When she incurs Neptune's wrath by finding a diamond ring buried under rocks in the ocean, Emily is put under a curse that will force her to choose to be either a mermaid or a human and split up her parents forever.

Once again Abby and her brother Jonah go through the magic mirror in their basement, and this time they find themselves interfering in the Little Mermaid story--and needing to set things right and make sure everyone has a happy ending.

Neptune, king of the ocean, sends half-mermaids Emily and Aaron to the land of the midnight sun to investigate the source of the dangerous storms brewing in the ocean.

A class trip to a beautiful island is overshadowed by a local myth about a mysterious ship that may have ties to the lost city of Atlantis.

Of all the creatures in the ocean, sea horses are Echo Reef's favorite. They're sweet and gentle and they glide through the water so gracefully. When Echo discovers that Rocky Ridge, one of her Trident Academy classmates, has his own pet sea horse, she wants one right away. Not everyone agrees sea horses should be pets, however. Perhaps they are happiest when swimming freely. But Echo thinks that if Rocky can make a sea horse happy, she can too!...

Mermaids Shelly and Echo are excited to begin third grade at the prestigious Trident Academy, but snooty Pearl, jokester Rocky, brilliant Kiki, grumpy Mr. Fangtooth, and an argument over their first project challenge the best friends. Includes facts about marine plants and animals and words to the Mermaid Tales Song.

"Fish Girl, a young mermaid living in a boardwalk aquarium, has never interacted with anyone beyond the walls of her tank until a chance encounter with an ordinary girl, Livia. Their growing friendship inspires Fish Girl's longing for freedom, independence, and a life beyond the aquarium tank"--

"Not one of the merkids in Shelly Siren's third-grade class can believe the shell-shattering news: Shelly is a princess! A real princess! It's been a well-kept secret in Trident City, but now the word is out, and Shelly doesn't know how to act! Should she start wearing a glittery crown? Or move to a grand undersea palace? Will her friends have to call her Your Highness? Being a princess may be exciting, but Shelly's not sure she can truly play this...

Lucas and Clara are floating on a raft when a wave casts them into the sea, where Lucas catches a glimpse of a coral kindom and a dark-haired mermaid helps him, but when his father, King Caleb, hears of this, he scolds Lucas and tells him he has broken an age-old pact.

"Traveling home by cruise ship should be a relaxing break after Emily's latest adventure, but things take a turn when the ship is overtaken by a pirate king and his crew. After the pirates collect everyone's riches, they steal something even more valuable: Aaron. The pirate king's eldest son takes Aaron captive, forcing him to help guide the pirates to the mythical Trident's Treasure. So Emily dives into action and joins the younger son's crew in...