Zebrafish Larva

Danio rerio

Type: freshwater, bony fish

Zebrafish Larva

Physical Characteristics

At this larval stage, the body is transparent with a distinct head, large dark eyes, and a long slender tail. Two small pectoral fins are visible protruding laterally. As it matures, it will develop horizontal blue stripes.

Habitat & Distribution

Native to the Ganges River region in India, Pakistan, Bangladesh, Nepal, and Burma. Found in slow-moving or stagnant waters such as rice paddies, streams, and ponds.

Size & Weight

Larvae are approximately 3-4 millimeters in length; adults grow to 3-5 centimeters long.

Similar Looking Species

Larvae of other Danio species such as the Pearl Danio (Danio albolineatus), which are also transparent and slender in early stages.

Ecological Role

Acts as a secondary consumer in the wild, feeding on small invertebrates; also serves as a significant prey source for larger fish and birds.

Diet

Larvae feed on microscopic organisms like paramecia and rotifers. Adults are omnivorous, consuming zooplankton, insects, and algae.

Behavior

Zebrafish are social, schooling fish. In the larval stage, they exhibit rapid 'burst' swimming patterns and are highly sensitive to light and movement.

Reproduction

High reproductive rate; females can spawn hundreds of eggs every few days. The eggs are non-adhesive and embryos develop rapidly, hatching within 48 to 72 hours.

Conservation Status

Least Concern (LC). Populations are stable in the wild.

Identification Tips

Look for a transparent, tadpole-like body with very large black eyes and small, vibrating pectoral fins near the head.

Interesting Facts

Zebrafish are a primary model organism in scientific research because they share 70% of their genes with humans and their transparent embryos allow scientists to observe organ development in real-time.

Identified on: 5/20/2026

Mode: Standard