| Invertebrates | Fish |

Cabrillo Marine Aquarium
- Selected Species Info (Invertebrates)

ABALONE (Haliotis sp.)

Abalone are distinctive shellfish which live in nearshore waters. Most people are surprised to learn that abalone are snails. In California, there are eight species of abalone which are hard-bottom dwellers. The different species are loosely stratified by depth and water temperature. Abalone are herbivorous. Small individuals scrape bacteria and diatoms from the rocky bottom. Larger abalone depend on drift algae, especially deteriorating kelp. Slow growing, it takes an abalone seven to fifteen years to grow to legal size. Abalone fall prey to a large number of animals. In early life, crabs, lobsters, fishes and octopuses reduce numbers severely. Larger abalone must contend with bat rays, which can crush the largest abalone in its powerful jaws; the sea otter, which uses a rock to break its shell; and humans, who use pry bars to remove them. Mortality rates can exceed 99 percent. In recent times, withering foot syndrome, sport and commercial uses of abalone have taken their toll. A mainland closure extending from Palos Verdes Point to Dana Point was established to assist in recovery of abalone populations. Another exists at Catalina Island from Lion Head to Arrow Point. Abalone are usually found at the Aquarium in tank number 3 and at the touch tank.

BAT SEA STAR (Asterina miniata)

The bat sea star is found from Alaska to Baja California in the low intertidal zone to about 950 feet on rocky and sandy bottoms. Bat sea stars usually have five webbed arms with suction cup tube feet that allows it to move and hold onto rocks. They are capable of regenerating lost arms. Although most commonly orange or light red, bat sea stars' colors vary from tan, orange, red or maroon and attain lengths of up to 20 cm. A bat sea star will eat almost anything (plant or animal) and is capable of turning its stomach inside out. The food is then actually digested externally. Bat sea stars reproduce by spawning and have separate sexes. Bat Sea Stars are usually found at the Aquarium in tank numbers 6, 21 and at the touch tank.

CALIFORNIA BROWN SEA HARE (Aplysia californica)

Resembling a crouched rabbit, the sea hare is a marine snail with a shell reduced to a small, thin internal remnant. It can grow up to the size of a football and its coloration various from olive green to reddish brown with mottling. Sea hares occur in sheltered habitats from the shore to 60 feet deep where they graze on a variety of algae. When handled or disturbed, they can eject a slimy, purplish fluid, a defensive mechanism that acts as an irritant against potential predators. This purplish ink is tied to the red algae in the sea hare's diet. Sea hares are hermaphrodites, animals having both male and female reproductive organs. Any individual may act only as a male, or only as a female. Whole chains of mating animals can be seen in the wild. Large stringy egg masses resembling a spilled pot of spaghetti are laid. A typical egg mass can contain in the neighborhood of 80 million eggs. California Brown Sea Hares are usually found at the Aquarium in tank number 3.

ELBOW CRAB (Heterocrypta occidentalis) Characterized by a wing-shaped carapace and very long, elbow-bearing arms, this distinctive crab is found on sand bottoms from intertidal to 70 feet. Its range is from Central California to Baja California. Elbow Crabs are usually found at the Aquarium in tank number 23.

FIDDLER CRAB (Uca crenulata)

Fiddler crabs are so named because the males have one large claw that they carry in front of their bodies and move back and forth at times like a fiddler. The large claw is also used to establish a territory and attract a mate. Found near salt marshes, they burrow their bodies in the mud. They feed on organic material found in the mud then deposit the leftovers by bringing up round, pea sized balls of mud to the entrance of their burrow and snapping the balls out with their legs. Human encroachment upon the wetland habitats of the crab has made the future of fiddler crabs uncertain. Fiddler Crabs are usually found at the Aquarium in tank number 26.

