Join me underwater for a look at some of the critters who make their home on the coral reef system of the Cayman Ridge. Coral reefs are an incredibly diverse and complex ecosystem so I can show you only a sampling. And today I’m going to narrow that down to just one kind of critter: sponges. Yes, sponges are animals.
Each sponge in that group in the photo above is as big as a person. They have been growing there for hundreds of years. Sponges are just one type of creature inhabiting this coral reef ecosystem, and like everything in these finely tuned worlds, they play a significant role in the health of this one. As anthropogenic climate change increases ocean temperatures, the sponges, with their critical structural and food web importance, will be changing. I’ll write more about the imbalances I’ve been seeing in the Caribbean reefs from my POV as a diver in a future article, but today I want to give you a sense of the diversity of a single small component of this spectacular ecosystem.
The Daily Bucket is a regular feature of the Backyard Science group. It is a place to note any observations you have made of the world around you. Rain, sun, wind...insects, birds, flowers...meteorites, rocks...seasonal changes...all are worthy additions to the bucket. Please let us know what is going on around you in a comment. Include, as close as is comfortable for you, where you are located. Each note is a record that we can refer to in the future as we try to understand the patterns that are quietly unwinding around us.
|
Sponges are invertebrates and have no body systems of the type we are familiar, like nervous, cardiovascular, excretory, respiratory, etc. This article has some nice diagrams showing how they perform their life functions..essentially feeding and reproduction, at which they are extremely effective. They are also very good at protecting themselves, with sharp internal needly spines and poisonous substances in their tissue.
Their shapes and colors vary. These are a few I saw on my dive trip recently in the West Indies. I’m still working on IDs from my trip, using the go-to books of Paul Humann-Ned DeLoach, and will edit this as I track them down.
A note about colors under the surface of the sea, which are pretty important in identifying sponges:
Within the range of light frequencies that penetrate the water, some wavelengths are absorbed more readily than others. The longest wavelngths, at the red end of our visible spectrum, are absorbed in the top few meters, which gives everything a bluish look below that regardless of its actual color. I used a red filter on my GoPro camera which restores any actual reddish color at short distances. As an example, here’s a Fireworm on a branching coral I took without and with the filter, at about 10 meters depth.
~ ~ ~ ~ ~
This late Saturday Daily Bucket is now open for your nature observations. Tell us what you’re seeing in your own neighborhood ecosystem these days.
"SPOTLIGHT ON GREEN NEWS & VIEWS" IS POSTED EVERY SATURDAY AT 5:00 PM PACIFIC TIME AND WEDNESDAY AT 3:30 ON THE DAILY KOS FRONT PAGE. IT'S A GREAT WAY TO CATCH UP ON DIARIES YOU MIGHT HAVE MISSED. BE SURE TO RECOMMEND AND COMMENT IN THE DIARY. |