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Ask a Marine Scientist: answers to Mollusca questions! Index To Questions BIVALVES GASTROPODS CEPHALOPODS GENERAL
BIVALVES
A. You may find some interesting information in the following journal article:
A. Black pearls are generally produced by the giant clam of the South Pacific, Tridacna. These giant clams may attain a length of over 1 meter (39 inches) and a weight of over 1100 kilograms (2400 pounds). The pearls are produced by these clams in the same way that other bivalves produce pearls. If an irritant enters the clam's shell, such as a grain of sand, the clam will produce the pearl material around the sand in order to protect itself. In the case of an oyster, the pearl is usually whitish in colour, although many different colour variations can be produced. The giant clam, Tridacna produces pearls that are very nearly black in colour. There is variation among these black pearls too, and a perfectly black and well formed pearl can fetch many thousands of dollars. Recently, researchers as Simon Fraser University have perfected a method by which an abalone (another type of mollusc) can be made to produce black pearls.
A. This is quite a complex question! You won't find much information about this topic unless you look in very specialized texts and scientific journals. There are many scientists that use bivalves like clams or mussels to study the nervous system (neurobiology) as well as the secretion of neurohormones and peptides.For example, the mussel, Mytilus edulis has been shown to contain serotonin and dopamine, which are complex protein molecules. Norepinephrine has also been found in the tissues of this mussel, and it interacts with both serotonin and dopamine. The heart of Mytilus edulis is excited by acetylcholine, and is inhibited by 5-HT. There are dozens of other hormone-like compounds that have been found in bivalves. They function together in very complex ways, and are involved in feeding, digestion, muscle movement, respiration, growth, reproduction and more. As far as HOW they secrete these hormones, this is a topic that is even more complex!!
Q: Looking for the life span of the soft clam. From spawn till death and what size they are at various stages in their life cycle. Thank you. A: Common names for animals usually tend to be a bit ambiguous, since there are many different species of clams which could be known as the soft clam. The species you're referring to could be Mya arenaria, the soft-shelled clam. This clam reaches a length of 15 cm (6 in), and is thin, oval, rounded in front and somewhat pointed at rear. There is a gape at both ends of the shell. It is found in the muddy intertidal zone in both marine and brackish areas, burrowing to 25 cm (10 in) depth. This clam is of commercial importance on the east coast of the United States and is also known as the Long Neck Clam or Steamer Clam. M. arenaria has a 2-4 week planktonic period before settling out in the intertidal zone. The size at settling varies geographically, from 0.4 mm in Norway to 0.5 mm in Nova Scotia. First reproduction generally occurs when the clam is between 2-4 years and at a size of between 20-45 mm, although this is geographically variable as well. The soft-shelled clam has been recorded to live up to 28 years.
A. All shells of animals in the phylum mollusca (snails, oysters, clams, etc. )are composed of basically the same materials. Calcium carbonate is laid down in layers by the shell glands of the mantle tissue. The calcium carbonate layers are generally of two types: an outer, chalk-like prismatic layer and an inner pearly lamellar or nacreous layer. The layers may incorporate a substance called "conchin", often in order to help bind the calcium carbonate crystals together. Conchin is composed largely of quinone-tanned proteins. Some shells may also contain pigments, which accounts for the fabulous colours of some sea shells. These shell pigments may include compounds like pyrroles and porphyrins, which are proteins.
A: There are many different types (species) of oysters. One of the most common oysters that you'll see on the west coast does not really belong there. It is Crassostgrea gigas, or the Japanese oyster. It was introduced to the west coast in 1902 or even earlier, and populations established themselves from B.C. to California. Our native west coast oyster, Ostrea lurida is smaller, and is much rarer.
Q: How is a clam's age determined and what is the life expectancy of a clam? A: There are a few ideas on the life span of clams depending on the species. Here are a few that I could find ages on. The giant white clam has been determined to be 20 years, the surf clam- 37 years, and Meretrix (a clam from India)- 7-8 years. One way that scientists determine age is by providing the clams with marked calcium that they make their shells with. They determine how much of the shell is produced in a certain amount of time, then extrapolate the age by determining how much shell the clam has and how long it would have taken the clam to make it.
