Fish Art

One of the "mini-project" assignments that my fish guys will be doing this summer is a look at the role played by fish in art, literature, and popular culture.  More on that tomorrow.  For tonight, check this out.  Samuel Fallours lived, in the early 18th Century, on an island called Amdon in what today is Indonesia what is now Indonesia. He painted fish caught in the local waters, in a region known as the Coral Triangle and famed for the diversity of fish found there.  His catalogue of paintings is one of the world's rarest publications on natural history, but they have been collected in a new book, Tropical Fishes of the East Indies, by Theodore Pietsch.

Fallours had either a keen sense of humor or a great aptitude for marketing.  His paintings were fanciful, in some cases downright imaginary.  He also spun some remarkable tales as back stories.  Read about it here at NewScientist, and enjoy the slide show.

Lots of catching up to do...

...but it's a busy time right now. Some news items tonight, and tomorrow some contributions from the Fish Brigade.

A new offering from Current Biology examines the stereo component of shark olfaction.  It's no secret that sharks can "track" small concentrations of substances (like blood) in the water.  The new research led by Jayne Gardiner at the University of South Florida determines that the fish can sense small delays in the time required to reach one nostril compared to the other.  When they do so, they turn in the direction from which the odor is coming.  This contradicts the long-held notion that directionality was determined by concentration differences - and makes more sense.  The work is summarized here at Science Daily.

The fish you live with

And, a piece from Stewart in the Fish as Pets category, looking at the popular betta.

The Siamese fighting fish, or simply fighting fish as it’s commonly referred to in the US, is a fish that comes to us from the rice paddies of Thailand and Cambodia. The species, Betta splendens, earned it’s common name from the fighting behavior exhibited by the males. In nature. the fish are greenish-brown in color - through selective breeding, however, they have be one of the most colorful and sought-after species for freshwater aquaria. The fish typically grow to a length of 2 inches or so, although some varieties can be twice that.  Bettas typically live 2-5 years in captivity.  They belong to the Order Perciformes, which contains nearly 40% of all bony fishes, and are the gourami family (Osphronemidae).  Ahough there are nearly 50 more species in the Betta genus, B. splendens is the most popular species among aquarium hobbyists.

B. splendens has an upturned mouths and is, primarily, a carnivorous surface feeders. In the wild, they feed largely on the larvae of mosquitoes and other insects.  Their reproductive behavior is particularly noteworthy.  To reproduce, the male flares his opercula, spreads his fins, then twists his body when he finds a female of interest.  The female darkens in color and curves her body back and forth. Males build bubble nests on the surface of the water. Then, the “nuptial embrace” takes place as the male wraps his body around the female. Eggs are released from the female as the male releases milt into the water, fertilizing the eggs externally. At this point, the male chases the female out of his territory for fear of her consuming all the eggs as food, and he does the work of retrieving them from the bottom and depositing them into the nest on the surface. Talk about a workout...

A YouTube of spawning bettas...

What fish am I eating?

A contribution from Jake, in the Fish as Food category.

Many people go to restaurants and order fish, but do they really know what type of fish they are ordering? Different restaurants may well use different types of fish.  A popular fish that is being used today for items such as fish sticks and fish patties is the pollock, Theragra chalcogramma. These fish reach lengths to almost four feet and a weight of close to 50 pounds. Recent catches of pollock total close 1.5 million tons per year, representing nearly 1/3 of all marine fish caught annually in U.S. waters. Although the annual catch is large, abundance of pollock is decreasing rapidly due to over-fishing and predators. In 2008, pollock abundance was said to be the lowest in the history of the U.S.-managed fishery.

Even though the pollock numbers are decreasing, the fish is still used today in many well-known restaurants, including Long John Silver’s. Long John Silver’s was founded in 1969 and set trends with the quick-service seafood restaurant.  As the world’s most popular quick-service seafood chain, it has over 1,200 restaurants worldwide.  Although they have not always used them, pollock is the main fish that Long John Silver’s uses today. It is typically served fried, but the restaurant also serves grilled fish, also pollock. 

