Post assignment
Homework Assignment
GITHUB POST
Noga Mano, 029354719
13/05/2026
Experiment Protocol
Experiment title: The effect of bacteria on planulae settlement
Introduction
Coral reefs are essential for marine ecosystems and human livelihoods, yet they have experienced significant, global, rapid decline due to natural and human-induced stressors. A promising way to recover coral reefs is to enhance larval recruitment. Indeed, many present scientists are focusing on finding the key factors for successful larval settlement – physically, chemically and biologically.
Research Question:
How do different bacterial species affect larval recruitment, settlement and survival of primary polyps of the coral Stylophora pistillata?
Research hypothesis (for every bacteria species):
- H0 – The bacterial strain has no effect on larval recruitment of the coral Stylophora pistillata
- H1 - The bacterial strain affects larval recruitment of the coral Stylophora pistillata
Methods
Variables:
· Independent Variable: Bacteria strain · Dependent Variable: Settlement rate, survival
List of materials and equipment:
- 360 fresh planulae of the coral Stylophora pistillata
- 5 Bacterial strains
- 12 Sterile six-wells plates, inoculated with a single-species bacterial biofilm
- MB medium
- 20µ Filtered artificial seawater 40ppt
- Sterile pipettes
- Incubator
- Binocular
Experiment Design:
Two sets of six wells plates inoculated with bacteria:
- Treatment 1: Bacteria strain #1
- Treatment 2: Bacteria strain #2
- Treatment 3: Bacteria strain #3
- Treatment 4: Bacteria strain #4
- Treatment 5: Bacteria strain #5
- Treatment 6: Control (MB medium) Planulae will be divided into groups (n=10).
Each group will be located in a well X six replicates. Larvae were randomly distributed among treatments to avoid bias.
Figure 1: An entirely well photo
| Date | Time | Replica | Swimming | Settled | Survival(%) |
|---|---|---|---|---|---|
| 01/05/2026 | 10:00 | #1 | 7 | 3 | 100 |
| 01/05/2026 | 10:00 | #2 | 2 | 5 | 70 |
| 01/05/2026 | 10:00 | #3 | 10 | 0 | 100 |
| 04/05/2026 | 08:00 | #1 | 6 | 3 | 90 |
| 04/05/2026 | 08:00 | #2 | 1 | 5 | 60 |
| 04/05/2026 | 08:00 | #3 | 4 | 3 | 90 |