Creature Feature: Let it Grow!

Written by: Zachary Mork, Naturalist at JNC

In this edition of our Creature Feature series, in which we uncover the meaning behind each month and how it connects to the creatures of our natural world, we will be examining the month of April. Although the Romans designated this time of year as “Aprilis”, scholars and historians are still not one hundred percent sure as to why they gave this month its name. One common theory suggests that the month is derived from another latin word, ‘aperire’. 

‘Aperire’, in Latin, means “to open”, which could correlate to this time of year, as it is when the buds and blossoms on trees and plants grow and develop. Although plants are in an entirely different kingdom than animals, the following creatures in this month’s feature do have the exciting possibility of plants growing on their bodies! 

Turtles

Michigan is home to ten species of turtles, a group of reptiles that possess a special shell that grows from their ribs and vertebrae. With a large surface area thanks to their shell, it is possible for turtles to swim and crawl around while carrying basic plants such as algae and moss. Take for example the common snapping turtle (Chelydra serpentina). Older snapping turtles have a high likelihood of having strands and clumps of algae on the tops of their shells, known as a “carapace”. With so much time spent in the water, it should come as no surprise to discover that they have their own little environment growing with them.

What happens to many of these pond turtles in the winter? How do they breathe if they are brumating (the reptililian version of hibernation) beneath the pond? Remarkably, turtles that brumate underwater are able to extract the dissolved oxygen in the water. To do this, the turtles have water enter their “cloaca”, a cavity that many vertebrates possess that is responsible for waste leaving the body. Within the cloaca are structures that collect the dissolved oxygen, which can then be carried throughout that body. This is the secret as to how turtles can survive the winter underwater.

Spotted Salamanders

Jumping over from reptiles to amphibians, let’s investigate a creature that has an interesting connection with plants. The spotted salamander (Ambystoma maculatum) dwells in the eastern half of North America, including Michigan. Black with yellow spots, their preferred habitats include mature forests that contain ponds and vernal pools, which are used for breeding. Even within their ideal habitat, spotted salamanders are secretive and only come out from the ground to forage, breed, and to avoid the buildup of rain.

As to how the spotted salamander connects with plants, researchers who have studied the life cycle of this salamander have found that there is a symbiotic relationship between these salamanders and algae. One specific algae enters the eggs of these salamanders, and from there, continues to grow within. As photosynthesis goes on inside the egg due to the algae, the embryo benefits from getting new oxygen released by the algae, while the algae obtains carbon dioxide from the embryo in order to continue the photosynthesis process.

This phenomenon has been known for the past few centuries. More recently, studies within the past few decades have shown that the algae remains within the adult salamanders bodies. It is possible that the spotted salamander can get an additional energy boost through the extra oxygen and carbohydrates that the algae produces as it goes through its photosynthesis. So far, this is the only case of vertebrate cells serving as a host for a microbe that creates an “endosymbiotic relationship” – where two different organisms live together, in which one organism is inside of the other organism.

Common Snapping Turtle

Spotted salamander