|Collecting Chthamalus spp. in my field site, Punta Culebra|
At the study site in Punta Culebra I climb over the rocks to get to the four different sites where I collect my organisms. I am a slave to the tides and must do my collection during low tide when the barnacles are easily accessible! Most days during low tide the weather has been just shy of blazingly hot. However, sometimes I am afforded a nice break and get to scrape barnacles off the rocks when it’s dumping rain! When I am done collecting, I head on over to the lab to examine their broods. There are a couple things I look for: 1) Do they have a brood—notable by an orange lamella that encompasses the embryos found on the dorsal surface of the barnacle 2) their current stage of embryo development and 3) the relationship between brood size and barnacle size.
Chthamalus spp. has a shell that ranges in color
from light grey to black.
There is another high amplitude tide scheduled for the beginning of August and I’m excited to see if this drop in percent brooding occurs again! Because I am only in the Collin lab for ten weeks it is impossible to observe their long-term reproductive cycle, but it would be very interesting to repeat this experiment in the dry season to see how the cycles differ from the current wet season. Other aspects to my experiment include the effects of competition and temperature on brood size…but that’s another story!
Although my barnacles are not the most charismatic bunch, I find them fascinating. The environmental stressors that these barnacles are subject to are also impacting the reproductive success and life cycles of a multitude of animals living in the intertidal zone. A better understanding of what factors limit the reproduction and fitness of invertebrates like Chthamalus spp. is becoming exponentially important as the threats of global warming continue to grow and change the marine environment.