An endangered Fish o' the Day - pygmy madtom

As I mentioned earlier, I'll be including some posts authored by students in my summer Biology of Fishes course.  Among their other assignments, they're completing weekly "mini-projects" dealing with a number of topics, including Fish o' the Day in different categories (invasive, endangered, etc.), Fish in Art/Literature, Fish as Food, and others.  A couple from last night's session.

An entry from Jason on the endangered pygmy madtom.

The pygmy madtom (Noturus stanauli) is the smallest member of the family Ictaluridae. This family of fish is easily recognized due to the barbels that extend from its upper jaw. The pygmy reaches a total length of only 2 inches. Coloration of the fish is typically a dark brown on the dorsal side and a solid white on the ventral side. It is believed that they have a short life span of approximately one year, but they may spawn multiple times.

Very little is known about the pygmy due to the lack of success in collecting efforts. In the two Tennnessee rivers that they are known to inhabit, successful collection only occurs 25% of the time for the Duck River and 50% of the time for the Clinch River, making this one of the rarest if not the rarest fish in North America.

Where collection efforts have been successful, it is noted that their habitat is a relatively silt-free zone, with a stable substrate, and a very high water quality. This is probably related to the pygmy madtom’s decline. Siltation resulting from environmental changes in the area and degradation of water quality may have diminished the amount of suitable habitat for this species, leading to a struggle to remain viable. It seems that the pygmy could be going the way of the dodo.

One bright note is that the pygmy madtom has been successfully bred in captivity. On a collection effort for other fish, two pygmy madtoms were collected and transported into an aquarium modified for their environment. Two spawning individuals were observed during this time, and 13 offspring were able to reach adulthood. This could lead to reintroduction to areas as long as the habitat is suitable.

One thing to be noted about the pygmy is that, in the areas where it is found, there is always a diverse assemblage of species around it. In the Clinch River, 80 species of fish and 18 federally listed mussels are associated with it pygmy habitat. In the Duck River, 90 species of fish are associated with it. This leads one to believe that the presence of the pygmy madtom is an indicator of a healthier river and ecosystem.

Breaking news...

Flow from BP continues

Fish o' the Day - cobia

The last of our coastal fish, for the time being.  Tomorrow, I anticipate having some entries contributed by the students in my summer fish class.  Tonight, we'll look at the cobia, Rachycentron canadum, the only living member of its family, the Rachycentridae.  The genus (and family) name translates roughly to "stinging spines" a reference to the short, stout spines supporting the dorsal fin.  Like a couple of freshwater fish we've seen (the bowfin comes to mind), the cobia is known by many other names to those that encounter it in tropical and temperate waters.  On the Gulf Coast, ling and lemonfish are common nicknames.  Where they're encountered in the Pacific, they may be known as black kingfish or aruan tasek.  Wherever found, they're big, powerful fish, reaching a length of six feet and weighing as much as 100 pounds.  The body is long and sleek, with a flattened head and small eyes.  A chocolate brown dorsal coloration grades to a white belly.  A pair of bands on their sides are more pronounced during the spawning season.  The lower jaw protrudes a bit past the upper jaw, giving them a pugnacious look.  The body shape, along with the large pectoral fins, gives them a distinctly shark-like appearance, and cobia hanging beneath the surface are frequently mistaken for small sharks.

Surprisingly, cobia's closest relatives include the remoras in the Family Echeneidae.  As juveniles, they more closely resemble remoras, although they don't have their characteristic dorsal attachment structure.  Cobia are pelagic fish (making their lack of a swim bladder a little surprising).  They're typically solitary, except when they form spawning aggregations.  They're fond of structure, and can often be found beneath floating objects (debris, seaweed, etc.).  Cobia will feed on a variety of prey, but seem to be particularly fond of swimming crabs.  They're migratory, with a population wintering off south Florida and migrating north in the spring.  They're fished heavily at that time, and the first "ling" of the year is always big news.

