Before you begin classifying on Zooniverse, let’s learn about the four common fish species at the Tapuae Marine Reserve in Taranaki.

• Blue Cod – Blue cod has three phases. The first one is small with mottled dark brown stripes and a white belly, and tends to rest on the bottom. The second is larger with pale brown stripes. The third is large and distinctive with a blue-grey back, a white belly, and a turquoise band behind the head.
  
• Scarlet Wrasse – Scarlet wrasse has three colour phases, all of which have a distinctive, triangular black wedge in front of the yellow tail, and a scarlet head with a white jaw and throat. Juveniles are pale pink-orange above, usually with faint banding, and white below. Females are red above, and yellow and red striped below. Males have a scarlet margin on each scale, making their whole body appear scarlet. For all three, it is often best in dim light to look for dark coloration above and a paler underside, as well as for the black tail wedge.
  
• Silver Sweep – Blue-grey (can appear silver) with oval to diamond-shaped body and small head. Juveniles up to 8 cm (almost 1 scale-bar band) are grey-green with orange spots. Rapid, birdlike movements.
  
• Snapper – Light copper-pink above, fading to silver below. Shiny blue dots scattered around on the upper body (may fade in large fish); iridescent blue arc above eye (not visible from all angles). Long sloping forehead; upper body ‘larger’ than lower body. The juveniles are very small miniature versions, on which you usually can’t see any spots; juveniles also have 4-5 dark bands on body, some of which split near the top.