Category: MOLLUSKS


TAXONOMY
Phylum: Mollusca
Class: Gastropoda,
Order: Nudibranchia (sea slugs)
Family Tethydidae

Genus/ species: Melibe leonina

YouTube VIDEO  http://youtu.be/Xe2bM2kKm-U

GENERAL CHARACTERISTICS: Color a translucent gray, greenish-gray, or yellowish-gray, with opaque brown hepatic diverticula. Melibe leonina has 4-6 pairs of large, leaflike or paddlelike cerata in two rows down its dorsum and a large oral hood with two rows of filiform tentacles around its margin.

Length up to 102 mm long (4 in), 25 mm (1 in) wide, and 51 mm (2 in) across the expanded oral hood.

DISTRIBUTION/HABITAT: West coast of North America from Alaska to Baja California in eelgrass beds, kelp (especially Macrocystis) beds, harbors. When swimming it is usually upside-down, and undulates back and forth.

DIET:  M. leonina feeds on Copepods, amphipods, and ostracods, as well as small post-larval mollusks. They firmly attache itself to a kelp blade and then sweeps its raised hood downward or to the side. When food lands on the lower surface of the hood, the melibe sweeps together the two sides of the hood, and its fringing tentacles lock in the prey. The hood contracts to force the captured food into the M. leonine’s mouth.

REPRODUCTION and DEVELOPMENT:  M. leonine are hermaphrodites (they have both male and female sexual organs), and fertilization is internal. The animal can lay as many as 30,000 eggs, which are enclosed in a long, gelatinous ribbon.

REMARKS:  Noxious secretions of the melibe smell like watermelon, according to aquarists. They are gregarious animals and probably use it to keep together as well as for defense.  Most predators avoid the noxious secretions of nudibranchs; but the kelp crab is an exception. 

This species has been used for neurological research.

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References

California Academy of Sciences, Steinhart Aquarium, Water is Life 2019

Ron’s WordPress Shortlink wp.me/p1DZ4b-fW

Ron’s flickr www.flickr.com/photos/cas_docents/sets/72157608597736188/

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/me…

EOL eol.org/pages/454874/details

 

VIDEO LINK https://www.flickr.com/photos/cas_docents/5443993471/in/album-72157659528522603/

YOUTUBE LINK  http://youtu.be/ei1Pe7r2kdI

TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Octopodidae
Genus/:Species: Enteroctopus dofleini

GENERAL CHARACTERISTICS: Giant Pacific octopuses are the largest species of octopus. Their large bulbous “head” (mantle) has 8 tentacles each bearing up to 280 suckers which have thousands of chemical receptors used to help detect prey. Very large specimens can have a tentacle span of more than 9 m (29 feet) from tip to tip, and weigh more than 45 kg (100 pounds).

DISTRIBUTION/HABITAT: Range throughout temperate Pacific waters, from southern California north to Alaska, west to the Aleutian Islands and Japan.
Giant Pacific octopuses are generally found in tidal pools and up to depths of 110 m (360 ft), although they can also reside in deeper waters of up to 1,500 m (4900 ft). They often live in dens or lairs, under boulders, and in rock crevices. Ideal habitat for this species includes a soft substrate of mud, sand or gravel that includes large boulders for creating dens.

DIET IN THE WILD: E. dofleini feed mostly on crustaceans (shrimps, crabs, scallops,) and mollusks (abalones, clams); fish and other octopuses are also Shells of prey that are difficult to pull or bite open can be “drilled” in order to gain access to the soft tissue: salivary secretions soften the shell, and a tiny hole is created with the radula (a toothed, hardened “tongue”). The octopus then secretes a toxin that paralyzes the prey and begins to dissolve it. The shell is pulled apart and the soft tissues are consumed.

REPRODUCTION: Lays up to 75,000 eggs in small caves where the female defends them until they hatch, which takes up to six months. The hatchlings then drift in ocean currents for several months, settle to the seafloor. Reproduction starts when they are one year old.

