Afternoon music

Right about now, I'm in Jacksonville watching my eldest receive her college degree. She took the circle route to get here, and it means all the more. There was a day, down in Santa Rosa County, when I used to rock her to sleep with Tupelo Honey. Van Morrison and his people apparently guard their music with religious zeal - maybe Richie Havens will do.

Edit - in looking back, I found the real thing....



Proud of you, babe.

Me and Lowell

Pulling out at 5:30 in the morning en route to Jacksonville. Lots of Florida asphalt under the wheels. But I'm still...



I been from Freeport to Fakahatchee, Sebastian to Sanibel.

Thanks to the Honors guys..

...gave the keynote talk at the Honors Program Banquet tonight. Outstanding group of young students - the type that will make a difference, if we give them a chance. The theme was from Warren's poem on Audubon - "What is man but his passion?". Managed to squeeze in photos of Warren, Audubon, Bette Davis, a robin, my kids, my dogs, the Florida Gators, a longnose gar, a redfin darter, a bowfin, etc., etc. Great fun, but it's somebody else's turn.

Regardless, thanks greatly for the invitation.

I'll be on the road for a few days, so the updates and the FODs may go on the shelf till I get back. Quite honestly, I'm exhausted - need a couple of days off. My eldest graduates from the University of North Florida in Jacksonville tomorrow at 4:00. I'll be on the road early.

Fish o' the Day - longnose gar

We'll probably deal with a couple more gar species eventually - today it's the longnose, Lepisosteus osseus. This is actually the common, large gar in most of our streams and rivers - we're a little too far from the coast to have the big alligator gars (although we certainly hear reported sightings). Actually, a lot of my students think this is the alligator gar, and it can be a pretty impressive fish. They can supposedly reach 6 feet in length and weigh 50 pounds, although a 4 footer weighing maybe 10-15 pounds is a big one. They sport the characteristic ganoid scales of all gars, along with the dorsal and anal fins far back on the body. The greatly elongated jaws are the most distinctive feature - at least as long as the rest of the head. They're heavily armed with sharp teeth - in a single row. That's the surest way to distinguish them from the alligator gar (Atractosteus spatula), which has a much broader snout characterized by a double row of teeth in the upper jaw.

Longnose prefer faster-moving waters than their smaller cousin, the spotted gar. They will often congregate in tailwater areas below dams, and we get them routinely in deeper areas of some of our local streams. The one up top came from a pool in Sumter County's Alamuchee Creek.

Young longnose feed on small crustaceans and insects, but quickly become piscivorous. They are primarily nocturnal feeders, and are strongly surface-oriented. Often, the gar will stalk fish from beneath which they take sideways in the mouths. Sometimes, they slash the mouth from side to side and impale small fish on the sharp teeth.

Like all gars, the longnose has a highly vascularized swim bladder that's connected to the gut by a pneumatic duct, and in the heat of the summer relies heavily on aerial respiration. We'll see them breaking the surface in the heat of the day to take air into the bladder.

Got any good quotes from Hamlet...

...other than, you know. Cause the folks at Science Daily have scooped me on "To evolve or not to evolve", in their press release on speciation in the small reef fish known as hamlets. A new paper in the journal Global Ecology and Biogeography looks at what hamlets have to tell us about evolution and speciation in the marine environment. There are ten Caribbean species of hamlets, a group of small, colorful seabass in the genus Hypoplectrus. Particular reefs may have several species, but most species are found only in specific locales. That's the blue hamlet (H. gemma) at right, and it's found only on Florida reefs. We'll see them in abundance on the Subtropical trip in November.

It has long been believed that different hamlet species had arisen following geographic isolation, perhaps the result of lower sea levels, and then been mixed when sea levels rose again. The new results, however, do not support an allopatric speciation model. Instead, it appears that the different hamlet species may have arisen sympatrically, perhaps as the result of ecological isolation. I have to admit that the abstract is not enough here - I think I'm going to have to get a copy of the whole thing.

Get rid of sea lice? You bet your wrasse

Sea lice are bad. Just ask the Norwegian aquaculture industry which loses NOK 500 million to 2 billion worth of salmon to lice every year. Chemical treatment isn't working any longer, because the sea lice, actually a family of ectoparasitic copeods, have become resistant to the chemicals employed The research council overseeing the industry is allocating millions to look for solutions. While most researchers are investigating traditional approaches, one research station is employing a fish, the Ballan wrasse, to eat the parasitic copepods off of infected salmon. Researcher have found as many as 300 lice in the stomach of a single wrasse. Here's the scoop at Science Daily.

Bee afraid, bee very afraid

Once again, I apologize. It's a little surprising that elephants would be afraid of bees, but apparently they are. The bees can give them problems if they sting them around the yes, or inside their trunks, and calves can be severely injured or even killed. The threat is serious enough that elephants have apparently developed a warning call specifically associated with the possible presence of bees. The results, published in PLoS One, are summarized in a press release here at Science Daily.