Q: I want to know whether the Ribbed Atlantic Mussel is edible or not? A: Yes the Ribbed Atlantic Mussel is
edible. You cannot harvest this mussel at low tide though. At
low tide the mussel closes its shell and the waste products that
accumulate are toxic to humans. I guess the best bet would be
to harves these mussells when they are submerged underwater and
not sitting high and dry.
Q: For oysters feeding is
depedent upon teperature; more food is consumed at higher temperatures
than at lower. Why is that? A: Oysters eat more as the
temperature goes up because the increased temperature increses
their metabolism. Basically this means that as it gets warmer
they need to eat more to keep their weight up.
Q: Do oysters reproduce sexually or asexually? A: Oysters reproduce sexually
by usually releasing the gametes into the surrounding waters
where they are fertilized. Some oysters can become male or female
as the need arises for reproduction purposes. GASTROPODS
A. Goodness! If we gave you all of the information that we have on conch shells, it would fill a book! Hopefully, you'll be satisfied with the following, and do some more research on your own.Conch are Molluscs, more specifically Gastropods which include sea snails, limpets and nudibranchs. There are many different species of conch, and they occur in tropical waters all over the world. For example, in the Caribbean, you might find the Queen Conch (Strombus gigas), the West Indian Fighting Conch (Strombus pugilis), the Hawkwing Conch (Strombus raninus) or the Milk Conch (Strombus costatus) There are many other species as well. Each different species of conch has a different shaped shell. The Queen Conch is one that you are probably familiar with, because it has a particularly large and attractive shell. These conchs are eaten by people in the Caribbean, and the shells often find themselves taken home by tourists. These is a danger to this, however --- The Queen Conch is relatively slow growing, and it can be overfished from local areas very quickly. Buying pretty tropical shells is a much too easy way for us to destroy delicate coral reef areas that exist far from our homes.
A: You found the egg case of the moon snail, Polinices lewisii. One of the largest intertidal snails in BC, the moon snail has a beautifully rounded shell with a low but distinct spire. The shells are usually light beige or brownish in colour, with a large aperture (opening) and very smooth interior. When the snail is extended, it covers almost the entire shell with its mantle (the outer edge of its body). P. lewisii feeds on clams and other molluscs by drilling into their shell. The shells of their prey are often found on the beach, with a neat little hole in them. Moon snails lay their eggs in the collarlike configuration which you described. The egg case is composed of two layers of sand held together by mucous secretions, with the eggs sandwiched in the middle. These egg cases feel almost rubbery to the touch, and are quite durable. I'm not surprised that you thought they looked like something someone dropped, because they are so perfectly and oddly shaped that they look artificial.
Q: How do conk shells form? A: That is a really good question!
Believe it or not, those large conch shells are formed by a soft-bodied
animal. The animal that makes it is a kind of snail (Phylum Mollusca:
Class Gastropoda), and the shell is part of its body. The shell
provides the snail with protection from other animals that try
to eat it. So even though it is really awkward for the snail
to carry its shell, it is very valuable and practical.
Once the juvenile snail hatches from its tiny egg , it begins feeding and starts to grow. As the snail grows it secretes a substance around part of its body which hardens to form the shell. Usually calcium carbonate and other minerals are secreted into a protein matrix in the area that is called the mantle. As the snail grows, the shell is pushed upward and more and more of the shell material is added to the bottom edge. Most conch shells are spiralled, and you should notice that the spirals get bigger at the bottom. The bottom part of the shell is the newest part, the place where the most recent growth has occurred.
Q: Limpets: how do limpets get back home? Retrace their "steps", or some other way? I understand it has been proven they return to a certain spot after a grazing trip across the rock, but how do they do it??? A: Studies on the homing ability of limpets indicate that it primarily depends on chemical cues laid down in the mucus that the limpet leaves behind during its feeding excursions. It has been suggested that the homing ability of limpets (ability to retrace their steps) helps to establish a grazing territory, and may reduce desiccation and predation because of the tight fit into the home site. In fact, in one study they found that in homing limpet species the mucus stimulated algal growth.
