by Greg Mayer
My Okinawa correspondents spent Boxing Day at the Okinawa Churaumi Aquarium, and sent me a bunch of pictures. The aquarium is a sprawling complex on the coast in northwestern Okinawa, and includes large areas of gardens and park land, and a recreation of traditional Okinawan homes and buildings, as well as the aquarium proper.
It reminded me, as I’m sure it did many of you, of the Sausalito Cetacean Institute. That’s Ie Shima island in the background.
One of the main attractions at the Aquarium is the Kuroshio Sea Tank. It’s enormous.
When my correspondents told me they were going to the Aquarium, they mentioned something about “whale sharks”, but I didn’t query them further. It turns out the Aquarium actually has whale sharks (Rhincodon typus), the world’s largest species of fish!
And not just one!
Although whale sharks are, for sharks, specialized feeders– they feed on plankton– they are “typical shark” shaped.
Sharks are cartilaginous fishes (Chondrichthyes), which are of two main types: the Holocephali, comprising the ratfishes and chimaeras (we’ve mentioned them here before at WEIT), and the Elasmobranchi, comprising sharks and rays. Most people have a good idea of what sharks and rays look like. Here are some more typical sharks (I don’t know what species– any shark people out there?) Note that the gill slits are on the side of the head; the fellow in the middle is male, as you can tell by the large claspers medial to the pelvic fins.
And here’s a typical ray (again, no ID). Note the flattened shape, and the spiracles (whitish bits) behind the eyes– these are the vestigial first pair of gill slits. The flat body of the ray is mostly the greatly enlarged pectoral fins.
Most people also know the manta ray (Manta birostris). It’s a little unusual for a ray, being pelagic and filter feeding, so the mouth is at the front tip of the body– and, it’s got those crazy cephalic fins or “horns”, from whence it gets the alternative vernacular name “devil fish”. Do note that the gills are on the bottom of the head.
There is more diversity among sharks and rays than most people realize. Sawfish, which look a lot like sharks with a saw strapped to their snout, are actually rays, but shouldn’t be confused with the similar looking saw shark, which is a shark. There are also angel sharks, which look a lot like rays, and guitarfish, which are rays that look a lot like sharks– in fact, more shark-looking than angel sharks.
I’ve never seen either angel sharks or guitarfish in any aquarium, and thus was delighted to find that Okinawa Churaumi has guitarfish (which, remember, are rays). Here’s a guitarfish surrounded by three sharks, with a typical ray off to the right (and a shadowy form below and to the right). If you look carefully, you can see the spiracle (again, whitish looking) on top of the head, behind the eye.
In the following picture, we get a really good view of why it’s a ray. Note that the gill slits are on the bottom of the head, as is the mouth (the latter is typical, but not diagnostic, of rays). And, the pectoral fin is joined seamlessly to the head– at a point above, in fact, of the gill slits (which is why the slits are on the bottom of the head). The spiracle, already spatially distant from the other gill slits in sharks, is thus, in rays, separated from the other slits by the interposition of the enlarged pectoral fin.
In the next (and last) picture, note that the dorsal, caudal, and pelvic fins all are at least passably shark-like, but that the enlarged pectoral fin is being flapped for locomotion in the manner of a ray. (Also, it’s a male– you can see the free distal ends of the claspers below the second dorsal.)
More on the Okinawa Churaumi Aquarium tomorrow.
I wasn’t quite sure where you were going when you said this, but I was thinking – that’s a similar number of gill slits to other fish – though in the modern bony fishes which most people are more familiar with, there is typically an “operculum” (if I remember the name correctly) which covers the exterior ends of the gill slits and has one posterior opening (which many people think of as the “gill slit”. Many operculua are also sufficiently muscular to be able to pump water across the gills while the animal is stationary, in contrast to the (not really accurate) trope that “sharks have to keep swimming forwards otherwise they’ll drown”.
Bit I see you went on to look more at the relative placement of spiracle, pectoral fin (soft) edge, and the remaining gill slits. Which I hadn’t really thought about before (especially the fin’s intrusion).
To “gilla” is to like something is swedish. I like this thread, I learned a lot!
Another place added to my bucket list! Thanks for the pix!
