimal ) in Amynthas gracilis collected in Furnas, S. Miguel and Ribeira, S. Maria which were exposed to Furnas, a volcanic environment and to place without volcanic activity, Fajã. Different letters above and below bars mean significant differences at p r 0.05. compared with the amount of internally sequestered metal (Vijver et al, 2005).…”

“…The epidermis tissue interface is known to act as the primary barrier protecting earthworms from potential bacterial infections (Fischer and Horvá th, 1977). Since the epidermis also plays functional roles in an ion transport, it is unsurprising that nonessential metal ions and xenobiotics enter the organism through it (Dietz, 1974;Clauss, 2001).…”

Epidermal ultrastructure and implications for sulfide tolerance in six species of deep‐sea polychaetes

“…Unusual shape, structure, and number of mitochondria are frequently interpreted as signs of cellular stress (Fischer & Horvath 1977;Duffy & Tyler 1984). Epidermal mitochondria of the 6 worms in the present study show many degenerate characteristics, such as a swollen appearance, fewer and enlarged cristae, and variations in size and shape.…”

A transmission and scanning electron microscopy study of the cuticle and epidermis of Pomatoceros lamarckii (Polychaeta: Serpulidae)

“…The cuticular fibres are reported to range from 15 nm to 50 nm in diameter in some archiannelids (Rieger & Rieger, 1976); between 60 nm and 0.3 pm in diameter in some polychaetes (Chien et al, 1972;Westheide & Rieger, 1978) and between 20 nm and 0.25 pm in diameter in some oligochaetes (Coggeshall, 1966;Goodman & Parrish, 197 1;Humphreys & Porter, 1976~). After routine heavy metal staining these fibres, in most cuticles appear "pale" or "white" in cross section (Richards, 1 9 7 4~;Fischer & Horvath, 1977;Desser & Weller, 1977), while in others they appear as tubules composed of 5 nm thick fibres (Chien et al, 1972). The majority of the orthogonally arranged fibres of P. lamarckii range from 0.03 to 0.20 pm but fibres with dimensions of 0.6 x0.2 pm are found in the thick cuticle of the opercular filament.…”