Brittle Star Essay, Research Paper

BRITTLE STAR

PHYLUM: Echinodermata

SPECIES: Ophioderma panamense

GEOGRAPHIC RANGE: From Peru and through Southern California

HABITAT: They have been observed in the mid and low tide zones, abundant on the sea floor underneath rocks and in crevices and moving about tide pools and in available habitats in southern California

NICHE: Omnivoire and filter feeder

ADDITIONAL NOTES: Sometimes often called serpent starts due to their snake like movements. The mouth is located on the underside of the central disc. The aboral disc and arms are dark brown to black, and the disc is usually about 25mm. in diameter and the arms near 180 in length. They have rounded bodies with five slender, flexible arms that are easily broken off by any external force but are readily regenerated. Their food consists of decaying matter and microscopic organisms. Their disc is covered with thick granules, which obscure the radial shields, the disc margin is almost straight between the arms, and the arm spines are short. Pg. 276

Specimen#2

BAT STAR

PHYLUM: Echinodermata

SPECIES: Patiria miniata

GEOGRAPHIC RANGE: It can be found from Alaska down through Mexico and is one of the most common species in Southern California. Also common in Alamitos Bay, Cabrillo Bay, Corona del Mar, Dana Point and Marina del Rey.

HABITAT: Found in tide pools in the low intertidal and subtidal zones hiding in protected bays on rocks under rocks and in and around wharf pilings.

NICHE: Omnivore and scavenger

ADDITIONAL NOTES: With short triangular arms it shape it truly “star” shaped. Bat stars range in a variety of colors from whitish to yellow or orange, red, purple – brown. The aboral face is scaly. They use tubed feet for locomotion. Batstars range from 1 inch in diameter to 6 inches. They don’t have a heart. The Bat star is almost always accompanied by a small commensal worm (Ophiodromus pugettensis), which lives in the ambulacral grooves of its host. They feed by extending their stomachs over a great variety of plants and animals, dead or alive. Usually having 5 arms and sometimes found with less or more. Pg. 271

Specimen#3

SOFT SEA STAR

PHYLUM: Echinodermata

SPECIES: Astrometis sertulifera

GEOGRAPGIC RANGE: They can be found in all areas from Washington to Baja and have been observed at Corona del Mar and La Jolla.

HABITAT: Around zone 4 and tide pools and protected rocky shores

NICHE: Omnivore and scavenger

ADDITIONAL NOTES: The arms numbers are 5 or 6 and the aboral surface is green to brown with orange and blue spines. The skeleton is composed of isolated ossicles and the arm span is almost 20 cm. . After the digested food is absorbed, the sea star pulls its stomach back inside its body and moves on. The skeletal structure allows specimens to readily shed their arms when handled. Pg.272

Specimen#4

SCALED WORM SHELL

PHYLUM: Mollusca

SPECIES: Serpulorbis squamigerus

GEOGRAPHIC RANGE: The know distributional range has gone from central to Baja California and around Corona del Mar.

HABITAT: They are abundant in all avalible habitats but are common on the under surfaces of rocks in the low tide zone.

NICHE: Passive filter feeder

ADDITIONAL NOTES: They are normally in large colonies attached to rocks and pilings . These animals are enclosed in twisted while calcareous tubes and are often mistaken for polychaete annelids. Pg. 134

Specimen#5

SEA HARE

PHYLUM: Mollusca

SPECIES: Aplysia californica

GEOGRAPHIC RANGE: This is an abundant species on all seashores of California from Elkhorn Slough to San Diego.

HABITAT: Often observed swimming in shallow water or stranded on the beaches at low tide. They live in the intertidal zone and subtidally to about 40 feet.

NICHE: Grazing herbivores

ADDITIONAL NOTES: The body may grow to a length of 45 cm. And like the octopus, it ejects a purple fluid when handled or disturbed. The body is brown, or mottled brown with almost black. They eat various kinds of algae and eelgrass. Sea hares can eat 10 percent of their weight a day. They have a complicated multi system stomached digestive system so they can cope with such food. Sea hares are simultaneous hermaphrodites which means they can act as male and female at the same time, however cannot fertilize their own eggs. A single sea hare can lay millions of eggs at once, which look like yellowish, yellowish green, to pick eggs that kind of resemble spaghetti. Pg.144

Specimen#6

GIANT KEYHOLE LIMPET

PHYLUM: Mollusca

SPECIES: Megathura cremulata

GEOGRAPHIC RANGE: It is known for distribution is from central to Baja California and Montery bay and Alamitos Bay.