Q: Here on the South African shore, lives a false limpet called Siphonaria. It is nixious but also camouflaged. It does not adhere to rocks as well as limpets do and can be removed with your finger. Why would it need to be camouflaged when nothing to our knowledge eats it? A: I did some research on the tropical limpet, Siphonaria, but I did not come across any information on its predators. However, there are some speculations as to why they are a well camouflaged species. Many studies on tropical gastropods, have shown that their main predators are visual predators, such as fish. Since Siphonaria is a high intertidal species, they would only be submerged during high tide. When they are covered by water they are susceptible to fish predation. Since fish are visual predators, it would be beneficial to be camouflaged, so that the limpets are difficult to see. If the predators of the limpets are only present, at high tide, under the water, this may be a good explanation as to why you have not witnessed any predation on Siphonaria. Another possibility, is that their predators are migratory birds, and you would only notice bird predation when these migratory birds are present. Sorry I could not give you a more precise explanation, but I hope this helps!
Q: I have typed Abalone into a bunch of web sites and haven't gotten any really specific information. I have gathered that sea otters eat abalone and that I guess it is a mollusk but how big are they? what do they eat? what color or size are they? A: One difficulty with searching
for information on marine animals on the internet is that you
usually get Here is some information on
a common abalone species found in the Pacific Northwest, it's
common name
Q: We have been operating our aquarium for three months and have some white spherical organisms growing on the sides of the tank. Any idea what they are? Also what is the best way to get ride of bristleworms in the tank? A: To answer your first question
it is very possible that you have a species of snail living on
the sides of your aquarium.. As for getting rid of the bristleworms
I found an excellent website that provides some answers for you
and methods of control for the future.
check this site
CEPHALOPODS Q: How can I tell if an octopus is angry? A: Most Octopi change color
if they are angry or irritated. In the case of the Blue ringed
octopus it can get almost glowing blue ringed spots on its body
when its mad. If it then bites you there is a good chance that
you will eventually die. An Octopi may also blast a jet of ink
if they are fearful or angry at something, although the ink blast
though is usually to escape from predators.
A: We'd have to disagree that no one has ever seen a giant squid, Architeuthis sp., in its natural environment. There are numerous examples of people seeing living giant squid in the ocean. For example, in 1966, a 47 foot long Architeuthis was caught by a U.S. Coast Guard vessel off the Bahamas after it had been involved in a fight with a sperm whale. Many other instances record people seeing giant squid near the surface of the ocean. Normally though, Architeuthis do not stay near the surface of the ocean, so perhaps you are asking why no one has seen a giant squid where they usually live - 300-600 meters deep over continental shelves. We have only very recently developed submersibles that are capable of diving to such depths, and have explored very, very little of the ocean. Architeuthis are fairly rare animals, and the odds of being in the right place 500 meters under the surface of the ocean at exactly the right time are pretty slim. With further exploration of the mid-ocean, it seems likely that someone in a submersible will spot a living Architeuthis at depth soon, if it has not already been done.
I am interested in the
study of giant squid. How big are their jaws? How big are their suckers
and do their suckers have hooks? How big are their eyes
and is it true that they have excellent eyesight? How long are their tentacles? How long and wide do giant
squid get? How much do they weigh? It should be noted that all of these measurements have come from giant squid specimens which have either washed up on beaches, been caught with fishing equipment or were recovered from the stomachs of sperm whales. No one has ever seen a giant squid alive in its natural habitat. References: Clarke, M.R. 1986. A Handbook for the Identification of Cephalopod Beaks. Oxford University Press, Oxford. Roper, C.F.E. and K.J. Boss. 1982. The giant squid. Scientific American. 246(4): 96-105. Ruppert, E.E. and R.D. Barnes. 1994. Invertebrate Zoology. 6th ed. Saunders College Publishing, New York.
A. This is a tough one! In the first place, there are many different kinds of squid in the ocean. There is the giant squid, Architeuthis sp. , many kinds of flying squid that have long tapered bodies and can shoot out of the water and glide for some distance, the tiny deep water squid Cranchia that has a fluid filled buoyancy chamber, and hundreds of others. We know very little about the life histories of most of these different types of squid. One species of squid that we know a little more about is the squid, Loligo opalescens. These animals are common inshore from Mexico to southern British Columbia, and are often seen around docks that are lit up at night. Adults come inshore, mate and lay their eggs on solid objects like rocks or dock pilings. The egg masses are called "candles", and are about 5 cm long, containing hundreds of eggs. After spawning, the animals die. Most spawning males and females appear to be three years old.
