3300 x 5402 px | 27,9 x 45,7 cm | 11 x 18 inches | 300dpi
Altre informazioni:
The three-spined stickleback, Gasterosteus aculeatus, is a fish native to much of northern Europe, northern Asia and North America. It has been introduced into parts of southern and central Europe, including Belgium, where the species was featured on a 14-franc postage stamp issued in Belgium in 1990 Three subspecies are currently recognised by the IUCN: Gasterosteus aculeatus aculeatus is found in most of the species range, and is the subspecies most strictly termed the three-spined stickleback; its common name in England is the tiddler, although "tittlebat" is also sometimes used. G. a. williamsoni, the unarmored threespine stickleback, is found only in North America; its recognised range is southern California, though there are isolated reports of it occurring in British Columbia and Mexico; G. a. santaeannae, the Santa Ana stickleback, is also restricted to North America. These subspecies actually represent three examples from the enormous range of morphological variation present within three-spined sticklebacks. These fall into two rough categories, the anadromous and the freshwater forms.
