The manta ray (Manta birostris), is the largest of the rays, with the largest known specimen having been more than 7.6 m (about 25 ft) across, with a weight of about 2,300 kg (about 5,000 lb). It ranges throughout all tropical waters of the world, typically around coral reefs.

Mantas have been given a variety of common names, including Atlantic manta, Pacific manta, devilfish, and just manta. Some people just call all members of the family stingrays, though stingrays comprise a separate family of rays (Dasyatidae). Recent studies have discovered that what is called manta ray are at least two different species, one smaller local and one much larger and migratory.

Anatomy

Mantas are most commonly black dorsally and white ventrally, but some are blue on their backs. A manta’s eyes are located at the base of the cephalic lobes on each side of the head, and unlike other rays the mouth is found at the anterior edge of its head. To respire, like other rays, the manta has five pairs of gills on the underside.

To swim better through the ocean[citation needed], they have a diamond shaped body plan, using their pectoral fins as graceful “wings”.

Distinctive “horns” (from which the common name Devil ray stems) are on either side of its broad head. These unique structures are actually derived from the pectoral fins. During embryonic development, part of the pectoral fin breaks away and moves forward, surrounding the mouth. This gives the manta ray the distinction of being the only jawed vertebrate to have novel limbs (the so-called six-footed tortoise, Manouria emys, does not actually have six legs–only enlarged tuberculate scales on their thighs that look superficially like an extra pair of hind limbs). These flexible horns are used to direct plankton, small fish and water into the manta’s very broad and wide mouth. The manta can curl them to reduce drag while swimming.
Manta ray at Hin Daeng, Thailand.
Manta ray at Hin Daeng, Thailand.

Evolution and taxonomy

Manta rays are believed by some to have evolved from bottom-feeding ancestry, but have adapted to become filter feeders in the open ocean. This allowed them to grow to a larger size than any other species of ray. Because of their pelagic lifestyle as plankton feeders, some of the ancestral characteristics have degenerated. For example, all that is left of their oral teeth is a small band of vestigial teeth on the lower jaw, almost hidden by the skin. Their dermal denticles are also greatly reduced in number and size, but are still present, and they have a much thicker body mucus coating than other rays. Their spiracles have become small and non-functional, as all water is taken in through their mouth instead.

Taxonomically, the situation of the mantas is still under investigation. Three species have been identified: Manta birostris, Manta ehrenbergii, and Manta raya, but they are quite similar, and the latter two may just be isolated populations. The genus Manta is sometimes placed in its own family, Mobulidae, but this article follows FishBase taxonomy, and places it in the family Myliobatidae, along with eagle rays and their relatives.

Behavior

Mantas are filter feeders: they feed on plankton, fish larvae and the like, passively filtered from the water passing through their gills as they swim. The small prey organisms are caught on flat horizontal plates of russet-coloured spongy tissue, that span the spaces between the manta’s gill bars.

Mantas frequent reef-side cleaning stations where small fish such as wrasses and angelfish swim inside the manta’s gills and all over its skin to feed, in the process cleaning it of parasites and removing bits of dead skin.

The predators of the Manta ray include mainly large sharks, however in some circumstances orcas have also been observed preying on them.

Mantas are extremely curious around humans, and are fond of swimming with scuba divers. Although they may approach humans, if touched, their mucus membrane is removed, causing lesions and infections on their skin. They will often surface to investigate boats (without engines running). They have the largest brain-to-body ratio of the sharks and rays.
Mantas are known to breach the water into the air.

Just in time for Easter, the oldest rabbit relation is bounding onto the scientific scene.

Tiny foot bones from a 53 million-year-old rabbit ancestor represent the oldest known record of hippity-hoppity mammals and their closest evolutionary relations, according to a new study.

The ankle and heel bones were discovered in a coal mine in Gujarat, in west-central India, and recently found by a team of paleontologists to belong to the Lagomorpha, a classification of mammals that includes modern-day rabbits, hares and pikas (pikas are hamster-sized rabbit cousins).

