Monstrilla grandis

Physical characteristics Adult females measure 0.147 inches (3.75 millimeters) in length, while males are 0.074 inches (1.9 millimeters). The fore body is long and the mouthparts are absent. The antennules are short in both males and females those of the males are bent. The first four pairs of thoracic limbs are well developed, but the last pair is small. They are in the shape of two rounded structures, or lobes. The short abdomen has a pair of egg-bearing spines and a pair of large structures...

Common Octopus Octopus vulgaris

Physical characteristics The mantle plus the longest tentacle is about 120 inches (3 meters) long. The ball-shaped mantle is variable in color but usually reddish brown. The skin is smooth but may temporarily have bumps of different sizes and shapes. The thick, armlike tentacles are four times the length of the mantle and have two alternating rows of suckers. The head is nearly as wide as the mantle and has a pair of distinctive eyes. Geographic range They are found worldwide in both cool and...

Daphnia pulex

Physical characteristics Common water fleas are small, measuring 0.008 to 0.1 inches (0.2 to 3 mm) in length. They are flattened from side to side. A large, folded carapace covers all but the head. They have two pairs of antennae and five pairs of leaflike limbs. Geographic range Common water fleas are found in North America, Europe, and the cooler regions of South America. Habitat Common water fleas live in freshwater lakes, ponds, rivers, and streams. Diet They eat algae and microscopic...

Pronunciation Guide for Scientific Names

Amphionidacea am-fee-oh-nih-DAY-see-ay Amphionides reynaudii am-fee-OH-nih-deez ray-NOH-dee-eye Amphipoda am-fee-POH-day Anaspidacea an-ah-spih-DAY-see-ay Anaspides tasmaniae an-ah-SPIH-dayz taz-MAY-nee-ee Antalis entalis an-TAL-is en-TAL-is Antrobathynella stammeri an-troh-bath-EE-nel-lay STAMmer-eye Apseudes intermedius ap-SEE-oo-dez in-ter-MEE-dee-us Argulus foliaceus AR-gyu-lus foh-lee-AY-see-us Armadillidium vulgare ar-mah-dil-LID-ee-um vul-GAR-ee Bathynellacea bath-ee-nel-AYS-see-ay...

Spiomenia spiculata

Physical characteristics The curved body is widest at the middle and becomes slightly narrower toward the rear. They are covered with long spines. The longest spines are at the rear of the body. The radula has twenty-two to twenty-five teeth. Each tooth has twenty-two or twenty-three denticles. Geographic range They are found in the West European Basin of the Atlantic Ocean. Habitat They live on the sea bottom at depths of 6,560 to 13,120 feet (2,000 to 4,000 meters). Diet Spiomenia spiculata...

Tongue Worm Linguatula serrata

Tongue worms live in the noses of dogs, foxes, coyotes, wolves, and cats. (Illustration by The Gale Group.) Tongue worms live in the noses of dogs, foxes, coyotes, wolves, and cats. (Illustration by The Gale Group.) Physical characteristics Tongue worms are long, tongue-shaped worms. The males are 0.71 to 0.79 inches (18 to 20 millimeters) in length, while the females are 3.15 to 4.72 inches (80 to 120 millimeters). Geographic range They are found worldwide, especially in warm tropical regions....

Behavior And Reproduction

Many free-living copepods gather food from the water by using their antennae and maxillipeds. The swimming movements of these appendages help to create a flow of food-carrying water toward their mouths. Both male and female copepods are required for reproduction. Males locate females by following their pheromone trails in the water. Pheromones (FEH-re-moans) are chemicals that attract members of the same species. Males place a single sperm packet on the female's abdomen. The sperm escapes the...

Odontodactylus scyllarus

Physical characteristics The body of a peacock mantis shrimp reaches a length of 6.7 inches (170 millimeters). Males and females are distinctively colored. Mature males are bright green with crimson and blue appendages females are more olive or brown. Young individuals are bright yellow. Geographic range This species is found in the Indo-Pacific Ocean, including Hawaii. Diet The peacock mantis shrimp is a smasher that hunts hard-shelled animals like clams, snails, and crabs. Behavior and...

Lepeophtheirus salmonis

Physical characteristics Adult females measure 0.27 to 0.49 inches (7 to 12.5 millimeters) in length, while males are 0.17 to 0.26 inches (4.5 to 6.7 millimeters). Their bodies are flat from top to bottom. The antennules of both males and females are short. The clawed antennae and mouthparts are used to grab the skin of their hosts. The mouthparts form a cone-shaped structure. The third pair of thoracic limbs makes an apronlike structure that forms part of a sucker on the fore body. The fourth...

