DaphTox II - Biomonitoring using Daphnia

Sensitive detection of toxic substances in water via computer-assisted digital image analysis

: bbe DaphTox II - Biomonitoring using Daphnia

The bbe DaphTox II observes daphnids, commonly known as "water fleas", under the influence of constantly running sample water. Based on the Extended Dynamic Daphnia Test, bbe developed a new sensitive method to detect hazardous compounds in water from rivers (source-water protection), plants, distribution systems and production drains to preserve human health and to monitor water.

Sensitivity data are available here.

Sample water (0.5 - 2 l/h) continuously runs through the measuring chamber containing the daphnia. The live images obtained using a CCD-camera are evaluated online with an integrated PC to analyse changes in the behaviour of the daphnia. If the change is statistically significant, an alarm is triggered. The method of image analysis enables a series of measurement methods and plausability tests to assess the daphnia's behaviour using different criteria.

Measurement using digital image analysis

: Measurement parameters of the daphnia

Observation of speed parameters:

average speed
speed distribution
distance between daphnia

Observation of behaviour:

swimming height
location
fractal dimension: measurements
for turns and circling movements, curviness

Observation of growth:

determination of daphnia size

Toxicity Index

The concept of the toxicity index is based on the evaluation of certain measurands, such as speed or height, and changes in these measurands. Only when 2 or more of the measurands simultaneously show unusual results within a fixed period of time does the DaphTox II trigger an alarm.

: Software screenshot: the parameter settings determine the calculation of the toxicity index

Applications

Surface water applications

dam monitoring
waterway analysis and assessment
general environmental monitoring

Drinking water applications

intake assessment
drinking water supply

Research applications

risk analysis
limnological work
research and education

Features

Chamber and camera

1-chamber system with up to 10 daphnids or other organisms
optional 2-chamber system with enhanced reliability
easily removable daphnia chamber - prevents air bubbles and increases detection rate

Sample preparation

integrated sample treatment (microfiltration, ultrasonic cleaning and pre-heating)
air-cooled peltier element - no separate cooling water

Low maintenance, few consumables

simple operation:
15" touchscreen PC with splash-proof flexible USB keyboard (supplied), Windows XP software
automatic, prepared concentrated algae feeder syringe - no algae culture necessary
few tube connections