Species interaction with negative influence on both is referred to as

Options

A. amensalism
B. mutualism
C. commensalism
D. competition

Explanation

**Step-by-Step Solution:**

1. **Understanding Species Interactions**: In ecology, species interactions are categorized based on the effects they have on the species involved. These interactions can be beneficial, harmful, or neutral.

2. **Identifying the Types of Interactions**:
- **Amensalism**: In this interaction, one species is harmed while the other is unaffected. For example, a large tree may shade smaller plants, hindering their growth without affecting the tree.
- **Mutualism**: This is a positive interaction where both species benefit from the relationship, such as bees pollinating flowers while obtaining nectar.
- **Commensalism**: Here, one species benefits while the other is neither helped nor harmed. An example is barnacles attaching to a whale; the barnacle benefits while the whale is unaffected.
- **Competition**: This interaction occurs when two species compete for the same resources (like food, space, etc.). In this case, both species are negatively affected because they are fighting for limited resources, which reduces their efficiency and fitness.

3. **Conclusion**: Among the options provided, competition is the only interaction that negatively influences both species involved. Therefore, the correct answer is that species interaction with a negative influence on both is referred to as **competition**.

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