MORTALITY/LONGEVITY: Predators include marine mammals (harbor seals, sea otters, and sperm whales). Also, occasionally are eaten by others of their own kind and are caught commercially. Life span is 4.5 to 5 years in the wild and captivity.

REMARKS:

They can move more than 700 pounds using all of their arms.

It is considered one of the most intelligent of all invertebrates.

References

California Academy of Sciences, Steinhart Aquarium 2018

Ron’s WordPress Link  http://wp.me/p1DZ4b-h5

Arkive www.arkive.org/north-pacific-giant-octopus/enteroctopus-d…

ADW animaldiversity.org/accounts/Enteroctopus_dofleini/

Cephalopod Page www.thecephalopodpage.org

YOUTUBE LINK  http://youtu.be/ei1Pe7r2kdI

Ron’s flickr link  http://www.flickr.com/photos/cas_docents/sets/72157608597736188/with/5443993471/

TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Sepiida
Family:i Sepiidae

Genus/species: Metasepia pfefferi

Ron’s flickr VIDEO LINK    https://www.flickr.com/photos/cas_docents/41499251715/in/album-72157659465376212/

GENERAL CHARACTERISTICS: The normal base color of this species is dark brown. Individuals that are disturbed or attacked quickly change colour to a pattern of black, dark
brown, and white, with yellow patches around the mantle, arms, and eyes. The arm tips often display bright red coloration to ward off would-be predators. The mantle and head are covered with flap-like, fleshy protuberances (papillae),and a V-shaped fleshy ridge runs along the underside. Yellow fins flutter along the sides to propel the animal slowly though the water or along the substrate.

Max mantle length: 6–8 cm (2.5-3.14 in)

DISTRIBUTION/HABITAT: The Flamboyant Cuttlefish is found from Indonesia, the Philippines, Papua New Guinea, to Australia. Found in shallow, low-energy tropical marine waters (3 to 85 m) with mud, sand, or coral rubble
substrate.

DIET IN THE WILD: M. pfefferi are active diurnal foragers on a variety of foods, especially fish and crustaceans, including “hard-hitting” mantis shrimp. Encircling the mouth are 8 purplish, blade-like arms with rows of suckers used to manipulate prey and 2 flattened, retractable tentacles which can be rapidly extended to catch prey.

LIFE SPAN. 18 and 24 months

CONSERVATION: IUCN: Data Deficient   <a href=”http://www.iucnredlist.org/details/162681/0″ rel=”nofollow”>www.iucnredlist.org/details/162681/0</a>. 2012

REMARKS: One researcher recently claimed M. pfefferi to be the only cuttlefish known to be toxic, asserting that muscle tissue of this species possesses a toxin as deadly as that of its cephalopod relative, the blue-ringed octopus!

They also can produce ink as a defense.

Animals displaying this color pattern have been observed using their lower arms to walk or “amble” along the sea floor while rhythmically waving the wide protective membranes on their arms. It has been suggested that this behavior advertises a poisonous or distasteful nature.

Ron’s WordPress Sshortlink  http://wp.me/p1DZ4b-hJ.

One of the most well known features of cuttles is the cuttle bone, which is often used by pet owners to provide calcium for caged birds. Cuttlefish use this multi chambered internal calcified ‘shell’ to change buoyancy by quickly filling or emptying the chambers with gas. Interestingly, while the cuttle bone of most cuttles is as long as the animal’s mantle, the diamond shaped cuttlebone of the Flamboyant is disproportionately small, thin, and only 2/3 to ¾ of the mantle length. The small size of the cuttlebone may make swimming difficult and may accounts for the Flamboyants preference to ‘walk’ along the bottom.

