National Aquarium dolphins through the years

A dolphin jumps out of the water Monday afternoon during a training session at the National Aquarium in Baltimore.

A dolphin jumps out of the water Monday afternoon during a training session at the National Aquarium in Baltimore.

Visitors at the National Aquarium in Baltimore watch a dolphin swim past the observation window Monday afternoon.

Atlantic Bottlenose Dolphins L-R Chesapeake and Maya during a training session at the National Aquarium.

A dolphin jumps at the National Aquarium in Baltimore.

Each dolphin eats between 30-35 pounds of fish a day.

Chesapeake, one of six female dolphins at the National Aquarium, plays with a ball during play and feed time at the aquarium.

Two of the six female dolphins at the National Aquarium are pictured during their play and feed time.

Spirit, who gave birth to a female calf in spring 2011 at the National Aquarium in Baltimore, gets a friendly tap on her nose.

Maya, foreground, gave birth to her calf (background) this spring at the National Aquarium in Baltimore.

At the National Aquarium in Baltimore, Allison Ginsburg, manager of dolphin training, feeds Spirit, one of the mothers who gave birth to a calf in spring 2011.

Caroline Trowbridge and Devon Minarik, both of Hunt Valley, kiss as they are photographed at the National Aquarium, Baltimore, in front of the dolphin exhibit.

Tamara Leak-Jones, a three-time cancer survivor and mother, got a surprise “dream day” today through the “The Experience Genie,” who is Joshua Dawson, 34, from Montrea. One of the stops was the National Aquarium in Baltimore where she watched a dophin show and got to pet a dolphin named Chinook.

Spirit (named after Sept. 11, in honor of the American spirit) jumps over a physio ball during the dolphin show at National Aquarium in Baltimore.

Maya (LT) and Spirit (center) show how they have adapted to their underwater world with their trainer Crystal Mumaw (RT) during the dolphin show at National Aquarium in Baltimore.

Dolphin trainers Leah Whetzel (LT) and Kerry Martens (RT) highlight Chinook’s porpoise behavior during the dolphin show at National Aquarium in Baltimore.

Dolphin trainer Crystal Mumaw works with Maya through the window for an underwater behavior during the dolphin show at National Aquarium in Baltimore.

Chinook porpoises through the air during the dolphin show at National Aquarium in Baltimore.

Jade is balancing the globe on her rostrum, a crowd favorite, during the dolphin show at National Aquarium in Baltimore.

Trainer Darlene Davis examines Shiloh, and plays with her before taking her temperature. The National Aquarium in Baltimore announced today that two of its Atlantic bottlenose dolphins, Shiloh and Chesapeake are pregnant. They are expected to give birth in late July or August. Chesapeake, born at the Aquarium in 1992, is the daughter of Shiloh, who is about 29 and has been at the Aquarium since 1990. The veterinary staff is already providing special care, and will institute 24-hour observations in mid-July, with the help of volunteers.

Beth Manning, Senior Marine Mammal Trainer, at National Aquarium in Baltimore, has been working with dolphins for nine years. This one is Nani.

Baltimore National Aquarium staffs and volunteers are working to cure dolphin Bob’s respiratory infection. Here, Leslie Larsen (LT) and Jill Natwick touch Bob to give him some affection since he is removed from other dolphins and lonsome.

Visitors at the National Aquarium in Baltimore watch a pair of dolphins play with a ball in front of the observation window Monday afternoon.

Allison Ginsburg, Manager of Marine Mammal Training, gets in the water with one of the Atlantic bottlenose dolphins.

Visitors can watch the training sessions at the aquarium for free.

A dolphin at the National Aquarium in Baltimore.

Children watching the dolphins swim at the National Aquarium in Baltimore.

Dolphin trainer Kerry Martens (R) gets some help from Julia Brodowski, 8, of Macumgie, PA down near the dolphin tank.