Animal of the Week September 9, 2014 -- a whole new...

Well, maybe it's a phylum, but the people who have described this week's animal of the week, two species in the new genus Dendrogramma (in the new family Dendrogrammatidae), aren't so bold as to create such a high level taxon. But if the suspicion that these organisms are most closely related to species thought to have gone extinct 540 million years ago is borne out, we'll have to change how we think about the history of life on earth...a bit.

They do look like mushrooms. © 2014 Just et al

The two species were found during examination of specimens connected from the deep sea continental slope of Australia in 1986, but have only now just been described fully in a paper published in PLoS One. Superficially they look like mushrooms, but the specimens available show they have a skin and a gut separated by jelly like material.

Unfortunately the preparation of the specimens in pure strong alcohol means that genetic material no longer exists for phylogenetic analysis. Later drying out and preparation with pure alcohol led to shrinkage and more changes in the physical structure, hampering further investigations. More specimens will be needed to see where these organisms hang on the tree of life. (Fortunately, I've got a birth certificate so while I have been prepared in copious amounts of alcohol [and possibly formalin in my most desperate moments] my position on the tree of life is well established.)

The researchers note similarities with the Ediacaran (or Vendian) fauna, ancient extinct organisms known from some of the oldest fossils that were thought to represent failed early experiments in the animal kingdom. If these new species are related to those animals, our understanding that they all died out will have to be rethought.

On divisions of life
A phylum is a group of organisms with a basic body plan that are distinct from other phylums. For example, humans are joined in the phylum Chordata with fish, frogs, birds, dinosaurs and sea squirts, all because at some point in their lifecycle they possess a tail with notochord backbone. Discovery of new species is remarkable enough, genera pretty special, families thoroughly exciting and any higher level distinction incredibly rare in this day and age...but who knows what else is out there.

Mnemonic for recalling the divisions of life
King Philip can only find green socks
Kingdom (eg, animal), phylum (eg, chordates), class (eg, mammals), order (eg, carnivores), family (eg, cats), genus (eg, big cats), species (eg, tiger)

Animal of the week Sept 2, 2014 -- Geeeecccckkkkkoooooosssss iiiiiiiiiiinnnnnnnnnn ssssssspppppppppaaaaaaaacccccccceeeeee

Luke J. Harmon - Harmon LJ—wikicommons

When Neil Armstrong set foot on the moon, and he pondered his place in the universe, one question dominated his thoughts: I wonder if geckos could breed in zero gravity. This week's animal has been all over the news this past couple of days, because finally it looked like we might have the answer to Neil's question. It's Phelsuma ornata (Mauritius ornate day gecko).

These small brightly coloured geckos originate on the tropical Indian Ocean island of Mauritius, they scurry around the treetops by daytime hunting insects and avoiding predators in the tropical sunshine.

Five geckos were blasted into space on my birthday, July 15, aboard the Russian Foton-M Satellite as part of an experiment to investigate the great mystery of whether geckos are able to reproduce under zero-gravity conditions.

The satellite returned to earth in the small hours of Tuesday morning. Unfathomable excitement turned to crushing disappointment when the satellite was recovered and the geckos hadn't reproduced at all. In fact, all five had died. Died some time ago, as they had started to desiccate and mummify. It's possible that the lizard died of cold...average daily celcius temperatures in Mauritius are in the mid 20s...in space, it's colder.

What a loss to science.

Animal of the week August 25, 2014 -- The rarest duck in the world

Still more common than animal of the week, this week's animal is maybe the rarest bird in the world. It's Aythya innotata (Madagascar pochard), a diving duck from Madagascar. Diving ducks, like pochards, scaups, and tufted ducks, obtain food by diving beneath the surface and picking food off the bottom of waterbodies; dabbling ducks, such as mallards and wigeon, glean food from the surface.

This critically endangered waterfowl was, for 15 years from 1991, thought to be extinct. It had vanished from its last known home on Lake Alaotra in central Madagascar, and surveys up to the early 2000s turned up a duck...or didn't. But in 2006, a small flock was found at Lake Matsaborimena in northern Madagascar. The Durrell Wildlife Trust, Wildfowl and Wetlands Trust, and the Peregrine Fund, along with Madagascan partners set up conservation efforts including a breeding programme, now there are 25 birds in the wild and 80 in captivity.

