Tag Archives: fish

Great White Sharks in Captivity

There aren’t any. But, aquaria have many times tried to make it so, and it always goes bad for the shark. The basic problem is that great white sharks are pelagic, and it is very hard to keep pelagic creatures in a confined space, and the largest aquaria are very confined from the point of view of a large pelagic animal.

greatwhitefeedingonsealAnother problem would eventually become important in the event that an aquarium managed to keep a great white shark alive long enough. When they are young, great white sharks dine on fish. When they are adults, they seem to prefer mammals. So, imagine feeding time at the zoo with an adult great white shark ….

Anyway, VOX has put together a really excellent video on the history of great white sharks in aquaria. Wildlife biology or marine biology high school teachers take note, this video has a lot of learning in it about stuff you probably teach!

For example, you learn what “pelagic” means.

Here’s the video:

I’ve seen great white sharks in the wild several times. You can to. You just need to know where to look. I suggest the southern coast of South Africa. Oh, and if you are going to go around spotting sharks, you’ll need a good shark spotting guide.

Wildlife Of The Galapagos: Updated Field Guide (Review)

Wildlife of the Galápagos: Second Edition (Princeton Pocket Guides), by Julian Fitter, Daniel Fitter, and David Hosking is both a field guide and a travel guide, focusing on the Galapagos Islands. It includes basic information about each island and each town or tourist destination, and a comprehensive guide to how to visit, what to bring and not bring, and otherwise plan your trip to these amazing evolution-drenched islands.

The wildlife that is covered includes birds, other land vertebrates including the famous tortoises and lizards, offshore mammals, fish, insects, and plants. There is even a short section on the different geological features, which are not technically wildlife, rounding off the guide as the only book you really need to bring. Oh, and there is also an overview of the Islands’s history.

Over 400 species are covered with 650 illustrations including maps and drawings. The wildlife (and geological features) are represented mainly as photographs. It is a pocket size pocked guide similar to your average portable bird book.

The authors are experienced guides and have been involved with Galapagos conservation and tourism for years.

The first edition of this book was widely used. The second edition has added fish, Spanish names, more information about history, climate, geology, and conservation, and of course, updated information on visitor sites.

You can’t go to the Galapagos without this book. You can, however, get this book and not go to the galapagos, and pretend you are going! (Or, get inspired, and start saving up now!)

Global Warming Coming To An Ice Fishing Contest Near You

Over the last several years, ice fishing contests, which are a big deal in Minnesota, have been repeatedly cancelled due to insufficient ice thickness on the relevant lake. Some of these contests have been permanently cancelled because the annual cancelations were becoming more frequent. Just now, the Maple Lake Ice Fishing Derby has been cancelled. That’s bad.

But even more disturbing is this:

Ice conditions for the Eel Pout Festival have created enough concern to prompt vehicle restrictions, according to the Cass County Sheriff’s Office.

Sheriff Tom Burch says vehicle traffic on Walker Bay during the event will be prohibited, but with the following exceptions: snowmobiles and Class 1 & 2 ATVs.

All vehicles must be removed from the ice by noon on Friday. Motorized traffic is no allowed until Sunday at 10 a.m.

This is a big deal because the Eel Pout Festival is different from the previously canceled ice fishing events. All those previously cancelled events, including Maple Lake, are in Central Minnesota, not far from the Twin Cities. The Eel Pout festival is way the heck up north, in a region where even with global warming affected climate, the ice still normally forms hard and thick.

I assume that the problem with the ice up on Leech Lake, where Walker Bay is located, is problematic this year because of a combination of rising global surface temperatures caused by human released greenhouse gas pollution, plus added warmth from the current El Niño. In a way, we are looking at the effects of global warming in the future, in a decade or two, when the “normal” elevated (non El Niño) temperatures will catch up with the extra elevated temperature of the combined effects.

While we are on the subject of the Eel Pout, let me clarify a bit. The fish known as Eelpout (one word) is a marine fish that looks a little like an eel. There are about 300 species, they are bottom dwelling, and some live at a great depth. They are not the same fish as the Eel Pouts (two words) in Minnesota. The Minnesota Eel Pout is also known as the Burbot, and it is a fresh water Cod, the only Cod that lives in fresh water. It is also known as Ling, Coney-Fish, Lingcod, and owing to its somewhat slimy nature and tendency to wrap itself around your arm when pulled out of the water, Lawyer. (I assume this refers to a specific subset of lawyers, not all lawyers.)

