Cruising Paradise Bay we came across several of these large Antarctic jellyfish; it was the first and only time I had seen these gelatinous sea animals down south. And I hadn’t appreciated their importance in the food chain.
Penguins and jellyfish commonly inhabit the same Antarctic waters, but until recently it was believed they didn’t have much to do with one another. However, that is not so.
Jellyfish have traditionally been regarded as “dead ends” in food webs because they are so low in calories being about 95 percent water. Until recently, it was thought that most predators would not benefit from eating them, especially penguins which have high caloric demands and typically seek energy-dense foods, like fish and krill. However, many penguin species frequently attack jellies as food.
Penguins have been seen to target carnivorous jellies, not herbivorous ones, suggesting they are gaining nutrients from the food eaten by carnivorous jellies, which include crustaceans that are too small for the penguins to target themselves.
Another possibility is that the jellies contain particular elements, like collagen fibers or amino acids, that the penguins need in their diet. The birds also feed selectively on certain parts of jellies, like their gonads, which are rich in fats and proteins and higher in calories. © Clara Davies 2020 - 28 days ago