Things are looking up, but the ducks will need a new home. The lake where those in the wild live now is a poor habitat for them, when chicks reach an age when they should start to be able to feed themselves they find the steep sided lake too deep to dive—up to 96% of chicks die before reaching adulthood.

So, the conservation groups are now scoping out possible new homes where they might reintroduce captive birds. But before they can they'll have to sort out the habitat, look into controlling introduced mammals and fish species that might eat the chicks, and engage with locals to make sure that farming practices and fishing techniques allow reintroduced birds to thrive.

On the EDGE list of all bird species, Madagascar pochards are number 568/9993. They aren't as high as former AOTW the giant ibis, because although they are fewer in number (100 vs 200) they are less evolutionarily distinct: other closely related species of diving ducks in the same genus are common and unthreatened, such as the common pochard (9825), canvas back (9826), and greater and lesser scaups (9829 and 98
30).

Animal of the Week May 7, 2014 -- look at her weiner

This week's animal of the week is Neotrogla, a whole genus of insects (at least four species but probably more—with 10 million species of animal out there, I've got to speed this thing up) in which the females have penis like appendages and the males have vagina like apparatus.

In almost all known animals with intromittent sexual organs, it's the male that does the insertion. But in the case of Neotrogla, Brazilian bark lice that live out their lives in lightless caves feeding on bat guano, the females have evolved the gynosome, an organ used to siphon sperm out of the males' phallosomes. If you are now wondering what defines a male and a female if not their sexual organs, it's actually the size of the sex cells—females produce fewer larger eggs, males produce many smaller sperm.

Girl's on top

In the list of things I find fascinating, sex is pretty high up there—thankfully, a lot of evolutionary biology is either directly or indirectly concerned with the study of sex. When it comes down to it, evolution is about reproduction: survival of the fittest is nothing if the fit genes don't get passed onto successive generations.

Why Neotrogla evolved this role-reversal is unknown. In the nutrient poor caves, the sperm might provide not only genetic material but also vital nutrients without which the females cannot reproduce, so creating competition for access to this resource which the unique arrangement somehow facilitates.

Of course, this also raises the question (although it's not one that keeps me awake at night) of why some male animals have penises? In some insects they are used to aid in competing with other males for delivering sperm: sometimes they are used to scrape out other males' offerings, and in extreme cases, they break off after mating and block any other male from inseminating a female. In mammals, size seems to correlate with the number of males competing for the attention of or access to females. The human penis is one of the oddest—larger in every dimension than those of our close relatives chimps, bonobos and gorillas, they also lack the baculum or penis bone that these species use to achieve erection and instead use blood pumped into spongy tissue. The human penis may not only serve a practical function, but also might be a visual sexual display.

A male penis is clearly an efficient mechanism of introducing sperm to eggs, but Neotrogla reminds us there is more than on way to achieve this, and excites my wholly theoretical interest in the subject.

Animal of the Week April 29, 2014 -- Birds on the EDGE

The EDGE (Evolutionarily Distinct, Globally Endangered) initiative has done a lot to highlight the plight of some of the world's most interesting and most threatened species. Scientists identify the most threatened species with few close relatives—the extinction of which would mean the loss of unique evolutionary history.

http://www.arkive.org/giant-ibis/thaumatibis-gigantea/

A couple of weeks ago, the EDGE team identified 100 bird species that are conservation priorities. One or two of the species high on the list are familiar AOTWs: the kakapo and the spoonbilled sandpiper for example. But number one on the list Thaumatibis gigantea (giant ibis) deserves an its own entry.

Everyone loves an ibis. This prehistoric-looking family can be found on every continent in a various different sizes and colours, but their overall shape leggy and long-necked with a lengthy downcurved bill changes little. But while they may have an unmistakable look, the evolutionary divisions in the group are deep, and many species, such as the giant ibis, represent the only species in monotypic genera.

