Are There Any Freshwater Octopuses?

Octopus resting on the ocean floor

Octopuses are amazing creatures usually found in the ocean. But have you ever wondered if they could live in freshwater, such as rivers and lakes? 

In this article, we’re going to look into the idea of freshwater octopuses. We’ll explore why octopuses normally live in saltwater and whether it’s possible for them to survive in freshwater. 

We’ll also check out some stories and claims about sightings of freshwater octopuses and see if there’s any truth to them. Let’s dive into this interesting subject and learn more about the so-called freshwater octopus.

Is There a Freshwater Octopus?

Octopus peeking from behind seaweed

According to science, there is no such thing as a freshwater octopus. Octopuses need saltwater to survive. While some species can handle brackish water, where the ocean mixes with rivers, none live in completely freshwater environments. The idea of a freshwater octopus is more myth than reality.

The story of freshwater octopuses usually comes from local legends and unusual sightings near rivers and lakes. These stories have been told for years, but they don’t have any real scientific evidence. 

Sometimes, people find octopuses in places where they shouldn’t be, like far from the sea. However, many of these are just stories that have been stretched a bit too far.

In fact, I have heard a few stories about freshwater octopuses in my childhood hometown in Florida. I recall one recent story that occurred in Mosquito Lagoon, a part of Indian River Lagoon. 

Reports say they found a common octopus there. Unfortunately, I haven’t had the chance to see one in person. 

Fun Fact: While many types of octopus live in saltwater, some species can survive in brackish water — a mix of salt and freshwater. Some examples of these are the Mud Octopus, Common Octopus, and Giant Pacific Octopus.

Why Do Octopuses Live in Saltwater?

Octopuses are well known for their remarkable adaptability, but they primarily live in saltwater environments. Have you ever wondered why this is the case? 

Here are a few reasons why octopuses live in saltwater:

  • Body Structure: Except for their beaks, octopuses have soft bodies. They rely on the buoyancy provided by the denser saltwater to support their structure. This natural buoyancy acts like a protective cushion that guards their delicate bodies from potential injuries and helps them move around.
  • Osmotic Conformity: Octopuses have a special ability known as osmotic conformity. This allows them to match the salt and water levels in their bodies with that of the sea. This is great for living in the ocean, but it doesn’t work in freshwater.
  • Availability of Prey: Their diet mainly consists of sea creatures like crabs, shellfish, and small fish, which are abundant in the ocean. The ocean’s diverse ecosystem provides octopuses with a rich feeding ground.
  • Habitat Diversity: The ocean is vast and offers a variety of habitats, from shallow coral reefs to the mysterious depths of the deep sea. This diversity gives octopuses many options for shelter and hunting grounds, something that a freshwater environment couldn’t offer.

The ocean is not just a home but a necessity for octopuses. It provides them with the right conditions for their body, food, and overall survival.

Fun Fact: Many capabilities of octopuses are designed to work in saltwater. For instance, octopus ink, one of their main defense mechanisms, is more effective in the ocean, considering its composition and method of delivery.

Why Can’t Octopuses Live in Freshwater?

Octopus with textured skin

Now that we know why octopuses fare well in saltwater, let’s try to figure out why they cannot survive the freshwater. 

Here are the main reasons why octopuses cannot live in freshwater:

  • Incompatible Salt Balance: Octopuses rely on saltwater to maintain a delicate balance of salts and water in their bodies, which is not possible in freshwater.
  • Density-Dependent Body Support: The density of saltwater is a must for supporting the soft body structure of octopuses. This support is not something freshwater cannot provide.
  • Gills and Kidney Function: The gills of an octopus are specially made to extract oxygen from saltwater and don’t work well in freshwater. Also, their kidneys are set up to handle a certain amount of salt and wouldn’t do their job correctly in freshwater.

In short, while octopuses are versatile and adaptive, their physiological and evolutionary traits require them to live in saltwater habitats.

Fun Fact: With a few species as exceptions, octopuses need a salinity level of at least 27 grams per liter in their environment to thrive. Surprisingly, even a small variation in salinity level can be harmful to them.

Freshwater Octopus Sightings: Fact or Fiction? 

The idea of freshwater octopuses has captured many people’s attention, but where did these stories begin?

