Lizardfishes and Relatives: Aulopiformes

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LIZARDFISHES AND RELATIVES: Aulopiformes

LONGNOSE LANCETFISH (Alepisaurus ferox): SPECIES ACCOUNTS
TRIPODFISH (Bathypterois quadrifilis): SPECIES ACCOUNTS

PHYSICAL CHARACTERISTICS

Lizardfishes are long-bodied and have a large head that looks like the head of a reptile. Some of the relatives have a first ray on the dorsal fin that is much longer than the other rays. The dorsal (DOOR-suhl) fin is the fin along the midline of the back. Rays are supporting rods in the fins. Other relatives have a series of red bars on their pelvic fins, or the rear pair, corresponding to the rear legs of four-footed animals. These fishes have yellow spots just above the lateral line and have rows of faint blue spots above and below the lateral line. The lateral (LAT-uhr-uhl) line is a series of pores and tiny tubes along each side of a fish's body and is used for sensing vibrations. The fins are pale white to clear. Some lizardfish relatives have a pencil-shaped body, a flat head with tiny eyes, and long, thick fin rays. Others have a long, sail-like dorsal fin that stretches from the head nearly to the tail. Still other relatives have tubular eyes that look like and are used as a telescope for detecting light in dim surroundings. Other relatives have fanglike teeth and lack scales.

GEOGRAPHIC RANGE

Lizardfishes and their relatives live in the Atlantic, Pacific, and Indian Oceans.

HABITAT

Lizardfishes and their relatives live at the bottom or swim freely in open water. These fishes live at depths from warm, shallow water near the shore to water so deep that light is almost absent. The bottom-dwelling fishes rest on rubble, sand, coral, rock, seaweed, or mud.

DIET

Lizardfishes and their relatives are predators (PREH-duhterz), or animals that hunt and kill other animals for food. Bottom-dwelling species eat smaller fishes and shrimps that they ambush and capture with their large, toothy mouths. At middle depths and in deep water lizardfishes and their relatives probably capture passing fish, squid, and shrimp.

BEHAVIOR AND REPRODUCTION

Scientists know little about the behavior of lizardfishes and their relatives. They do know that the bottom-dwelling species use camouflage and make very little movement. These characteristics allow the fish to ambush prey and avoid predators. These fishes swim in short, rapid bursts and then bury themselves. The fishes that live in middle depths and deep water may swim rapidly in pursuit of prey or food animals. Smaller species may hover in the water and swim only to hunt prey or to travel to the surface at night. Some species swim with their tails down and their heads up.

Lizardfishes and their relatives have two mating systems. In one system male and female sexes are separate. Fishes that live in shallow water spawn in the open water and release eggs that when fertilized (FUR-teh-lyzed), or penetrated by sperm, drift to the bottom for development. In the other mating system the fish can be both male and female at the same time and reproduce by fertilizing themselves.

LIZARDFISHES, THEIR RELATIVES, AND PEOPLE

Although the meat of shallow-water lizardfishes and their relatives is bony, some people eat it.

CONSERVATION STATUS

Lizardfishes and their relatives are not threatened nor endangered.

LONGNOSE LANCETFISH (Alepisaurus ferox): SPECIES ACCOUNTS

Physical characteristics: Longnose lancetfish have a long, thin body with a very long and high dorsal fin. These fish reach a length of more than 7 feet (2 meters). The mouth is large and has two fangs. The body is pale silver or shiny white or cream but is darker along the back and upper sides. At times the color has hints of light blue, green, or red. The fins are brown or black. Longnose lancetfish do not have a swim bladder, or internal sac that fishes use to control their position in the water.

Geographic range: Longnose lancetfish live in the Atlantic and Pacific oceans.

Habitat: Longnose lancetfish live in open water from the surface to the middle depths, depending on the time of day. They sometimes swim near the shore.

Diet: Longnose lancetfish eat invertebrates (in-VER-teh-brehts), or animals without a backbone, such as squid and shrimp, and fishes. They also eat bottom-dwelling animals such as sea squirts.

Behavior and reproduction: Scientists do not know much about the behavior and reproduction of longnose lancetfish. These fish probably produce eggs in open water, and the larvae (LAR-vee) or young live in open water.

Longnose lancetfish and people: Longnose lancetfish are caught accidentally with other fishes but are not valued as a food fish.

Conservation status: Longnose lancetfish are not threatened or endangered. ∎

TRIPODFISH (Bathypterois quadrifilis): SPECIES ACCOUNTS

Physical characteristics: Tripodfish have a long, thin body and reach a length of about 7 inches (18 centimeters). The pectoral, pelvic, and tail fin rays are all very long. When erect, these rays act as a tripod on which the fish balances itself on the bottom. Tripodfish are bronze to pale with gray on the head and belly and along the lower back.

Geographic range: Tripodfish live on both sides of the Atlantic Ocean.

Habitat: Tripodfish live on sand and rubble in the deep part of the ocean.

Diet: Tripodfish eat smaller fishes and crustaceans that they ambush on the bottom. Crustaceans (krus-TAY-shuns) are water-dwelling animals that have jointed legs and a hard shell but no backbone.

Behavior and reproduction: Tripodfish can "walk" on the bottom using their tripod. To reproduce they act as both sexes at the same time. The eggs and larvae drift in open water.

Tripodfish and people: Tripodfish are of no commercial importance but are a curiosity of science.

Conservation status: Tripodfish are not threatened or endangered. ∎