GHOST SHRIMP (Callianassa californiensis) This mud-dwelling shrimp is found in bays and sloughs from Alaska to lower California. Digging elaborate burrows with turn arounds, the ghost shrimp obtains its food from the mud/sediment. Called ghost shrimp because of their whitish-yellow color, they range in length from 2 to 4 inches. The one larger pincer serves as a weapon of offense and defense. Each of the five pairs of legs have a definite function to perform in the walking process as well as other duties. Only the third, fourth and fifth pairs of legs are used for walking while the fourth pair are used for bracing against the walls of the burrow. The second and third pairs of legs are also used like shovels for digging while the brushes on the fourth and fifth pair of legs are used for personal cleanliness. Ghost shrimp are food for birds and fish. They are also heavily harvested as fishing bait. Ghost Shrimp are usually found at the Aquarium in tank number 26.

HERMIT CRAB (Pagurus sp.)

There are many species of hermit crabs ranging from Alaska to Mexico. Although usually found in tide pools, they can also be found at depths of up to 50 feet. Hermit crabs feed on plant debris and are such effective scavengers that they have been described as the garbage collectors of the intertidal zone. They are also an important food source for fish including pile perch. Hermit crabs use empty snail shells as protection into which they will retreat quickly if bothered. As the hermit crab grows, it is necessary for it to find larger snail shells. They do not kill snails for their shells, but larger hermit crabs have been know to evict smaller hermit crabs from a shell. Hermit crabs inspect prospective shells very thoroughly before changing shells. Because hermit crabs cannot always find a readily available and suitable shell, anything hollow is sometimes used until they find something better. The tail appendages of the hermit crab are modified into hooklike structures that cling to the shell so firmly that a hermit crab will nearly always allow itself to be split in two before it can be pulled out of a shell. It is always best to gently handle and then return all animals and shells to the tidepools. Hermit Crabs are usually found at the Aquarium in tank numbers 1, 3 and 9.

LOBSTER (Panulirus interruptus)

West Coast lobster, commonly known as "California Spiny Lobster", lacks claws (like most lobsters!) and depends upon the many sharp spines on its body and antennae to help protect them from predators. The antennae have the ability to make sound which may also ward off enemies and help detect unusual movement towards them. Belonging to the decapod family of crustaceans, lobsters have 10 legs and 2 pairs of antennae. Female lobsters brood up to 50,000 eggs underneath their abdomen for 70 days before they hatch. Found in rocks and in caves off the coast from Point Conception southward, lobsters are scavengers and come out at night to eat bits of plant and animal material that fall to the ocean floor. They swim by flapping their tail very rapidly and have the ability to crawl in any direction. Lobsters grow bigger by molting their exoskeleton. After crawling out of their old skeleton, their soft body gets bigger and hardens into a new skeleton in about a day. They can regenerate lost legs and antennae. Big male lobsters, known as "bulls", have been known to grow up to 16 to 20 pounds and may be 75 to 100 years old. Lobsters are found at the Aquarium in tank numbers 13, 21 and at the touch tank.

MANTIS SHRIMP (Hemisquilla ensigera)

What animal strikes faster than a cheetah, has the eyesight of an eagle, is (almost) as ferocious as a great white shark, and looks like a cross between an insect and a lobster? In fact, it can be found in the shallow waters right off the shores of Palos Verdes and Catalina Island, among other areas in southern California. The mantis shrimp is a formidable, and highly predatory, carnivore with lightning-quick reflexes, and stalked, compound eyes that diligently scan its environment. It often waits motionless in its burrow quickly snatching any unwary passerby for its next meal, but it can also be observed stalking its prey and aggressively smashing it to bits with its front appendages. The diet of stomatopods consists of a variety of prey items including small crustaceans, snails, clams, sand dollars, heart urchins, brittle stars, worms and fish. Four species of mantis shrimp live in the cool temperate waters and soft, sandy mud environments found off southern California. Burrows, about 1-4 inches in diameter, with shelly debris surrounding the openings are the homes of mantis shrimp and may continue, parallel to the surface, for 3-10 feet. Burrows play a crucial role in the lives of mantis shrimp and are used for defense, feeding, mating, reproduction and molting activities. Mantis Shrimp are usually found at the Aquarium in tank number 9.

