When we usually watch some videos of whale jumps, we will notice that some whales are covered with white bumps, making people with dense phobias look uncomfortable, and these white bumps are communities of marine parasites, mainly whale lice and barnacles. Because of the impression, many people think that whales have whale lice and barnacles, but in fact, there are only a few cetaceans that these two parasites like to attach to the most. (There is no discomfort picture in the text)
Taxonomy of the suborder Baleen whale
Humpback whales, gray whales, right whales four species, these 6 species of baleen whales are whale lice and barnacles favorite hosts, other cetaceans have few barnacles, and toothed whales represented by killer whales have almost no shadow of these two parasites.
The head and jaw of humpback whales are most easily attached to parasites
▲ The white spots on the surface of the gray whale are parasites, which have become a major feature of the gray whale and improve their recognition
The parasite of the right whale's head can even be used to infer the age of the whale by the size of the parasite
The whale lice is a marine arthropod that looks like a white scorpion, with a body length of 0.8-2 cm, bites the whale's skin through hard jaws and arthropods, and follows the whale around the ocean, and the water generated by the whale's swimming is convenient for them to ingest algae and plankton.
Barnacles are indicated at the stage of development
Barnacles look like shellfish, but they are actually arthropods that cling to reefs, whales, turtles, and other places where they can parasitize. They secrete a very sticky substance, called "barnacles", which are more powerful than artificial glue, and will also burrow into the whale's skin, growing interconnected siding boards and firmly fixing themselves to the whale's skin. Barnacles are hermaphrodites, and once successfully attached, they are very likely to multiply and form communities, so barnacles select a whale and will entangle it for a lifetime until the whale dies.
A large baleen whale can have up to 100,000 whale lice and barnacles of about half a ton, which can cause itchy whale skin, and whales sometimes jump out of the water just to get rid of the whale lice on their bodies. The attachment ability of barnacles is much stronger than that of whale lice, and once the upper body is difficult to get rid of, it will increase the burden on cetaceans. Barnacles will also be attached to the bottom of the boat, so the sea vessel should regularly remove the barnacles at the bottom of the boat, so as not to affect the speed and increase fuel consumption.
So why do whale lice and barnacles like to "bully" these baleen whales? Is it because they're too honest? Why are these two parasites rarely seen in the famous killer whales? I think the reasons are as follows:
Gray whales can grow up to 40 tons, humpback whales can grow up to 61 tons, and the largest species of the right whale family can exceed 100 tons, of which bowhead whales (Arctic right whales) are the second heaviest cetaceans after blue whales. Killer whales are much smaller than they are, with the largest being 9.45 meters long and weighing about 10 tons.
The third in the lower left corner is a right whale, with white spots on its body is a gray whale, and in the middle is a humpback whale
Baleen whales are large enough to provide more area for whale lice and barnacles to attach, and the larger the size, the larger the target, and it is much easier to find a minke whale in the vast sea than to find a killer whale. The larvae of whale lice and barnacles float in the sea in search of a host, while large cetaceans are their preferred attachment objects.
Swimming speed is also very important, killer whales swim much faster than large baleen whales, swimming slowly to provide an opportunity for parasite attachment. Because the juveniles of whale lice and barnacles have poor swimming ability, try to find a host that swims slowly.
Biologist Wethey believes that the speed of water flow is the main consideration for barnacles to choose a host.
After several experiments, he found that the water flow rate/inclination on the surface of the substrate was critical: above 50/s, the probability of attachment was high. Once it exceeds 100/s, the adhesion rate is greatly reduced. If 400/s is reached, no larvae are able to attach to it.
Barnacles eat
Therefore, the travel speed of the host will have a great impact on the attachment of barnacles.
Barnacle glandular larvae
Humpback whales swim at a speed of only 8-15 kilometers per hour. Although gray whales are the mammals with the longest migratory distances, traveling up to 22,000 kilometers, they can only travel about 180 kilometers per day, and gray whales usually swim at a speed of only 7 km/h and a maximum speed of less than 15 km/h. Right whales have a top speed of less than 10 km/h. They are the slowest cetaceans and are therefore the most susceptible to parasites.
Fin whales "cruise" at high speed, like submarines
In contrast, blue whales can sprint at speeds of up to 48 km/h, fin whales can exceed 50 km/h, and killer whales can reach a maximum of 55 km/h, so they are also large, but there are few attachments on their bodies.
There is also an important reason that is easy to overlook, that is, body color.
The upper part is a blue whale and the lower one is a fin whale
Blue whales and fin whales have few attachments not only because they swim fast, but also because of their lighter body color, and blue whales have a bluish body color, hence the name. Fin whales have a grey back and a white belly. Gray whales, humpback whales, and right whales are all darker in body color, and humpback whales and right whales are all dark black.
Right whales are big fat men with black
Barnacles have the characteristics of energy neutrality, and the roughness of the surface of the attachment base in the ocean, light and color will affect the selection of barnacles. The dimmer the light attached to the substrate, the more the barnacles will be more willing to attach.
Such a big black guy swimming slowly in the sea will naturally become the most ideal place for whale lice and barnacles larvae.
Therefore, we can conclude that large, slow-moving, darker cetaceans are the most easily attached to whale lice and barnacles, so humpback whales, gray whales, and right whales have the most attachments and fewer attachments on other whales.
These three conditions are not satisfied except for the third, so the whale lice and barnacles will not use it as a host. So it is not because the killer whale has a fierce personality, but because it is small, fast swimming, and flexible, so it will not be targeted by whale lice and barnacles, and other toothed whales that are smaller than killer whales naturally have few parasites attached to them.
Sharks are similar to toothed whales, and sharks are cartilaginous fish with specialized shield scales on their body surface, equivalent to "lock armor", which can make whale lice and barnacles difficult to attach.
Although sharks do not have whale lice and barnacles, they are plagued by another parasitic fish, that is, bass fish, commonly known as sucker fish, which will be adsorbed on sharks, hitchhiking, picking up shark food residues, making sharks living in tropical waters very distressed.
The sucker fish on the lemon shark make it look like a fighter with missiles hanging on it
Suction cup fish on whale sharks
The distribution area of the great white shark is almost staggered from the suction cup fish, so the suction plate fish rarely appears on the great white shark.
Fortunately, suckerfish do not stay in a host for too long, they will choose the right time to automatically disengage, to find the next parasitic target. Compared with the barnacles' kind of "nail households", it is still a conscience.
I am Encyclopedia Chihiro, pay attention to nature, love nature, more wonderful content, stay tuned!