Today’s FOTD is about the humpback whale. These giants grow up to 50 feet long and weigh up to 40 tons. They are highly migratory and spend their summers feeding in the nutrient-rich polar waters and travel to tropical waters to breed.
There is little food for humpbacks in the warm waters of the tropics so they essentially live off their fat reserves, which they build up during their summers in the polar waters.
Because it’s Friday, I thought I’d give you a bonus FOTD!
The pea crab is a tiny crustacean about the size of a pea. They are soft-bodied and so small that they actually spend most of their lives inside the shells of other little animals, like mussels or tubeworms.
There is some debate as to whether or not the relationship between the pea crab and its host is parasitic or not. Pea crabs rely on their host for protection and food but it is unclear if this is harmful to the host.
Female pea crabs are translucent and larger than the yellowish males. Check out this picture of a pea crab and have a great weekend!
The oarfish is the longest bony fish in the world -- there have even been some reports of fish up to 50 feet long (and weighing up to 600 pounds)! They are so long that many believe that these fish are the cause of some early tales of sea serpents and sea monsters. Because of its sinuous body, it is occasionally called the ribbonfish.
Dugongs, often called sea cows, use their split tail and paddle-like front flippers to slowly maneuver while grazing on sea grasses in shallow waters. They uproot the grasses with their fleshy lips and gently shake their food to avoid ingesting large amounts of sediment.
Wonder how the Spanish dancer, or Hexabranchus sanguineus, got its common name? When it swims, the frilled edges of its mantle resemble the color and movement of the skirts of a flamenco dancer.
When they're not swimming, Spanish dancers crawl along relatively flat surfaces with the edges of their mantle tucked up close to their bodies (see the picture). They feed on sponges and can produce a toxic chemical to protect themselves from predation.
Of the approximately 100 species of cuttlefish, the Australian giant cuttlefish is the largest cuttlefish in the world. They can grow almost five feet long and weigh almost 30 pounds.
The coolest thing about these colossal cephalopods is their ability to change color for a number of reasons, including aggression, excitement, camouflage, or mating. They can change color so effectively that they can become almost entirely invisible when hiding among rocks and in caves. When they want to be noticed, they can put on a brilliant display of colors and flashes, particularly during the winter mating season.
The final FOTD for Shark Week is on the fascinating great white shark, or white shark. Despite their reputation as man-eaters, great white sharks are actually more threatened by humans than vice versa.
Today’s FOTD is about the beautiful zebra shark. These sharks get their name from the impressive stripes found on the juveniles.
As they grow into adulthood, these stripes change into spots, which is why this shark is occasionally also called the leopard shark. (Taxonomists even originally thought that juvenile zebra sharks were actually a different species than the adult zebra sharks because their markings are so different!)
Today’s FOTD is brought to you by the letter C, which is for cookie…and cookiecutter shark.
Unlike most of the other sharks I’ve written about so far, the cookiecutter shark is a relatively small shark; they only reach about 20 inches in length. Like some other sharks, such as great white sharks, female cookiecutters are larger than their male counterparts.
Despite their small size, these sharks still have quite a bite. They latch onto their prey and create suction with their large lips. Then they use their powerful jaws and many teeth to carve a circular chunk of flesh out of the unlucky victim. (Get it? Like a carnivorous, marine cookiecutter?)
Cookiecutter sharks attack large fish like tuna or even whales and dolphins; the prey usually survives the attack but the telltale round scar remains. They are also bioluminescent; they have a patch on their bellies that glows in the dark, deep waters where they live. They use their bioluminescence to attract potential prey.
See you tomorrow for another shark FOTD and I hope you’re enjoying Shark Week as much as I am!
You asked for it so here it is: a FOTD on the sandtiger shark!
Sandtiger sharks go by many names including the ragged-tooth shark and the gray nurse shark. When unprovoked, these sharks are fairly docile, despite their frightening appearance.
Female sandtiger sharks give birth to two live pups, one from each of their two uteri. Because of the relatively small litter size, sandtiger shark populations have a particularly slow growth rate and it takes them a long time to recover from population decreases.