Q: I need to know about squid reproduction, scientific classification and features. A: Squids are classified in the Kingdom Animalia, Phylum Mollusca, Class Cephalopoda, Subclass Coleoidea, and Order Teuthoidea. For reproduction, male squids have a specially modified arm called a hectocotylus, which they use to transfer sperm in a package called a spermatophore. The male inserts the spermatophore into the female's mantle cavity, near the oviducts where the eggs are discharged from. Once the eggs are fertilized, the female surrounds them in a gelatinous mass and attaches them to the sea floor in clusters. Squids have many interesting features. They are soft-bodied animals with eight arms and two tentacles surrounding their mouth. They use a funnel or siphon to expel water from their mantle (body) cavity and swim using this jet propulsion. Squids have attained the largest size of any invertebrate - the giant squid (Architeuthis sp.) is believed to reach a length of 20 m (66 ft)! For more information on squids head down to your local library and look for books on Invertebrates or Cephalopods.
A: There are many hundreds of species of squid in the world. Most squid are dioecious, which means that there are both males and females. In general, squid copulate, and the male transfers sperm to the female in a variety of ways, depending on the species. The female lays a number of eggs, again depending on what species of squid we are talking about. The eggs may drift in the zooplankton or may be attached to a surface. There is no parental care of juvenile squid by the adults.
Q: Recently, I had some lobster ravioli with striped pasta and a garlic cream sauce which was excellent. The pasta was black and white striped and I was told the black was squid ink. First, I thought the ink was brown or is this just because it is under water when it is released? Secondly, is the ink stored in a gland that can be removed and handled for cooking purposes? Thirdly, I assume the ink is non-toxic or is it up until the exposure to cooking heat? Finally, (getting my monies worth) what does the ink taste like? Bitter? Sweet? Thanks for your time and as you can tell, we had a lot to talk about at dinner! A: Squid
ink is manufactured and stored in an ink sac which lies along
the intestine and empties via a duct into the rectum just behind
the anus. This gland, which would be removed before cooking,
secretes a sepia-brown fluid (black in octopi) which contains
a high concentration of melanin pigment. The ink is released
when an animal is alarmed, creating a cloud of inky water in
the shape of a "dummy" squid to confuse the predator.
The alkaloid nature of the ink is believed to anaesthetize the
chemoreceptors of predators, particularly fish. Since squid is
the favourite food of many marine animals (e.g. seals, whales,
sea birds and fish), it is not likely that the ink is toxic.
In fact, a report on the Falkland Island sea lions noted that
they eat so many squids that their digestive tract is stained
by the ink. Unfortunately I cannot comment on the taste of squid
ink as I've never tried it, and the only information I could
glean from my colleagues was that it smells funny!
Q: Can you describe the mobility of the squid? A: Squids move by jet propulsion, by contracting the muscles in their mantle cavity to move water into their mantle cavity (the main body cavity in squid) and shoot the water out, which pushes them forward (opposite direction from which the water is being expelled). Squid are the highly adapted for jet propulsion swimming and can achieve the fastest swimming speeds of any invertebrate, up to 40 km/hr! Squid have two types of swimming, escape swimming and slow swimming. 1. Escape swimming: Squid have two types of muscles in their mantle cavity, circular and radial muscles. There are also two types of circular muscles, one type contracts for slow swimming and the other contract for fast escape swimming. The water enters the mantle by the circular muscles relaxing and the radial muscles contracting which increases the volume of the mantle cavity. The radial muscles contract only in escape swimming. The circular muscles contract to expel the water from the mantle cavity, which not only increases the water pressure but also locks the the edges of the mantle tightly around the head. The contraction of the circular muscles cause mantle flap valves to shut, thus sealing the underside of the mantle cavity and the water is forced out through a tubular funnel. This funnel is highly flexible and can be directed forward or backwards. When the funnel is directed backwards the fastest swimming in achieved when the squid move forward. 2. Slow swimming: Water enters the mantle cavity by the expansion of the cavity due to a springing back of the collagen fibers (stretchy fibers) that extend along the mantle wall. The expansion of the mantle cavity causes the mantle flap valves to shut, thus sealing the underside of the mantle cavity and forces the water out through a tubular funnel. The funnel is directed in the opposite direction that the squid wants to move. Additional propulsion is achieved from the movement of the fins, located on the sides of the squids' body.
