Skip to main content

Scorpion Fish, Catfish, and Eels

Another fish that depends on camouflage is the scorpion fish (family Scorpaenidae), a heavy animal with ridges and spines on its back. The fins and spines contain venom that protects this fish from predators. Warts and skin tassels covering its body make the scorpion fish look like part of the reef. This animal waits patiently for prey to get close then literally sucks it in.
scorpion fish (family Scorpaenidae)
Scorpion fish (family Scorpaenidae)

The bandtail puffer (Spheroides spengleri), like other species of puffers, has a very different way of protecting itself. By filling its abdomen with water, the little fish can inflate its body, giving it a bigger and fiercer appearance. In addition, an inflated fish is more difficult for a predator to swallow than an uninflated one.
bandtail puffer (Spheroides spengleri)
Bandtail puffer (Spheroides spengleri)
A close relative, the porcupine fish (Diodon hystix), uses the same mechanism when it feels threatened. Porcupine fish are covered with damaging sharp spines that deter predators. Shallow reef waters and turtle grass beds are some of the places where porcupine fish hunt for prey. Both porcupine fish and bandtail puffers have two fused teeth in each jaw that give their mouths a beaklike appearance. This type of jaw is efficient at crushing the hard shells of crabs and mollusks.
porcupine fish (Diodon hystix)
Porcupine fish (Diodon hystix)
The moray eel (family Muraenidae), seen in the upper color insert on page C-7 has a fearsome reputation because its gaping mouth is full of sharp teeth. In reality members of this group are shy and retiring animals that spend their days hiding in reef crevices. Morays hold their mouths open so that water can be pumped over the gills. Their long, muscular bodies are highly modified for living among rocks and coral. Morays are scale-less, and both their pectoral and pelvic fins are absent. In addition, their remaining fins are fleshy ridges that are covered with thick skin. This body streamlining is an adaptation that helps morays navigate through the narrow passages of the reef structure. When they emerge at night to look for invertebrates, they swim by moving their entire bodies back and forth in an S-shaped pattern.
The moray eel (family Muraenidae)
The moray eel (family Muraenidae)
Another long, fierce-looking reef fish is the great barracuda (Sphyraena barracuda), a slender animal whose body ends in a pointed head with a narrow snout and sharp teeth. Barracudas usually hover around the edges of reefs, waiting for prey to appear. Once a potential meal is spotted, they rush forward aggressively to grab it. Some barracudas reach impressive lengths of 6 feet (1.8 m).
The great barracuda (Sphyraena barracuda)
The great barracuda (Sphyraena barracuda)
 The only catfish on the reef are the coral catfish (Phetusus angularis). These small fish have venomous notched spines near their dorsal and pectoral fins. When young, coral catfish school, or live in groups, by the hundreds near the reef floor; however, as they get older, they form smaller groups of about 20 animals. Maturity also changes they way they look. Young catfish are black, but adults develop a brown color with yellow or white horizontal stripes. They feed on crustaceans, mollusks, and worms, which they find by stirring up the reef floor.

catfish (Phetusus angularis)
Catfish (Phetusus angularis)

Popular posts from this blog

Advantages and Disadvantages of an Exoskeleton

More than 80 percent of the animal species are equipped with a hard, outer covering called an exoskeleton. The functions of exoskeletons are similar to those of other types of skeletal systems. Like the internal skeletons (endoskeletons) of amphibians, reptiles, birds, and mammals, exoskeletons support the tissues and give shape to the bodies of invertebrates. Exoskeletons offer some other advantages. Serving as a suit of armor, they are excellent protection against predators. Also, because they completely cover an animal’s tissues, exoskeletons prevent them from drying out. In addition, exoskeletons serve as points of attachment for muscles, providing animals with more leverage and mechanical advantage than an endoskeleton can offer. That is why a tiny shrimp can cut a fish in half with its claw or lift an object 50 times heavier than its own body.
Despite all their good points, exoskeletons have some drawbacks. They are heavy, so the only animals that have been successful with them …

Differences in Terrestrial and Aquatic Plants

Even though plants that live in water look dramatically different from terrestrial plants, the two groups have a lot in common. Both types of plants capture the Sun’s energy and use it to make food from raw materials. In each case, the raw materials required include carbon dioxide, water, and minerals. The differences in these two types of plants are adaptations to their specific environments.
Land plants are highly specialized for their lifestyles. They get their nutrients from two sources: soil and air. It is the job of roots to absorb water and minerals from the soil, as well as hold the plant in place. Essential materials are transported to cells in leaves by a system of tubes called vascular tissue. Leaves are in charge of taking in carbon dioxide gas from the atmosphere for photosynthesis. Once photosynthesis is complete, a second set of vascular tissue carries the food made by the leaves to the rest of the plant. Land plants are also equipped with woody stems and branches that …

Prokaryotic Cell Structure

Prokaryotic cells are about 10 times smaller than eukaryotic cells. A typical E. coli cell is about 1 μm wide and 2 to 3μm long. Structurally, prokaryotes are very simple cells when compared with eukaryotic cells, and yet they are able to perform the necessary processes of life. Reproduction of prokaryotic cells is by binary fission—the simple division of one cell into two cells, after DNA replication and the formation of a separating membrane and cell wall. All bacteria are prokaryotes, as are the archaea.

Embedded within the cytoplasm of prokaryotic cells are a chromosome, ribosomes, and other cytoplasmic particles (Fig. 1). Unlike eukaryotic cells, the cytoplasm of prokaryotic cells is not filled with internal membranes. The cytoplasm is surrounded by a cell membrane, a cell wall (usually), and sometimes a capsule or slime layer. These latter three structures make up the bacterial cell envelope. Depending on the particular species of bacterium, flagella, pili (description follows)…