Me time

Time enough for fish - weekends are for playing. Night music from the Avetts.

Kids tomorrow

A new venture at Small Southern. The first Science Saturday event will welcome 20 elementary school kids to learn about what lives in their woods. Wish me luck.

Fish o' the Day - Atlantic salmon

A fish o' the day for a good man who loved all things Scot.

The Atlantic salmon, Salmo salar, is native to the North Atlantic and the river there feed into it. It's an anadramous species, meaning that salmon are born in fresh water but live much of their life in the sea. Scottish salmon may actually live in the rivers for four or more years before migrating downriver to the Atlantic, where they remain for several years. Using a variety of types of information they return to the rivers of their birth to spawn. The spawning migration takes a tremendous toll, and many Atlantic salmon die after spawning. Unlike their Pacific cousins, however, Atlantic salmon are not necessarily destined to die after spawning. On occasion, they're able to recondition and repeat the migration/spawning cycle.

The Atlantic salmon is, of course, one of the world's great great game fish. Tremendously strong and acrobatic, they're known to leap ten foot waterfalls in the course of their migration. They can reach lengths of over 4 feet and weights well over 50 pounds. A magnificent fish - the king of fish in the eyes of some.

A good man passes

Rest in peace, Rich.

There are bargains, and then there are bargains

$60 millon dollars. That's what it would take to expand the IUCN Red List of Threatened Species to include some 160,000 species, including some that we haven't found yet, and provide the information we need to get a good feel for global biodiversity protection. That's the opinion of a group of leading conservation scientists, including E. O. Wilson. This in a paper appearing in Science entitled "The Barometer of Life."

Thus far, almost 50,000 species have been assessed for the IUCN Red List, at a cost of about $4 million per year. While some groups have been reasonably well assessed, others are woefully lacking information.

$60 million to understand what we have to do to preserve the future. A B-1 bomber goes for about $200 mill. You tell me...

Fish o' the Day - bowfin

Another favorite - this one because he's one tough SOB. The bowfin, Amia calva, is the only surviving member of the Family Amiidae. For that matter, he's the only surviving member of the Order Amiiformes. As you might be beginning to suspect, he's a bit of a throwback. There are several fossil forms that go back as far as the Mesozoic. And the one that's left looks like he would have been perfectly comfortable back in a time when dinosaurs were dinosaurs and fish were too.

They're widely distributed across the eastern part of North America, where they frequent rivers and lakes. They're particularly fond of oxbows and beaver ponds, and that's where we usually find them. Their physostomous swim bladder is highly vascularized, enabling it to function as a lung when the bowfin finds itself in oxygen-depleted waters. Simply rise to the surface, gulp some air, and get on with your business. They are one of the most "primitive" fish to show parental behavior, with the males clearing a nest for the female and protecting the young after they hatch.

They can grow quite large, approaching 3 feet in length, and can weigh in excess of 15 pounds. The most distinctive external features are the long, undulating dorsal fin that runs the length of the back and the hard, gular plate under the throat. They're fairly vicious predators, taking pretty much anything they can get in their mouth, and they've torn more than a few rigs tossed by bass anglers over a backwater stump. Torn up a few boats too, when brought in green.

They're the proud possessor of the most colloquial names of any freshwater fish in the country. Bowfin is the accepted common name, but most southerners know them as grinnel. In the Florida Panhandle, I grew up calling them cottonfish. In other areas, they're dogfish, or swamp bass, or any of several other monikers. And then Louisianans, who have their own unique name for just about everything, know this relict as "tchoupique."

Dwarf lemurs...

...live. This is good. In Madagascar, of course. Discovered in 1896 but uninvestigated throughout the 2oth Century, the location of a population of some 1000 individuals is excited conservation news.

The state of the profession...

...from the American Association of University Professor's 2009-2010 Report on the Economic Status of the Profession. Yes, these are tough economic times. But some seem to be handling it better than others. If you want to do some exploring, check out the state tables for specific institutions for this academic year. If you want to do some more exploring, check out the same tables from 2007-2008 and 2008-2009.

My colleagues and I work pretty hard here at Small Southern University. Hard to tell, though. Just sayin'.

Fish o' the Day - Atlantic flying fish

Well, actually just flying fish in general. Cheilopogon melanurus, is one of some sixty species in the Family Exocoetidae which are fairly common in tropical and subtropical oceans. Their most distinctive features, and the source of their remarkable airmanship, are their greatly elongated pectoral fins. Flying fish, when threatened by predators (and sometimes, apparently, just for the heck of it), reach speeds in excess of 40 mph and project themselves out of the water. If they hit it just right, they may glide for as much as 50 m. The tail has to beat mightily to get them in the air, with as many as 70 strokes per second, sort of the aquatic equivalent of the wings of a hummingbird. At the end of their glide, they may fold the wings back along the body and drop into the water or angle the tail into the water to whip themselves airborne again.

