Integumentary uptake of acetate and propionate (VFA) by Tubifex sp, a freshwater oligochaete. II. Role of VFA as nutritional resources and effects of anaerobiosis

Abstract

The freshwater oligochaete Tubifex tubifex is able to absorb 14C‐labeled short‐chain carboxylic acids (VFA) from ambient water (Hipp et al., '86). In this paper evidence is given that VFA are transported across the body surface (autoradiography) and not taken up to any significant extent by bacteria or accumulated on the surface layer. Absorbed carboxylic acids are metabolized, as shown by the appearance of label in respiratory Co2 as well as in glycogen content. Rates of uptake are determined by the metabolic state of the worms. Under anoxic conditions, uptake is rapidly reduced. However, only 30 to 60 minutes of aerobic recovery were needed to regain aerobic control levels of uptake. Comparison of potential rates of VFA accumulation to rates of oxidative metabolism suggest that acetate and propionate might serve as an important nutritional supplement to these benthic freshwater animals.

Effects of oxygen deficiency on survival and glycogen content of Chironomus anthracinus (Diptera, Chironomidae) under laboratory and field conditions

“…This supports the hypothesis that uptake of DOM is incompatible with the processes of ion-and osmoregulation in non-marine organisms . However, under laboratory conditions two freshwater invertebrates can achieve a considerable uptake of short chain, volatile carboxylic acids from the medium ; in the pulmonate snail Biomphalaria glabrata (Say) acetate contributes about 6% (Thomas et al, 1984) and in Tubifex tubifex (MUller) propionate can cover up to 40% of the basal metabolism (Hipp et al, 1986) .…”

The distribution of short chain carboxylic acids in eutrophic drainage channels

“…In the Lewes Brooks, no propanoate or butanoate was detected in the sediment and this was also the case in studies, reported by Thomas et al (1984), Goodwin & Zeikus (1987) & Phelps & Zeikus (1985). However, concentrations as high as 110 jM and 20 #jM of propanoate were found by Molongoski & Klug (1980) and Hipp et al (1986b), in Wintergreen Lake and a small mesotrophic pond, respectively.…”

“…Under oxygenated conditions, the acids are rapidly taken up and metabolized to CO 2 by bacteria (Sepers, 1977;Siebers, 1982;Wright & Hobbie, 1966), algae (Sepers, 1977;Wright & Hobbie, 1966) and invertebrates (Hipp et al, 1986b;Thomas et al, 1984). The C 2 -C 5 acids are also metabolised under anaerobic conditions by a number of distinct groups of bacteria.…”

“…It is known that these acids are a major metabolic end product of the bacteria involved in the decomposition of dead organic matter under anaerobic conditions (Large, 1983). This process is responsible for the high concentrations of short chain carboxylic acids recorded in decaying aquatic macrophytes (Patience etal., 1983a;Sterry et al, 1985), anaerobic sludge (Runquist, 1981), soils (Batistic, 1974) and freshwater sediments (Monakova, 1975;Lovley & Klug, 1982;Molongoski & Klug, 1980;Jones & Simon, 1985;Hipp et al, 1986b;Phelps & Zeikus, 1985;Thomas et al, 1984).…”

Snail cadavers as sources of short-chain carboxylic acids to scavenging freshwater invertebrates

“…There is also evidence that these acids may be taken up through the integument of freshwater detritivores such as pulmonate snails (Thomas et al, 1984;Daldorph, 1988) and oligochaete worms (Hipp et al, 1986a & b;Hoffmann et al, 1986). Uptake by this route may satisfy a significant proportion of the basal metabolisms of the organisms (Thomas et al, 1984;Hipp et al, 1986b, Hoffmann et al, 1986. As juvenile snails, in common with other aquatic invertebrates, suffer heavy mortalities of up to 902, the surviving molluscs, which are known to be scavengers, could thus obtain substantial amounts of energyrich food in a cost-effective way.…”