Twait shad

The twait shad is a silvery fish that looks a bit like a herring but wears a stylish row of dark spots along its sides. It splits its time between the salty Atlantic and Mediterranean, swimming up rivers to lay eggs in fresh water. These fish take their time growing up, only starting families after their third birthday.

• Wears 6 to 10 dark spots like polka dots on its silver sides.
• Lives in the ocean but travels up rivers to have babies.
• Waits until age 3 or older before starting a family.