The Atlantic flying fish is not the most impressive of the bunch - members of the genus Cypselurus actually employ two pairs of fins to stay in the air longer. C. melanurus, however, are an important part of pelagic food webs in the Atlantic. They feed largely on plankton, and are themselves fed upon by a number of large predatory fish like sailfish. That's assuming, of course, that the sails can catch them.

Here you go. I think this is from the Life series. The audio is a little patchy, but it's better than listening to Oprah. Check out the asymmetry of the tail.

Queezy quolls...

...OK, I apologize. I confess that I had never heard of a quoll until tonight, although for some reason it reminded me of the Kevin Spacey character in The Shipping News. This is a pretty impressive piece of work, though. The northern quoll (Dasyurus hallucatus) is a critically endangered Australian marsupial about the size of a house cat. They're omnivores, feeding on fruits, invertebrates, and the occasional amphibian. It's the amphibian part that's causing problems. The native range of quolls has been invaded by the highly toxic cane toad (Bufo marinus), an invasive toad that has been spread from its native South America to many Pacific and Caribbean islands. When disturbed (and being eaten will do that) they secrete bufotoxin, which has be can be lethal to small predators.

It is to quolls, and ingestion of cane toads is one of the primary reasons that quolls are on the decline. The problem is that quolls are relatively small, and cane toads are pretty big. The toxins of the cane toad, rather than teaching the quolls to avoid feeding them, simply kill the toad-eaters. So, researchers took 62 young quolls and taught half of them a lesson. They did this by feeding them small cane toads which carried a nonlethal dose of toxins and which had also been treated with a chemical, thiabendazole, which induces nausea in animals that ingest it. Video observation afterward indicated that the treated quolls were less likely to attack cane toads when presented with them. When they were returned to the wild, the treated quolls survived as much as five times longer than quolls that had not learned their toad lesson.

I'm not sure about the general applicability of this approach - not sure how many cases there are of introduced species whose toxicity is killing off native predators. But it certainly demonstrates an innovative approach to this particular problem.

Speaking of cane toads....

Born to sushi

This is interesting. It appears the Japanese are genetically better equipped to eat sushi than the rest of us. Porphyra, the red algae used to wrap Japanese sushi. It's cell walls the polysaccharide porphyran. The breakdown of porphyran requires an enzyme, porphyranase, which is produced by some marine bacteria that decompose the algae. New research appearing in Nature indicates that porphyranase is produced by gut microflora. In Japanese. Not in North Americans. This likely results from a long history of sushi-eating, through which the Japanese people have introduced this particular gut flora into their digestive tract.

Fish o' the Day - blacktail shiner

A fairly low-profile choice for tonight. The blacktail shiner, Cyprinella venusta, is one of the more common fish in many of our local streams. It's particularly abundant in Alamuchee Creek, one our favorite haunts that we've been sampling for decades. It's difficult to dip a seine in those waters without pullling up a blacktail. They're minnows, members of the Family Cyprinidae. The cyprinids are the largest family of freshwater fish, with over 2,400 species. They include some large fish like the carp, but most of them are small and rather undistinguished looking. And they can be pretty tough to tell part - it often comes down to counting the pharyngeal teeth on the gill arches. That's one reason I sometimes get fumble-fingered when we pull one up I don't recognize. "Sorry guys, didn't get a good look at it."

That's one thing I like about the blacktails - they're distinctive. The large basicaudal spot stand out. They can be pretty handsome little guys too, reaching 4 or 5 inches in length with silvery, almost bluish sides. While some shiners like slow-moving water, the blacktail likes swift currents and does well there. We can count on pulling a few out of the fastest riffles in the Alamuchee. Interesting, they're pretty vocal, with sound production apparently playing a role in reproductive behavior.

Big fish, but not from around here

I want to talk in more detail about invasive fish later. Probably when my Con Bio guys start looking at exotics. But here's an interesting study looking at the way in which introduced fish species have increased the average size of fish assemblages. The exotics are bigger than the natives by a full 12 cm - that's a ton. I guess it makes sense - we've been moving fish around, deliberately or not, for thousands of years. And I suppose, on average, the one's that we move around are bigger than the ones we don't.

Goes without saying that the introduction of large fish, in abundance, can seriously alter ecosystem function. Many of the introduced big guys are top predators, like largemouth bass (Micropterus salmoides) or the butterfly peacock bass (Cichla ocellaris) pictured above. Exotic detritivores like carp also have significant impacts on energy flow in aquatic systems.

We're already knew that invasive species will be one of the prime concerns for biology in the 21st Century. Doesn't help matters when those introductions are the bullies on the block.

