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Dive Dry with Dr. Bill

#606: Another Warm Water Critter in Our Midst

When I was a youngster (just a few years ago), I was fascinated by the heavens. When Sputnik was sent into orbit by the Russians back in 1957, I sold greeting cards door-to-door so I could earn enough to buy my first real telescope. I wanted to see the wonders of the universe first hand. We even formed the NJAS (Northbrook Junior Astronomical Society) that year so some of us science nerds could get together to talk about space. When President Kennedy challenged the country to go to the moon, we were ecstatic.

The thrill of discovery is not limited to outer space... there is still plenty here on the Water Planet we have yet to reveal. Marine biologists most frequently find unknown and undescribed species in remote places like Papua New Guinea or the bottom of the deep ocean. However, one can find "new" species even here in our island waters. One of them has been pretty abundant this warm summer and I've been filming it frequently on my night dives.

I'm referring to a tiny little sea anemone that abounds attached to the blades ("leaves") of giant kelp, the nasty invasive Sargassum horneri and other algae. At least the giant kelp blades that still exist in our waters this year. I've observed and filmed it for many years, although it seems most frequent during periods of warmer water. If global warming is happening (and I believe it is), we may see them more and more over the coming years. Unfortunately under that scenario, the warmer waters will probably spawn more hurricanes in Mexican waters and monsoon storms in the Southwest creating surge and swell that will impact our island coast. Diving may be more difficult under those conditions and I may have to seek more "pacific" waters even during summer.

This summer underwater photographer Bonnie Pelnar posted a close-up image of this tiny sea anemone that showed more detail than I can accomplish even with my high definition video camera. Seeing her image triggered a desire in me to finally determine what this "unknown" species was. I contacted several museum curators in California and one suggested I e-mail Dr. Meg Daly at Ohio State University. I sent her some of my images and she suggested it might be a species in the genus Bunodeopsis. I turned to Google using that search term and found a 2001 paper by Dr. Jack Engle and Dan Richards. I knew Jack at UCSB and through the Catalina Conservancy Divers, and Dan from the Channel Islands National Park.

Jack and Dan listed several species that were either new records for the Channel Islands or for a new island in the archipelago where it hadn't been reported before. One of them was most likely the Bunodeopsis species I have been seeing here in Catalina waters. Their observations were made during the 1997-1998 El Nino. The suggestion made was that these normally subtropical species were shifting northward during periods of warmer water. Again, if global warming is fact, and our waters continue to increase in average temperature, we will be seeing more subtropical forms appear and eventually establish breeding populations here.

Jack and Dan referred to Bunodeopsis as "the stinging anemone." I must admit that I was wearing gloves when I touched them so I felt nothing. Since this one was not identified to species level, it has no common name. I've read that crabs in some parts of the world attach members of this genus to their claws as a defense mechanism. I've seen that with different species of anemones in Asia and elsewhere. In Mexico one predator on anemones of this genus is a nudibranch (shell-less snail). Nudibranchs often eat members of the phylum Cnidaria (including anemones, hydroids, coral, etc.) and incorporate their stinging cells (nematocysts) into their body as a defense. Not sure if any of their usual predators have also moved north with them. As for their mating, it is pretty boring so I won't even go there.

My research also uncovered an interesting study of medical significance regarding members of the genus Bunodeopsis. Sea anemones incorporate toxins which enter those unfortunate enough to be stung by them. This is valuable both in capturing live food and in defense. Medical researchers have discovered that the toxin in members of this genus may be valuable in reducing some of the side effects of cisplatin, a chemical used in chemotherapy for victims of lung cancer. You never know where the next miracle drug may come from!

A number of years ago, I observed a species of oyster that attached to our local gorgonians (soft corals). After researching it, I was pretty certain it was a Pacific winged oyster (Pteria sterna) but was told by some specialists that couldn't be. Well, although I trust museum-based taxonomists for an ID on critters, many aren't out in the real world often enough to know how species distributions are changing as climate changes. Jack and Dan's paper also referenced this species appearing in the waters off the Channel Islands so I was vindicated. Divers (especially diving biologists) often see things that lab-based biologists don't.

These are not isolated incursions into our waters from the south. Many of my readers probably know of the beautiful scythe butterflyfish (Chaetodon falcifer) that has established populations at both of our quarries (and other sites) as well as the finescale triggerfish (Balistes polylepis) seen right in our own Lover's Cove. There are many others from south of the border: the orangethroat pikeblenny (Chaenopsis alepidota), pink cardinalfish (Apogon pacificus). the ornate fireworm (Chloeia viridis) and the Panamic arrow crab (Stenorhynchus debilis) to name just a few I have observed and filmed. Yes, "the times they are a changing..."

© 2014 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Anemones of the genus Bunodeopsis attached to giant kelp blades and stipe and as seen through microscope.

This document maintained by Dr. Bill Bushing.
Material and images © 2014 Star Thrower Educational Multimedia