Q. Beside the internal cuttle bone in a cuttlefish and the pen shell in a squid, what if any other anatomical differences exist between these two animals? A. Although the differences
in shell composition constitute the major delineating factor
between squid (Order Teuthoidea) and cuttlefish (Order Sepiodea)
there are several other anatomical differences between these
two animals. I don't have all of the details on hand, but I do
know that the following characters differ between the two groups:
tentacles and presence/absence of hooks or pits; the fins of
the two groups are remarkably different (fins of squid have approximately
equal length:width, whereas cuttlefish fins are usually longer
than they are wide), the structure of the eye, and the length
and texture of the mantle. This is an incomplete list - in addition
there are many major behavioural and ecological differences between
these two groups . While the squids are predominantly planktonic
animals that roam the water column, cuttlefish typically are
benthic dwellers and hang out close to the ocean floor. Both squid and cuttlefish have a "foot", which is homologous to the foot in the other molluscs such as snails and clams. In the evolution of the cephalopods the body became greatly lengthened along the dorsoventral axis, and as a result of a change in locomotion, this axis became the functional axis. The foot is modified as an extension of the head (hence the name: cephalo= head, pod= foot). Cephalopods swim by a water jet produced by contracting the mantle wall. The shell in these animals is reduced and internal (or even lost altogether) freeing the mantle wall for the water pumping action. Most cephalopods seize their prey with a pair of prehensile tentacles and hold it with the eight arms, all provided with suckers. The prey is dispatched with a horny parrot-like beak and a pair of poison glands. The radula (which is a rasping mouth part common to all molluscs) functions as a tongue, pulling in pieces of tissue torn off by the beak. There are many other features that all Cephalopoda have in common. Many of these features are directly or indirectly related to their active life and high metabolic rates. Some of these features include secondary folded gills; absence of gill cilia; blood-vascular system with arteries, veins and capillaries; accessory branchial hearts; presence of hemocyanin; highly developed eyes; complex nervous system and behaviour; chromatophores; ink glands.
Q: What Kingdom, Phylum, class, order, family, Genus, and species do octipi belong to? A: I am going to give you
the classification of the giant Pacific Octopus. The classification
for all other species of octopods is the same up until the genus
and species:
A. We can say with some confidence that an octopus has 8 arms. They are not called legs by scientists, and the general public (or teachers!) should not call them legs either. Incidentally, a close relative of the octopus, the squid, has 10 appendages, arranged in 5 pairs around the head. Eight of these are short and heavy, and are called arms while the fifth pair are much longer and are called tentacles.
A. The female Octopus will care for the eggs during the 5-7 month development period, so you should keep any disturbance to a minimum during this time. Eggs hatch in early spring, but this is dependent on water temperatures and latitude. We're not sure about the exact dates of hatching for Octopus dofleini eggs in Alaska. The young are very very tiny when hatched, and are pelagic for about one month. This means that they essentially float about in the water column, and do not settle to a surface. We had difficulty keeping juvenile Octopus in tanks at Bamfield Marine Station - they kept going down the drain, and a drain cover that was small enough to exclude them kept clogging. If you can overcome this problem, you will have to feed them. The best food for juvenile Octopus would be freshly caught zooplankton. If you have access to a plankton net and a boat, this should be no problem. If not, you will have to try commercial juvenile fish food that is designed for livebearing fish. This food floats in the water column (not on the surface), and the octopus juveniles may have a chance to find and eat it. Good Luck and let us know how it goes!
The colour change phenomenon seen in octopus and other cephalopods is one of the more fascinating in nature. The reaction that takes place is not chemical in nature. The skin of an octopus contains many pigment cells, or "chromatophores". These chromatophores may be one of several colours: yellow, orange, red, blue or black. Each chromatophore is only one colour. The chromatophores may be individually expanded or contracted - this process is under the control of the nervous system, and perhaps hormones. The expansion and contraction of chromatophores is accomplished with tiny muscles attached to the outside of the cells. When the muscles are contracted, the pigment in the cell is pulled out into a flat plate, and the colour in the cell is displayed. When the muscles are relaxed, the cell and colour concentrate into a small, hard to see dot. By expanding and contracting different chromatophores of different colours, the animal can change its external appearance. Because the chromatophores are under neural control, colour changes can be accomplished very rapidly.
