What sensory system do dolphins use to get mother’s milk?

Unlike land mammals, dolphins and other marine mammals have limited olfactory capabilities — their sense of smell is largely nonfunctional in aquatic environments. Researchers have therefore speculated that dolphins have other ways of sensing their surroundings and detecting food. A recent study has discovered that juvenile bottlenose dolphins have specialised receptors for detecting the fatty acids in their mother’s milk. The researchers found special structures in the tongue of young Indo-Pacific bottlenose dolphins that may help it detect fat. And at the back of the tongue, a row of taste receptors that are specifically tuned to pick up fatty acids were found. These receptors also have enzymes that help break down the fat, making it easier for the dolphin to sense and process it. The ability to detect fatty acids in their mother’s milk is part of a specialised fat taste receptors in their oral cavity that can detect long-chain fatty acids contained in their mother’s milk thus helping dolphins assess the nutritional value of their food. Mother’s milk was found to have seven saturated and 16 unsaturated long-chain fatty acids. Behavioural tests in captive common bottlenose dolphins showed that a juvenile can recognize the presence of milk in water.