Shark food

Nothing terribly dramatic here, but it's about sharks eating stuff - therefore, we've gotta talk about it. A new study in the Journal of Fish Biology looks at the diet of three smallish sharks found in relatively deep waters in the Cantabrian Sea off the coast of Spain. The three species, blackmouth catsharks (Galeus melastomus), velvet-belly lantern sharks (Etmopterus spinax), and birdbeak dogsharks (Deania calcea), were found to feed opportunistically on available foods including fish and crustaceans.

Perhaps more interesting is the manner in which the sharks have partioned the habitat available to them. The researchers looked at a samples collected down the slope of a bank, from the top at a depth of about 500 m depth down to a basin with depths over 1,000 m. The blackmouth catshark (that's him up top) and velvet-belly lantern shark occupy the top of the bank. In the deeper parts of the basin, however, the lantern shark is replaced by the birdbeak dogshark. In the deepest parts of the basin, the catsharks and dogsharks are able to coexist without competition, as they have specialized on different types of foods in those deep waters.

Why don't you come in and check out my place?

This good-looking guy is the purple-throated carib, Eulampis jugularis, a small hummingbird native to a number of Caribbean islands. He's certainly attractive, but he's not banking on that to bring in the lovely ladies. Turns out that flashy plumage is all well and good, but it's his stash that counts. Two researchers, the Smithsonian's John Kress and Amherst's Ethan Temeles, have discovered that male caribs ensure their reproductive success by protecting territories containing many times the nectar supply that they can use - part of it reserved exclusively for the female guests that they hope to entice.

Caribs are sexually dimorphic. Although coloration patterns are somewhat similar between the sexes, males are considerably larger than females and have a greater wingspan. The females, on the other hand, have a much longer, downturned beak. This means that the females can draw nectar from flowers that are not available to males. This phenomenon, known as sexual resource partioning, leads to malesw feeding from one type of Heliconia flower and females feeding from another. And the females choose males on the basis of the nectar that his territory can provide her. This means the males are highly motivated, in an evolutionary sense, to protect a quality territory.

For more detail, hit it.

Clovis hunters, revisited...

If you've been keeping up, you've no doubt noticed that the debate over what led to the extinction of the North American megafauna some 13,000 years ago is almost as heated as teh debate over what became of the dinosaurs 65 million years earlier. Another entry....

What we know is that shortly after the end of the last ice age, the glaciers that covered much of North America began to melt and retreat toward the pole. However, a sudden cooling period known to geologists as the Younger Dryas reverse the retreat for a period of over 1,000 years. During that time, something dramatic happened to the great mammals of North America - the mammoths and mastodons, the sloths and sabertooths, almost all of them, vanished. What we don't know is - why?

The prevailing hypothesis for some time has been that of human hunting overkill - the idea that sophisticated hunters of the developing Clovis culture took advantage of a naive fauna and hunted them to extinction. This is supported by the many Clovis sites that have been uncovered that provide evidence of hunting activity. One of the best studied is the Murray Springs site in southeastern Arizona, where a Clovis hunting camp is in close proximity to a mammoth and bison kill. The overkill hypothesis has been challenged recently by a group claiming that evidence points toward an extraterrestrial impact (that's a comet or an asteroid, not a spaceship), with the resultant climatic changes that entails. This, of course, is similar to the impact theory that currently holds sway regarding the disappearance of the dinosaurs at the K-Pg boundary 65.5 million years ago.

In a new paper appearing in the Proceedings of the National Academy of Sciences, a group from the University of Arizona takes a look at the evidence suggested to support the extraterrestrial impact theory. That evidence takes three main forms: spherical magnetic particles (thought to be formed by impacts) found in soil at the Murray Springs site, high concentrations of iridium (a component of asteroids) in soils dating to the time of the extinctions, and high charcoal content (an indication of the fires that would have resulted from an impact). The group concludes that there is nothing in these three lines of evidence that cannot be explained by terrestrial answers. In other words, they can't rule out an asteroid impact, but the evidence doesn't require one. I suppose this leaves the overhunting hypothesis as the default explanation.

It's worth mentioning the the man most associated with notion of a Clovis megafaunal wipeout is Paul Martin, who first proposed the possibility of Pleistocene overkill in the 1960s and has published extensively on the topic. Paul Martin is now professor emeritus at - the University of Arizona.

Excellent summary here at Science Daily.

