Tag: Biology

Pearls and Mother-of-Pearl: Nature’s Fascinating Defense Mechanism | July 14 2025, 20:58

I realized that I don’t know much about pearls and started reading up on them today. It turns out that pearls are formed as a natural defense by oysters to irritation: when a micro-particle (a grain of sand, a piece of shell, or a microorganism) gets into the shell, the oyster begins to cover it with layers of nacre. Nacre (nacre) — the inner layer of shells, thin layers of calcium and protein. Interestingly, nacre and pearls are essentially the same in composition. The word “nacre” comes from German and means “mother of pearl” (Perlmutter). A single layer of nacre can form several times a day to several weeks, and it takes up to 2 years for a full pearl to form.

Wild pearls are extremely rare (one in 10000), as not all mollusks are capable of producing them — only some species can. There is also black pearl, found only in the southern part of the Pacific Ocean, and the colors of natural pearls vary from white and grey to green, blue, and red.

Most of the pearls on the market are cultured: humans manage to “trick” the oyster by placing a bead or a piece of fabric inside the shell so it starts the process of covering it with nacre. In other words, to put it simply, almost all the pearls in the market have a plastic bead inside, and nacre is just a thin “skin” around it. Cultivation of pearls occurs on special farms, where oysters are provided ideal conditions for growth and are regularly cared for. The mortality rate of mollusks after transplant is between 10-40%.

Pearls can burn: this is an organic material (97% calcium and 3% water and proteins), and it does not withstand high temperatures, it also dissolves in vinegar.

It turns out, edible oysters also produce pearls, but they are not as shiny.

Exploring the Luminescent Life of Fireflies | July 05 2025, 05:02

While walking with Yuka, suddenly the owner falls on his knees and digs around in the grass for a while. That’s when I found a firefly and wanted to capture it lighting up. The firefly Photinus pyralis is quite common here, but I never got around to studying it closely.

Interestingly, the females of another genus of fireflies, Photuris, use the flashes of Photinus males to locate and eat them. It has been discovered that the females acquire special steroids called lucibufagins from their prey, which repel spiders.

(While figuring this out, I learned something new. Luciferase, an enzyme responsible for the glow, is extracted from these fireflies. It’s named after the word Lucifer, Latin for “light-bearer.” Interestingly, Greece also had its Lucifer, “light-bearer,” known as the god Phosphorus. Incidentally, the element Phosphorus was discovered by alchemist Hennig Brand through the evaporation of urine. He named the discovered element phosphorus mirabilis, from Latin meaning “miraculous light-bearer.” This just shows how many things in the world are connected.)

How Frequent Tick Bites May Reduce Lyme Disease Risk | July 01 2025, 04:38

#science Today I found another tick on me; it didn’t have time to latch on, but did manage to bite. And like before, I suffer from these tick bites being very itchy and taking a long time to heal. A couple of times because of similar symptoms I ended up in Emergency, where I was diagnosed with Lyme based on symptoms and put on doxycycline, but later tests did not confirm Lyme, though I already took the doxycycline. And if there was anything, it’s long dead. Question is, why do ticks love me so much.

I just found an interesting scientific article about this. “Hypersensitivity to Ticks

and Lyme Disease Risk” (link in comments)

The authors say that many people living in areas with a high prevalence of tick-borne diseases such as Lyme develop a more acute reaction to tick bites—redness and severe itching, a dermatological-hypersensitivity reaction—that’s exactly my case. They analyzed 1,500 cases and concluded that the more frequent a person’s itching after a bite (more than 3 times a year), the lower their chance of contracting Lyme disease—the risk was reduced by about 7 times (odds ratio ~ 0.14, p=0.01).

They write that this is linked to the fact that the itching helps to notice the tick sooner, consequently – remove it faster and prevent the infectious agent from entering the body (borrelia is not transmitted immediately, but after 1–2 days). There may also be immune mechanisms that interfere with the tick’s feeding and transmission of borrelia.

Conclusion: Recurring reactions to tick bites (itching + redness) create a kind of “anti-tick” immunity. This reduces the risk of contracting Lyme disease, and likely, could be the basis for developing a vaccine against tick pathogens. Quite intriguing, because such medications exist for dogs (full protection against ticks), but haven’t been invented for humans yet.

