New Cetaceans

To find a new species of insect is not too outstanding: there are probably still hundreds of thousands of insects ye to be named and described. But new mammal species are hard to come by, particularly if they belong to a group of fairly large mammals, like say cetaceans. However, since the turn of the century three, possibly four new species have been descibed.(Nature 445: 703–705; 2007)
Left, top: The Perrin's beaked whale, Mesoplodon perrini (Ziphiidae), was described in 2002 based on DNA analysis of four specimens that had washed ashore dead on the coast near San Diego in the mid-1970s. (see) (M. L. Dalebout et al. Mar. Mammal Sci. 18, 577–608; 2002)
Right: Balaenoptera omurai (Balaenoptiidae) was discovered in 2003, when a research group at the National Research Institute of Fisheries Science in Yokohama, examined the DNA of individuals identified as Bryde's whale, also called Eden's whale, and concluded they embraced three species, Bryde's, Eden's and B. omurai. Nature (426, 278-281)
Left: In 2005, a new dolphin species, the Australian snubfin dolphin Orcaella heinsohni (Delphinidae), was described based on analysis of bones and DNA from speciments collected in Asia and Australia. (I. Beasley et al. Mar. Mammal Sci. 21, 365–400; 2005).
Right: Three types are recognized in the killer whale Orcinus orca (Delphinidae) that differ in size, diet, song and coloration. Type A (leftmost), the classic black-and-white look, is typically found in open water and feeds mainly on minke whales. Types B and C (rightmost) are grey and white, and are found near shore in pack ice, and feed on seals and toothfish respectively. Given these differences, it has been discussed for some time whether these Types constitute separate species. Genetic work is ongoing that might help resolve the issue.

Blanket Octopus

The octopi of the genus Tremoctopus are characterized by dorsal arms much longer than the ventral arms; and having a deep web present between dorsal arms. The stringlike structures seen in the lower-left of the left photo are actually the slender arms extending beyond the web.

A close-up of the web shows these have an ocelli design. The web and the arms can be automotized along fracture lines (like lizard tails).

Females can grow to over 2 meter, while males measure only 2.4 centimeters, i.e., the females can be 10 times larger and up to 40,000 times heavier - an extreme case of sexual dimorphism!

These species of octopi are also immune to the poisonous jellyfish Physalia physalis (Portuguese Man O'War), and females rip off their tentacles and carry them in their suckers. One article (E.C. Jones. 1963. Science: 764-766) reports "75% of the suckers of each dorsal arm" as having suckers rendering these arms "non-functional as conventional grasping arms". Jones further illustrates that suckers of the dorsal arms appear adapted for attaching themselves to coelentrate fragments; and argues that this use of Physalia arms may have an offensive function for stinging and caputuring plankton and small fish.

Colossal and Giant Squids

A gigantic 10m-long squid, believed to be the largest ever found, has been caught by New Zealand fishermen in the Ross Sea. Weighing an estimated 450kg, the Colossal Squid (Mesonychoteuthis hamiltoni) was eating a hooked toothfish when it was hauled to the surface of the New Zealand vessel San Aspiring, owned by the Sanford seafood company.

Dr. Steve O'Shea describes it as "a conventional looking squid, it's a long arrow squid, with two enormously long tentacles. A Colossal Squid has got this huge balloon on the back, with enormous muscular fins and quite disproportionately short arms and short tentacles. "

Recently a Japanese research team captured the first video footage of a giant squid (Architeuthis). The elusive creature was taped as it was captured off the Ogasawara Islands, south of Tokyo. The squid was caught attacking bait and emitting short bright light flashes, possibly to attract a mate or to communicate. The squid, which measured about 7m (24ft) long, died in the process of being caught.

Chemical Sequestration

Many organisms achieve chemical defense against predators not by directly producing toxic chemicals, but by sequestering these chemicals from their food. A variety of invertebrates (including insects, like the beetles and monarchs refered recently in this blog, and nudibranchs) sequester compounds thought to play a role in defense.

Recently, a case of a vertebrate was discovered. On the left is a photo of a juvenile Rhabdophis tigrinus snake from Ishima, a Japanese island (Credit: Old Dominion University, Alan Savitsky). These snacks are by themselves non-poisonous, yet are able to store toxins in their neck glands, which they obtain from the toxic toad that it eats. In the absence of a toad diet, the snake with turn and flee in the presence of danger, rather than hound their ground and release the stored toxin defensively.

Rafflesiaceae (in picture: Rafflesia arnoldii) includes the plants with the world's largest flower -- reaching a full meter across, weights close to 7 kg, and with a bud the size of a basketball.

They are a plant parasites, lacking leaves, stems, or roots. They tap into the phloem of a host plant (typically of the grapevine family), from which they derive their nutrients.

Their fleshy, red flower smells like decaying flesh, and in some cases emit heat, ideal caracters for attracting the carrion flies that pollinate them.

Their lack of homologous morphology with other plants, and the loss of many functional genes used to reconstruct molecular phylogenies, have made it dificult to discover its closest relatives. Recently, a team led by Charles C. Davis, from Harvard University, sequenced 11,500 bp pf DNA, and discovered that rafflesia's closest relatives are in the Euphorbiaceae family, many of which have blossoms just a few millimeters in diameter. This means that over the last (perhaps) 46 million years, there was very rapid evolution of flower size in the lineage leading to rafflesia: a 73-fold increase in flower diameter

Monarch butterflies (Danaus plexippus) migrate south for the winter. Tens of millions of monarchs, from populations east of the Rocky Mountains, migrate to Central Mexico, where they overwinter on Oyamel fir trees (Abies religiosa). The Oyamel fir grows only at high altitude (2,400-3,600m) and has a very limited distribution in Mexico - they are found only on 12 isolated mountain tops along Mexico's Transverse Neovolcanic Belt. The overwintering monarchs seek out the cool and realtively moist environments prefered by the firs. The cool temperatures allows for slow metabolism and conservation of energy. The clustering of butterflies as well as the forest canpoy prevent an excessive drop in temperature.

Pseudocopulation

Male insects can become convinced that certain flowers, because of the chemical odors they produce and/or their morphological characteristics, are their female counterparts, to the extent that the males try to copulate with the flowers: pseudocopulation. In so doing, the insect is in fact facilitating the sexual reproduction of the plant, by inadvertently collecting pollen from one flower and then depositing it on another. Here we see a male of the bee Andrena nigroaenea pseudocopulating with an orchid Ophrys sphegodes. More fotos of pseudocopulation can be found here.