Do Lobsters Have Gills? (Explained)

Lobsters are animals that we can encounter on the ocean floor, often hiding in their shelters. We don’t usually see them out of the water, so have you wondered if they’re exclusively marine animals, how they breathe, and if they have gills? In this post, we’ll talk all about that but let’s begin with a quick answer:

Lobsters have gills located in a gill chamber that protects them. When a lobster breathes, the water enters its gills through the opening between the legs, and the lobsters absorb the oxygen from the water.

However, this certainly doesn’t tell the whole story. Below, I’ll explain more about lobsters’ gills and how they breathe. Furthermore, I’ll explain if lobsters can breathe air and if they can drown. Next, I’ll explain if lobsters can survive in freshwater or out of water. Read on!

Lobsters’ gills

The gills are lobsters’ main organs to remove oxygen from the seawater. They extend into the branchial cavity from the openings between the lobsters’ legs, called pereiopods, and are located inside the gill chamber that protects the gills. The gill chamber lies close to the lobsters’ heads.

There are three types of gills, categorized based on the site of implantation: podobranch, arthobranch, and pleurobranch gills. Podobranch gills arise from the coxa – at the base of the leg, the arthobranchs arise from the arthrodial membrane – soft, flexible tissue at the base of the appendage, and the pleurobranchs arise from the adjacent body wall.

The modified second maxillae, called gill bailers, push water inside the branchial chamber. Water enters at the carapace’s posterior margin and between the legs’ coxae and exits anteriorly. Interestingly, the beat of the gill bailers can reverse the water flow to clear particulate matter from the gill surfaces.

How do lobsters breathe?

Lobsters breathe oxygen from the seawater using their gills. As mentioned above, the water enters through the opening between the lobsters’ pereiopods, and lobsters remove the oxygen from the water. Interestingly, lobsters can breathe only in seawater and can survive in freshwater, which I’ll explain more later.

After the gills, the oxygen then enters the circulatory system of the lobster. Next, the cells take the oxygen from the bloodstream and perform cellular respiration. The oxygen concentration is higher in the water than in the blood, so oxygen diffuses into the blood and allows the animal to breathe.

In the same way, the blood contains higher concentrations of carbon dioxide than the water, so carbon dioxide diffuses out of the blood at the same time oxygen diffuses in. This is similar to how our lungs work, except that aquatic animals like lobsters use water where we use air.

When it comes to the oxygen consumption rate, it usually correlates with water temperature, degree of crowding, animal size, and feeding. For instance, crowding causes higher animals’ activity as they walk more, and as a result, they consume more oxygen. When it comes to size, smaller animals consume more oxygen than large ones.

Can lobsters breathe air?

Lobsters cannot breathe air directly, but they need water on their gills to survive out of the water. They can only extract oxygen from the water, which is why they can’t survive out of the water for too long. If the gills become too dry, they will move closer together, reducing the amount of oxygen the animal can absorb. Eventually, they will collapse, causing suffocation.

This is one of the reasons why lobsters almost never come close to the shore. Interestingly, crabs can survive without water for longer, but they still need their gills to be moist. When it comes to fish, they usually can’t survive longer than a few minutes out of the water.

A coconut crab is actually a species whose gills evolved into the branchiostegal lungs. They’re a spongy tissue, something between gills and lungs. They still need to be kept moistened, but they can actually exchange gas with the air. Lobsters, however, do require water in the gas exchange.

Can lobsters drown?

In general, lobsters cannot drown, but they can suffocate underwater as they need a proper lever of oxygen absorbed from the water. These animals are very sensitive, and if the water temperature isn’t suitable or the oxygen in the water has been used up, they will suffocate.

Can lobsters survive in freshwater?

Lobsters are exclusively marine animals and cannot survive in freshwater due to their state of isotonic stability with the surrounding saltwater. This means that the same amount of water moves between body tissues and the salt water.

Lobster bodies’ tissues, the cells, have a permeable membrane that allows water to flow in and out of the cell body, helping to soothe the cell’s vital needs. Based on chemical principles, the water will always flow to an area with a higher concentration of salts and minerals through a permeable membrane.

In freshwater, the state between the lobster and the surrounding water is unstable. The cells of the animal contain higher ions of salt and other minerals. Water invades cells, causing them to swell and eventually break. This kills cells as minerals try to diffuse into the water and dilute.

Can lobsters survive out of water?

Lobsters cannot survive out of water for longer than one or two days, depending on how moist their gills are. They need water on their gills to absorb oxygen as they don’t have lungs. This is also why lobsters don’t live on land, as hot shores or beaches would quickly dry them.

Do lobsters have lungs?

As you probably already know, lobsters don’t have lungs but gills. However, it’s interesting to know how other marine animals adapted to their environment, having both gills and lungs. An example of an animal like this is a fish called “lungfish”.

This fish has “lungs”, which is a modified swim bladder. Other fish species use swim bladder for buoyancy in swimming, but the lungfish can absorb oxygen from the air by using it. Why would these fish have this unique skill?

In nature, everything happens for a reason. Lungfish live in rivers and lakes in Africa, South America, and Australia. They have to manage a life-threatening situation, which is drought. During low water levels, they secrete a thin layer of mucus around themselves that dries into a cocoon. They can live out of water in this cocoon for up to a year, absorbing oxygen from the air only until it rains again.

Lobsters, however, haven’t developed this skill yet as they don’t have these life-threatening situations and, hopefully, will never have to.