URBAN TURTLE ECOLOGY RESEARCH PROJECT
TURTLES of the CENTRAL CANAL
Of the 13 species of freshwater turtles native to Indiana, six species reside in the Central Canal. Here we provide a brief accounts of each. For more specific information based on the results of our research, check out the What we know page. Remeber to click on the picture of the turtles for full size images. More images will be added in the near future.
Graptemys geographica: the Common Map Turtle
This is the most commonly seen turtle along the Central Canal. Throughout spring, summer, and fall, map turtles can be seen basking on rocks and trees sticking out of the water. When they emerge from the nests in the spring, map turtles are just a wee bit larger than a quarter and weigh about 6 or 7 grams (less than one quarter of an ounce). From these humble beginnings, map turtles can grow to more than five pounds...that's nearly a 400 fold increase! It takes several decades for this type of growth, and some of the older map turtles in the canal are likely to be in their mid-sixties or older. Male map turtles don't grow nearly that large, however. In the Central Canal, the male map turtles rarely get much more than 6-7 inches long and don't ever weigh even close to a pound. Map turtles have a very special diet, preferring to dine on snails.
Sternotherus odoratus: the Musk Turtle or Stinkpot
While the map turtles are the most visible members of the Central Canal turtle community, the stinkpots are equally abundant, but they are rarely seen. Stinkpots are not aerial bask like the map turtles and sliders, but instead spend most of their time near the canal's substrate. One of the consequences of this lifestyle is that musk turtles frequently carry dozens of leeches. They are omnivorous scavengers. This is also the smallest species in the Central Canal (not to mention one of the smallest in North America), and full grown adults usually weigh about half a pound and are only around 6 inches long or so. Adults of both sexes are the same size. The common names reflect the fact that these turtles contain two pairs of musk glands, and when handled, they release the contents of the glands, a thick volatile substance that certainly stinks. The scent from processing a trap full of stinkpots can stick to you all day.
Chelydra serpentina: the Common Snapping Turtle
This snapping turtle must be the most charismatic member of the Central Canal, and if not exactly charismatic, they certainly attract more attention than other turtles. They don't bask arially like map turtles and sliders, instead they sit in shallow water at the edge of the canal. Of course, the most captivating feature of the snapping turtles is their extremely quick and powerful biting action. Like all turtles, they have a much longer neck than you'd expect, and when they snap, the neck gets fully extended and can reach nearly half way across the carapace. We always treat the snapping turtles with respect, because even small ones have the speed and power to inflict seriously damaging bites. Snapping turtles will eat whatever they can, including the fish that inhabit the canal. The largest snapping turtle we have caught in the Central Canal weighed about 25 pounds, but most of those we catch are considerable smaller, about 10-15 pounds.
Trachemys scripta: the Red-Eared Slider
The red-eared slider is one of the most common turtles in the eastern United States, owing to its wide distribution. They can be found in all sorts of wetlands, from small ponds in South Carolina, to major lotic systems like the Missouri and Mississippi rivers. Sliders are reasonably close relatives of map turtles, and are prominent in the Central Canal because of their basking behavior, but they are not nearly as numerous as the map turtles. We estimate that the map turtles are about 4 or 5 times as numerous than the sliders in the Central Canal. On average, the females can get as large as the female map turtles, and while the males don't get as big as the females, they do get closer to female size than the male map turtles.
Chrysemys picta: the Painted Turtle
Painted turtles are members of the same turtle family as map turtles and sliders (for the record, that's the family Emydidae). Of the three emydid species in the canal, the painted turtles are the rarest. We have found one painted for about every 50 or 60 map turtles. The fact that we haven't caught any hatchlings or juveniles gives us some concern about the fate of painted turtles in the Central Canal. Painted turtles are aerial baskers, but they are smaller than map turtles or sliders. Painted turtles feature bright red markings on their limbs, face, and the underside of the marginal scutes on the shell.
Apalone spinifera: the Spiny Softshell Turtle
Spiny softshell turtles are like none other in the canal. Instead of a hard bony carapace and plastron, softshell turtles have a rather fleshy shell. (Some local folks refer to softshell turtles as "leatherbacks" but leatherbacks are actually humongous sea turtles.) Spiny softshells feature a beautiful spotted carapace and a snorkel-like nose. The spiny part of spiny softshell is nothing more than a series of little bumps along the anterior of the carapace; smooth softshell turtles, also native to Indiana but not found in the Central Canal, lack these little tubercles. Despite the fact that they don't have a hard beak like the other turtles in the Central Canal, the spiny softshell has a very painful bite. We catch fewer spiny softshells than any other species, but this is not necessarily because they are more rare, just that they are not attracted to out traps...yet.