References: California Academy of Sciences Steinhart Aquarium, Hidden Reef  Richard Ross

Advanced Aquarist Volume IX › October 2010 › Aquarium Invertebrates: Metasepia pfefferi – the aptly named Flamboyant Cuttlefish. www.advancedaquarist.com/2010/10/inverts.      Great overview

Animal Diversity Web animaldiversity.org/accounts/Metasepia_pfefferi/

Ron’s WordPress Sshortlink wp.me/p1DZ4b-hJ.

Ron’s flickr https://www.flickr.com/photos/cas_docents/6179762044/in/album-72157659465376212/

 

TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Subclass: Pteriomorphia
Order: Pectinoida
Family: Pectinidae

Genus/species: Crassedoma giganteum

GENERAL CHARACTERISTICS: Giant Rock Scallops have coarsely ribbed shells called valves. The upper valve is usually scallop-shaped but the lower valve takes the shape of the substrate to which it’s attached. Between the valves, the margin of the orange mantle can be seen, with a row of tiny blue eyes and a sparse fringe of short tentacles

SIZE: up to a diameter of 15 centimetres (5.9 in) in the intertidal zone and 25 centimetres (9.8 in) in the subtidal zone.

DISTRIBUTION: Pacific coast California and Canada and south to Baja California and Mexico usually inside crevices and under boulders, or cemented to rock surfaces, Depth down to about 80 metres (260 ft).

DIET IN THE WILD: C. gigantea is a suspension feeder, filtering phytoplankton from water as it passes over the gills. The particles are moved by cilia along grooves to the mouth where edible matter is separated from sediment particles. The waste is incorporated into mucous balls which are removed from the mantle cavity periodically by a clapping of the valves.

REPRODUCTION: The sexes are separate in C. gigantea. The veliger larvae that develop from the eggs form part of the zooplankton for about 40 days before settling, undergoing metamorphosis and beginning to form a shell. Juveniles are free-living, are able to swim and can attach themselves temporarily to the substrate by byssus threads. 

PREDATORS: Sunflower starfish (Pycnopodia helianthoides) and purple sea star (Pisaster ochraceus).

REMARKS: The scallops eyes can’t see images as we can, but they allow the scallop to adjust to the brightness of light. This can be of benefit when it opens its protective shells to pump water over their gills filtering food thus exposing its soft body parts to predators. As a predator approaches at least some light will be blocked and the scallop closes it shells.

References

California Academy of Sciences Steinhart Aquarium Dr Charles Delbeek 2018

Ron’s flickr  https://www.flickr.com/photos/cas_docents/39884701811/in/album-72157675344287795/

iNaturalist  www.inaturalist.org/taxa/54526-Crassadoma-gigantea

Global species: www.globalspecies.org/ntaxa/913354

Reef.org www.reef.org/resources/galleries/invertebrate?page=1

Eyes. www.chuckkopczakphotography.com/blog/2015/11/13/the-eyes-…

TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Vetigastropoda
Superfamily: Trochoidea
Family: Turbinidae

Genus/specie: Megastraea undosa

GENERAL CHARACTERISTICS: The Wavy Turbin Snail has a heavy, sculptured shell with undulating ridges in a turbinate-conical shape with a thick, pearly lining.
The light brown or tan shell color is caused by the fibrous periostracum covered with coralline algae and other epiphytes.

Size: up to 6 inches

DISTRIBUTION/HABITAT: Found from Point Conception and the coastal Channel Islands to northern Baja California, Mexico. They range from the intertidal zone down to depths of over 250 feet.

DIET IN THE WILD: M. undosa are herbivores feeding on various types of algae.

REPRODUCTION; Year around with peaks in spring and fall.

CONSERVATION: Because wavy turban snails are hand-picked by divers, the fishery is at low risk for bycatch .
Wavy turban snails are abundantly available and have a high productivity rate, so over- harvesting is less likely.

REMARKS: The shells of wavy turban snails are used to make buttons!

The meat has an abalone-like texture and taste; foot of the snail is processed and sold to restaurants as an abalone-like product, “wav alone”.  They can be prepared many ways: grilled, sautéed, battered and fried, in pastas, in chowders and soups, and in stir fries.

