Most fish identification articles here have been admittedly focused on Caribbean creature. I’ll try to balance it out in the future, starting today with the longhorn cowfish.

Physical description

Longhorn cowfish can grow up to 20 inches (50 cm) in length. A member of the trunkfish family, they are characterized by their distinctive box-shaped body. In addition, the long, forward protruding “horns” on the front of their body give these fish their name.

Their bodies are yellow and covered with small white spots all over. Their fins are made of translucent rays, and include dorsal, anal, and caudal. They have a unique manner of swimming with their pectoral fins, which gives them the appearance of hovering rather than swimming.

Just like the rest of their family, their scales are fused together into a box-like carapace. This makes them strong, but slow swimmers.

Their goofy appearance makes them popular aquarium pets, despite being poorly-suited to an aquarium environment.

Geography and habitat

Longhorn cowfish live in the Indo-Pacific region. They generally live on coral reefs in depths up to 50 meters (150 feet). They are often found in shallow depths.

Toxins

Like the rest of the trunkfish family, longhorn cowfish secrete a toxin from their skin that protects them from predators. This toxin is only harmful when ingested, though. However, it is strong enough to kill some sharks, giving this fish practically no natural predators.

Further reading

Wikipedia
The Marine Center
Animal-world

Photo by Drow_male

Have you ever heard of this? The mammalian dive reflex is a reaction in your body to cold water that allows you to stay underwater longer. It is used extensively by aquatic mammals, like otters, dolphins, and seals. It is also observed in animals like penguins and, of course, humans.

In humans, the water has to be colder than 21 C / 70 F, and it has to be in contact with the face. The sensitives nerves in our nasal cavity are responsible for relaying this information to our brain. When this happens, up to three things can occur:

1. Your heart slows down 10 to 25 percent! That’s pretty dramatic, but nothing compared to seals, who can experience a drop from 125 beats per minutes all the way down to 10!
2. Blood circulation to your extremities is restricted. This means your fingers and toes start to feel numb.
3. On very deep dives, fluid is allowed to flow freely through your thoracic cavity. This keeps pressure evenly distributed so no organs get crushed.

I’ve never gotten scientific about this, but it seems pretty conclusive that I’d experience a drop in heart rate if I dunked my face in cold water. In fact, we try this out when we splash cold water on our faces to relax or wake up in the morning. See, science has practical benefits, too.

Photo by mikebaird

Scuba-dive.org shares some interesting Puerto Rico dive sites.

Lots on wreck diving this week. Michael at Precision Diving lays out where he thinks are the best wrecks to dive in the world.

Scuba Diver Girls Blog talks about divers exploring the ruins of Cleopatra’s palace in Egypt.

While in that part of the world, AquaViews has an article about Egypt’s most controversial wreck, the Salem Express.

Enjoy, and I’ll see you tomorrow!

The Diving Blog turns five months old today! Our first post was on January 1, 2010. Since then, there have been over 100 posts on a variety of topics, including gear, buoyancy, physics, and fish identification.

In the sidebar on the right, you can see some of our most popular posts based on traffic. We have many more gems buried in the archives, articles like

Location of Sound Underwater
Weighting Guide
What Diving Equipment Should I Buy?

I encourage you to check these out and more.

Thanks for a great 5 months, and I look forward to the next!

Want your chance to make things better? Contact me or leave a suggestion in the comments if you have any ideas for making The Diving Blog better. I’d love to hear from you!