While all merpeople are different, they all share the same basic traits.
When mermaids come into contact with water for ten seconds, they grow long copper colored tails and a matching top. Their tails are covered in scales and end in a classic dolphin-shaped fluke. They also have a short dorsal fin running along the backs of their tails from their waists to a little more than halfway down the tail.
When mermen come into contact with water for ten seconds, they grow long light blue colored tails. Their tails are covered in scales and end in a classic dolphin-shaped fluke. They also have a short dorsal fin running along the backs of their tails from their waists to a little more than halfway down the tail.They also lose their clothes they were wearing in human form which reappear when they become human again. There is a possibility that they could absorb their clothing into themselves as a side effect of their metamorphosis into mermaids. Their hair keeps it's natural color and length, but any hairties, headbands, hairclips or hairspray disappears, along with their clothes. When they dry, their hair will return to whatever hairdo it was in. Born mermaids turn naked when they first come out of water because they had no clothes to begin with.
Hydrokinesis is the power currently possessed by Zac.
It allows him to move water without touching it as well as expand it and mold it into different shapes. With this power a mermaid/merman can create balls of water, blasts of water or even geysers strong enough to lift people off the ground.
Cryokinesis is the power currently possessed by Lyla. It is the power to create ice as well as create and control blizzards and snowfalls. This is an upgraded version of Hydro-Cryokinesis.
Gelidkinesis is the power currently possesses by Lyla. It allows a merperson to change the viscosity or thickness of water. Gelidkinesis has been shown to be able to turn water into a jelly-like substance. After a short time however this power has been shown to wear off as the water reverts back to it's liquid state. There is a disadvantage to this power: it makes water or drinks undrinkable.
Substanciakinesis is the power currently possessed by Nixie. Is the power to turn water into a solid state, without freezing it. It can be seen as an enhancement of Gelidkinesis in that it solidifies water instead of merely jellying it.
Aerokinesis is the power currently possessed by Nixie. It is the power to create and control wind and air currents. This is an upgraded version of Hydrokinesis.
Telekinesis is the power currently possessed by Zac. It is the ability to move objects and people with the mind, often in ways not visible to the naked eye.