Q: Where can I find the life cycle of an octopus? A: Octopuses are dioecious (separate sexes, male and female). The male and female are 2 or 3 years old when they mate depending on the species. The male courts the female and if she is receptive he will deposit spermatophores,that contain sperm, into the mantle of the female. The female will keep the spermatophores in her mantle cavity until she is ready to fertilize her her eggs. The male octopus will die shortly after he deposits his spermatophores into the female. When the female is ready to lay her eggs she stops feeding and finds a safe place to lay her eggs. The female lays her eggs in strings and it is usually attached to rocks on the roof of her home. Octopus vulgaris will lay thousands of eggs and it may take a week or more to lay all the eggs. After laying the eggs the female stays with the eggs to aerate and protect them. After 4 to 6 weeks the eggs hatch. Shortly after the eggs hatch the female octopus will die. When the young octopuses hatch they spend a portion of their time as plankton in the ocean. The amount of time they spend as plankton depends on the ocean temperatures and the type of octopus. For example, Octopus vulgaris can spend 33 days to 3 months as plankton depending on water temperatures (colder temperatures = slower development, more time spent as plankton). When the young planktonic octopus find a suitable place they will settle and feed on shrimp and crabs. In 40 days at 25 degrees Celsius, a young octopus can increase ten times in size. Most octopus live two years and die off after they mate. Some octopus may live past two years but it is rare. If you would like more information on octopuses I suggest you check out your local library for books on marine invertebrates and cephalopods (octopuses and squids).
Q: Hi My family and I have a pet octopus it is a small (Its body is about 6" in Diameter ) red octopus. We looked up some info on her last night because we discovered some white almost transparent egg sacks, under the rock she likes to stay under. I found out that she will die when the eggs hatch. Since i am kind of attached to her and would like to save her I was wondering if I separated her from the eggs if she would survive. For example if I put her back down into the Puget sound - her original habitat- and left the eggs in our aquarium, or visa versa. Please let me know on this as soon as you can. Thanks, Haley A: Most octopuses, including the type of octopus you have, live short lives and all females will die shortly after the eggs hatch whether she is an aquarium or in the ocean. A female octopus will only lay her eggs once and this signifies that she is nearing the end of her life. Even if the eggs are no fertilized by a male and do not hatch, she will still pass on. Once a female lays her eggs she will stop eating (as you have probably noticed) and will concentrate on protecting her eggs and keeping water circulating over the eggs. The life of an octopus is short, even at the Vancouver Aquarium, when their female octopus lays her eggs they know she is at the end of her life and there is nothing much they can do. The best thing for you to do is leave your octopus where she, protecting her eggs is where she will be happiest. It sounds like you have learned a lot about your octopus and that's great! I think that your passion for your octopus shines through and I am sure she had a great life.
Q: Do octopi have a specific "home" (like a shelter they might sleep in?) or are they more nomadic? If you could answer my question as soon as you can that would be great! Thanx. A: Yes octopods do have a specific home. An octopus home is called a den and is usually a crevice or cave in rocks or reefs in the tropics. Octopods will forage for food near their dens or will wait at the entrance of their lair for a tasty food item to pass nearby. You can usually spot an octopus den by looking for a pile of empty shells and crustaceans (their favourite food). Octopods will usually stay quite close to their den. For example, Octopus dofleini, found in the Pacific Northwest, will forage for food in areas no more than 250 metres away from their den.
Q: Can you tell me the names of demersal fish that eat octopi? Your site says that they eat benthic crustaceans but what demersal fish eat them? A: North Atlantic water: Cod
(Gadus morhua), hake (Merluccius sp.), haddock
(Phenacogrammus aeglefinus), as well as deepwater genadiers
(Macrourus sp.) are known to prey on the octopuses Eledone and Bathypolypus.
