Most of the time in this article series we cover a specific species of fish. Today, we are going to broadly cover the entire family of goatfish. There are specific, named species, but in this case it’s probably not terribly useful to learn them all.

Physical description

Goatfish tend to be smaller, growing up to about 10 inches (30 cm) in length. There are some species, however, that can reach twice this size. Their bodies tend to be elongated, with a deeply forked caudal fin and two separated dorsal fins.

All goatfish have the ability to change their color depending on their activity. The exact colors and activities that spur those changes varies from species to species. Usually the changes occur whilst feeding (at night) and schooling during the day.

The most distinctive feature of goatfish is the long pair of “whiskers” that protrude from their chins. They use these to dig through sediment on the ocean floor in search of food.

Geography and habitat

Goatfish can be found all throughout the reefs of the Atlantic, Pacific, and Indian oceans.

During the day goatfish form schools, often mixing with fish of other families. At night, the schools disperse as each fish feeds along the ocean bottom. Goatfish are commonly followed by scavengers hoping for a free meal stirred up by the goatfish’s whiskers.

Small goatfish can be seen feeding during the daylight hours.

Further reading

Wikipedia
Wet Web Media
Seafriends

Photo by Paul and Jill

I thought we’d do something a little different today. Everyone is familiar with dolphins in some shape or form, but did you know there are 18 genera (plural of genus) of oceanic dolphins? We are going to cover some of the more common ones. Then you can look smart when someone shouts “Dolphin!” and say, “More specifically, that’s a Pacific white-sided dolphin.”

Common dolphin

It’s called the common dolphin, but is probably not the most familiar. There are over 20 species of common dolphin, in all shapes, sizes, and colors. Generally speaking, the common dolphin has a dark back with a white underbelly. Two of the most common variety are the long-beaked and short-beaked. These, like many dolphins, are found in pods of 10-50.

Bottlenose dolphin

If a dolphin should come to mind when you hear “common dolphin”, it should actually be the bottlenose. This is the dolphin of pop culture (Flipper) and seen in marine parks worldwide. These are the one of the larger types of dolphin, and are seen the world over, everywhere except in polar waters.

They have a short, well-formed snout that resembles an old-fashioned bottle. They tend to be grey all over, with slightly lighter bellies. Bottlenose dolphins also have more neck flexibility than other dolphins, making them capable of all the expressions that they have become well-known for.

Right whale dolphin

Right whale dolphins are predominantly black with small white underbellies. They are distinguished as being one of the only dolphins without dorsal fins.

Right whale dolphins tend to remain in the colder aquatic regions, although they have been spotted in warmer waters. They are divided into species of northern right whale dolphins and southern right whale dolphins. They can be distinguished based on their white patterns: southern right whale dolphins have white that extends further on their body, including their snout and flippers. If still unsure, you should also be able to tell the difference based on where you are in the world.

Killer whale

The killer whale, or orca, is actually a dolphin. Not surprisingly, it is the largest oceanic dolphin. Killer whales are apex predators, and thus have no natural predators.

Killer whales probably need no description, but they have black backs, white chests and sides, and a white patch above their eyes. They range in size from 5-8 meters (16-27 feet).

There’s probably not much you haven’t heard about this group, so here’s an interesting tidbit. To travel faster, killer whales will leap out of the water while swimming. This technique is called porpoising.

Next time we’ll get into the more obscure dolphins.

Common dolphin photo by mikebaird
Bottlenose dolphin photo by The Pug Father
Killer whale photo by *christopher*

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

With over 28,000 individual species of fish (and the number keeps growing), it would take about 540 years for the fish identification series to cover them all.

Fortunately, we don’t have to do that. Using some common sense, we can get that number down to something reasonable. First, we can limit based on fish we may actually encounter while scuba diving. With this filter, the number drops to around 4,000. This is still too many, but much closer to being manageable.

Second, we can combine fish that are nearly the same. For instance, it is not critical to always know the difference between a white-mouthed moray eel and a spotted moray eel (although in this case it should be obvious). Simply knowing that they are both moray eels should suffice. Applying this idea we can reduce the list down to 30-50 fish families. Not bad! Now things are getting reasonable.

Some people like to combine these families even further into about 12-15 large groupings based on common characteristics. This is fine for subdividing a large task, but these groups generally don’t have a convenient name to use, so at the end of the day it doesn’t buy you all that much.

I’ll list the fish families and loosely group them based on similarities. Many of these families will look familiar, since we have covered them (or specific species in that family) in previous articles.

Ok, here we go:

Don’t be overwhelmed. Many of these families you can probably identify already. The rest should take no time at all. I’ll update links on this page as we cover each family. I may also add a family or two as I see fit.

Porcupinefish are always a fun sight on dives. They are sometimes called blowfish.

Physical description

The porcupinefish gets its name from the many long spines located all over the head and body. They are members of the pufferfish family, but should not be confused with pufferfish. The porcupinefish’s spines are visible even when they lay flat, whereas they are not usually visible on a pufferfish.

