Diatom

Tiny plants live in the sea and soil.

They have hard shells. These shells look like jewels.

They use sunlight to make food. This helps them make the air we breathe.

These plants can live alone. They can also live in groups. Some groups look like stars or fans.

When they die, their shells sink. These shells can turn into soft rock. This rock is called diatomaceous earth.

We use this powder for many things. It can help clean water. It is also used in cat litter.

Diatoms are tiny living things found in oceans and soil.

They are a type of phytoplankton. These are tiny plants that float in the water. Diatoms are very important to our world. They make about 20 to 50 percent of the oxygen on Earth.

They also use sunlight to make food through photosynthesis. This is a way to turn light into power.

Every diatom has a special shell called a frustule. This shell is made of silica. Silica is a hard material like glass. These shells can look like bright jewels.

There are two main shapes for these shells. Some are round and have shapes like stars. We call these centric diatoms. Others are long and look like lines. We call these pennate diatoms.

When diatoms die, their shells sink to the bottom. Over a long time, they make a soft rock. This rock is called diatomaceous earth. People use this powder to clean water. It is also used in cat litter.

Diatoms are tiny living things found in oceans, waterways, and soil.

They are a type of phytoplankton, which are tiny plants that float in water. These small organisms are very important to our planet. They produce about 20 to 50 percent of the oxygen on Earth each year. They also take in over 6.7 billion tonnes of silicon every year.

Diatoms make up nearly half of the organic material in the oceans. They are a huge part of the biomass on our world.

Each diatom is surrounded by a hard shell called a frustule.

This shell is made of silica, which is a material like glass. The shell has two halves that fit together like a box. One half is called the epitheca and the other is the hypotheca.

When a diatom divides, each new cell keeps one of these halves. Then, the new cell grows a smaller half inside it. This means the average size of the group gets smaller over time.

Scientists study diatoms through a branch of science called phycology.

We can find fossils that show diatoms lived a very long time ago. Some evidence suggests they existed during the early Jurassic period. This was about 150 to 200 million years ago. The oldest fossil found is a specimen from Thailand. It was found in amber from the Late Jurassic period. These fossils help us understand how life has changed.

Diatoms come in many different shapes and sizes.

Some are called centric diatoms because they are round and symmetric. Most are called pennate diatoms because they are long and symmetric. Individual cells can be as small as 2 micrometers. Some can grow as large as 2000 micrometers.

There are about 12,000 documented species of diatoms. Many more species likely exist that we have not found yet.

You can see the work of diatoms in many places. When they die, their shells sink to the ocean floor. These shells can form a soft rock called diatomaceous earth.

People use this powder to filter water and make cat litter. It is even used to help stabilize dynamite. Diatoms also help fertilize the Amazon basin. This happens when wind carries 27 million tons of shell dust from Africa.

Diatoms are a massive group of microscopic algae found in oceans, waterways, and soil.

These organisms are classified as eukaryotes, meaning they have a cell nucleus enclosed in a membrane. They are a type of phytoplankton, which is the most common form of plankton.

As part of the Earth's biomass, they play a vital role in our global ecosystem. They are responsible for generating about 20 to 50 percent of the oxygen produced on Earth each year. Additionally, they absorb over 6.7 billion tonnes of silicon from their environments annually.

In the oceans, diatoms constitute nearly half of all organic material.

The most unique feature of a diatom is its cell wall, known as a frustule. This structure is made of silica, specifically hydrated silicon dioxide.

The frustule consists of two overlapping halves: the larger epitheca and the smaller hypotheca. These halves fit together like a petri dish or a box. The cell wall is often highly patterned with ribs, pores, and spines. These intricate designs allow the frustule to produce structural coloration. This effect is so beautiful that diatoms are often called "living opals" or "jewels of the sea."

Diatoms follow a specific process to grow and reproduce. They convert light energy into chemical energy through photosynthesis, using yellowish-brown chloroplasts.

To build their shells, they synthesize biogenic silica inside their cells. They polymerize silicic acid monomers and then extrude the material to the cell exterior. When a diatom undergoes asexual multiple fission to divide, each daughter cell keeps one of the original frustule halves. The new cell then grows a smaller half inside the old one. This causes the average size of the population to decrease over time. To fix this, they eventually form an auxospore through sexual reproduction to regain their large size.

Scientists divide diatoms into two main morphological groups. The first group is centric diatoms, which are radially symmetric. These cells often have a large central vacuole filled with cell sap. The second and larger group is the pennate diatoms, which are broadly bilaterally symmetric.

Pennate diatoms can move along solid surfaces using cytoplasm that streams along slits called raphes. While most diatoms move passively with ocean currents or wind, the male gametes of centric diatoms possess flagella. This allows them to swim actively to find female gametes. Some unique species, called dinotoms, even host diatom endosymbionts inside them. These endosymbionts have lost their silica cell walls, making them the only known shell-less diatoms.

The history of diatoms stretches back millions of years. Fossil evidence suggests they originated during or before the early Jurassic period.

This was roughly 150 to 200 million years ago. The oldest known fossil specimen is an extant genus, Hemiaulus, found in Late Jurassic amber from Thailand. Today, phycology is the branch of science dedicated to studying these organisms. Scientists have documented about 12,000 species, though many more likely remain undiscovered. They use diatoms to monitor water quality and study past environmental conditions.

Diatoms have a massive impact on the physical world through their remains. When they die, their silica shells sink and become part of marine sediment.

These accumulations form diatomaceous earth, a soft, silica-rich sedimentary rock. This material is easily crumbled into a fine powder with particles between 10 and 200 micrometers. Humans use this powder for water filtration, as a mild abrasive, in cat litter, and to stabilize dynamite. Even the Amazon basin relies on them, as 27 million tons of diatom shell dust are carried from the African Sahara to fertilize the region annually.

Recent studies show that changes in the ocean can affect diatom populations. In the mixed layer of the ocean, waves and currents churn to bring nutrients to the phytoplankton.

However, a NASA study found that diatom populations declined by more than 1 percent per year between 1998 and 2012. This happened because the mixed layer became shallower, meaning fewer nutrients reached the diatoms. This decline is significant because it may reduce the amount of carbon dioxide drawn from the atmosphere. If fewer diatoms are present, less carbon is transferred to the deep ocean for long-term storage, affecting the entire global carbon cycle.