Researchers played recordings of bees to families of elephants and observed that the animals fled from the sounds. Not only that, but they made a low, "rumbling" call and shook their heads as they were fleeing. The scientists also found that a recording of the alarm call was enough to produce the flight response, even in the absence of bees. When the call was played for elephant families, six of ten fled in the opposite direction from the loudspeaker. When the call was frequency-adjusted, or replaced with a control rumble, only two of ten elephant families fled. The sample size may be a little small to draw an emphatic conclusion, but it's pretty interesting. Entertaining too, as you'll see below.

Further work is planned to determine if the call is employed for types of threats other than bees.

Got lucky with YouTube. Check it out.

Fish o' the Day - thresher shark

Thought it was time for another shark. In a couple of weeks, most of marine biology types will heading off the Sea Lab in a few weeks to start their Sharks and Rays short course - here's a little something to whet their appetities.

The thresher sharks are group of several species (three or four, the geneticists are working it out) in the genus Alopias. They're primarily open water animals, seldom seen in inshore waters, and are cosmopolitan in tropical and temperate oceans. The common thresher (A. vulpinus) is most common in shelf waters. Threshers can be big - the common thresher A. vulpinus can reach lengths of about 20 feet and weigh more than a half ton. The pelagic thresher (A. pelagicus) is the smallest, topping out at about 10 feet. That's a pelagic at left. Of course, a significant part of the length is made of the long tail which may be the same length as the rest of the body. They are ovoviviparous, with eggs hatching internally and the young being delivered at sizes in excess of a meter in length. Like the sand tiger, they're known for intrauterine cannibalization among embryos.

Threshers feed primarily on schooling fish, and have been observed to use their huge caudal fin to stun baitfish prior to feeding on them. Threshers are acrobatic, and are one of only a few shark species known to leap clear of the water surface.

There are no verified acounts of thresher attacks on humans, although there's a really dramatic ocean legend of one decapitating a fisherman with its tail.

All three of the recognized species are listed by the IUCN as vulnerable; if we decide that there's a fourth species, it will be too.

Texas pterosaur

Nothing like alliteration with a silent "P".

The discovery of a 95 million year old pterosaur in Texas is detailed here in Science Daily, with the publication in the Journal of Vertebrate Paleontology. This is one of the most recent members of the Family Ornithocheiridae, and only the second one from North America. The medium size flying reptile, dubbed Aetodactylus halli, would have had a wingspan of about 9 feet. The time and location at which it lived, as well as its morphology suggest that it may have been a fish-eater, the case with many of the pterosaurs.

Overfishing outlook

Many of the world's fisheries are collapsing as the result of overfishing. The folks at Scientific American discuss a new PNAS study indicating that new regulations may not be helping.

Overachieving amphibians

Globally, amphibians aren't doing so well. This most endangered class of vertebrates is being hammered from all sides by a whole suite of environmental impacts. Still, there are groups and places where they're doing OK - the salamanders of the Appalachians are amphibians who're getting the job done. New research coming out in the Proceedings of the National Academy of Sciences takes a look at how they might be doing that.

The Appalachians support the greatest diversity of salamanders of any place on earth. The eastern mountains are home to 70 species, 30 in the Great Smoky Mountain National Park alone. Evan Grant, one of the researchers involved in the study makes an excellent point when he stresses that, while we're often rightly preoccupied with species that are threatened with extinction, "it is also important to look at the populations that are doing well, and to understand what makes the population or species more stable. You can apply this to interpret what might be happening with populations that are declining."

In the PNAS study, researchers marked over 2500 individuals belonging to two species of lungless salamanders (Desmognathus fuscus and D. monticola) in small streams of Shenandoah National Park (that's D. fuscus up top). While the salamanders are primarily aquatic, particularly are larvae, they are able to move over land and sometimes will travel between adjacent streams. Results indicated that, while salamanders prefer to disperse upstream, there is significant movement between streams, especially among juveniles. This movement within stream basins adds significantly to the probability of a population surviving. This is a common finding in metapopulation studies, which show that ever moderate levels of immigration between subpopulations can go a long way toward fighting the loss of genetic diversity that plague small populations.

Also of significant import on the conservation side of this study, is the significance of the terrestrial habitat between the streams. I think many of would focus our attention on the stream basins and riparian forest - this study indicates that even terrestrial areas quite distant from the stream itself may be critical in maintaining salamander diversity.

Fish o' the Day - flathead catfish

The FOD for tonight will have to be a quick one - too much of the real world intruding right now. The flathead, Pylodictis olivaris, is one of the largest of the North American catfish in the Family Ictaluridae. Their only competition would be the blue cat, Ictalurus furcatus, and it would be a pretty tight finish, as flatheads have been known to reach 1.5 meters in length and 120 pounds. Their broad, flat head makes them easy to recognize. Flatheads are usually big water fish, most common in large lakes and rivers, although we've pulled a few out of some of our smaller local streams. Like most catfish, they're largely benthic in their feeding. Unlike many of the ictalurids, they seem to prefer their prey alive, and feed heavily on small fish. Flatheads go by an assortment of other names - locally, yellow cat seems to be the preferred moniker.