Oniscus asellus

Physical characteristics The body of the common shiny wood-louse is egg-shaped, has a shiny grayish brown back, and reaches a length of approximately 0.6 inches (16 millimeters). It has a pair of long antennae. Geographic range Originally from only western and northern Europe, this species is now also established in both eastern Europe and North America. Habitat The common shiny woodlouse lives in almost any damp habitat, particularly in forests. It is usually found under rocks and logs. Diet...

Conservation Status

No species of fish lice is considered threatened or endangered. Physical characteristics The abdominal lobes of fish lice are broadly rounded. The notch between the lobes is not very deep and less than half the length of the lobes. The first three pairs of thoracic limbs are dark at their bases. Adult females measure 0.39 inches (10 millimeters) in length, while the males are 0.35 inches (9 millimeters). Geographic range They are found in Europe, east to central Asia and Siberia. Habitat Fish...

Vampyroteuthis infernalis

Physical characteristics This squid's skin has many light-producing organs. There are large, circular light-producing organs just behind the fins on the mantle. The tentaclelike arms are covered by tiny, hairlike structures called cirri (SIH-ree). The arms have suckers only on the outer halves. Geographic range This species is found in all cool and warm water oceans. Habitat Vampire squids live in open waters at depths of 1,965 to 4,920 feet (600 to 1,500 meters). Diet They probably eat...

No Common Name Itoitantulus misophricola

Physical characteristics The larvae have long appendages on the tips of their abdomens. The thoracic limbs are used for swimming the last pair has a long, curved spine on each tip. The sac where adult males or females develop is formed behind the sixth thoracic segment. Males have an unsegmented abdomen with distinct appendages on the tip. Geographic range Itoitantulus misophricola (abbreviated I. misophricola) are found from the southern Japanese island of Okinawa, south to the Philippines....

Vargula hilgendorfii

Physical characteristics This ostracod measures 0.12 inches (3 millimeters) in length. It has a beaklike projection on the front of the smooth, round, clear carapace. The black eyes are visible through the carapace. The carapace has large notches through which the antennae stick out. The appendages at the tip of the abdomen are very large and visible between the folded halves of the carapace. Geographic range They are found along the Pacific coast of central Japan. Habitat This species is very...

No Common Name Othona plumfera

Physical characteristics Adult females measure 0.039 to 0.059 inches (1 to 1.5 millimeters) in length, while males are 0.029 to 0.039 inches (0.75 to 1 millimeters). The fore body is egg-shaped and has a beaklike projection on the front. The female's antennules have very long hairlike structures, while those of the male are bent. The max-illipeds are well developed. The first four pairs of thoracic limbs are also well developed, but the last pair is small and feathery. Each has a bristle at the...

Epiperipatus biolleyi

Physical characteristics Epiperipatus biolleyi adults measure up to 1.5 to 2 inches (38 to 52 millimeters) in length and are rusty brown or pinkish with dark papillae and a stripe along the back. Antennae and legs are gray. Females have 30 pairs of legs, while males have 26 to 28. Geographic range They are found in Costa Rica. Habitat Epiperipatus biolleyi (abbreviated as E. biolleyi) live in low mountain forests inside rotting logs or in natural cavities in the soil. Diet Nothing is known...

No Common Name Phoronis ijimai

Physical characteristics Fully stretched out, these flesh-colored or clear-bodied phoronids may reach a length of 5 inches (120 millimeters) and are 0.02 to 0.08 inches (0.5 to 2 millimeters) thick. The lophophore sometimes is clear and has white spots. The lophophore is horseshoe-shaped, or coiled with a single spiral, and has as many as 230 tentacles. Each tentacle is 0.08 to 0.2 inches (2 to 5 millimeters) long. Geographic range This species is found in the eastern and western Pacific Ocean...

Cryptochiton stelleri

Physical characteristics This is the largest chiton in the world, measuring up to 13 inches (330 millimeters) in length and 5 inches (130 millimeters) across. It resembles a brick-red meatloaf. Its large size and color distinguish this species from other chitons. The leathery and reddish mantle wraps around the entire body and hides all of the valves. It is covered with bundles of tiny spines. Geographic range Gumboot chitons are found from the Aleutian Islands in Alaska, south to San Miguel...

No Common Name Corolla spectabilis

Physical characteristics The body of this small, jellylike species is transparent. The dark contents of its digestive tract are clearly visible from the outside. It does not have a shell. Large, winglike plates stick out from the sides of the body. Adults measure up to 3 inches (80 millimeters) long, while the wing plates span 6 inches (160 millimeters) across. Geographic range This species is found in the Atlantic and Pacific Oceans, between the latitudes of 40 North and 5 South. Habitat This...