3-spined stickleback 

Gasterosteus aculeatus

Where is it found?
Marine, brackish and freshwater

Diet and foraging method

Searches for and actively pursues its prey

Key adaptations

Their anti-predator adaptations include the spines on their back, and bony plates on their body which are thought to act as armour.  They have a streamlined, torpedo shaped body and a broad tail fin. In the breeding season, males exhibit bright red colouring which attracts the females. 

Social organisation and mating system

Picture
Form shoals with relatives or familiar individuals. 
Picture
Polygynous mating system with paternal (male) parental care. Males establish a territory and build a nest there. Males then attract females over and they lay their eggs into his nest.

Did you know that...?

Male three-spined sticklebacks use their fins to fan the eggs in their nest to provide them with oxygen. They also protect them from predators and play an important role in their offspring's learning and development before they leave the nest.

Taxonomy

Picture

Picture credits:

"GasterosteusAculeatusMaleHead" by Piet Spaans (Viridiflavus) - Own work. Licensed under CC BY 2.5 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:GasterosteusAculeatusMaleHead.JPG#/media/File:GasterosteusAculeatusMaleHead.JPG
"PICT0246-1" by Viridiflavus - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:PICT0246-1.JPG#/media/File:PICT0246-1.JPG
"Gasterosteus aculeatus (brood care) 02" by Tino Strauss - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Gasterosteus_aculeatus_(brood_care)_02.jpg#/media/File:Gasterosteus_aculeatus_(brood_care)_02.jpg