“This is 35 million years older than anything that’s ever been called a lagomorph on India, totally unexpected,” said lead researcher Kenneth Rose, a professor in the Center for Functional Anatomy and Evolution at the Johns Hopkins University School of Medicine in Baltimore. “Undoubtedly it’s a new species; undoubtedly it’s a new genus; it could even be a new family.”

The pipsqueak would have been much smaller than the classic Easter bunny, about the size of a hamster, weighing well under a half pound (less than 100 grams). The bones were found embedded in material deposited in land once covered with swamps and bays near a shore, suggesting the animal may have lived in some sort of near-shore environment.

The new lagomorph, detailed online recently in the journal Proceedings of the Royal Society B, would also be the earliest known mammal identified in India from the Cenozoic era, aka the Age of Mammals, which occurred after the extinction event that wiped out non-avian dinosaurs, Rose said.

Rose’s analysis of the Indian foot bones involved comparing them with eight living species of rabbits and hares, as well as two species of pika, which live today in the Rocky Mountains and other mountainous regions.

Rabbits and hares belong to one of two lagomorph families, called Leporidae, while pikas are members of the other family called Ochotonidae. Past evidence suggested the two lagomorph families had diverged some 35 million years ago.

Rose’s team found the bones, which are four to five times smaller than those of modern-day jackrabbits, resemble pikas in some of their primitive features. But unlike pikas, which don’t hop, the bones showed some advanced features that would’ve made this rabbit-like animal quite a hopper. In fact, the bones showed similar, yet more advanced, features to previously unreported Chinese rabbit fossils that date to the Middle Eocene epoch, about 48 million years ago.

“These foot bones look more like cottontail [rabbit] foot bones,” Rose told LiveScience. “They’re from some more specialized, little running, jumping lagomorph.”

Rose added, “Most likely, the lagomorphs originated somewhere in Central Asia and dispersed, and a small rabbit-like form got down to India quite early, around the time of the collision of India with Asia.”

Source:livescience

On yesterday’s XPN Morning Show I recounted meeting my neighbors’ hairless cat Captain Jack Sparrow, named for Johnny Depp’s character in the Pirates of the Caribbean series. He’s very animated (the cat) and loves to pirouette around while holding a peacock feather in his mouth that’s five times longer than he is. One of our boardies requested a photo on this blog.

The cat looks like something that jumped off a computer screen or arrived from outer space. He’s multi-colored, grey and pink with translucent brown feet that seem to be made of rubber, and his neck skin wrinkles in concentric circles.

It turns out that hairless cats, which were bred after a mutation, need to be bathed a couple of times a week to prevent buildup of the oil that cats secrete. Cats with fur distribute the oil through their pelt when they lick themselves, but no such luck for the hairless ones. (Wonder why they’re called hairless if the thing they’re missing is fur…???).

Anyway, I got an e-mail from Ruth K, whose friend has a hairless cat named Flanny:

I mentioned that when my neighbors’ cat ran up, it looked like a chihuaha at first. Here’s Ruth’s chihuahua Elvis:
And here comes the musical payoff
……Flanny yodels

The Sphynx (also known as Canadian Skinless or A Cat Without Skin) is a rare breed of cat. The Sphynx appears to be a Skinless cat, although it is truly hairless. The skin should have the texture of chamois. It may be covered with very soft, fine down, which is almost imperceptible to both the eye and touch. On the ears, muzzle, tail, and feet, a short, soft, fine hair is allowed. Lack of coat makes the cat quite warm to the touch. Whiskers and eyebrows may be present, either whole or broken, or may be totally absent. Their skin is the color their fur would be, and all the usual cat marking patterns (solid, point, van, tabby, tortie, etc) may be found in Sphynx too. People are surprised by how different their personalities are. Many describe them as part monkey, pig, and human because of how intelligent, extroverted, and affectionate they are.