Fish o' the Day - Lake Tanganyika scale-eating cichlid

You may know that the Great Rift Valley Lakes of East Africa support an incredible diversity of cichlids. We'll undoubtedly be talking more about those later. For now, we're going to look at one very remarkable species. The Lake Tanganyika scale-eating cichlid, Perissodus microlepis, has become a textbook example (literally) of the manner in which frequency-dependent selection can affect the evolution of a species. As the image above (courtesy of A. Meyer) illustrates, the mouth of these remarkable little fish take a decided twist to the left or right. This apparently support their feeding habit of approaching another unsuspecting fish from behind and plucking off the scales on which Perissodus feeds. The left-handed and right-handed forms cycle in frequency - left-handed forms dominate for a while, then are gradually replaced by the right-handed forms. Why? Well, when left-handed forms are the most frequent, potential prey species must be on their guard for attacks on their right side. This makes them more vulnerable to attacks by the rarer right-handed scale-eaters. This selective advantage leads to a gradual shift in the gene frequencies.

Australopithecus sediba

There is, of course, a tremendous amount of information coming out about the new hominin find in South Africa, from the original paper in Science to the somewhat critical perspective of Donald Johanson. There was even a report tonight on 60 Minutes. I'm inclined to hold off a while and see what develops.

Rarest of the rare

The Wildlife Conservation Society has released it's 2010-2011 edition of State of the Wild - A Global Portrait. It contains their listing of the Rarest of the Rare List, a group of animals considered to be among those most in danger of extinction. It's a slightly biased list - not an invertebrate to be seen - but it still brings some attention to some species in trouble. The list includes a single amphibian (an immediate indication of incompleteness), two reptiles, one bird, and six mammals.

Among those staring the grim reaper in the eye (with links to the IUCN Red List profile)...

The green-eyed frog, Lithobates vibicarius, a small ranid frog with a few hundred individuals surviving in Costa Rica and Panama. This little guy seems to be falling victim to the the fungal disease chytridiomycosis.

The Cuban crocodile, Crocodylus rhombifer, is a moderately-sized crocodile with a population of perhaps 4,000 individuals. The primary threats are loss of habitat, illegal poaching for meat, and hybridization with the more common American crocodile.

The ploughshare tortoise, Astrochelys yniphora, a native of Madagascar which may number fewer than 200 individuals in the wild. You may recall that we discussed the ploughshare's congener, A. irradiata, just last week. The ploughshare is falling victim to habitat destruction and the illegal pet trade.

The Grenada dove, Leptotila wellsi, a native of the island in the Lesser Antilles. Leptotila has a very small local population tha thas been hammered by habitat loss and hurricanes. As few as 30 reproductive pairs remain.

The Florida bonneted bat, Eumops floridanus, was believed extinct for several years, but there have been scattered sightings in south Florida and a small colony apparently persists in Fakahatchee Strand. The bats are sensitive to habitat loss, particularly the removal of cavity trees. Pesticide spraying for mosquitoes may be responsible for their decline over much of south Florida.

Hunter's hartebeest, Beatragus hunteri, is one of Africa's most threatened antelopes. The numbers remaining in their original range are uncertain, probably less than 1,000. A translocated population in Tsavo National Park numbers some 100 individuals. Also known as hirola, they have suffered due to hunting, habitat loss, and competition with livestock.

The island gray fox, Urocyon littoralis, is found on six of California's Channel Islands. It's the U.S.'s smallest fox. A major impact has been predation by golden eagles, although diseases like canine distemper may have also played a role in their decline. Population estimates the put the surviving numbers at perhaps 500 animals.

No list of the critically endangered would be complete without a primate - this one has two. First is the Sumatran orangutan, Pongo abelii. Around 7,000 of these apes survive on the northern part of the island of Sumatra. The primary threat is habitat destruction through logging, both legal and illegal, as much of the region's forests are converted to agricultural land and palm plantations. Animals are also captured and killed, but this appears to result primarily as the result of habitat conversion as the poor orangutans just can't understand that it's not their jungle any longer.

One of the lesser-known animals on the WCS list is the vaquita, Phocoena sinus, a small oceanic porpose native to the northern parts of the Gulf of California. They probably number less than 1,000, the result largely of drowings resulting from entanglement in gill nets.

Our second primate is the white-headed langur, Trachypithecus poliocephalus. Hunting and habitat loss have left a population of some 60 monkeys on a small island off the coast of Vietnam. Why hunt them? Well, your quant little Chinese apothecary needs it's supply of monkey balm.

Thrown in with the bad news - a little good. State of the Wild includes an account of two species that seem to have turned the corner toward recovery. The lucky ones? Przewalski's horse (Equus ferus) and Rober's tree frog (Liuixalus romeri).

Hawaiian canyons

A new paper appearing in Marine Ecology examines the biodiversity of marine canyons in the Hawaiian archipelago and comes up with some interesting discoveries. The study, which involved 36 submersible expeditions at depths ranging from 350 to 1500 me, showed that the canyons support diverse communities of fish and invertebrates, and yielded 41 species not found elsewhere in the Hawaiian Islands.