Gasterosteus
Gasterosteus is a genus of small, ray-finned fish belonging to the family Gasterosteidae, commonly known as sticklebacks. These fish are found in coastal waters of the Northern Hemisphere, inhabiting a wide range of habitats, including freshwater, brackish, and saltwater environments. Their unique characteristics, including their spiny dorsal fin and armor plating, have made them a popular subject of scientific research.
Common Names
The species within the genus Gasterosteus are commonly referred to as "sticklebacks," a name derived from the three sharp spines located on their dorsal fin. Some species have additional common names, such as the "three-spined stickleback" for Gasterosteus aculeatus and the "ninespine stickleback" for Gasterosteus novemspinus.
Characteristics
Sticklebacks are small fish, typically ranging in size from 3 to 10 centimeters. They possess a streamlined body shape, well-suited for navigating through aquatic environments. Their most defining feature is the presence of three sharp spines on their dorsal fin, which serve as a defense mechanism against predators. Sticklebacks also have a series of bony plates along their sides, providing additional protection.
Sticklebacks are sexually dimorphic, meaning that males and females differ in appearance. Male sticklebacks often exhibit bright coloration during breeding season, while females typically retain a more drab coloration. Males are also known for their elaborate nest-building behavior, using plant materials and other debris to create nests that attract females.
Environments
Sticklebacks are highly adaptable fish, able to thrive in a variety of environments. They are found in both freshwater and saltwater habitats, including coastal waters, estuaries, lakes, and streams. Their ability to tolerate a wide range of salinities allows them to inhabit diverse locations.
Some stickleback species have adapted to live in specific environments. For example, the threespine stickleback (Gasterosteus aculeatus) has evolved into distinct populations that inhabit lakes, rivers, and marine environments. These populations have adapted to different ecological conditions, exhibiting variations in their morphology, physiology, and behavior.
References
For more information on Gasterosteus, refer to the following reliable sources: