Blennioidei

Blennies are small fish. They have long bodies. Some look like eels. They have large eyes and mouths. Many have tiny whiskers on their heads.

These fish live near the sea floor. They hide in cracks in rocks. Some hide in old shells. Some even dig in the sand.

Some blennies are very fast. They can jump out of the water. They land on rocks to reach new pools.

Most blennies like to hide. They use colors to blend in. One kind has sharp fangs. These fangs can sting to keep them safe.

You can find them in many lands. They are fun to watch!

Blennies are small fish with long bodies. Some even look like eels. They have large eyes and big mouths. Many have tiny whiskers on their heads. These whiskers are called cirri.

Most blennies live near the sea floor. They hide in cracks in rocks or reefs. Some hide in empty shells. Others dig into the sand. Some blennies are called rock-hoppers. They jump out of the water onto rocks. This helps them reach new pools.

Many blennies use colors to blend in. This helps them stay hidden. Some blennies use mimicry. Mimicry is when an animal looks like another kind. One blenny looks like a cleaner fish. It gets close to other fish. Then it takes bites out of them!

Most blennies are safe. But one group is different. The genus Meiacanthus is venomous. This means they have poison. They use hollow fangs to sting. This helps keep them safe from danger.

You can find these fish in many places. Some live in salt water. Others live in fresh water. They live in many parts of the world.

Blennies are a diverse group of small fish. They belong to a large group called the Blenniiformes. These fish live in salt water and fresh water. Some even live in brackish water where salt and fresh water mix. There are nearly 900 different species of these fish. Scientists have described about 151 different genera. Many blennies live on the sea floor. They are called benthic fish because they stay near the bottom. Some hide in cracks in reefs or in empty shells. Others burrow deep into the sand to stay safe. Some species are even called "rock-hoppers." These fish leap out of the water to reach new pools.

Blennies have very specific body shapes. Most are small, but some reach 55 cm in length. They often have long bodies that look like eels. Their eyes and mouths are relatively large. Most have long dorsal fins that run along their backs. They also have short pelvic fins with one spine. Many blennies have tiny, whisker-like structures on their heads. These are called cirri.

Scientists have studied these fish for a long time. The earliest known fossil is called Exallias vectensis. This fossil comes from the Early Eocene period in France. However, most skeletal remains appear later in the Miocene. The way we group these fish has changed. They were once part of the Perciformes order. Now, they are part of the percomorph clade called Ovalentaria.

Blennies use clever ways to survive. Many use mimicry to look like other fish. One type looks like a cleaner wrasse. It gets close to other fish to take bites. Most blennies use colors to hide in the sand or rocks. One special group called Meiacanthus is actually venomous. They have hollow fangs to inject poison. This helps them stay safe from predators.

These fish are found all over the world. The Blennidae and Tripterygiidae families live everywhere. The Clinidae family lives mostly in temperate areas. The other three families are mainly Neotropical. Scientists think the formation of the Isthmus of Panama helped them evolve. Changes in the Tethys Sea also played a role. This makes them great for studying how life spreads.

Blennies are a highly diverse group of ray-finned fish. They belong to the suborder Blennioidei within the order Blenniiformes. The name "blenny" comes from the Greek words for mucus or slime. These fish live in many different environments. They inhabit marine salt water and freshwater habitats. They also live in brackish water, where fresh and salt water mix. There are nearly 900 described species within this order. Scientists have identified about 151 different genera.

The physical shape of a blenny is quite distinct. Most are small fish, though some reach 55 cm in length. Many have elongated bodies that look almost like eels. They possess relatively large eyes and large mouths. Their dorsal fins, which are on their backs, are often long and continuous. The pelvic fins are short and slender. These fins are located before the pectoral fins and usually have one embedded spine. Most blennies have rounded tail fins. A unique feature is the presence of cirri. These are elaborate, whisker-like structures found on their blunt heads.

Taxonomy, or the way scientists classify life, has changed for these fish. They were once classified as a suborder of the Perciformes. However, the 5th Edition of Fishes of the World moved them. Now, Blenniiformes is part of the percomorph clade known as Ovalentaria. This clade also includes Cichliformes, Mugiliformes, and Gobiesociformes. The definition of "true blennies" was further refined by Eschmeyer's Catalog of Fishes. This catalog added damselfishes and clingfishes to the Blenniiformes order. This left the suborder Blennioidei to represent the true blennies.

There are six specific families that make up the true blennies. The Blenniidae are known as combtooth blennies. The Chaenopsidae are called pikeblennies, tubeblennies, or flagblennies. The Clinidae include the giant kelpfish. The Dactyloscopidae are known as sand stargazers. The Labrisomidae is another distinct family. Finally, the Tripterygiidae are called threefin blennies. Each of these families has its own unique characteristics within the suborder.

The history of blennies can be traced through the fossil record. The earliest known blennoid fossil is a species called Exallias vectensis. This fossil was found in France and dates to the Early Eocene. While this species is known, skeletal remains are rare in older fossils. Most skeletal remains of blennies only appear in the fossil record during the Miocene.

Blennies use several survival strategies to stay alive in the wild. Many are benthic fish, meaning they live on or near the sea floor. They use cryptic coloration to hide from predators. Some species are reclusive and live in reef crevices or empty mollusc shells. Others burrow into sandy substrates. Some are even called "rock-hoppers" because they leap onto rocks to reach different pools. Some blennies use mimicry to survive. For example, Aspidontus taeniatus mimics the bluestreak cleaner wrasse. This allows the blenny to approach other fish closely. Instead of cleaning them, the blenny takes bites out of the unsuspecting fish.

Only one genus of blenny is truly venomous. This genus is named Meiacanthus. These fish have hollow fangs located on their jaws. They use these fangs to inject venom into others. The venom contains several substances, including neuropeptide Y, phospholipase, and an opioid-like enkephalin. This serves as a powerful defense mechanism.

Blennies are important for studying biogeography, which is how life is distributed across the planet. The Blenniidae and Tripterygiidae families have global distributions. The Clinidae families are mostly found in temperate regions. The other three families are largely Neotropical. Scientists believe certain geological events helped these fish evolve. The formation of the Isthmus of Panama split the Tethys Sea. This event, along with Pliocene warming, likely influenced how blennies spread.