DIVE DRY WITH DR. BILL #758: HELP ME FIND MY IDENTITY!
Back in 2006 I made several dives during that year on Farnsworth Bank, located about 1 1/2 miles off the windward coast of Catalina.. It is my all-time favorite Catalina dive site followed by Ship Rock and Little Farnsworth off our leeward coast. There are several reasons for its appeal. One is that this series of pinnacles starts at about 65 feet and drops down to depths I'd never attempt on SCUBA (my limit is 200 fsw). It has an intriguing topography. As a marine biologist, it is also home to some unusual critters like the purple hydrocoral (Stylaster californicus), the yellowish-orange zoanthid Epizoanthus giveni named after Dr. Bob Given... and the subject of this week's column.
On each of the dives I made there that year, I encountered an unusual starfish I've never seen anywhere else. Of course I hoped it was new to science and I might be the one to describe and name it. When I returned home, I spent time searching the Internet (thank you classmate Al Gore! Tee hee) for information and learned there had been previous sightings. At the time it was not known to have been scientifically described so we referred to it as the "red spotted starfish (aka sea star for the PC crowd).
I later heard that it had been scientifically described and named, but I lost the note with that information. It's probably buried under the tons of paper on my computer desk. Recently I received an e-mail from diver Dana Rodda who had seen a previous Dive Dry column of mine about this sea star. She asked if I knew the name for it. That initiated a search for more current information and led me to a publication about sea stars collected from an eroded volcanic island, Rocas Alijos, located about 300 km (180 miles) off the Pacific coast of Baja California.
I discovered that our red spotted starfish might be a relatively "new" species collected by my dive friend Jeffrey Bozanic working with Dr. Gordon Hendler, curator of echinoderms at the Natural History Museum of Los Angeles County! Dr. Hendler had named the starfish collected there after Jeffrey, Hacelia bozanici. I sent an e-mail to Jeffrey with an image of one I saw on Farnsworth and also wrote Dr. Hendler to see if he could confirm it was the same as the one out on Farnsworth.
When Jeffrey collected the single specimen at Rocas Alijos, he did so on a rebreather at a depth far greater than I could dive, 76 meters (about 250 feet). Even though I've dived to 150 feet on Farnsworth Bank, the specimens there were all at shallower depths than that. I found that interesting since it appears the species prefers deeper and colder water way down south of the border. Up here off Catalina, the water is colder and therefore the species can be found at reasonable SCUBA depths. This may be an example of submergence to deeper depths in warmer waters although more data is needed to ascertain that.
When Dr. Hendler got back to me, I was informed that our local specimen could not be attributed to Hacelia bozanici with 100% certainty and he suggested we consider it an unknown species in the genus Hacelia instead pending further study. The specimen collected in Mexico was much smaller than the 10-12" diameter individuals we've been seeing out on Farnsworth. He needed a smaller specimen of about 4-5" diameter to compare the two. Until then our "red spotted starfish" will have to wait to be assigned a scientific name with certainty! Sadly it still has no identity, at least as far as science is concerned.
I haven't been able to dive since last July due to my cancers (yep, plural) so I'm reaching out to divers in southern California to see if we can locate a specimen of the appropriate size for Dr. Hendler to compare with the one from Rocas Alijos. Hopefully we can finally solve the mystery and give this attractive sea star a true scientific name! Feel free to contact me via e-mail at bushing@post.harvard.edu.
© 2018 Dr. Bill Bushing. For the entire archived set of over 750 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Dana Rodda's image from Farnsworth Bank and three of mine from the same site.
Back in 2006 I made several dives during that year on Farnsworth Bank, located about 1 1/2 miles off the windward coast of Catalina.. It is my all-time favorite Catalina dive site followed by Ship Rock and Little Farnsworth off our leeward coast. There are several reasons for its appeal. One is that this series of pinnacles starts at about 65 feet and drops down to depths I'd never attempt on SCUBA (my limit is 200 fsw). It has an intriguing topography. As a marine biologist, it is also home to some unusual critters like the purple hydrocoral (Stylaster californicus), the yellowish-orange zoanthid Epizoanthus giveni named after Dr. Bob Given... and the subject of this week's column.
On each of the dives I made there that year, I encountered an unusual starfish I've never seen anywhere else. Of course I hoped it was new to science and I might be the one to describe and name it. When I returned home, I spent time searching the Internet (thank you classmate Al Gore! Tee hee) for information and learned there had been previous sightings. At the time it was not known to have been scientifically described so we referred to it as the "red spotted starfish (aka sea star for the PC crowd).
I later heard that it had been scientifically described and named, but I lost the note with that information. It's probably buried under the tons of paper on my computer desk. Recently I received an e-mail from diver Dana Rodda who had seen a previous Dive Dry column of mine about this sea star. She asked if I knew the name for it. That initiated a search for more current information and led me to a publication about sea stars collected from an eroded volcanic island, Rocas Alijos, located about 300 km (180 miles) off the Pacific coast of Baja California.
I discovered that our red spotted starfish might be a relatively "new" species collected by my dive friend Jeffrey Bozanic working with Dr. Gordon Hendler, curator of echinoderms at the Natural History Museum of Los Angeles County! Dr. Hendler had named the starfish collected there after Jeffrey, Hacelia bozanici. I sent an e-mail to Jeffrey with an image of one I saw on Farnsworth and also wrote Dr. Hendler to see if he could confirm it was the same as the one out on Farnsworth.
When Jeffrey collected the single specimen at Rocas Alijos, he did so on a rebreather at a depth far greater than I could dive, 76 meters (about 250 feet). Even though I've dived to 150 feet on Farnsworth Bank, the specimens there were all at shallower depths than that. I found that interesting since it appears the species prefers deeper and colder water way down south of the border. Up here off Catalina, the water is colder and therefore the species can be found at reasonable SCUBA depths. This may be an example of submergence to deeper depths in warmer waters although more data is needed to ascertain that.
When Dr. Hendler got back to me, I was informed that our local specimen could not be attributed to Hacelia bozanici with 100% certainty and he suggested we consider it an unknown species in the genus Hacelia instead pending further study. The specimen collected in Mexico was much smaller than the 10-12" diameter individuals we've been seeing out on Farnsworth. He needed a smaller specimen of about 4-5" diameter to compare the two. Until then our "red spotted starfish" will have to wait to be assigned a scientific name with certainty! Sadly it still has no identity, at least as far as science is concerned.
I haven't been able to dive since last July due to my cancers (yep, plural) so I'm reaching out to divers in southern California to see if we can locate a specimen of the appropriate size for Dr. Hendler to compare with the one from Rocas Alijos. Hopefully we can finally solve the mystery and give this attractive sea star a true scientific name! Feel free to contact me via e-mail at bushing@post.harvard.edu.
© 2018 Dr. Bill Bushing. For the entire archived set of over 750 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Dana Rodda's image from Farnsworth Bank and three of mine from the same site.