When threatened, the porcupinefish can inhale air or water to inflate its body to over twice the normal size. Additionally, this causes the spines to stand up, making the porcupinefish edible only by large predators.

You are not likely to see an inflated porcupinefish, even if you attempt to chase one. I have heard if you manage to grab one by the tail they will inflate, but we all know that’s not a good idea, don’t we? I have also heard that inflating is stressful and has an effect on the fish’s lifespan.

Porcupinefish are a grayish tan color, with white on the underbelly. They are usually covered with small black spots or splotches.

They can reach up to 36 inches (91 cm) in length. They have large heads which taper off towards the caudal fin. They are also distinguished by their large, round eyes which appear to watch you when swimming by. They also have oval-shaped mouths which are usually open.

Geography and habitat

Porcupinefish are found worldwide in tropical, and sometime temperate, regions.

They live in holes on reefs at pretty much all depths. Usually you will encounter them swimming out above reefs, though.

They tend to be solitary, but occasionally you will see them in small groups. They also tend to move very slowly, although they still swim faster than most scuba divers.

Toxins

Porcupinefish are known to produce toxins in their organs and on their skin. Nevertheless, they are known to be eaten in some areas. My guess is that the toxin is mild enough to only be dangerous to smaller predators.

Further reading

Wikipedia
Florida Museum of Natural History
Shedd Aquarium

Usually referred to as a “schoolmaster”, this fish is part of the snapper family and could also be referred to as a “schoolmaster snapper.”

Physical description

Schoolmaster can reach lengths up to 24 inches (60 cm), but are common around 12 inches (35 cm).

Schoolmasters are most often recognized by two attributes. First, they have a sharply pointed snout. Second, they have bright yellow fins, which include caudal, pectoral, pelvic, dorsal, and anal.

Sometimes you will also see light vertical bands along their body, as in the schoolmaster pictured here.

Geography and habitat

Schoolmaster snapper are found all along the western Atlantic down to South America, from Massachusetts to Brazil.

You’ll find them in clear, warm water, usually over coral reefs. They usually maintain a short distance above the sea floor.

Unlike most fish we cover, schoolmasters are often found in groups. The size of these groups can range from just a few fish up to a few dozen.

Further reading

Wikipedia
FishBase.org
Reef Guide

Today’s fish is a member of the infamous scorpionfish family.

Physical description

Spotted scorpionfish are large for their family. They average around 12 inches (35 cm) long, with some males reaching 18 in (45 cm) in length.

They have wide, fan-like pectoral fins as well as dorsal spines that make this a formidable looking fish. The fleshy plumes covering their eyes give them the appearance of a grumpy old man.

Spotted scorpionfish usually have a reddish color. Their pectoral fins have a combination of white stripes and spots, hence the name. The tails also have three white stripes.

You’d think all of this would make the spotted scorpionfish fairly distinctive, but the truth is they are not always easy to spot, for several reasons. First, they are almost always stationary on the ocean bottom. When they come to rest, they stir up silt which settles along their body, effectively disguising them.

Second, their red-rust hue becomes grey even in relatively shallow water. Lastly, their recognizable striped fins are only visible while they are swimming (or threatened).

Nevertheless, once you learn to recognize them, you will start spotting them everywhere.

Geography and habitat

Spotted scorpionfish are found all along the western Atlantic down to South America, as well as in the Pacific from Baja California down to The Galapagos. I believe the western Pacific even has a variety.

These fish are found on the sea bottom or resting on rocks. Often this is under coral or outcroppings, so you may have to look around to find them.

Like most scorpionfish, the spotted variety is a loner.

Venom

Spotted scorpionfish are venomous, like all its cousins. The dorsal spines contain the venom, although it is only used for self-defense. Keep a sharp eye if touching the sea bottom so that you’re not getting an (un)healthy dose of scorpionfish venom!

Further reading

Marine Bio
Living Reefs
Ocean Oasis Field Guide

Today’s fish is the yellowtail snapper, or sometimes just called the yellowtail.

Physical description

Being a snapper, the yellowtail has that perfectly shaped oval “fish” body. The caudal fin is deeply forked, hinting at the swift movement of this active fish.

A yellow line marks this fish, beginning at the snout and widening down the length of the body until it covers the entire tail, hence the name.

Yellowtail snapper can grow up to 30 inches in length, although lengths of around 12 inches are probably more common in diving environments.

Geography and habitat

Yellowtail live in the western Atlantic, off the eastern coast of the U.S. all the way down to Brazil. This makes them a standard Caribbean sighting.

You’ll sometimes see them in schools, although a solitary yellowtail is not an uncommon sight. They also like to feed near the bottom.

Seafood

Yellowtail have a slightly sweet flesh, making them a popular game fish. They are classified as “Eco-OK”, which means they are fine to eat in moderation.

Further reading

Wikipedia
Florida Museum of Natural History
Environmental Defense Fund