It is very edible, I hear, though I’ve yet to eat one.

This is also an example of where Wikipedia gets it wrong. In the entry for “Eelpout” (one word) Wikipedia correctly describes what Ellpouts are, but then adds this, under the “popular culture” heading:

The Eelpout Festival that takes place in February in Walker, Minnesota, in the United States, celebrates the burbot, which is actually a cod-like fish misleadingly known locally as the eelpout

Bad Wiki. First of all, we spell the name of the fish differently (two words, not one word). Second, the Minnesota Burbot has been called the Eel Pout for a long time. Eel Pout, as well as Eelpout, are common terms, not scientific names, so of course there is some sloppiness. I don’t see Wikipedia saying it is wrong to call an Elk a Moose in Europe, do I?

Anyway, here is what the Eel Pout Festival looks like:

Humans being loud under water, Cuttlefish

Last June (and May and July and part of August) we had a lot of precipitation in Minnesota. This caused lake levels to rise modestly. One lake, which is large enough to have meaningful waves, has older settlement along it so lots of cabins, boat houses, and such are right on the shoreline. With the lake level up, waves threatened the material possessions of rich white people, so naturally something had to be done. A No-Wake Rule was put into effect.

A No-Wake Rule means the oversized fishing boats and smallish cabin cruisers that normally ply this large exurban lake need to all go at 5 m.p.h. or less, and forget about wake boarding, water skiing, and all those other fast, wake churning activities. The result? A lot of butt hurt, a near First World depression setting in in the Twin Cities wester suburbs. Somebody took away our boy toys!

But then, somebody went fishing. It isn’t a great fishing lake. It is mainly a go-fast lake. In fact, it is on this particular lake, I believe (with no evidence I quickly add) the method of fast-trolling for muskies was invented. This is a way to “go fishing” and go fast at the same time. You drag the lure behind you as fast as your boat will go. It is said you can catch muskies this way. To my knowledge it has never happened. Just more boy toy.

Anyway, somebody went fishing on the No Wake Lake, and guess what happened? They caught a boat load of fish! Literally! Then their friends went out fishing, and they caught a boat load of fish too! Pretty soon all the fisherpersons who had access discovered that when you don’t drive giant boats back and froth across the lake at high speed all day, the fish feed. When you do, they hunker down, feed infrequently, and grow slowly.

Now, I’m not going to vouch for this relationship just yet, but it makes intuitive sense. In my own experience, quiet places are where you catch fish. If I’m fishing up at the lake, once the boats start driving around skiing (say on a fourth of july weekend) I might as well reel it in and go get a beer, because that’s the end of the fishing. I’m pretty sure my best fishing has been on Wednesday and Thursday, before the startup of the loud and noisy weekend. And that’s on a quietish part of a relatively quiet lake.

The only reason I’m mentioning this now is because I came across this story from my Science News Roundup:

The blare of human noise causes birds to pipe down and frogs to breed less frequently. Now, scientists have found a humanmade sound that has a far more colorful effect: The boom of a ship’s engine makes common cuttlefish (Sepia officinalis) change the complex swirls of skin hues, stripes, and spots that they use for camouflage and communication. …when researchers placed a loudspeaker near cuttlefish tanks and played the sound of an underwater engine, the animals swam more and changed colors more often. They also raised their first pair of arms, which are used to sense water movements, more frequently…The sounds of crashing surf had no effect, providing the first evidence that engine noise may stress the animals out.

The original story is here, in American Naturalist.

I would love to see a large number of large lakes shut down for boating. No motors. Eventually, of course, there will be no gas powered motors, with the shut down of fossil fuels. I promise you, when we start using quiet electric boats for fishing, the fishing will get better.

The strangest supposed “fish” yet?

