This week let's look at some (mostly) smaller mystery animals associated with water! Thanks to Richard J., Janice, and Simon for the suggestions!

Further reading:

What Was the Montauk Monster?

The black-striped pipefish. Also, that guy has REALLY BIG FINGERTIPS:



The Pondicherry shark, not looking very happy:



A ratfish. What BIG EYES you have!



The hoodwinker sunfish, weird and serene:



The Montauk monster, looking very sad and dead:



Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

Let’s finish off the year with an episode about a few mystery animals, specifically a few mystery animals associated with water. Thanks to Richard, Janice, and Simon for the suggestions!

We’ll start off with a mystery suggested by Richard J, but not the Richard J. who is my brother. A different Richard J. Apparently half the people who listen to my podcast are named Richard, and that’s just fine with me.

Richard wanted to know if there are there such things as freshwater seahorses. We’ve talked about seahorses before in episode 130, but seahorses are definitely marine animals. That means they only live in the ocean. But Richard said he’d heard about a population of seahorses native to Lake Titicaca in Bolivia, which is in South America. I put it on my suggestions list, but Richard was on the case. He sent me a link to an article looking into the mystery, which got me really intrigued, so I bumped it to the top of my list. Because I can do that. It’s my podcast.

Freshwater seahorses are supposedly known in the Mekong River and in Lake Titicaca, and sometimes you’ll see reference to the scientific name Hippocampus titicacanesis. But that’s actually not an official scientific name. There’s no type specimen and no published description. Hippocampus is the generic name for many seahorse species, but like I said, they’re all marine animals and there’s no evidence that any live in freshwater at all. Another scientific name supposedly used for the Mekong freshwater seahorse is Hippocampus aimei, but that’s a rejected name for a seahorse named Hippocampus spinosissimus, the hedgehog seahorse. It does live in parts of the Indo-Pacific Ocean, including around Australia, especially in coral reefs, and sometimes in the brackish water at the Mekong River’s mouth, but not in fresh water.

On the other hand, there’s no reason why a seahorse couldn’t adapt to freshwater living. A few of its close relatives have. There are a few species of freshwater pipefish, and in the world of aquarium enthusiasts they are actually sometimes called freshwater seahorses. The pipefish looks like a seahorse that’s been straightened out, and most of them are marine animals. But some have adapted to freshwater habitats.

This includes the black-striped pipefish, which is found off the coasts of much of Europe but which also lives in the mouths of rivers. At some point it got introduced into the Volga River and liked it so much it has started to expand into other freshwater lakes and rivers in Europe.

The pipefish is closely related to the seahorse, but while it does have bony plates like a seahorse, it’s a flexible fish. It swims more like a snake than a fish, and it can anchor itself to vegetation just like a seahorse by wrapping its tail around it. It mostly eats tiny crustaceans and newly hatched fish, since it swallows its food whole. It usually hides in vegetation until a tiny animal swims near, and then it uses its tube-shaped mouth like a straw to suck in water along with the animal. Just like the seahorse, the male pipefish has a brooding pouch and takes care of the eggs after the female deposits them in his pouch.

So where did the rumor that seahorses live in the Mekong come from? The Mekong is a river in southeast Asia that runs through at least six countries, including China, Thailand, Cambodia, and Vietnam. Parts of it are hard to navigate due to waterfalls and rapids,