Cabrillo Marine Aquarium
 
 
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Creature Feature


Spiny Sand Crab
Blepharipoda occidentalis

Everyone loves a sand crab. You know the kind you feel wriggling in the sand under your feet and when you pick them up, they tickle your palm…

Spiny sand crabs, Blepharipoda occidentalis, are just like these only they reach three times the size, have sharp spines jutting out along the sides of their carapace and two sizable spiny claws in front…not to mention they may eat their smaller sand crab cousins for dinner!

At a whopping 3” long and 1.75” wide, the spiny sand crabs can be found burrowing off the wave swept beaches of California and Baja. While you may expect to find them between the tides with the others, they prefer to live in the fine grained sand of the deeper sub-tidal zone. They can even be found 98 feet down. It is common for them to burrow so deep that only their eyes and antennae extend past the sand. In this position they can easily hide at the first sign of trouble.

Juveniles keep these feathery antennae fanned out to filter food passing by. It is not until adulthood that they expand their palate of plankton and detritus to include the remains of smaller dead sand crabs. This feeding strategy is why scientists look to sand crabs as an indicator species. The more plankton they consume, the more domoic acid can accumulate in their bodies. While this is not good for the sand crabs, it does provide us with important information on the level of natural toxins in the water.

Even worse for the spiny sand crabs, their heavily armored bodies are no match for fish like the queen croaker and the barred surf perch. Luckily, for the fish at least, most of the spiny sand crabs they eat also come with a side of clams. It turns out Mysella pedroana, a commensal mollusk, can be found living inside the bronchial chamber of 2/3rds of the population. Some individuals have been found with 22 mollusks inside!

It is not too common to find a live spiny sand crab (and their tiny clams) on the beach but you may be lucky enough to find a molt. If you do, pick it up, take a good look, but always remember to watch out for the spines.


- Alix Lomas, Aquarium Educator

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Southern California Species

The Cabrillo Marine Aquarium is home to more than 200 species of animals that live in and around the waters of Southern California. Do you have a question about these and other Southern California species? Ask a Biologist.


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Haliotis sp.

Young abalone with a shell size of less than 3 cm take shelter within the spines of sea urchins for protection.

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Balanus spp.

Barnacles are hermaphroditic (they have both female and male sex organs).

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Cetorhinus maximus

The basking shark is the second largest species of fish in the world.

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Asterina miniata

When two bat stars bump into each other they begin a slow-motion “arm wrestling” match. Each sea star tries to get its arm on top of the other’s arm.

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Nycticorax nycticorax

Black-crowned night herons feed at night in the same areas that other heron species feed in the day.

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Prionace glauca

The blue shark has one of the largest ranges of all species of sharks.

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Balaenoptera musculus

The blue whale is the largest living animal.

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Lythrypnus dalli

These peaceful fish are often territorial with members of their own species.

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Sebastes paucispinis

The bocaccio can live up to 45 years.

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Tursiops truncatus

The bottlenose dolphin uses echolocation to find its prey.

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Pelecanus occidentalis

The brown pelican is the smallest of all pelicans and is the only one that plunges from the air into the water to catch its food.

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Aplysia californica

Each Sea hare may lay up to eighty million eggs. However, most of the eggs are eaten by predators.

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Leuresthes tenuis

Unlike other fish, grunion come completely out of the water to lay their eggs in the sand.

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Paralichthys californicus

The California halibut is a flatfish with both eyes on one side of its head!

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Mytilus californianus

While feeding, a mussel filters 2 to 3 quarts of water per hour.

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Scorpaena guttata

The California scorpionfish has venom in its spines.

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Zalophus californianus

Sea lions use their long front flippers to steer and propel themselves through the water.

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Semicossyphus pulcher

The California sheephead are all born as females.

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Raja inornata

The California Skate has a skeleton made completely out of cartilage.

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Panulirus interruptus

California Lobsters do not have front claws.

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Alopias vulpinus

The common thresher shark uses its long tail in a whip-like fashion to deliver incapacitating blows to its prey.

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Phronima sedentaria

The eyes of this amphipod are so large that they make up nearly a quarter of the entire body.

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Aequorea victoria

Crystal jellies can expand their mouth to eat prey half their size!

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Zostera marina

Eel grass is a true plant (not a seaweed) and is one of the few flowering plants that grow in the ocean.

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Uca crenulata

Males have a large claw that they wave back and forth like a fiddler.

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Balaenoptera physalus

The Fin whale is the second largest animal after the blue whale

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Hypsypops rubicundus

Garibaldi is the California State marine fish.

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Hypsypops rubicundus

Garibaldi is the California State marine fish.

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Macrocystis pyrifera

Under ideal conditions, giant kelp can grow about two feet a day.

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Heterostichus rostratus

The giant kelpfish can quickly change color during courtship or territorial displays.

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Stereolepis gigas

This fish is huge, growing over 7.5 feet long and weighing over 500 pounds.

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Pollicipes polymerus

Gooseneck barnacles can live 20 years, or more.

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Eschrichtius robustus

The gray whale is a baleen whale.

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Carcharodon carcharias

The great white shark is capable of explosive bursts of speed and has been known to jump 3 meters (10 feet) out of the water.

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Anthopleura xanthogrammica

Some fishes develop resistance to the green anemone's sting by covering themselves with mucus.

Harbor Porpoise   Arrow
Phocoena phocoena

The harbor porpoise is one of six species of porpoise

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Phoca vitulina

The Harbor seal is the most widely distributed species of pinniped.

