Cohort cultures of Psammoryctides barbatus (Grube) and Spirosperma ferox Eisen: a tool for a better understanding of demographic strategies in Tubificidae

Adreani, L.; Bonacina, Carla; Bonomi, Giuliano; Monti, Carlo

doi:10.1007/978-94-009-6563-8_20

“…by predation) causes both the percentage maturation and the specific fecundity to increase, so leading to an overall numerical growth. This new situation in its turn will bring out, through the decreased maturation and fecundity, a decline in the population size (Adreani et al, 1984). From population dynamics modeling, density dependence appeared to be extremely important as far as regulation of population abundance of the tubificids was concerned (Bonacina et al, 1989b).…”

Section: Life Cycle and Population Dynamicsmentioning

confidence: 99%

Sludge reduction by predatory activity of aquatic oligochaetes in wastewater treatment plants: science or fiction? A review

Ratsak¹,

Verkuijlen²

2006

Aquatic Oligochaete Biology IX

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Biological aerobic wastewater treatment plants (WWTPs) produce a lot of excess sludge. The costs for handling this residual product are increasing, so the search for alternative techniques to reduce the amount of sludge has to be continued. Activated sludge consists of inorganic and organic substances, bacteria, protozoa and metazoa. Due to incomplete biomass conversion, sludge consumption yields less oligochaete biomass. From a technological point of view, the application of aquatic oligochaetes to reduce the sludge production offers interesting perspectives. This paper aims to review the feasibility for the reduction of activated sludge in WWTPs by means of aquatic oligochaetes. Also the current techniques concerning sludge reduction are taken into account. Several of the WWTPs relevant parameters, which may influence predatory activity of aquatic oligochaetes, are discussed: particle size, organic content of substrate, bacteria preference, life cycle and population dynamics of aquatic oligochaetes, temperature, pH, oxygen and process conditions. From the literature it appeared that most research has been performed on laboratory scale. Only a few authors mention a significant reduction of the sludge production by 'sessile' species such as Lumbriculus. Vermicultures for the reduction of activated sludge are rather common in developing countries. Incidentally large annelid blooms have been noticed in WWTPs. It remains obscure which factors trigger the initiation of annelid blooms in WWTPs and which are of importance to maintain a stable annelid population in WWTPs. The influence of a considerable worm bloom on the waste sludge production is still under investigation.

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“…Maturation time is revealed as density dependent and depends on the individual growth rate. Density affects negatively the percentage of the population that reaches maturity and the specific fecundity (Adreani et al, 1984).…”

Section: Life Cycle and Population Dynamicsmentioning

confidence: 99%

Sludge Reduction by Predatory Activity of Aquatic Oligochaetes in Wastewater Treatment Plants: Science or Fiction? A Review

Ratsak

¹

,

Verkuijlen²

2006

View full text Add to dashboard Cite

Biological aerobic wastewater treatment plants (WWTPs) produce a lot of excess sludge. The costs for handling this residual product are increasing, so the search for alternative techniques to reduce the amount of sludge has to be continued. Activated sludge consists of inorganic and organic substances, bacteria, protozoa and metazoa. Due to incomplete biomass conversion, sludge consumption yields less oligochaete biomass. From a technological point of view, the application of aquatic oligochaetes to reduce the sludge production offers interesting perspectives. This paper aims to review the feasibility for the reduction of activated sludge in WWTPs by means of aquatic oligochaetes. Also the current techniques concerning sludge reduction are taken into account. Several of the WWTPs relevant parameters, which may influence predatory activity of aquatic oligochaetes, are discussed: particle size, organic content of substrate, bacteria preference, life cycle and population dynamics of aquatic oligochaetes, temperature, pH, oxygen and process conditions. From the literature it appeared that most research has been performed on laboratory scale. Only a few authors mention a significant reduction of the sludge production by 'sessile' species such as Lumbriculus. Vermicultures for the reduction of activated sludge are rather common in developing countries. Incidentally large annelid blooms have been noticed in WWTPs. It remains obscure which factors trigger the initiation of annelid blooms in WWTPs and which are of importance to maintain a stable annelid population in WWTPs. The influence of a considerable worm bloom on the waste sludge production is still under investigation.

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“…There is no doubt that the study of populations of aquatic Oligochaeta has progressed in the last few years and that this is the result both of a finer approach to the analysis of natural populations and of the application of quantitative data which have been supplied by the study of laboratory cultures (Adreani, Bonacina & Bonomi, 1981;Adreani, Bonacina, Bonomi & Monti, 1984;Adreani & Bonomi, 1980;Archipova, 1976Archipova, , 1980Kosiorek, 1974;Poddubnaya, 1973Poddubnaya, , 1980aPoddubnaya, , 1980bPoddubnaya, , 1980cTimm, 1974Timm, , 1980Timm, , 1984. A contribution is being made by our research group, which has worked with aquatic oligochaete cultures -mainly cohort cultures-since 1978.…”

Section: Introductionmentioning

confidence: 99%

Progress in cohort cultures of aquatic Oligochaeta

Bonacinal¹,

Bonomi²,

Monti³

1987

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Our laboratory work on the life cycle of aquatic Oligochaeta has been extended to the tubificids Potamothrix hammoniensis and P heuscheri, as well as to the lumbriculid Bichaeta sanguinea.Basically we measured the duration of the time required for the embryonic development inside the cocoons, at different temperatures. In addition, cohorts of these species were cultured and the time required to attain the sexual maturation and the cocoon laying stages were estimated.The results concerning these three species are consistent with the field observations, as far as their value as indicator species is concerned, and contribute to a further understanding of the role of biotic factors in determining the distribution and succession of some aquatic Oligochaeta.

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Cohort cultures of Psammoryctides barbatus (Grube) and Spirosperma ferox Eisen: a tool for a better understanding of demographic strategies in Tubificidae

Cited by 15 publications

References 6 publications

Sludge reduction by predatory activity of aquatic oligochaetes in wastewater treatment plants: science or fiction? A review

Sludge reduction by predatory activity of aquatic oligochaetes in wastewater treatment plants: science or fiction? A review

Sludge Reduction by Predatory Activity of Aquatic Oligochaetes in Wastewater Treatment Plants: Science or Fiction? A Review

Progress in cohort cultures of aquatic Oligochaeta

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