Many people with typical allergies to furry cats find that they tolerate the sphynx breed. This may be due to the fact that the proteins in cat saliva are often the culprit. Because sphynx lack hair and do not leave it behind, many have fewer difficulties living in harmony with the breed. There is no guarantee, however, and allergies vary greatly between individual people.

Sphynx cats are not maintenance-free. Their lack of hair results in increased body oils. Regular bathing is often necessary. Care should be taken to limit the Sphynx cat’s exposure to outdoor sunlight at length, as they can develop a sunburn, similar to that of human exposure. In general, Sphynx cats should never be allowed outdoors unattended, as they have limited means to conserve body heat in colder temperatures, and their curious nature can take them into dangerous places or situations.
Two-week-old Sphynx kitten.
Two-week-old Sphynx kitten.

The Sphynx breed is known for a sturdy, heavy body (many cats of this breed also develop a pot belly), a wedge-shaped head, and an alert, friendly temperament. Although hairless cats have been reported throughout history (hairless cats seem to appear naturally about every 15 years or so), breeders in Canada have been working on the Sphynx breed since the early 1960s. The current American and European Sphynx breed is descended from two lines of natural mutations:

* Dermis and Epidermis (1975) from the Pearsons of Wadena, Minnesota, USA.
* Bambi, Punkie, and Paloma (1978) found in Toronto, ON, Canada and raised by Shirley Smith.

Other hairless breeds might have different body shapes or temperaments than those described above. There are, for example, new hairless breeds, including the Don Sphynx and the Peterbald from Russia, which arose from their own spontaneous mutations. The standard for the Sphynx differs between cat associations such as TICA, FIFE and CFA.

It has been theorised that Sphynx hairlessness might be produced by an allele of the same gene that produces the Devon Rex (re), with the Sphynx allele being incompletely dominant over the Devon allele and both recessive to the wild type. However a different genetic symbol (hr) is given to the Sphynx gene and it is more likely that these are different genes interacting with each other. Sphynx were at one time crossbred with Devon Rex, but unfortunately this led to the introduction of some genetic diseases and is now forbidden in most breed standards associations. Herediary spasticity and Hypertrophic Cardiomyopathy (a genetic heart defect) were introduced by the Devon Rex breed. The only allowable outcross breeds in the CFA are now the American Shorthair and Domestic Shorthair. Other associations may vary and the Russian Blue is a permitted outcross in the GCCF. In Europe mainly Devon Rex has been used for outcrosses.

In 1999 SGC Apophis Nordstrom of Classical Cats won the TICA International Alter of the Year. In 2006 SGC Classical Cats Valentino won the TICA International Cat of the year. In the Cat Fancier’s Association, GC, RW, NW Majikmoon Will Silver With Age was Cat of the Year for 2006. The following year, GC, RW, NW Enchantedlair NWA Cornflake Girl was Kitten of the Year. These awards are handed out for the highest scoring cats, across all breeds.

Popular culture

* A Sphynx, Mr. Bigglesworth, appears in the Austin Powers movies as Dr. Evil’s cat. Mr. Bigglesworth was played by SGC Belfry Ted Nude-Gent, owned and bred by Michelle Berge of Belfry Sphynx.

* In the Friends episode ‘The One with the Ball’, Rachel Green buys a Sphynx cat named Mrs. Whiskerson (”What am I gonna call her, Fluffy?”). Both Ross (”Why is it inside-out?”) and Joey (”It’s not a cat!”) think it’s hideous.

* In the reality TV show LA Ink, tattoo artist Kat Von D has a pet Sphynx named Ludwig.

* In the Disney cartoon series “Kim Possible”, villain Camille Leone is always seen with her Sphynx cat named Debutante.

* At the beginning of Ghostbusters 2, Peter Venkman (played by Bill Murray) introduces next week’s show as “Next week on “World of the Psychic”. Hairless cats… weird.” as he holds one up. Ghostbusters 2 was released in 1989.