Looking into the history of these tales, we find that they mainly come from two closely related stories. One is about the so-called Oklahoma octopus, and the other involves freshwater octopuses in North American rivers.

The Tale of the Oklahoma Octopus

This story finds its roots in Native American tales, which speak of a freshwater octopus lurking in Oklahoma’s lakes

The legend describes a 20-foot-long creature with reddish-brown, leathery skin and long tentacles. It’s said to live in Lake Thunderbird and Lake Tenkiller. 

The tale has been around for over 200 years, but it resurfaced after being shown on Animal Planet’s “Lost Tapes.” 

Here’s a trailer video for the episode of Lost Tapes on the Oklahoma Octopus:

Even though there’s no scientific proof of the Oklahoma octopus, some believe it to be true. However, others think it’s just another myth in Oklahoma’s collection of folklore.

Freshwater Octopus in North American Rivers

Apart from the Oklahoma octopus, there have been reports of freshwater octopuses in various rivers across North America. These stories add to the legend of what many believe to be a mythical creature.

Here are some notable sightings of the so-called freshwater octopus:

  • 1933 Reports: One of the first recorded reports talked about a small freshwater octopus, about two to three feet long. This early mention has intrigued people for years and fueled the myth.
  • 1999 Ohio River Incident: On the banks of the Ohio River in Indiana, someone found a dead octopus. It was a type usually found in the Atlantic Ocean. This discovery led to many questions about how it got there.
  • 2003 Lake Conway Discovery: In December 2003, John Mazurek Sr. from Illinois caught a large octopus at Lake Conway’s dam, an unusual event for the lake. The octopus likely ended up in the lake after outgrowing an aquarium. This catch added to the lake’s history of mysterious occurrences.

Despite the fact that many of these stories are already disproved, they give us an insight into how and why the myth of the freshwater octopus lives on.

Recent Freshwater Octopus Sightings

In recent years, there have been several surprising encounters with octopuses in freshwater. These sightings continue to puzzle many. 

Here are some of them:

  • Welsh Beach Octopus (2017): In Wales, a very unusual event occurred when more than 20 octopuses were spotted walking on a beach. This rare sighting sparked a lot of interest and questions about these sea creatures.
  • Gig Harbor Donkey Creek Octopus Sighting (2022): In a rare occurrence, a full-grown male octopus was observed swimming in Donkey Creek, Gig Harbor. This event, captured on video on October 3, 2022, added to the intrigue surrounding freshwater octopuses.
  • Mosquito Lagoon Octopus Sighting (2023): At Mosquito Lagoon in New Smyrna Beach, there was a rare sighting of a common octopus. This unusual event was reported by News-JournalOnline.

Many of these stories are about octopuses turning up in surprising locations. These unusual sightings grab people’s attention and make headlines, which sometimes leads to misunderstandings. 

Do Freshwater Cephalopods Exist?

Octopus spreading tentacles wide

Freshwater cephalopods do not exist. All cephalopods, like octopuses and squids, live in the ocean, not in freshwater. 

However, some cephalopods can be found in brackish water, which is a mix of fresh and salt water, but none live in purely freshwater areas.

Here are some known species of cephalopods that live in brackish water:

  • Bigfin Reef Squid (Sepioteuthis lessoniana): This squid is usually found in warm ocean waters but sometimes goes into less salty, brackish waters. They do this mainly to find food or for a safer place to breed, away from ocean predators.
  • Common Octopus (Octopus vulgaris): The Common Octopus, which normally lives along rocky shores, is sometimes found in brackish waters. They go there to hunt because these waters are full of nutrients and prey. The lower salt levels in these areas might also help them during important times, like when they lay eggs.
  • Mudflat Cuttlefish (Sepia pharaonis): This cuttlefish, good at hiding in sandy or muddy places, sometimes moves into brackish waters. These areas usually have lots of food and less competition than the open sea, making them good spots for feeding and breeding.

While some cephalopods are found in brackish waters, this is often for reasons like feeding or breeding, not because they can live in freshwater.

So, what are your thoughts about these creatures? Do you think there are freshwater octopuses just waiting to be discovered? Share your thoughts by leaving a comment below!

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