Energy Reserves and Metal-storage Granules in the Hepatopancreas of Oniscus asellus and Porcellio scaber (Isopoda) from a Metal Gradient at Avonmouth, UK

Abstract

Isopods taken from populations of Onsicus asellus and Porcellio scaber from long-term polluted sites in the vicinity of metal smelting works at Avonmouth, South West England, and from a control site near Tübingen, South Germany, were examined for the frequency and size of metal-containing granules (spherites), lipid droplets and glycogen in their hepatopancreas. The number and size of spherites in the hepatopancreas of O. asellus increased with decreasing distance to the smelter, but such a trend was not found in P. scaber. A trend towards massive reduction in hepatopancreatic energy reserves (lipid, glycogen) with increasing soil metal pollution was observed for O. asellus while, in contrast, the lipid and glycogen content of P. scaber midgut gland cells was independent of the distance to the smelter. In view of previous reports on metal accumulation and biochemical responses to metal pollution, we propose that the two investigated isopod species, which form stable populations in the Avonmouth metal gradient, use different strategies to survive.

Stress Proteins (hsp70, hsp60) Induced in Isopods and Nematodes by Field Exposure to Metals in a Gradient near Avonmouth, UK

“…Indeed, in an electron microscopy study, Gra¨ff (1997) did not find pathologically damaged organs in freeliving soil invertebrates, including isopods, even if they derived from heavily metal-polluted stands. Also Schill and Ko¨hler (2004) did not find any severe histopathology in isopods from Avonmouth populations which could have quenched the stress response. Additionally, electron microscopy on the hepatopancreas of these animals did not reveal pathological symptoms (R. Triebskorn and R.O.…”

Physiological indicators of fitness in benthic invertebrates: a useful measure for ecological health assessment and experimental ecology

“…One is based on the activity of the ATP-consuming enzyme luciferase (e.g. from glow worms, commercially available kit) measuring the ATP-dependent bioluminescence (Giesy et al 1983;Koelsch 2001;Schill and Koehler 2004b). The other method uses a cascade of enzyme-controlled reactions that produce NADH in a distinct stoichiometric ratio, which is in turn measured photometrically (Jaworek and Welsch 1984).…”

“…The effects of single environmental factors on physiological status were observed for different taxa (Buckley 1979;Grieshaber et al 1994;Koelsch 2001;Schill and Koehler 2004b). In addition, the energy transfer from adults to their offspring was analysed (Thiyagarajan et al 2003;Darriba et al 2005), and for some species, the female condition was correlated with fitness (Jönsson et al 2009;Takahashi and Pauley 2010).…”

Does the Environment or the Source of the Population Define Stress Status and Energy Supply in the Freshwater Amphipod, Gammarus fossarum?

“…Stable populations of isopods (P. scaber) living in a metal gradient in the South of England seemed to follow the same principle of evolutionary adaptation to the long-term polluted sites: they showed low hsp70 levels at the sites with the highest heavy-metal concentrations (Arts et al, 2004). Schill and Ko¨hler (2004) as well as R. Triebskorn and R.O. Schill (unpublished) did not find any severe histo-or cytopathology in these isopods which could have quenched the stress response.…”

“…In addition to adenylate parameters we examined energy reserves, lipid and glycogen, which both could be affected by minimal food quality (Steinberg, 1989) or active avoidance of contaminated food (van Capelleveen, 1987;Donker, 1992;Schill and Ko¨hler, 2004). All residents showed a good supply of lipid and glycogen in the hepatopancreatic tissue, the main metabolic organ of G. fossarum.…”