HABITAT: They have been observed in all available habitats but known to live in the low intertidal zone and to depths of 110 feet on rocky substrates.

NICHE: Grazing herbivore

ADDITIONAL NOTES: They often attain the length of 10 cm. They have an oval shaped shell. In color they are noted, as the mantle is deep unicolorous black, or a tan with dark brown markings. Pg. 130

Specimen#7

PURPLE SEA URCHIN

PHYLUM: Echinodermata

SPECIES: Stronglylocentrotus purpuratus

GEOGRAPHIC RANGE: Known from Alaska to Southern California, and Cook’s inlet, and Baja California.

HABITAT: Depth range from the low intertidal zone to 10 m. usually found in tide pools in-between rocks.

NICHE: Grazing herbivore; passive carnivore

ADDITIONAL NOTES: Diameter about 3 to about 8.5 cm. , short purple spines. The color ranges from a light purple to a dark purple, They have a complex five-part jaw the five-part jaw described by Aristotle and know as Aristotle’s lantern. The jaw is located on the oral surface. The three jawed pinching organs are called the pedicellariae which they use to clean and defend themselves with and it contains a powerful toxin. Kind or resembles the look of a pincushion. The spines and tube feet are what help the urchin to gather food. They feed on algae. Pg.281

Specimen#8

STRIPPED SHORE CRAB

PHYLUM: Arthropoda

SPECIES: Pachygrapsus crassipes

GEOGRAPHIC RANGE: It is know to be anywhere from Oregon to Baja California.

HABITAT: It is omniprescent in tide pools and among rocks and jetties.

NICHE: Primarily a scavenger

ADDITIONAL NOTES: The carapace varies in color from green to red, and is distinguished from other grapsids by the transverse stripes on the dorsum of the carapace. The carapace of mature individuals is between 3 – 4 cm. in length. Like lobsters and shrimps, a female crab carries her eggs under her abdomen for protection until they hatch into small larvae. Crabs have a hard outer shell, or exoskeleton, that protects them from crashing waves as well as from biting fish. They are very agile and can scamper rapidly over the sharp, jagged rocks on their nimble feet. The tips of their walking legs have short stiff spines that grab on to the rock and prevent wearing away of the legs on the rough surface. Pg. 240

Specimen#9

CONSPICUOUS CHITON

PHYLUM: Mollusca

SPECIES: Stenoplax conspicua

GEOGRAPHICAL RANGE: From Southern California and especially in Dana Point.

HABITAT: Found on the underside of large rocks during the daylight hours. Found in the low tide zone.

NICHE: Grazing Herbivores

ADDITIONAL NOTES: They have an eight part calcareous shell that is embedded in a leathery skin. They are nocturnal. It is negatively phototaxic and as a consequence will be found under rocks. Their color is a gray green with a pinkish dorsal and color of the girdle is gray green. Chitons are slow moving, but are not immobile. A chiton can roll itself up into a ball, exposing only the hard shell, when it feels threatened. Chitons feed upon seaweed and algae. Chitons clamp themselves to rocks using their foot and their “girdle” (the part of the shell that encircles the chiton & 8 plates) to withstand weather & wave action. It crawls by means of muscular undulations of the foot. The mouth, located in front of the foot, contains a toothed scraping organ, the radula. Mature individuals are almost 10 cm. in length. Pg.124

Specimen#10

CALIFORNIA SPINEY LOBSTER

PHYLUM: Arthropoda

SPECIES: Panulirus interruptus

GEOGRAPHICAL RANGES: San Luis Obispo, California to Rosalia bay and Baja California

HABITAT: Depths range from 10 to 60 m. Tide pools but usually small if seen there.

NICHE: Scavengers

ADDITIONAL NOTES: Spines cover their long antennae and the front of their bodies. They lack having the large claw characteristics of the Atlantic lobster. Mostly nocturnal and foraging at the bottom at night. Can reach the length to about 60 cm. and can weigh 25 pounds. Mature individuals can be observed in fish markets and occasionally a specimen is observed in the water at times of the lowest tide. 45 species of spiny lobsters of the Palinuridae family. The heavily armored antennae can inflict a tearing wound when the lobster thrashes them whip-like against an opponent. Unlike the American lobster, spiny lobsters seem to enjoy each other’s company and often share their dens. They may warn other lobsters of danger with loud rasping sounds they make by rubbing the base of their antennae against serrated ridges below their eyes. Hundreds, sometimes thousands, of spiny lobsters form columns of as many as 60 lobsters to migrate en masse, often after a storm.

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