NORRIS' TOP SNAIL (Norrisia norrisi)

Commonly found on kelp from Point Conception to Baja California, the Norris' top snail feeds mainly on brown algae. Also known as smooth brown turban snails, they use their file-like tongue or radula to scrape holes in the kelp. Norris top snails are common food for sea stars. Undergoing a daily vertical migration, they move down the kelp during the day and up the kelp beginning at dusk. The shell of the snail grows up to 55mm in diameter, is light brown on the exterior and often has coraline algae growing on the shell. The umbilicus, or center, is a beautiful chartreuse. Norris' Top Snails are usually found at the Aquarium in tank number 3.

OCHRE SEA STAR (Pisaster ochraceous)

Distinguished by the dense weblike pattern formed by its small white spines, the ochre sea star grows to lengths of 6-12 inches and is usually brown, orange, or purple. Adult ochre sea stars appear to have few enemies, but some are eaten by sea otters and sea gulls. Capable of clinging to rocks in the intertidal to depths of 300 feet from Alaska to Baja, California, they feed on attached or slow-moving prey like mussels, barnacles, snails, limpets and chitons. Feeding is accomplished by utilizing tube feet to pry mussel shells slightly apart and inserting its muscular stomach into slits as narrow as 0.lmm. Digestion actually occurs inside the shells. Ochre sea stars may attain a ripe old age of over 20 years. Ochre Sea Stars are usually found at the Aquarium in tank number 1 and at the touch tank.

TWO-SPOTTED OCTOPUS (Octopus bimaculoides)

This intelligent marine creature is appropriately named because of the two obvious blue spots located behind the eyes. The two-spotted octopus, which grows up to a 2 foot arm span, lives in holes and crevices in the intertidal area to depths up to 70 feet from San Simeon to Baja, California. They move primarily utilizing their arms but can also jet propel. The adults feed on mollusks, crustaceans, and occasionally fish. Prey are subdued with a parrotlike beak and toxic secretions through a salivary gland. Their food is then scrapped out with a radula. Predators of two-spotted octopus include adult moray eels, scorpionfish and humans. Arms often lost during a fight with a moray eel can regenerate. Females lay up to 150,000 eggs under rocks from late winter to early summer, then broods on them continuously for 2-4 months. During brooding, the female doesn't feed and usually dies just around hatching time. The young remain on the bottom after hatching and have a life span of 2-3 years. Two-Spotted Octopus are usually found at the Aquarium in tank number 17.

PURPLE SEA URCHIN (Strongylocentrotus purpuratus)

The purple sea urchin is found from Alaska to Baja California from the low intertidal zone to about 30 feet. In response to the pounding surf, the purple sea urchin will excavate circular holes into sandstone and shale rocks using their sharp spines and teeth, aided by motions produced by waves and tides. When the spines break off, they regenerate. The favorite food of the purple sea urchin is kelp. Urchins can dramatically affect the growth of kelp beds by eating young kelp plants and grazing upon the holdfasts of adult kelp plant. The elimination of the sea otter, a predator of the urchin, allowed the urchin population to grow, which contributed to the decline of kelp forests along the southern California coast. The eggs of the sea urchin are considered a delicacy in Asia and the Mediterranean. Purple Sea Urchin are usually found at the Aquarium in tank number 3 and at the touch tank where you can feel the spines move.

SAND DOLLAR (Dendraster excentricus)

Sand dollars, like their close relatives the sea urchins, are found on sandflats from the low intertidal to about 30 feet, from Alaska to Baja California. Adapted for a life style of burrowing in sand, sand dollars use their many spines to drive itself into the sand. When burrowing is done, they position themselves at an angle with its posterior end projecting above the sand surface . Cruising across the sand surface is accomplished by the spines on the lower surface which operate in waves. In rough waters, these animals lie flat on the surface of the sand. When it comes to eating, sand dollars may be likened to feeding factories as they engage an assembly line of hundreds of tiny appendages in their food processing system. Spines, tube feet and pedicellaria (tiny pincers) on both sides of the body help in the complex capture, transport and sorting of food items. Tiny whiplike cilia on the surface of the sand dollar sweep the very small, immobile particles. Larger immobile particles are collected by tube feet. A five-toothed apparatus called Aristotle's lantern chews up the food. Sand dollars release sperm and eggs into the water from about May through July in southern California. Sand dollars reach a diameter of about 75 mm and have a life span of about 8 years. Predators include California sheephead, starry flounder, spiny sand star and pink star. Sand dollars avoid approaching pink stars by burrowing down. Sand Dollars are usually found at the Aquarium in tank number 23.

