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Ever since I was young, I have been

collecting fun facts about animals.By the time I was ten, I could name

more than 200 mammals off the top ofmy head at the dinner table. Althoughmy parents raised their eyebrows at me,they supported my voracious curiosity.ey gave meMarine Mammal BiologyforChristmas and e Illustrated VeterinaryGuide for my birthday. I absorbed all theanimal facts I could find and quoted themback to my surprised parents, finding someparticularly interesting ones. Althoughwe like to think the human species is the

pinnacle of evolutionary success, I want toshare some extraordinary facts that remindus of the many animal species whoseabilities far exceed our own.

Sea Dragons: Creatures YouNever Imagined

I like to believe that I knew about seadragons before anyone else. In sixth grade,I chose to write my marine biology reporton these understudied creatures when myclassmates were writing reports on starfish

and dolphins. Relatives of sea horses andpipefish, sea dragons are members ofthe Syngnathidae family that live in thewaters off the coast of Perth, Australia.ere are two species, weedy and leafy,named for their habitat and correspondingcamouflage.

Sea dragons have long snouts and bony

rings around their bodies, with leafy orweedy appendages.eir small, transparentdorsal and pectoral fins can propel them inthe water, but sea dragons spend most oftheir time driing in patches of seaweed.

Sea dragons survive on a diet of Mysidshrimp and amphipods (6, 10). Like maleseahorses, male sea dragons are responsiblefor child rearing. When a male sea dragonis ready to mate, his tail turns bright yellow,and the female deposits bright pink eggsonto the brood patch on the underside ofhis tail. e male carries the eggs for about

four to six weeks, at which point he releasesthe fullyformed baby sea dragons.

The Wolverine Newt

Imagine you are a newt: you have theshort stubby legs of a primitive amphibianand it is impossible to outrun a predator.Most salamanders and newts have avoidedextinction by either hiding or advertisingtheir toxicity through bright warningcolors.

e Spanish ribbed newt takes an

entirely different approach to survival.When confronted with a predator, it sticksits pointed ribs outward through its skin,exposing poison barbs (9). First noticed bya natural historian in 1879, this salamanderwas the subject of recent research thatrevealed that the defense comes in twoparts. When the newt is threatened, it

secretes a noxious substance on its skinand then contorts its body to force thesharp tips of its ribs through its skin. eribs become fierce, poisontipped barbsdeterring attackers. ese spearlike ribsmust break through the newts body walevery time it evokes the defense. Howeveras is characteristic of many amphibians, theSpanish ribbed newt posses rapid tissueregeneration characteristics that allow it torecover from its puncture wounds (9)

Antifreeze BloodFish are ectotherms: the externa

environment determines their internal bodytemperature.is form of thermoregulationmeans that fish are the same temperature athe rivers and oceans they inhabitevenwhen the water is below freezing. AntarcticNotothenoids are fish that inhabit the frigidwaters of the Antarctic, where temperaturesare constantly below 0 degrees Celsius. Inorder to keep ice crystals from formingin their blood, fish from the suborder o

Notothenioidei have unique antifreezeproteins in their circulatory system.Unlike commercial antifreezes, these

glycoproteins do not lower the freezingpoint of water. Instead, Notothenioidsantifreeze glycoproteins (AFGPs) bind toice crystals as soon as they form, blockingother water molecules from binding andthereby preventing the development of alarger crystal. ere are several structura

varieties of AFGPs that have convergentlyevolved in several families of colddwellingfish. Recent research suggests that these

Extremely Interesting Animal Facts

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e Exciting Physiologies of Different Animals

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proteins evolved from mutations inpancreatic trypsinogens and adapted forsurvival in frigid water (5).

Eat a Bedtime Snack or YoullDie

Hummingbirds are one of the onlyspecies of birds capable of hovering becauseof their complex, figure eight wing patterns.

However, this agility comes at the cost of ametabolism which demands a near constantsupply of nectar. e aerial performanceof hummingbirds approaches the upperbounds of oxygen consumption and musclepower input for all vertebrates (4). Whilenectar is popularly perceived as the food ofchoice for hummingbirds, insects actuallyprovide the primary source of nutrition.

Fasting becomes a problem at night,when hummingbirds need to sleep. Inorder to survive the night without starvingto death, hummingbirds enter a state

called torpor (8). When hummingbirdsenter torpor, their body temperaturedrops and their metabolism slows. A coldhummingbird body has lower energyneeds than a warm, flying one and burnsfewer calories. Because hummingbirdscannot both sleep and eat at the sametime, entering torpor at night enableshummingbirds to survive until their nextmeal in the morning.

Mammals vs. Reptiles:Locomotion and Respiration

Reptiles and amphibians still retainthe ancient form of locomotion practicedby our fishy ancestors: lateral undulation.Reptiles swing opposite pairs of their legsforward, with their legs scrunching at theirside as they move. Unfortunately for these

reptiles, the muscles that control their legsalso control their lungs (3). As reptiles flexsideways, they compress a lung shuntingair between their two lungs, rather thanexpelling old air and inhaling fresh air.As a result, lizards must always travel in arun-stop-run pattern.

Mammals, unlike reptiles, havediaphragms. e diaphragm is a musclethat contracts to create a vacuum insidethe chest cavity thereby causing the lungsto expand. Because the diaphragm isindependent of the muscles that power

locomotion in mammals, we are able tobreathe and run at the same time. Highbreathing rates enable a greater oxygenintake and stronger, more frequent musclecontractions. Perhaps the diaphragmis a strong component of mammalsevolutionary success; if migration wasquick and easy, our rodent-like, primitiveancestors could travel more easily to findnew resources.

Colors We Cant See:

In our eyes, we have two types ofcells called rods and cones that send lightinformation to our brain. Rods are the mostsensitive to stimulation than cones andare found mostly at the edge of the retinawhere they contribute to the motionsensitivity of our peripheral vision. Cones

give our world color.

ere are diff

erentypes of cones, with each type containinga pigment that is sensitive to a particularwavelength of light. In humans, there arethree types of cones: red, green, and blueese are the same RGB colors of theLEDs in lampposts, stoplights, and streetssigns that mix to produce the spectrumof colors we are familiar with. Humans are

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thus classified as trichromads (7). Whenone of these cones is non-functioning, itcauses vision distortions, such as redgreencolorblindness.

Birds are tetrachromads: they havean extra type of cone and can see into theultraviolet (UV) spectrum (7, 1). Mostdinosaurs had four cones, but mammalslost two of these cones when they became

nocturnal and had little use for colorvision. When mammals diversified in theirlater evolution, some regained a differentthird cone to see into green wavelengths tocomplete our RGB set (7). Others did notand remained dichromads. Birds, however,being phylogenetically close to dinosaursretained their four cones which are sensitiveto UV wavelengths.

Birds have another jump on mammals:specialized oil droplets in birds cones

narrow the spectral sensitivity of thepigments, enabling birds to distinguishmore colors than with pigments alone (7).Recent studies suggest that bird plumage iseven more colorful than we can imagine (1,2).

e more I learn about animaladaptations and evolution, the morethe complexity of the world amazes me.

Although I envy the naturalists of the 1800swho stepped on a new species in theirbackyard and went on to publish hundredsof papers about their findings, I knowscience is far from complete and much hasyet to be discovered.

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