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Pagurus sp.

Hermit crabs protect their rear ends by hiding it in a snail shell.

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Heterodontus francisci

The female horn shark lays a distinctive spiral-shaped egg case.

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Megaptera novaeangliae

The humpback whale has distinct patterns on the tail flukes used to identify individuals.

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Paralabrax clathratus

Kelp bass reproduce by spawning (release egg and sperm into the water column) and form large aggregations in the summer months.

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Orcinus orca

The killer whale, as known as the orca, is the largest dolphin.

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Krill  

Thysanoessa spinifera

Krill are eaten by whales, seals, penguins, squid and fish.

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Phoebastria immutabilis

The wings of a laysan albatross are adapted to lock open into a wingspan of nearly seven feet.

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Triakis semifasciata

Leopard sharks are bottom feeders and are named because of their stripes.

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Hemisquilla ensigera

Mantis shrimp are not true shrimp, but get their name because of their appearance.

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Limosa fedoa

The marbled godwit has a long, slightly upturned bill with a dark tip and pinkish base.

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Loxorhynchus crispatus

The masking crab decorates itself with bits of algae, sponges and bryozoans.

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Balaenoptera acutorostrata

The minke whale is the smallest of the rorqual whales

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Gymnothorax mordax

This eel's favorite prey is the octopus.

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Norrisia norrisi

These snails travel up and down kelp every day.

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Pisaster ochraceous

These sea stars are able to digest their prey outside of their bodies.

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Squatina californica

The Pacific angel shark superficially looks like a ray, but is a true shark.

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Eptatretus stoutii

Hagfish are considered to be the most primitive species of all living fish.

Pacific Hake   Arrow
Merluccius productus

The Pacific hake can live up to 15 years.

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Scomber japonicus

The Pacific mackerel is also known as the chub mackerel or blue mackerel.

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Sardinops sagax

The Pacific sardine form large schools of up to 10 million fish.

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Hippocampus ingens

The Pacific seahorse reverses traditional birthing roles.

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Strongylocentrotus purpuratus

Sea urchins have tube feet, which they use for attachment, locomotion and feeding.

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Grampus griseus

Adult Risso's dolphins bodies are typically heavily scarred, while calves have little or no scarring

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Salema  

Xenistius californiensis

These fish have an up-turned mouth to better eat plankton.

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Dendraster excentricus

You can't spend these dollars, they are relatives to sea stars.

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Sargo  

Anisotremus davidsoni

The sargo is the largest of the Pacific grunts.

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Renilla koellikeri

A sea pansy is not a flower, but is an animal that is related to sea jellies.

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Isurus oxyrinchus

The shortfin mako shark is able to elevate its body temperature almost 20°F above the surrounding water.

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Enhydra lutris nereis

Sea otters do not have blubber to keep warm, instead they have very dense fur (up to one million hairs per square inch).

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Physeter macrocephalus

The sperm whale is the largest of the toothed whales and the largest toothed predator.

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Pachygrapsus crassipes

The striped shore crab spends at least half its time on land, but submerges at times to wet its gills.

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Cephaloscyllium ventriosum

When stressed, the swell shark can “swell” by inflating its stomach by swallowing water.

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Eucyclogobius newberryi

The tidewater goby is an endangered species.

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Octopus bimaculoides

Octopus are extremely intelligent and have well-developed eyes.

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Larus occidentalis

The Western gull typically lives about 15 years, but can live to at least 25 years.

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Cryptolepas rhachianecti

Whale barnacles live attached to the skin of whales.

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Atractoscion nobilis

The white seabass is the largest species of croaker in California.

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Tringa semipalmata

The willet is very territorial and will aggressively defend their nesting and feeding territory.

 

Creature Feature Archive


      9/20/2020 Sea Otters (Featured)
      8/17/2020 Shark Week
      6/5/2020 Bony Fishes
      6/3/2020 Spring Outdoor Program
      5/23/2020 Birds
      5/15/2020 Whales
      5/8/2020 Salt Marsh
      5/1/2020 Rocky Shores
      4/23/2020 California Grunion
      4/15/2020 Celebrate Earth Day!
      4/7/2020 Sandy Beach Invertebrates
      3/11/2019 Channel Island Fox
      11/14/2016 Piddock Clam
      6/22/2016 Giant Pacific Seahorse
      3/2/2016 Spiny Sand Crab
      12/22/2015 Northern and Southern Tidewater Gobies
      9/16/2015 Tuna Crab
      6/17/2015 Snake Skin Brittle Star
      2/23/2015 Humboldt Squid
      12/15/2014 Allen’s Hummingbird
      5/17/2013 Killer Whale
      3/31/2013 Cowcod
      2/15/2013 Crystal Jelly
      11/1/2012 Risso's dolphin
      9/6/2012 Lacy Crust Bryozoan
      8/16/2012 California sheephead
      7/31/2012 Chitons
      7/17/2012 Splitnose rockfish
      2/28/2012 Green Sea Turtle
      12/26/2011 Gray Whales
      11/16/2011 California Brown Pelican
      8/23/2011 Oarfish
      2/21/2011 Pacific Mackerel
      6/28/2010 Football Fish
      3/3/2010 Grunion
      1/12/2010 E. coli, Oh My!
      7/22/2009 Cabrillo's Fossils
      3/9/2009 Garibaldi
      11/3/2008 Laysan Albatross
   
 
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