Flatworm
Scientific Name: Platyhelminthes (class Turbellaria, order Tricladida for freshwater planarians)
Order & Family: Platyhelminthes (Phylum), Turbellaria (Class), Tricladida (Order) for free-living flatworms like planarians.
Size: Most free-living flatworms range from a few millimeters to several centimeters in length. The one in the image appears to be a smaller specimen, likely less than 1 cm.
Natural Habitat
Found in various aquatic environments (freshwater, marine) and moist terrestrial habitats. The one in the image appears to be in an aquarium or similar water-based setting.
Diet & Feeding
Most free-living flatworms (like planarians) are carnivorous scavengers or predators of small invertebrates (e.g., worms, insect larvae, snails, detritus). They primarily feed using a protrusible pharynx.
Behavior Patterns
They are typically bottom-dwelling and can glide across surfaces using cilia on their ventral side. Many are nocturnal and avoid light. They are known for their remarkable regenerative abilities; even a small piece can regenerate into a full organism. Reproduction can be sexual or asexual (fission).
Risks & Benefits
In home aquariums, some flatworm species (such as Planaria) can be considered pests as they might prey on small shrimp, snails, or fish eggs, especially if their population explodes due to overfeeding. They are generally harmless to humans. Ecologically, they are part of the aquatic food web and play a role in decomposition and nutrient cycling. They are also widely studied in biology for their regenerative capabilities.
Identified on: 9/5/2025