Nice video here of a group of cobia.

Worth knowing

BP apparently has enough money in their PR budget to buy sponsored links on major search engines.  Try it out. 

Perhaps that money could be better spent providing some protection from the coastlines currently under assault from their incompetence.  That might be a more appropriate way of dealing with their image.

Sargassum

A nicely done piece from the Mobile Press-Register looking at a fragile, floating, Gulf ecosystem.

Backpedaling

"Well, when I said Autumn, what I meant was..."

Fish o' the Day - hardhead sea catfish

Discussion of surf-fishing in the Panhandle and the common fish along the beaches leads to a consideration of this one - Ariopsis felis. The hardhead belongs to the Family Ariidae, unlike our freshwater catfish in the Family Ictaluridae. The primary difference between the two families? Ictalurids have a set of barbels adjacent to the nostrils - they're lacking in the sea cats. Hardheads are one of the most common fish off our Gulf beaches, and in our bays too, for that matter. At times, it can be difficult to fish with live bait for anything else, because the catfish will have it within seconds of it reaching the bottom. I can't vouch for them as table fare - I've always been told that they weren't any good to eat, although some folks say differently. It certainly wouldn't be a problem to find out. Hardheads can reach a couple of feet in length, and can weigh up to 10 pounds. Considerably smaller is much more common.

They're known as hardheads because of a bone that extends rearward from the head toward the dorsal fin. They should be handled with care - the dorsal and pectoral fins are equipped with very sharp, serrated spines that can go through a glove or a tennis shoe. If they bury one of those in your flesh, the pain is excruciating. This is I can verify from personal experience. An interesting fact - they're mouth-brooders. The male carries the fertilized eggs in his mouth for a month or so prior to hatching.

And, from Otis Cam..., er, Haley Barbour...

It's not the oil, it's the media. Heck, ah use more oil 'n that on mah franch fries.

Till Autumn?

Admiral Thad Allen, the Coast Guard official in charge of the U.S. response to the BP oil spill, said on a number of news outlets today that the cleanup could last into the Fall. I assume that's just a ridiculously optimistic outlook.

Damn damsels

Until the 1980s, staghorn corals (Acropora sp.) were a dominant member of Caribbean coral reefs. They were hit hard by a variety of diseases, hurricanes, and anthropenic impacts. So hard that they're now endangered. There's been an unforeseen complication. The three-spot damselfish, Stegastes planifrons, kill portions of coral to culture algae and provide hiding spots. They're aggressive, and defend their gardens ferociously. When staghorn corals were abundant, the damselfish preferred to set up housekeeping among their branches, and the relatively fast-growing staghorns could stay ahead of the damage caused by the fish. In the absence of staghorns, damselfish have taken to slower-growing head corals, and they are wreaking havoc on the already stressed corals.

The impact of the damselfish has been recognized for some time, although it was believed that their increase in abundance and impact was the result of a release from predation resulting from overfishing of large fish like groupers. A new paper appearing in PLoS One identifies the changing nature of Caribbean coral reefs as the root of the problem.

Deep reefs at risk

We've heard a lot about the deep plumes of oil and dispersants that are drifting through the Gulf as a result of the Deepwater Horizon disaster (although I suppose that BP is still denying their existence). One ecosystem that may be particularly at risk are the deep-sea coral reefs found in the Gulf and the Florida Straits. In this article at Science Daily, researchers from the University of Miami discuss the threat that the deep plumes represent for these particularly fragile systems. Unlike shallow-water corals, the deep-sea species lack photsynthetic symbionts and are dependent on food particles sinking down from surface waters. If food from the top has to drift through an undersea plume of oil, it will likely be toxic to the deep-dwelling corals. The figure at left, produced by the folks at UM, illustrates the problem.

Night music for a Sunday morning

I wake up with Elizabeth Cook every morning. Of course, she doesn't know anything about it - she's hosting her show on Sirius XM radio and I'm driving to work with my coffee. But still....

A young lady who deserves a lot more attention.