This is a perfect example of being there too soon as I was in Okinawa from 1995-2000, just two years before this part of the park opened. I went to the Expo site on the Motobu peninsula once but there was not much going on as yet. It is the site where they had a world fair/expo back in 1975. They were in the process of building this.
I loved the place and hope to go back sometime. It is a long haul to see this park I might add. All flights to Okinawa are thru mainland Japan. Once you get to Okinawa, you will see this location is a bit remote but they do have a toll road that gets you to Nago pretty fast. Maybe 30/35 miles. You must use this one high speed road or you will take half a day getting there. Hopefully they have some type of bus or public transportation to go there now?
Way cool whale sharks!
(Boxing Day 2015 in Okinawa, you say? Funny, my ol’ man dropped by there on April Fools Day ’45.)
What branch of service was he Ken? Worst battle of the pacific and also the last.
Navy, Randy. Anchors aweigh, my boys, anchors aweigh.
Very rough time for the Navy as you know. The Kamikaze were everywhere and many ships lost. The peace park in Okinawa is a very emotional thing to see.
Yeah. My dad said his ship drew fairly easy duty at Okinawa since they had been in the thick of things a couple months earlier at Iwo Jima — and a couple months before that at Leyte Gulf.
He never talked much about the battles themselves (a few times to me when I was older — I think, because I was the firstborn, we were really close, and I asked). He had a lot of stories about his time in the service, though. Mostly stuff like standing on the deck of his destroyer passing under the Golden Gate bridge as he shipped out for his first tour, or raising hell on shore-leave in Hawaii, or the initiation new sailors got first time they crossed of the equator.
Sure wish I could hear those stories again now.
Yes, the greatest generation is nearly gone now and we are certainly going to miss them. Thanks for the information – Okinawa will always be a special place for me.
If you have not heard of it – one very good account of the battle is a book, Tennozan.
The Atlanta Aquarium used to have Whale Sharks in their huge tank, but they had problems keeping them alive, I think. I hope Okinawa know the secret for keeping them well fed.
A quick web search indicates the Georgia Aquarium still seems to have Whale Sharks … “Georgia Aquarium protects whale sharks through research and conservation efforts in the field, in the laboratory and through our unique position as the only aquarium in the western hemisphere to display these elusive gentle giants.”
I had the good fortune to dive with whale sharks in the Galapagos, and I spotted a guitar fish off the East shore of South Africa. The whale sharks where expected, but were still a great thrill. The guitar fish was a big surprise though, and very exciting to see along with other exotic life there.
Star Trek’s Cetacean Institute was actually The Monterey Bay Aquarium. Note it even has the same logo as its fictional counterpart.
A few years ago I was in Dubai, and visited the self-styled seven-star Hotel Atlantis.
It’s done up in the most luxurious, extravagant style, and has a huge aquarium, with all types of exotic marine life, consistent of course with the “Atlantis” theme.
It even has a whale shark!
What shocked me was that the whole show was just that, a show. I could find no posters or notices anywhere explaining what we were seeing, informing about the nature and life of the animals, or anything like that. It was just window-dressing, without any hint of education.
Some of the malls in Dubai have aquariums too, but one or two at least give some information about the exhibits.
The aquarium itself reminds me of Melbourne Aquarium & Oceanarium which I have been fortunate enough to visit. Top Pics btw 🙂
I also had the pleasure of visiting this aquarium a couple of years ago. While it was a wonderful ‘first’ to see whale sharks up close and personal, what occupied my mind mostly while watching them was the perennial issue of the ethics of aquariums and zoos keeping these sorts of large animals in captivity. While it’s a fair guess that animals like sharks don’t suffer the emotional and other stresses that large mammals (e.g., dolphins and killer whales in other aquariums) do in these sorts of environments, one can’t help but wonder if keeping an animal that is used to traveling vast distances in the wild in an (admittedly huge) tank in which all it can do is circle monotonously day in day out is really an ethical endeavor. This aquarium makes the usual claims of the benefits to whale sharks of the research and education that can be done with these captive animals, but somehow I still have doubts. I have my suspicions that the funds put in to promoting the fact that they have the whale sharks as an attraction far outweighs their research and educational budget. In short, I left this aquarium more troubled than when I went in, but still absolutely captivated by the beauty of these great creatures of the wide oceans.