Dive Dry with Dr. Bill

#599: Blow Your Own Horn

I have absolutely no talent when it comes to making beautiful sounds. I almost failed my 8th grade music class because I never understood transposition. My junior high school band leader asked me never to blow through the mouthpiece of my trombone when the band was in public. Today although I go to karaoke religiously on the weekends, the chances of hearing me sing are almost nil. It takes a very pretty woman or a fair bit of adult beverage to do that. For some reason the first is an extreme rarity and since I'm a diver the second seldom happens. I've heard Wayne Griffin and the Chamber of Commerce are very happy about that since my singing outside of my own shower has been known to clear all the boats out of Avalon Bay. That just wouldn't be good for business on a summer weekend. However, I do appreciate listening to music of many kinds, and thoroughly enjoy the Xceptional Music Company's free concerts during summer out on the Wrigley stage. Thanks, Ray!

Jacques-Yves Cousteau referred to the ocean as "The Silent World" in his 1956 underwater documentary of that name. Of course most divers are aware that it is far from silent down under. Most landlubbers aren't aware that there is an entire orchestra awaiting those of us who make the descent into the briny deep. I'm referring to the cornet fish, guitarfish, drums, sawfish, bass, harp seal, and I'm not even going to mention Hootie's Blowfish! Oops, I just did. Today's column will focus on one of my favorites, the Atlantic trumpetfish (Aulostomus maculatus) which is occasionally called the flute fish by those who don't know the difference between a brass and a woodwind instrument! Heck, even this musically challenged biologist does.

During my recent trip to the Dutch Antilles, I was able to film a number of Atlantic trumpetfish in the waters off Bonaire and illustrate some of their interesting behavior. These fish are long-bodied, up to at least 30" with some reported to 36 inches. The long, tubular mouth supposedly gives this fish its name, but since there are no keys to press I'd consider it more like a bugle than a trumpet. However, what do I know about music? The fish's lower jaw projects forward of the upper jaw. The tail or caudal fin is short and stubby, distinguishing it from the similar-looking cornetfish in the Pacific which has a long, whiplike tail. The body is usually brown or reddish brown and covered with lines, spots and other features. These patterns help the fish camouflage over tropical coral reefs. There is a yellowish phase where the upper head region and sometimes the entire body are bright yellow, and a purple phase where mostly the upper head region is purple.

The Atlantic trumpetfish frequents tropical reef habitats and can be fairly common. It is known from Florida, the Bahamas, the Caribbean, the Gulf of Mexico, Bermuda and as far south as Brazil. Another species of trumpetfish (Aulostomus chinense) is found in the tropical Pacific and I have observed and filmed it in places like the Philippines, Thailand, Tahiti, Fiji and Australia. The two look very similar even to my "highly trained" (but largely blind) eyes. Perhaps they are distinguished as separate species by the obvious fact that they are geographically separated enough to prevent mating. Then again, maybe one trumpets in A flat minor and the other in F sharp. I wouldn't be able to tell the difference.

Speaking of mating (and when don't I?), I have never witnessed that event in trumpetfish. They must be a bit more reserved than some species I catch in the act. In my research for this column I did find mention that they use elaborate courtship dances to entice their partner. I just step on the toes of mine, which usually destroys their mood. Sigh. The trumpetfish's ability to change color, which is useful in camouflage, apparently also comes into play here to increase their visual appeal. My cheeks just turn red during courtship. Apparently the trumpetfish is related to the seahorse and, like their cousins, places the burden of child rearing on the male. The female transfers her eggs to the male which fertilizes them and carries them in a pouch until they hatch.

These predators target small fish and shrimp. They often hunt them through stealth, using their camouflage to sneak up on the unsuspecting prey. They change color to match their surroundings and often remain very still until they strike. Trumpetfish are often seen hovering vertically in the water column and will dart down from above on a chosen munchy. They will also use this vertical posture to hide among the rod-like soft corals or gorgonians. Prey is sucked in through the narrow mouth, which is somewhat elastic and can expand to accommodate larger food as well. I must be related to these fish.

One of the trumpetfish's interesting behaviors is known as "shadowing." No, they aren't spies for one of our intelligence agencies. They shadow or follow other fish which are not considered a threat to their usual prey. I often filmed trumpetfish shadowing mostly herbivorous parrotfish by swimming on the opposite side or just above them. Parrotfish feed on reef coral and algae and are not seen as predators by many of the small fish or shrimp the trumpetfish seeks. By hiding behind these "harmless" (unless you are a coral or seaweed!) grazers, the trumpetfish can dart out when it sees something edible.

Now Catalina has been blessed over the years with much musical talent. Many of our local bands such as Blackjack and Hot on the Range are lots of fun to listen to. And of course there musicians such as Spencer Davis, Malcolm Jones, Verne Altieri, Roger Connelly, James Moody, Jessica Zumberge and a host of others in our midst. Of course I doubt any of them could teach this knucklehead to transpose! However, our waters do not sound with the same musical talent found in the tropics. Yes, there are the frequent bass, the occasional drums and the somewhat rare guitarfish. However, to truly enjoy the Un-Silent World is one of the reasons I have to travel the world to tropical waters occasionally... even if I can barely understand a single note!

© 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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Yellow phase of the trumpetfish and close-up of conventionally colored one;
two trumpetfish shadowing parrotfish to avoid detection by their prey

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