References

California Academy of Sciences Steinhart Aquarium Tidepool 2017

Ron’s flickr https://www.flickr.com/photos/cas_docents/34539982943/in/dateposted-public/

Spearboard.com www.spearboard.com/showthread.php?t=99314

U of CA San Diego caseagrant.ucsd.edu/sites/default/files/fact-sheet-wavy-t…

Gastropods.com www.gastropods.com/2/Shell_292.shtml

Ron’s WordPress Shortlink  http://wp.me/p1DZ4b-1Qf

TAXONOMY
Kingdom:Animalia
Phylum: Mollusca
Class: Polyplacophora
Order: Neolocrcata
Family: Acanthochitonidae

Genus/species: Cryptochiton stelleri

GENERAL CHARACTERISTICS: The gumboot is a long, meatloaf-like chiton with a brick-red mantle covering the eight plates of their jointed shell. The shell plates are completely internal in adults. This is the largest chiton in the world; it grows to 33 cm (13 in). It may live up to 20 years.

Gumboot Chiton32905300616_5519787bf4_k

DISTRIBUTION/HABITAT: Found from Alaska west to Japan and south to the Channel Islands, the gumboot chiton inhabits rocky intertidal areas to 80 feet, often among kelp.

DIET IN THE WILD: A nocturnal grazer, it used its long, tongue like radula to scrape off the upper tissue of soft red algae and various coralline algae, giant kelp and oarweed, in the process getting nutrition from the tiny organisms that live on the algae’s surface. The radula is covered with tiny, very hard teeth that give it the texture of rough sandpaper.

2997683294_70ce9df050_b

PREDATORS: Its only known predator is the large rock snail Ocenebra lurida, which drills through the chiton’s outer covering with its radula to feed on the flesh below.

REPRODUCTION: The sexes are separate; eggs and sperm are broadcast into the sea.

CONSERVATION: IUCN Not Evaluated

REMARKS: California coastal Native Americans may have eaten them, as shell plates have been found in middens. An Academy researcher states that this chiton was a food of the last resort, “tastes ghastly!”

The radulae of chitons and limpets are unique in having a high percentage of iron magnetite incorporated into the feeding teeth. Magnetite is so named because it is strongly attracted to magnets, and you can actually pick up this chiton’s teeth and radula with a magnet!
When exposed to air during low tide, the gumboot chiton can breathe at a reduced rate by absorbing oxygen from the atmosphere.

The red fuzzy stuff often on the surface is red algae. About 20 species of red algae are known to live on subtidal individuals. This chiton’s diet of red algae also contributes to its color.

Chitons are among the most ancient living mollusk groups, dating back to 400–500 million years ago.

References

California Academy of Sciences Steinhart Aquarium Tidepool 2017

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/gu…

ADW animaldiversity.org/accounts/Cryptochiton_stelleri/

EOL eol.org/pages/403806/details

Ron’s WordPress shortlink  http://wp.me/p1DZ4b-1LP

Ron’s flickr https://www.flickr.com/photos/cas_docents/32905300616/in/album-72157660640336765/

 

 

TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Octopodidae

Genus/species: Octopus bimaculoides

GENERAL CHARACTERISTICS: Usually a mottled-brown color with a dark deep-blue ovoid spot under each eye. It can use the chromatophores in its skin to change its color and texture when hunting for prey or hiding from predators (including its eye spots).

Size to 3 feet (including its body and outstretched arms)

2spot Octopus25853155380_e17555cef7_k

DISTRIBUTION/HABITAT: Found from central California to northern Baja California among reefs and pilings on the sea floor.

DIET IN THE WILD: Limpets, black abalone, snails, clams, hermit crabs and small fishes. Prey are subdued with a parrotlike beak and toxic secretions through a salivary gland. Their food is then scraped out with a radula.