The giant ibis is the largest member of the family: over a metre in length and weighing 4 kg. The 200 or so remaining birds are found in remote Cambodia, having been driven to the brink of extinction by habitat loss and disturbance, climate change, and hunting. Sparsely distributed, they have possibly never been particularly numerous, but their range did once extend into Laos, Thaland, and Vietnam. And their restricted range means that the remaining birds are vulnerable to local disturbances.

Whereas various other ibis species live in close proximity to people (Herodotus wrote of streets in Alexandria crowded with the birds that would have the benefit of snaffling up pests and discarded waste, but counteracted this by fouling everywhere), the giant ibis avoids human contact, preferring to feed on earthworms, eels, crustaceans, and small amphibians far from human habitation.

Tawny bellied seedeater
http://www.flickr.com/photos/dariosanches/

The reason it has taken 2 weeks for me to get around to the AOTW is that the considerate EDGE people provided a list of nearly 9993 species with their positions on the list...which took me some time to wade through. The bird at the bottom of the list, the least EDGEy species? The rather dainty Sporophila hypoxantha (tawny bellied seedeater), a finch from south Africa with a wide range and many closely related species (30 species in the genus Sporophila compared with just one in the genus Thaumatibis).

Animal of the Week March 31, 2014 — How deep is your dive?

This week's animal of the week is a record-holding mammal, able to dive deeper or longer than any other. As reported in PLOS One, Ziphius curvirostris (Cuvier's beaked whale) can dive almost 3 km in depth remaining submerged for over 2 hours.

When George Cuvier first described this species, he thought it was an extinct species, but now they are known to be found around the world in all oceans except the high polar regions. The beaked whales are a widespread group of cetaceans, and despite there being quite a few species that are probably not uncommon, their open-ocean deep-diving habits mean they are poorly known—all but a few species having escaped the attention of the whaling industry, whence a lot of our knowledge of whales comes (not that that makes whaling a good thing). The northern bottlenose whale, one of which popped up the Thames to die back in early 2006, is also a species of beaked whale.

Beaked whales are named for their mouth, which notably protrudes from their head. They typically have only one pair of teeth and in many species these only erupt through the gums in the males—in older Cuvier's males these tusks protrude from the jaw, and combat between males are likely the cause of the parallel striations seen on the skin of many male whales. They hunt by sucking up squid and small fish on their forays into the deep ocean. To aid their impressive diving feats they have a very high proportion of myoglobin (the equivalent of haemoglobin that permeates muscle tissue), which keeps their muscle well oxygenated on deep dives, they are able to collapse the air cavities in their bodies on diving, and they have a very waxy blubber.

The previous record holder for mammal deep diving was an elephant seal that dove not quite as far for not quite as long—such is the nature of records. It's possible that other beaked whales and sperm whales dive even deeper, but until we know better, we salute you Cuvier's beaked whale. Great diving!

Animal of the Week March 16, 2014 -- first butterfly of the year

I'm a simple and predictable man. Just as I will let out a yelp of glee at the first bee of the season, the first sighting of a butterfly each year, usually a few weeks later, also elicits a broad grin. And that first butterfly is invariably this week's animal Gonepteryx rhamni (brimstone)—spotted this weekend in NW5.

The brimstone is somewhat unusual among UK butterfly species in that it hibernates as an adult, rather than migrating here from warmer climes, or overwintering as a pupa as many other butterflies do. This habit means it is often the first butterfly one sees in the year.

The brimstone is almost unmistakable. Other yellow butterflies, such as the rarer clouded yellows have substantial black markings on their wings and don't have the same, odd, geometrical wingshape of the brimstone.

The name brimstone obviously comes from their colour (related to sulphur, also known as brimstone, and yellow in colour). But oddly enough, one theory for the origin of the word butterfly is that it originated with the brimstone—ie, the butter-coloured fly.

However, a lot of other old words for butterfly in Germanic languages derive from a mediaeval belief that butterflies were witches in disguise that would steal unguarded milk, cream or butter; and this may be the true origin of the word. These words have been replaced with other terms related to Latin Papilio, but the German word for butterfly schmetterling is thought to derive from smetana, the Czech word for cream, and the belief that butterflies were milk-thieving witches.