Blennies: Blennioidei

views updated

BLENNIES: Blennioidei

STRIPED POISON-FANG BLENNY (Meiacanthus grammistes): SPECIES ACCOUNTS
MIRACLE TRIPLEFIN (Enneapterygius mirabilis): SPECIES ACCOUNTS

PHYSICAL CHARACTERISTICS

Blennies have a variety of body types from short and stout and covered in scales to long and blunt-headed and entirely lacking scales. Most have short fringe on their heads, and some have large spines on their heads. The color ranges from drab, mottled brown and tan to brilliant red, yellow, and blue. Blennies are small, usually less than 4 inches (10 centimeters) long.

GEOGRAPHIC RANGE

Blennies live all over the world except in the Arctic.

HABITAT

Blennies live in almost every underwater habitat, and some even climb out of the water onto rocks. Most are bottom dwellers on coral and rocky reefs. A few blennies live in freshwater streams and rivers.

DIET

Most blennies eat small, bottom-dwelling invertebrates (in-VER-teh-brehts), or animals without a backbone. Some eat algae (AL-jee), or plantlike growths that live in water and have no true roots, stems, or leaves.

BEHAVIOR AND REPRODUCTION

Blennies usually sit on rocks or coral rubble and use their pelvic fins, the pair that corresponds to the rear legs of four-footed animals, to lift their head off the bottom. Some blennies sit just above the waterline and when threatened leap from the rock and skip across the surface of the water to the next rock.

Some male blennies guard a small territory, often an empty shell or a rock crevice. The female enters the male's territory; lays eggs that stick to the shell or rock as they are fertilized (FUR-teh-lyzed), or joined with the male's sperm, and then leaves. The male then guards the eggs and fans water over them until they hatch. Newly hatched young swim toward the surface and feed on plankton, or microscopic plants and animals drifting in water, before returning to the bottom.

BLENNIES AND PEOPLE

Although they are eaten in some areas, blennies are used mainly as aquarium fish.

CONSERVATION STATUS

The World Conservation Union (IUCN) lists one species of blennies as Vulnerable, or facing a high risk of extinction in the wild.

STRIPED POISON-FANG BLENNY (Meiacanthus grammistes): SPECIES ACCOUNTS

Physical characteristics: Striped poison-fang blennies reach a length of 3½ inches (9 centimeters). They have a poison-producing gland in the base of each lower-jaw fang. Black and white stripes run the length of the body from the snout almost to the tail, where they break up into small black spots. The dorsal and anal fins have a black stripe. The dorsal (DOOR-suhl) fin is the one along the midline of the back. The anal (AY-nuhl) fin is the one along the midline of the belly.

Geographic range: Striped poison-fang blennies live in the western part of the Pacific Ocean.

Habitat: Striped poison-fang blennies live on or near coral reefs, seeking shelter in holes.

Diet: Striped poison-fang blennies eat small, bottom-dwelling invertebrates.

Behavior and reproduction: Striped poison-fang blennies inject venom using fangs in the lower jaw. Scientists know little about the reproduction of these blennies. The male tries to entice one or more females to lay eggs in a hole in the reef and probably guards the eggs until they hatch.

Striped poison-fang blennies and people: Striped poison-fang blennies are sold as aquarium fish.

Conservation status: Striped poison-fang blennies are not threatened or endangered. ∎

MIRACLE TRIPLEFIN (Enneapterygius mirabilis): SPECIES ACCOUNTS

Physical characteristics: Miracle triplefins are a little more than an inch (3 centimeters) long. They are light red with lighter spots. These fish have long spines in the first dorsal fin. The second dorsal is divided so that it looks like two fins, thus the name "triplefin."

Geographic range: Miracle triplefins live in the western part of the Pacific Ocean near Australia.

Habitat: Miracle triplefins live on coral reefs.

Diet: Scientists know little about the diet of miracle triplefins. The tooth structure suggests these fish eat small, bottom-dwelling invertebrates.

Behavior and reproduction: Miracle triplefins have not been observed alive underwater. The eggs are probably fertilized outside the female.

Miracle triplefins and people: Miracle triplefins are not used by humans.

Conservation status: Miracle triplefins are not threatened or endangered. ∎