Order - Amphipoda
Freshwater amphipod
A small, shrimp-like animal that hops along the bottom, eating decaying plants and helping to keep the water clean.
- Common Name
- Freshwater amphipod
- Scientific Name
- Order - Amphipoda
- Realm
- Freshwater
- Biome
- Freshwater Lake, Lakeshore
- Introduction Method
- Introduced as part of a mixed wild-collected microfauna batch to seed the newly established Freshwater Lake.
- Current Estimated Population
- Stable and growing. They are highly abundant, with many different sizes active throughout the system.
- Population Status
- Uncertain
- Carrying Capacity Status
- Thriving. Since the predatory flagfish was removed on April 5, 2026, these amphipods have expanded their presence. They now graze openly during the day and utilize all the plant and sand habitats in the lake.
- Date Last Observed
- May 02, 2026
Section Notes
Freshwater amphipods became more visible and grazed more openly during the day after flagfish removal, suggesting reduced fish predation pressure and increased functional presence in the Freshwater Lake. This is a cautious behavioral interpretation, not a confirmed population estimate.
- Trophic Level
- Detritivore
- Feeding Niche / Method
- Detritivore and algae grazer
- Dietary Inputs
- Fine detritus, bacteria, algae, microbes, and suspended organic particles
Section Notes
Trophic classification is Detritivore. Food-web role: Small-particle detritus recycler. Feeding method: Detritivore and algae grazer. Dietary inputs: Fine detritus, bacteria, algae, microbes, and suspended organic particles
- Temperature Range
- Highly adaptable to water temperatures ranging from 50°F to 82°F (10°C to 28°C). They thrive in typical room temperatures inside the cabinet system (68°F to 77°F).
- pH Range
- Prefers neutral to slightly alkaline water (pH 6.8 to 8.2) to support healthy shell growth and successful shedding (molting).
- Lighting Requirements
- No special lighting needed. They naturally prefer shaded or darker areas, but are perfectly fine with standard day/night cycles, seeking cover under thick plants when the lights are bright.
- Flow / Aeration Preference
- Prefers still or slow-moving freshwater. While they do best with stable oxygen levels, they are much tougher than most other water creatures and can survive temporary drops in oxygen.
Section Notes
Very tough and highly resilient to organic waste and nutrient spikes. However, they are highly sensitive to copper, water chemical treatments, and temperatures that rise above 86°F (30°C).
- Expected Lifespan
- Typically 6 to 12 months under stable aquarium conditions, shedding their shells regularly as they grow.
- Reproductive Strategy
- Males clasp and carry females to mate. The female then carries fertilized eggs and developing babies in a specialized belly pouch (marsupium), eventually releasing them as fully formed, miniature amphipods.
- System Reproduction Status
- Confirmed reproducing. Multiple size cohorts (from tiny juveniles to breeding-sized adults) are actively present throughout the system.
- Growth Rate
- Rapid. Reaches adulthood and starts breeding in just 3 to 5 weeks under warm water temperatures with plenty of food.
Section Notes
They reproduce continuously in the system. The absence of a fish predator has allowed young amphipods to survive and grow after leaving their mother's brood pouch, leading to excellent population growth in the thick plant cover.
- Ecological Role
- Fine-particle nutrient cycling
- Symbiotic Relationships
- Strongly associated with submerged vegetation, which provides both safety from predators and surface area for their microbial food to grow.
- Microhabitat Preference
- Thick vegetation zones along the shoreline, particularly among the submerged leaves and stems of Ludwigia repens. They also gather on the sandy bottom, around plant roots, and in pockets of decaying organic debris.
Section Notes
They play a vital role as primary recyclers. By feeding on decaying plant leaves and grazing on microscopic biofilm, they keep plant surfaces clean and help process organic waste. They also serve as an important food source for larger residents like crayfish and ghost shrimp.
Biomes This Species Lives In
Follow this species across the habitats where it currently appears in the miniBIOTA biosphere.
April 17, 2026
Change
Fish removal reopens the lake food web
Freshwater amphipods are part of the post-removal microcrustacean layer being watched in the lake story.
Context
Biome: Freshwater Lake
View primary chronicle