Monday, March 30, 2020

Natural History: greater siren (Siren lacertina)

At the Caw Caw Interpretive Center we saw a variety of herps ranging from the ribbon snake to the green tree frog. One of my favorites was the greater siren, also known as Siren lacertina, as I have never seen one in the wild before! If I were to have seen one before taking this class I would have never thought that they are a salamander as I thought that all salamanders have four limbs. Greater sirens have aquatic habitats. They specifically live in ditches, ponds, lakes and other slow bodies of fresh water. They estivate to escape times of drought, which basically means that they burrow in the mud and become dormant. They can be found in southern Maryland all the way to southern Florida and southern Alabama in the costal regions. It was a little hard to capture a photo of it at first as it was very slippery and constantly trying to escape from one's grasp as they tried to pick it up. However, I think that it eventually got tired out so a good picture was able to be taken.
Unlike other herps that some individuals caught with their hands, the siren was caught from the preset traps. One could immediately tell that this was a siren as it only had forelimbs, which is a key characteristic of sirens. In addition, its external gills were very noticeable and another key characteristic of sirens as they are paedomorphic. At first the identification of the siren was a little difficult as we were contemplating between the greater and lesser siren. We decided that it was a greater siren as the sides had yellowish/greenish dots. 

Juveniles have light lateral stripes and a light dorsal fin that becomes dark with age, which leads me to believe that this is an adult greater siren as I did not see these distinguishing features. It was very long as seen next to the eastern newts. 
I was trying to do some research on how to determine the sex of the greater salamander, and according to the University of Florida there is no way to externally determine the sex of this species. 
However, I would love to hear from anyone if they have any input on this!
Overall, I really enjoyed getting to see and touch the herps as they were alive in their natural habitat, which is very different from observing them in the lab as their colors are not as vibrant. I think the field trips really help to ingrain the knowledge learned in class. I wish we were able to do more field trips, but I am really excited to use my knowledge that I have gained to identify different amphibians and reptiles that I come across!

1 comment:

Allison Welch said...

So exciting! Special thanks to our friend, Naturalist Jake, who took a photo to confirm the identification by counting the costal grooves.