Three-spined stickleback – Gasterosteus aculeatus

Three-spined stickleback, Three-spined Stickleback - Gasterosteus aculeatus, Gasterosteus aculeatus

The Three-spined Stickleback, scientifically known as Gasterosteus aculeatus, is a small, spiny fish commonly found in coastal waters and freshwater habitats. It is a fascinating species with a remarkable ability to adapt to a wide range of environmental conditions, making it a successful inhabitant of diverse ecosystems.

Description & Characteristics

The Three-spined Stickleback is easily recognizable by its slender, fusiform body, which can reach a maximum size of 11.0 cm. Its most defining characteristic is the presence of three sharp spines on its back, which serve as a defense mechanism against predators. This species exhibits a wide range of color variations depending on its habitat and season, with individuals typically displaying a silvery-grey to olive-green coloration, often with dark bars or spots.

Habitat and Occurrence

The Three-spined Stickleback, Gasterosteus aculeatus, is a remarkably adaptable fish that thrives in a wide range of habitats, from coastal marine environments to freshwater lakes and streams. This species exhibits a remarkable depth range, being found in depths of 0.0 to 100.0 meters.

Gasterosteus aculeatus is widespread throughout the Northern Hemisphere, inhabiting coastal regions of the Atlantic Ocean, the Pacific Ocean, and the Arctic Ocean. This includes temperate marine zones as well as brackish and freshwater habitats. This species is considered a crucial component of many aquatic ecosystems, playing a role in the food web as both predator and prey.

Taxonomy

The species Gasterosteus aculeatus belongs to the Class: Teleostei, Order: Perciformes, and Family: Gasterosteidae. This taxonomic classification places the Three-spined Stickleback within a group of fish characterized by their spiny fins, which includes other notable species like the Sea Stickleback and the Tube-snout Stickleback.

Feeding

The Three-spined Stickleback is an opportunistic feeder, consuming a variety of organisms depending on availability. This diverse diet includes: algae, aquatic plants, carrion, copepods, Daphnia salina, fish eggs, fish larvae, insects, krill, ostracodes (seed shrimps), snails, worms, and zooplankton. Its feeding habits play a significant role in the regulation of populations within its ecosystem.

Associated Species

Image References

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