SEA ANEMONE (Anthopleura sp.)

These soft-bodied flower-like animals are closely related to jellyfish and corals. They almost never move but when they do it is accomplished by gliding on their base, crawling on their side or walking on their tentacles. The tentacles are equipped with thousands of stinging structures called nematocysts which are used to capture prey such as crabs, fish and plankton. Discharging nematocysts feel like scotch tape when you touch them. The captured prey is then drawn into their central mouth which is surrounded by an oral disc. Predators of sea anemone include shag rug nudibranchs, wentletrap snails and leather sea stars. They reproduce asexually by splitting in half repeatedly forming identical individuals known as clones. Sea Anemones are usually found at the Aquarium in tank numbers 1, 4, 10, 27 and at the touch tank.

SEA CUCUMBER (Parastichopus parvimensis)

Related to sea stars and sea urchins, sea cucumbers are slow-moving, soft-bodied cylindrical creatures with small spines in the skin, tube feet on the underside and branched tentacles sometimes visible at the mouth end. Mostly inhabiting soft sand or mud floors, they recycle nutrients and wastes found in the sand or mud floor. Sea cucumbers have few known predators other than man. Females produce many small eggs, which are fertilized after release and develop into free-swimming plankton-feeding larvae. Sea Cucumbers are usually found at the Aquarium in tank numbers 6, 21 and at the touch tank.

SEA PANSY (Renilla kollikeri)

These colonial animals are common on sand flats from Santa Barbara to Baja California. Sea pansies are purple in color with a heart-shaped body and a fleshy stalk that extends downward into the sand to hold it in place. Moving about a great deal, they mainly feed on microzooplankton. When disturbed or attacked, they produce waves of blue/green light across their body called bioluminescence. They are preyed upon by nudibranchs and sea stars. Sea Pansies are usually found at the Aquarium in tank number 23.

STRIPED SHORE CRAB (Pachygrapsus crassipes)

The Striped shore crab is found along the rocky shores or in estuaries from Oregon to Baja California. The crabs spend time out of the water, but submerge to wet their gills and feed. Striped shore crabs have a square dark body with green cross stripes and are usually 1 to 2 inches in length across the body. It takes 3 years for adults to reach full size. Like lobsters, crabs have an exoskeleton which they shed or molt as they grow. They will molt about 20 times to reach full size. They are also able to regenerate parts of their legs and claws. Crabs have excellent eyesight and often eat at night. As scavengers they feed on plants and animals utilizing a pattern of picking and scraping up food with their left and right claws alternately. A female crab can brood about 50,000 eggs under her abdomen and breeds 1 to 2 times a year. Striped shore crabs are usually found at the Aquarium in tank number 10.

SUNFLOWER SEA STAR (Pycnopodia helianthoides)

Growing up to 36 inches in diameter, sunflower sea stars are found in the tidal zone of Central and Northern California near rocky shores and in shallow water along rock bottoms. They utilize their very strong sense of smell and very sensitive indicators of light and dark to find and feed on purple sea urchins and smaller sea stars. The sunflower sea star has as many as 24 arms which gives it the appearance of a giant sunflower. Pycnopodia is one of the "fastest" moving stars in the sea. It is able to move around using over 15,000 tube feet on the bottom of the body which have suction cups and allow them to cling to the rocks. The suction cups on the feet are so strong that if you pull a sea star off the rocks the suction cups can break loose from the tube feet and remain clinging to the rocks. Although they are able to regenerate lost parts of their bodies, it should be left where it is (undisturbed). The backs of sea stars have pinching structures called pedicellariae on them to keep any other animals from attaching to their backs. Sunflower Sea Stars are usually found at the Aquarium in tank numbers 7 and 21.