REPRODUCTION: Females lay up to 150,000 eggs under rocks from late winter to early summer, then brood on them continuously for 2-4 months. During brooding, the female doesn’t feed and usually dies when eggs hatch.

Two-spot Octopus26033508582_96a0c27793_k

Life Span: One-and-a-half to two years.

PREDATORS: Moray eels, scorpionfish and humans. Arms are often lost during a fight with a moray eel and can regenerate.

CONSERVATION: O bimaculoides is very sensitive to impaired water quality, thus water pollution is an issue for its survival.

References

California Academy of Sciences Steinhart aquarium Animal Attractions 2016

Ron’s flickr  https://www.flickr.com/photos/cas_docents/26033508582/in/album-72157629304397467/

Animal Diversity Web animaldiversity.org/accounts/Octopus_bimaculatus/

Jaffe Laboratory jaffeweb.ucsd.edu/node/twospottedoctopus

Monterey bay Aquarium  www.montereybayaquarium.org/animal-guide/octopuses-and-ki…

Cabrillo Marine Aquarium www.cabrillomarineaquarium.org/exhibits/socal-species-det…

Ron’s WordPress Shortlink  http://wp.me/p1DZ4b-1G9

 

 

TAXONOMY
Kingdom:Animalia
Phylum: Molluska,
Class: Gastropoda
Family: ‪Aeolidioidea‬ (superfamily of sea slugs, the aeolid nudibranchs)

Genus /species: Aeolidia papillose

GENERAL CHARACTERISTICS: Its color appears to be quite variable, depending upon locale and food resources. This large aeolid grows to about 10 cm(4 in) in length and its body is covered with close obliquely arranged rows of flattened cerata.

Aeolidia papillose 6873953510_5aecc605bd_k

DISTRIBUTION/HABITAT: Common on the Atlantic coast of Europe and North America and the Pacific coast of North America. Also from  both west and east coasts of South America  Found on rocks, or may be on floats or docks often near its preferred prey. Intertidal to 380 m (116 ft) deep.

DIET IN THE WILD: Feeds almost exclusively on sea anemones.

MORTALITY/LONGEVITY: This species is famous for obtaining undischarged cnidae (cells which bear nematocysts) from its Cnidarian prey and moving to the tips of the cerata , where they are likely used for defense. If disturbed they sometimes wave their cerata. If one of the cerata is broken off, muscles within it contract, expelling the nematocysts, which then discharge . The chemical composition of A. papillosa mucus changes and does not trigger a discharge of nematocysts in the sea anemone.

REPRODUCTION/: Nudibranchs are hermaphroditic, and thus have a set of reproductive organs for both sexes, but they cannot fertilize themselves.

REMARKS: Their eyes are simple and able to discern little more than light and dark. The eyes are set into the body, are about a quarter of a millimeter in diameter, and consist of a lens and five photoreceptors.

Tidepool.

References

Ron’s flickr https://www.flickr.com/photos/cas_docents/6873953510/in/album-72157660640336765/

Encyclopedia of Life eol.org/pages/402852/details

Ron’s WordPress shortlink http://wp.me/p1DZ4b-1CP

 

TAXONOMY

Phylum: Mollusca
Class: Bivalvia
Order: Filibranchia
Family: Mytilidae

Genus/species: Mytilus californianus

GENERAL CHARACTERISTICS: California mussels are relatively large mussels, with a blue-black shell with strong radial ribs and irregular growth lines. Maximum size is about 13 cm (5 in). The shell surface is often worn and eroded.

 

DISTRIBUTION/HABITAT:  California mussels form extensive beds, commonly mixed with gooseneck barnacles (Pollicipes polymerus). Attached firmly to the substrate by tough proteinaceous byssal threads, mussels are able to thrive in the most surf-swept areas. Mussel beds break the force of waves and collect organic debris, and so provide shelter and food for other organisms. Worms, chitons, snails, clams, isopods, crabs, and sea cucumbers are among the invertebrates found in mussel beds.

