NOTES ON EUGLENA ACUS EHRENBERG FROM SEWAGE TREATMENT PONDS
By A. HAUGHEY* Auckland Regional Authority, New Zealand.
The morphology and occurrence of Euglena acus Ehrenb. in sewage treatment ponds are described in the light of regular examinations of a number of ponds at treatment plants around
Auckland City, New Zealand. Variation from normal morphology has been noted and aberrant forms described. Details of seasonal abundance and changes in free ammonia values are presented. It is suggested that other Euglena species and turbid conditions due to dense algal growth may inhibit the growth of E. acus.
The examination of sewage treatment pond samples from the Auckland area over a number of years has provided information on the occurrence of a number of algae. Euglena acus is one type often encountered in these ponds and the following information was compiled from detailed counts of the algae and from pencil sketches of living organisms made at the time of observation.