Aniak the northern sea otter at the Seattle Aquarium ate a nice big meal Monday morning, so that probably means she still won't deliver her much awaited otter pup Monday, says C.J. Casson, director of life sciences at the aquarium.

Aniak, relaxing Monday amid all the fuss about her much-awaited delivery of a sea otter pup. Photo by C.J. Casson, courtesy of Seattle Aquarium

"Many of us have been here late into the night, watching and waiting," Casson said Monday. "The last two mornings she woke up earlier than the other otters, but she just ate a big meal, so it probably won't be today."

Researcher Shawn Larson said Aniak is particularly packing in the fresh clams. And she's doing just fine. "We are seeing lots of fetal movement, she's doing really well."

Aniak has been feasting on lots of clams. Here she is having a snack and a swim at the aquarium Monday. Video by Pam Lamon, courtesy, Seattle Aquarium.

Based on normal gestation rates, Aniak is right in the middle as far as her expected delivery date, with delivery typically between 200 and 250 days after implantation of the embryo. Aniak is estimated to be at about 220 days, which puts her right in the comfort zone of normal.

Captive births of northern sea otters are rare and special, so the level excitement around her imminent delivery is high. "All her hormone levels point to this week," Larson said.

"We must get asked 20, 30 times a day: Well? Well? It's getting crazy," Casson said.

Aniak reposes with her paws above an expectant tummy. Photo by C.J. Casson, courtesy, Seattle Aquarium

The pregnancy was not an intended breeding, but a surprise.

The aquarium's goal was to limit breeding to make room for stranded sea otter pups, in partnership with the U.S. Fish and Wildlife Service and the Association of Zoos and Aquariums. To do that, Aniak's breeding was suspended, using birth control.

No one knew the longevity however of the birth control method being used with sea otters. So, aquarium scientists were keeping track of Aniak's hormone levels for the past four years. They were surprised to discover her pregnancy last June. Hormone levels had lead biologists to believe she was not capable of becoming pregnant.

Aniak was born of Lootas, one of the aquarium's other sea otters, who came to the facility as a rescue. The three sea otters are among the most popular exhibits at the aquarium and if all goes well with the birth, the public will be allowed in to see the pup right away.

Baby sea otters are rare in captivity, the aquarium was the first facitlity in the world to successfully breed a northern sea otter.

Birth for any mammal is a perilous time, and so it is for sea otters, who deliver breathing young into water.

The baby otter's eyes will be open and it will be capable of floating right away, buoyed by a special natal pelage that is extra fluffy, to keep the baby otter afloat -- when it's not snoozing on Aniak's belly as she floats on her back.

Delivery at first seemed likely over last weekend, but it came and went with no pup. More clams anyone?

"Any day now," Casson said. "Keep your flippers crossed."