Branchiura sowerbyi
[ref. ID; 1353]
Test system
Long-term experiment
Strain
From a population living in a pond of a Botanical Garden.
Toxicants
LAS
Temperature
15 degrees C.
Test design/concentration
Pond sediments (the initial concentration of LAS in treated sediments was 25.87 mg/kg, and 3.99 mg/kg in control), dark, food (decomposed lettuce).
Measurements
Numbers of coccons, number of oocytes per coccon, total number of oocytes, period of embryonic development, percentage of degenerated coccons and percentage of hatching worms.
[ref. ID; 1354]
Test system
96-hr acute toxicity & chronic toxicity
Toxicants
LAS
Test design/concentration
- Acute toxicity: Petri dishes of 12 cm diameter and 2 cm depth, with 50 ml of dechlorinated city tap water: LAS concentration (15, 20, 25, and 30 mg/l) x 3 replicates, temperature (10 degrees C).
- Chronic toxicity: Petri dishes of 19 cm diameter and 8 cm depth, with 1 L dechlorinated city tap water +1 cm layer sediment: LAS concentration (0.5, 2.5 and 5.0 ppm), temperature (20 degrees C), 12L:12D, food (decomposed lettuce).
Evaluations
LC50 by probit analysis, MATC, LOEC, NOEC.
[ref. ID; 6632]
Test system
Effect of temperature for sublethal bioassay
Strains
Toxicants
Sediments was collected in Big Creek Marsh, Lake Erie.
Test design
The method of Reynoldson et al. (1991).
The tests were carried out in 250 ml beakers with 100 ml of seive sediments (250 um sieve) and 100 ml of dechlorinated tap water. The beakers were placed in the incubator at 22.5 (+/-1) degrees C for Tubifex tubifex and at 25 (+/-1) degrees C in one test series and at 30 (+/-1) degrees C in another for Branchiura sowerbyi. T. tubifex: 4 worms per beaker (20 beakers), B. sowerbyi: 5 worms per beaker (25 beakers). The beakers were not aerated and food was not added throughout experiments. Water level in the beakers was maintained by adding dechlorinated tap water as required every 2-3 days.
Measurements
At the end of the week, the adults, young, full and empty coccons and eggs per cocoon were counted (5 beakers). Eighty-five cocoons were cultured at 25 degrees C and 30 degrees to determine the hatch time for B. sowerbyi and ninety-four cocoons at 22.5 degrees C for T. tubifex.
Evaluations
The mean specific daily growth rate (Gw %), embrionic development, egg production per surviving worm.
[ref. ID; 6698]
Test system
96-hr acute toxicity
Strains
From local ponds. (L=3.00+/-0.01 cm; W=0.84+/-0.04 g).
Toxicants
Synthetic pyrethroid cypermethrin (dissolved in water and dissolved in 0.5% acetone: 9-1000 ug/L)
Test design
Static biossay (the method of the APHA (1995)): 500 ml beakers containing 300 ml of water (temperature 20 degrees C, pH 8.23+/-0.04; free CO2 5.1+/-0.3 mg/L; dissolved oxygen 5.9+/-0.2 mg/L; total alkalinity 70.75+/-3.77 mg/L as CaCO3; hardness 249.33+/-11.01 mg/L as CaCO3) and 10 test organisms. 3 replicates.
Measurements/observations
Worms number.
Evaluations
LC50 by probit analysis.