The body wall of Halicryptus spinulosus (Priapulida) — ultrastructure and changes induced by hydrogen sulfide

Abstract

Halicryptus spinulosus (Priapulida) is extraordinarily resistant to hydrogen sulfide. As described previously, the body wall of specimens from oxic and from hydrogen sulfide-contaminated habitats differs strikingly in colour. In the present paper the ultrastructure of the body wall of specimens kept under oxic conditions is described. These findings serve as a reference for changes induced by exposure to hydrogen sulfide. There are marked ultrastructural differences between epidermal and muscular mitochondria exposed to hydrogen sulfide. Epidermal mitochondria of individuals subjected to hydrogen sulfide are often associated with dense granules of unknown composition. Findings are compared with those from other taxa which may encounter hydrogen sulfide in their environment.

Sulfide detoxification and tolerance in Halicryptus spinulosus (Priapulida): a multiple strategy

“…A similar ATP-independent mitochondrial sulfide oxidation clearly would facilitate sulfide detoxification. The involvement of mitochondria in sulfide detoxification in Halicryptus spinulosus is also proved by ultrastructural studies: mitochondria of epidermis and body wall tissue show altered electron densities caused by sulfide (Janssen & Oeschger 1992). Moreover there were electron dense inclusions in epidermal mitochondria after sulfide incubation suggesting the deposition of substances resulting from sulfide detoxification.…”

“…It is an important fauna1 component with high abundances and it survives for extended periods at environmental anoxia (Weigelt & Rumohr 1986). Previous studies on H. spinulosus dealt with its anaerobic capacity (Oeschger 1990, Oeschger & Storey 1990, energetic studies , and with histological and ultrastructural peculiarities of sulfide impact on the animals (Oeschger & Janssen 1991, Janssen & Oeschger 1992.…”

Different degrees of tolerance to hydrogen sulphide in populations of Macoma balthica (Bivalvia, Tellinidae)

“…One mechanism to reduce toxic effects of sulphide could be the binding of metal-sulphur precipitations within veslcles in the mantle edge, a phenomenon which was found in Macoma balthica from Hiddensee (Windoffer & Jahn 1994 and which is comparable to sulphide precipitation in other species (Nun 1984, Levitt & Arp 1991, Oeschger & Janssen 1991, Jahn et al 1992, Janssen & Oeschger 1992, Oeschger & Pedersen 1994, Dubilier et al 1995). Yet, calculations on sulphide diffusion demonstrated that metal stocks in the tissues will be exhausted very quickly (Jahn 1997).…”

Mitochondrial depolarization following hydrogen sulfide exposure in erythrocytes from a sulfide-tolerant marine invertebrate

“…If the irreversible mitochondrial toxicity observed in the present study occurs in epithelial cells of sulfide-adapted animals in their natural environment, then it may be an important factor affecting sulfide tolerance by necessitating substantially upregulated mitochondrial repair or degradation and biogenesis. In support of this, some histological studies of epithelial tissues from sulfide-adapted, sulfide-exposed invertebrates have identified mitochondrial swelling and the presence of electron-dense mitochondrial matrices and granules (Duffy and Tyler, 1984;Janssen and Oeschger, 1992;Jouin and Gaill, 1990;Arp, 1993, 1998;Menon et al, 2003), which may be evidence of mitochondrial injury, but such changes have not been seen in all studies (Dubilier et al, 1997). Irreversible mitochondrial depolarization from sulfide would be likely to result in MOMP, which would be followed by release of mitochondrial pro-apoptotic factors into the cytoplasm and cell death soon thereafter (Green and Kroemer, 2004).…”