Galactic Etymology: Tracing the Milky Origins in the Night Sky | June 29 2025, 12:57

I am looking at photos and reading material about the Milky Way and noticed that the word galaxy (any) essentially means “milky” from Greek. Κύκλος Γαλαξίας. Essentially, lac from lactose, and gala from galaxy essentially come from the same Proto-Indo-European ģlákts. Unexpected.

Risks of High-Pressure Activities on Eye Health and Hearing | June 28 2025, 23:52

Interesting. I learned, for example, that the human retina is not really attached to the vascular tunic, but is held in place only mechanically by intraocular pressure. Because of this, those who jump from heights or engage in diving, and generally anything that increases intraocular pressure, are at risk of retinal detachment.

(By the way, about pressure, I had a slight barotrauma in my left ear today during airplane landing: after landing there was a lingering feeling of stuffiness and muffled sounds, and while in the air it even hurt a bit. That is, some traces of sensation remained several hours later, but probably, by tomorrow morning I will recover fully).

https://youtu.be/QmX60IgWCGk?si=GrWzDtuZTpFeig-X

Exploring Maya Ruins and Termite Tunnels in Playa del Carmen | June 27 2025, 18:59

Here in Playa del Carmen, there are about a dozen abandoned Maya-era buildings that you can climb over and into, of course free of charge and at any time. Inside one of them, in a small room, I found interesting termite mud tunnels, which I had never seen in person before.

Exploring Faust and the Zoologist: The Dual Life of Translator Khodkovsky | June 18 2025, 04:06

I’m listening to the second part of Faust and simultaneously googling translator Holodkovsky. It turns out that translating Faust was something of a hobby for the scholar-zoologist Holodkovsky, spanning 60 years. Holodkovsky has hardly any original writings—only translations, and from the translations, everything else, as they say, is minor details.

That is, Goethe wrote Faust for 60 years, and the entomologist-translator translated it for 40 years and spent another 20 catching bugs, imagine? What a scale of projects.

In fact, apart from being the author of probably the best translation of Faust, Holodkovsky is almost absent in literature. But as a zoologist, he left much more of a mark. True, it’s hard for non-entomologists to read without a smile, but here are his main works: “Male Genitalia of Diptera,” “Atlas of Human Helminths,” “On the Oral Organs of Some Insects Parasitizing Humans,” “Coexistence and Societies of Animals,” and others.

Why Shiba Inu Training Fails: A Waiting Game for Lisa | June 09 2025, 17:11

This is why the Shiba Inu is difficult to train. He’s not in the mood today, waiting for Lisa. And the cat is waiting for Lisa too. Their daughter is finally moving back from campus, already loaded everything into the truck. Yuki is looking out the window. Trying to feed him boiled chicken fails — food is not much of a motivator for him. He last ate about 15 hours ago, so he should be a bit hungry in theory. No, he’s not sick — this behavior has been observed throughout his four years. Waiting.

A Close Encounter with a Scentless Fawn | June 04 2025, 15:13

I walked with Yuki and he passed by a little deer less than a meter away without noticing. This is a dog that can smell a hare running past the house by scent. It turns out that fawns are born almost odorless, and this saves their lives.

It is precisely because of their nearly complete lack of smell that does leave their young alone for extended periods. Mothers leave fawns for several hours at a time during the first weeks after birth so that their own smell does not transfer to the babies. During this time, the mother returns several times a day to feed her young. Although she may not be continuously near the fawn, she is usually somewhere close by, and surely worried about seeing us around her baby.

However, it’s not only the lack of smell that helps fawns remain hidden from potential predators. The white spots on their fur are another protective measure. When a fawn walks, the spots may seem obvious, but when the mother leaves it to hide in tall grass or other covers, these spots mimic dappled sunlight falling on the forest floor, as noted by the Iowa Department of Natural Resources. Such spotted coloring, combined with the faint smell, makes it difficult for predators to find fawns. Typically, the spots disappear by winter when young deer are old enough to survive on their own.

It is said that fawns are born in late May-early June. Today is precisely June 4. They’re right on schedule!

Despite the fact that he is lying in the open sun in thirty-degree heat, overall, if necessary, he can move on his own. Fawns are born generally ready for life in the wild and are generally able to run immediately after birth (albeit poorly).