DIVE DRY WITH DR. BILL #762: TRIVIA PURSUIT
No, you didn't read the title of this column wrong. I wouldn't be writing about Trivial Pursuit since I'm such a deep thinker (down to 200 fsw). My topic this week will be a small snail that was one of the first things I identified when I moved from the East Coast to Catalina back in the late 1960s.
Back then, my subject was called Trivia solandri and was a somewhat rare critter. It is often referred to by its common names, the coffee bean and Solander's trivia. Not sure who Solander was but he must have discovered it. I found my first one on a drifting kelp raft, suggesting it may have hitched a ride from the mainland to Catalina (or more likely from Long Point to Toyon Bay). Its shell fascinated me due to the ribbing you can see in the pictures.
Initially I couldn't find it in the few marine life field guides I had (back in the daze before my Harvard classmate Al Gore invented the Internet!). That was as close to a "trivia pursuit" as I came. When I was able to uncover more information about this species, I found that its geographic distribution ranged from southern California south to Peru. Therefore it was at the northernmost extent of its range. Perhaps I should have researched Mexican and South American marine life field guides instead.
Since this snail's distribution reaches only as far north as SoCal, we may assume it is limited by cold water temperature. Of course this may not be the case as it could be limited instead by other environmental factors or the availability of a preferred type of food. Global warming, including the warming of ocean waters, is an established fact. What some may predict based upon it may not be, including my thought that as ocean waters warm Trivia solandri may move further north. Of course I may be wrong (it has happened a few times), but I feel comfortable presenting this hypothesis.
Geography is not the only was this snail may be moving. Biologists known as taxonomists, who focus on the naming andf categorizing of critters have also moved it from the genus Trivia into the genus Pusula. In the past taxonomists have had to use physical characters, physiology or behavior to place species in the proper category. Today through the wonders of molecular genetics, they can actually look at the genetic structure of different individuals to see how closely they are related. Of course this still requires a judgment call by the biologist, but at least it is based on something more fundamental.
Now the genus Pusula originated back in 1832, "slightly" before I was born. It is in the mollusc family Triviidae, which is commonly known as the false cowries. There is a related species in our waters, Pusula (formerly Trivia) californiana, known commonly as the California coffee bean. One can tell them apart because the "ribs" on the shells of P. solandri do not cross the top of the shell while those of P. californiana do. There are a number of other coffee bean species in this snail family.
So what do coffee beans eat? Starbucks had no information so I resorted to Google and discovered they like to chow down on tunicates. Now there is little family resemblance, but tunicates are the closest invertebrate relatives to humans! The snail sneaks up on small tunicates and nips them in the bud (so to speak). Then they use their scraping radula to slurp up the rest of the tunicate. But don't worry, given its poor eyesight and the fact we humans look nothing like our relatives, we can safely dive down without fear of attack.
As for their sex life, don't ask for they will not tell!
© 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: Pusula californiana (by Kevin Lee) and Pusula solandri (by Michael Francisco); and views of P. solandri shells from Catalina waters.
No, you didn't read the title of this column wrong. I wouldn't be writing about Trivial Pursuit since I'm such a deep thinker (down to 200 fsw). My topic this week will be a small snail that was one of the first things I identified when I moved from the East Coast to Catalina back in the late 1960s.
Back then, my subject was called Trivia solandri and was a somewhat rare critter. It is often referred to by its common names, the coffee bean and Solander's trivia. Not sure who Solander was but he must have discovered it. I found my first one on a drifting kelp raft, suggesting it may have hitched a ride from the mainland to Catalina (or more likely from Long Point to Toyon Bay). Its shell fascinated me due to the ribbing you can see in the pictures.
Initially I couldn't find it in the few marine life field guides I had (back in the daze before my Harvard classmate Al Gore invented the Internet!). That was as close to a "trivia pursuit" as I came. When I was able to uncover more information about this species, I found that its geographic distribution ranged from southern California south to Peru. Therefore it was at the northernmost extent of its range. Perhaps I should have researched Mexican and South American marine life field guides instead.
Since this snail's distribution reaches only as far north as SoCal, we may assume it is limited by cold water temperature. Of course this may not be the case as it could be limited instead by other environmental factors or the availability of a preferred type of food. Global warming, including the warming of ocean waters, is an established fact. What some may predict based upon it may not be, including my thought that as ocean waters warm Trivia solandri may move further north. Of course I may be wrong (it has happened a few times), but I feel comfortable presenting this hypothesis.
Geography is not the only was this snail may be moving. Biologists known as taxonomists, who focus on the naming andf categorizing of critters have also moved it from the genus Trivia into the genus Pusula. In the past taxonomists have had to use physical characters, physiology or behavior to place species in the proper category. Today through the wonders of molecular genetics, they can actually look at the genetic structure of different individuals to see how closely they are related. Of course this still requires a judgment call by the biologist, but at least it is based on something more fundamental.
Now the genus Pusula originated back in 1832, "slightly" before I was born. It is in the mollusc family Triviidae, which is commonly known as the false cowries. There is a related species in our waters, Pusula (formerly Trivia) californiana, known commonly as the California coffee bean. One can tell them apart because the "ribs" on the shells of P. solandri do not cross the top of the shell while those of P. californiana do. There are a number of other coffee bean species in this snail family.
So what do coffee beans eat? Starbucks had no information so I resorted to Google and discovered they like to chow down on tunicates. Now there is little family resemblance, but tunicates are the closest invertebrate relatives to humans! The snail sneaks up on small tunicates and nips them in the bud (so to speak). Then they use their scraping radula to slurp up the rest of the tunicate. But don't worry, given its poor eyesight and the fact we humans look nothing like our relatives, we can safely dive down without fear of attack.
As for their sex life, don't ask for they will not tell!
© 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: Pusula californiana (by Kevin Lee) and Pusula solandri (by Michael Francisco); and views of P. solandri shells from Catalina waters.
