Data Documentation: SP08a Toxicity Test Dataset
1. Dataset title
Acute toxicity experiments on Daphnia magna exposed to three Prymnesium parvum strains at varying cell concentrations (24–72 h).
2. Context and purpose
This dataset was generated within ODER~SO subproject SP08a to evaluate the acute toxicity of three Prymnesium parvum strains (ODER1, UTEX2797, RCC3427) on Daphnia magna. The study benchmarks strain-specific toxicity to support interpretation of P. parvum bloom impacts in natural systems.
3. Experimental design
- Test organism: Daphnia magna neonates (≤24 h old)
- Exposure medium: f/2 medium at 4 ppt salinity
- Exposure duration: 24 h, 48 h, 72 h
- Strains: UTEX2797 (A-type), ODER1 (B-type), RCC3427 (C-type)
- Cell concentrations: 5,000–200,000 cells/mL
- Replication: 4 wells per treatment
- Controls: f/2 medium only
- Individuals per well: 5
- Observation: immobilization (absence of movement within 15 s)
4. Methods summary
Strains were cultured under standard conditions and diluted into target concentrations. Neonates were exposed in 6-well plates and immobilization recorded at 24, 48, and 72 h following OECD Guideline 202. Percent immobilization calculated as (dead / live) × 100.
5. Data structure
Dataset includes strain identity, prymnesin type, exposure concentration, replicate ID, alive/immobilized counts, and percent immobilization at each time point.
6. Processing steps
- Raw counts entered directly into Excel
- Percent immobilization calculated from observed counts
- No exclusions or transformations
- Manual double-checking performed
7. Quality control
Control wells met OECD validity criteria (≤10% immobilization at 48 h). Replication balanced across treatments.
8. Limitations
Lab conditions differ from natural systems; only one Daphnia clone and one P. parvum strain per toxin type used; immobilization ratio uses (dead/live).
9. Contact
Abrehet Mehari (abrehet.mehari@igb-berlin.de)
Subproject SP08a — ODER~SO