I’m sure that several years ago a bunch of out of work “oceanographers” like the people here got board and started faking various “fish” that only they ever saw in the wild and only they ever photographed and that lived in the “deep” ocean where nobody could verify their existence. I assume this was a funny joke that got out of hand and now they’re stuck with having to come up with a new “fish” every so often to keep up the ruse. Here’s the latest, a fish with a see-through head:

For the first time, a large Pacific barreleye fish – complete with transparent head – has been caught on film by scientists using remotely operated vehicles at the Monterey Bay Aquarium Research Institute. The deep-sea fish’s tubular eyes pivot under a clear dome.

Man fishing for bluegills catches shark by hand instead

This is funny:

Just so you know, he was not fishing for “bluegills” This is a bluegill:

A nice bluegill
A nice bluegill

Bluegills live in fresh water and are like “sunfish” and “pumpkinseeds” and “crappies” etc. all of which are in the bass family.

Bluefish live in the ocean and roam along littoral regions in large schools. This is what large bluefish look like:

skip_leadingva_bluefish

Of course, when one is fishing for bluefish, there is always the possibility of catching the fish that eats them, such as striped bass. Like this:

nantucket_elistriper

The striped bass is not in the “bass family” referred to above. Striped Bass are Moronidae, bluegills, largemouth bass, etc. are Centrarchidae.

Anyway, sometimes you catch a shark.

Japan Nuclear Disaster Update # 37: Glow in the dark fish, and the meaning of “Power”

As a result of our last posting on Fukushima, we had a discussion initiated by commenter Daedelus2u about radioactive istopes of Cesium becoming concentrated in fish. I thought I’d take this opportunity to expand on that discussion a little. This relates to the possibility that radioactive elements spilled or spewed from a nuclear reactor site (as per normal or following a meltdown and China Syndrome, as in the case of Fukushima) can become part of our diet especially in fish, and how much concentration of radioactive isotopes we might expect.

Continue reading Japan Nuclear Disaster Update # 37: Glow in the dark fish, and the meaning of “Power”

World’s Largest Fish that is not a whale* on film!

This sucker was filmed in the Gulf of Mexico swimming among the oil rigs!!! It propelled itself with undulations of its dorsal fin and looks a lot like a sea serpent. In fact, it is said to be “the origin of the sea serpent myth” but I’m not quite sure what the difference is between being “the origin of the story of a 30 foot long fishy snaky thing with an undulating dorsal fin” and being a “30 foot long fishy snaky thing with an undulating dorsal fin” …

Continue reading World’s Largest Fish that is not a whale* on film!

“I only fish for the fishing, not the catching”

There are two lies you will hear from anyone who is into the sport of angling. 1) “It was THIS BIG!” and 2) “Catching fish isn’t the point. It’s the experience of fishing that matters.”

i-70187539ed531a1b78b3c8230388d053-Largemouth_bass_mocking_variety.jpg

The Mocking Bass. For four years this fish watched me cast lures and live bait from the end of the small dilapidated dock in the lagoon behind the cabin, without ever showing interest in what I had to offer. Two weeks ago I dropped a plastic worm on his head. The worm slid off and rested on the bottom. The mocking bass reoriented towards the worm and took a sniff. I jiggled the worm. And, BANG. He took the bait. My drag was set to medium, so WZZZZZZZZZZZZZZZ .. he took off across the lagoon. I tightened the drag a little because he was running into brush and he turned direction and jumped. But I kept the rod tip up and used his jump to bring him in. He ran back and forth across the lagoon two more times and then headed out. WZZZZZZZZZZZZZZ against the harder drag with his last bit of strength, and one more jump. Then I brought him in, letting him struggle and tire a little more because they always manage to pull off that one last bit of resistance, the one where you lose most of the big ones. I got on my knees and pulled him out just as he got near the dock… And that fish was THIS BIG!!!!!
Continue reading “I only fish for the fishing, not the catching”

Hybrids of Blind Fish Can See

Blogging on Peer-Reviewed ResearchThe loss of sight in cave dwelling species is widely known. We presume that since sight in utter darkness has no fitness value, the mutation of a gene critical to the development of the sense of sight is not selected against. Over time, any population living in darkness will eventually experience experience such mutations, and these mutations can reach fixation. Continue reading Hybrids of Blind Fish Can See