Flatheads are the primary quarry of catfish grabblers across the South, which means this post would't be complete without a Girls Gone Grabblin' video...




Daniel Hall, if you're out there... you owe me a trip.

Spitters

I remember reading a story when I was a kid about an African adventurer and an encounter with a spitting cobra. I've been fascinated by them ever since. Nice video here. This is Naja ashei, Ashe's or the giant spitting cobra. It's the largest of the spitters, reaching lengths in excess of 2 meters. Technically, it's a relatively new species as it was only recognized as distinct from the black-necked spitting cobra (N. nigricollis) in 2007.

Rattlesnakes and Con Bio...

...doesn't get much better than that, at least from the standpoint of subject matter. Turns out, though, that the new isn't too good. A group at Cornell has investigated the impact of 80 years of road contruction in upstate New York on the genetic diversity of timber rattlesnakes (Crotalus horridus) in the region. As you might imagine, the impact has been to lessen the genetic diversity in hibernacula (quarters in which groups of snakes overwinter) that are significantly isolated by roads. This reinforces studies with many other groups illustrating the effect of anthropogenic fragmentation of habitats is having in reducing local population sizes with the resulting loss of genetic diversity.

In this study, which appeared in Conservation Biology, researchers examined some 500 rattlesnakes from 19 hibernacula in four regions. They found that genetic clusters never crossed roads, serving to illustrate that roads are even more of a boundary to the free exchange of genetic material in these snakes than we might have imagined.

Another big new lizard

A new species of large monitor from the island of Sanana in the Moluccan Islands if Indonesia. It's yet another member of the genus Varanus, which includes the fruit-eating Varanus bitatawa described recently from the Phillipines, as well as the Komodo dragon (V. komodoensis). This one is V. obor, and is being referred to as the torch monitor (that's meaning of the species epithet in Indonesian, as well). The common name refers to the bright orange head set off from the dark body, giving the impression of a flaming torch. V. obor is a moderately sized monitor, reaching a length of 4 feet or so, and they feed on a variety of smaller animals and carrion.

The new species is described in Zootaxa by Valter Weijola and Samuel Sweet. Here, Sweet discusses the reasons why large monitors are common in this region of the world. In the region to the east of Wallace's Line the absence of large mammalian predators opens a niche that the monitors have been able to fill.

The discovery of another large, strikingly colored predatory lizard has additional significance. It serves as an indication just how much biodiversity remains unknown to us.

Fish o' the Day - American eel

A great fish that most people don't know much about. The American eel, Anguilla rostrata, is a member of the Familiy Anguillidae, along with the European eel (Anguilla anguilla) and a dozen or so other species and subspecies. All are catadramous, meaning that they are born at sea, make their way into freshwater rivers and lakes where they live their lives prior to returning to the sea to spawn and die. The opposite pattern from the more well-known anadramous pattern shown by Pacific salmon. The American eel is found in lakes and rivers along the Atlantic and Gulf coasts, where the females can reach lengths of 4-5 feet. The males, which often remain in the lower reaches of rivers, are smaller, usually not much over 2 feet in length.

A Chesapeake Bay eel....

They're easy to recognize, of course, with their snake-like body with a single continuous median fin, and no pelvic fins. They're predators, feeding on a range of prey from inverts to small fish. They're largely nocturnal in their feeding - back in the days of my youth they were a common catch on trotlines.

The most dramatic thing about American eels is their spawning migration. When they reach maturity, at about 5 years of age, they begin a downstream migration. They make their way into the ocean and migrate to the region of the Sargasso Sea, west of the Bahamas. There, at great depth, they spawn and die. The millions of eggs produced by the female, when fertilized, develop into a strange, leaf-like larva known as the leptocephalus. These larval stages, assisted by ocean currents begin the long trek back towards the continent. As they travel, they gradually metamorphose into progressively more "eel-like" forms. By the time they reach river mouths, they are small, pigmented forms known as elvers, which migrate upriver to their adult homes.

Interestingly, European eels also spawn in the Sargasso Sea region of the Atlantic. Anguilla anguilla is virtually indistinguishable from the American eel, differing in vertebral number (A. anguilla has more) and in the number of chromosomes. However, their development is staggered in timing for the much longer transit that they have to make in returning to their native rivers in Northern Europe. Where the voyage of the larval American eel requires about a year, that of the developing European eels may take as much as three years.

I don't think there's much of a market for American eels in this country. I do have a memory of reading, as a kid, a biography of Babe Ruth. One of those little blue biographies that my elementary school library was full of. I have vivid memories of the stories of his mom Kate pickling eels in the Baltimore home of his childhood. Now, it's the Asian and European markets that are driving eel consumption. And there's plenty of it - this year Greenpeace International added the eel to their Seafood Red List.