Studies showed manatees eating Syringodium seagrass require what compared to eating romaine?

Taste buds in manatees are evenly distributed across the tongue.

Manatees in these studies were trained using primarily positive reinforcement with bridges and small preferred food items.

The African manatee is the only sirenian that lives in both saltwater and freshwater environments.

Manatees showed tactile acuity roughly equivalent to human fingertip discrimination.

Manatees have a lower critical temperature that is higher than many other marine mammals.

The cooperative effort between the Chicago Police Department and the Illinois Department of Corrections included

Anal glands found near the rectum in manatees may play a role in chemical signaling.

Manatees in the Isla de la Juventud area were frequently observed exhibiting solitary behavior.

What does the low cone-to-rod ratio in the manatee retina suggest?