The upper limit of the mussel beds is set primarily by physical factors, particularly time out of water. The lower limit is set in part by the predation of the ochre star (Pisaster ochraceus), which practices vertical foraging, moving up and down with the tides. Mussels range from low intertidal to 40 m (131 ft) deep and are common in surf-swept, rocky areas, and are found from Alaska to southern Baja California.

 

DIET IN THE WILD: Mussels filter fine organic detritus and living plankton from sea water. A mussel filters 1.8 l to 2.8 l (2 to 3 qts) of water an hour.

        

PREDATORS: California mussels are favored food items of seas stars (especially ochre stars), crabs, predatory snails, shorebirds, sea otters, and humans. Sea otters have devastated formerly extensive mussel beds in Monterey Bay.

 

REPRODUCTION: Mussels are either male or female. During breeding they broadcast sperm or eggs into the sea where fertilization occurs. They spawn November to May. Mussel larvae are free-swimming for about four weeks. After settling and attachment they grow to full size in about three years.

 

Remarks

  • The California mussel attaches to rocks by fibers called byssal threads. These threads are produced as a liquid by the byssal gland. The liquid runs down a groove formed by the foot. When the foot pulls back, exposing the liquid to sea water, the liquid solidifies into a thread.
  • A large mussel moves by breaking old threads, then attaching new ones to another spot; a small mussel creeps around on its foot.
  • By filtering algae spores from the water, mussels may limit algae growing around mussel beds.
  • Coastal areas are at risk from development and pollution. Mussels are also at risk because many of their homes are in danger of being ‘loved too much’ by too many tide pool visitors.

References

California Academy of Sciences Docent Guide 2015

flickr http://www.flickr.com/photos/cas_docents/5118861762/in/set-72157608597736188/

WordPress shortlink:  http://wp.me/p1DZ4b-wF

Encyclopedia of Life eol.org/pages/449960/details

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/ca…


TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Family: Dorididae

Genus/species: Peltodoris nobilis

GENERAL CHARACTERISTICS: Color variable: may be pale yellow to a deep rich yellow or orange. Back is covered with tubercules and dark spots. Fleshy antennae (sensory organs) and a rosette of gills protrude from the back of a sea lemon’s slim, flat body. One of the largest of all nudibranchs; 4 to 4.5 inches (10 to 11.5 cm).

Sea Lemon Nudibranch3124713462_3c7ecb3ff5_b

DISTRIBUTION/HABITAT: found from Alaska to Baja California in
rocky areas, mostly at low intertidal and subtidal depths to 300 feet (91 m). Often seen on harbor pilings. California is well-known for the diversity of nudibranchs found in its coastal waters.

DIET: uses a file-like radula to eat sponges.

Sea Lemon Nudibranch3123887143_7648580fb9_b

REPRODUCTION: like all nudibranchs, is hermaphroditic and can produce both sperm and eggs.

LIFE SPAN: approx. one year

CONSERVATION: abundant.

REMARKS: P. nobilis is one several dorid nudibranchs with a fruity, distinct lemon scent usually given off when the animal is handled, thus its common name. When concentrated, the odor repels many predators.

COLOR OF LIFE Note: Concealment by camouflage. Has a bumpy surface typical of those corals and sponges.

Sea Lemon Nudibranch2997671850_b9f4546718_b

References

California Academy of Sciences Color of Life docent training 2015

Ron’s flickr  https://www.flickr.com/photos/cas_docents/2997671850/in/album-72157608597736188/

Metropolitan Oceanic Institute and Aquarium  www.svsu.edu/~tkschult/moia/sea-lemon.html

Monterey Bay Aquarium  www.montereybayaquarium.org/animal-guide/invertebrates/se…

EOL eol.org/pages/451875/details

Ron’s WordPress shortlink  http://wp.me/p1DZ4b-1AF