Q: What is the blue-ringed octopus' genus & species? A. The blue-ringed octopus, Haplochlaena
maculosa, is among the smallest of the cephalopods (class
that includes octopus, squid and cuttlefish) and is found in
shallow waters and tide pools off the coast of Australia. Blue-ringed
octopus are usually dark brown or dark yellow in colour and
covered in blue rings that glow brightly when the animal is
frightened. These animals are the most toxic of all the cephalopods,
as they harbour a poison that they use to paralyze and trap
their prey. Blue-ringed octopus will bite humans, usually when
they are handled, and the paralysing effects of the poison
are quite drastic and can often be fatal. at MarineBio.org
Q: Where would I find information about the systems of the nautilus? A: The
Cephalopod Page is a good site with
a lot of information. Check out the YouTube video of Nautilus swimming!
A: A chambered nautilus is a mollusc in the class cephalopoda, and is related to octopus and squid. It is the only living cephalopod with a shell, although there are several fossil forms known. They have a spiral shaped shell that is divided up into several chambers. The animal lives in the last chamber and is able to swim around in the water column. The gas filled chambers of the Nautilus' shell provide buoyancy that counteracts the weight of the shell.
Q: I'm doing a report on mollusks(squid)and I'd like to know what the smallest squid is? A: It took a bit of searching,
but I have found a group of uniquely small squid (at adult size),
that contains the smallest squid.
Q: Could you please answer my three questions on sepia (cuttle fish) 1. classification 2. occurrence 3. life cycle. Could you tell me about the parental care in fishes and amphibians? A:
The cuttlefish has the following classification: Cuttlefish spawn in large groups in the
water column. After a female has mated, she will lay eggs. Each egg is put
into a separate egg case that is about 1-2 cm long. Ink is added to the egg
case to make it dark. Each egg case is attached individually to things on
the bottom. Cuttlefish can lay eggs several times at the end of their life.
Eggs take about 2 months to hatch, but this time depends a lot on the temperature
of the water that they are in. Babies are about 50mm long (again, this is
mantle length and does not include the head and arms), and grow quite rapidly.
They mostly eat small (less than 50 mm long) crustaceans. a good site for cephalpods of all sorts: CephBase About the parental care of fish and amphibians, they variety of species and different behaviours in these groups is too vast for me to summarize. Many species of abandon eggs upon fertilization but about 90 families of bony fish engage in some level of parental care be it guarding the nest or brood hiding (pouches, mouth etc). I suggest narrowing it down to one or two species that you are most interested in and then doing a web search for info or going to your local library to check out books about fish and parental care. Good luck!
Q: Do you know anything about squid? If so I need to know what the appearance of the the squid is like. What dose the squid eat or what is it's diet ? A: Squids are cephalopod molluscs. They are closely related to octopi and in the same phylum as clams and snails. Squid have generally long, arrow shaped bodies, with a pen (internal shell-like shaft). They have 8 arms and 2 tentacles that they use to capture prey. They move by jet propulsion, by sucking water into their body cavity and expelling it with great speed. Cephalopods are thought to be the most intelligent of all molluscs and possibly of all invertebrates. Their diet consists mainly of fish, crustaceans (crabs, amphipods, krill etc), and worms. Squids range in size from the giant squid (Architeuthis sp.) to the smallest Idiosepius sp. The largest giant squid ever recorded (Architeuthis princeps) was captured in 1878. One of the "arms" (probably a tentacle) measured 35 feet long. It is estimated that the animal weighed in the neighbourhood of 4000 pounds. The smallest Idiosepius squid found was 6mm. Squids are very diverse. So for your report you might want to pick one genus or species to look into more in depth. The loligo squid is the most common squid worldwide.
Q: Can you tell me about the respiration of octopods? A: Cephalopods (including octopi) are
different in many ways from all other molluscs. They are considered more
advanced - in terms of intelligence, sensory structures, and cardiovascular
systems.
Q: 1. What attracts squid to the lights
that commercial squid fishermen shine on the water? A: Experiments have shown that squid are
attracted to white light, and so lights are often used for fishing. Squid,
and other cephalopods, have excellent eyesight - rivalring our own. I am
not sure exactly what attracts to them to the light. Some squid are also
capable of bioluminescing (they can light up themselves!), so perhaps light
attraction is for communication purposes. It is not clear what individual
colours in the spectrum that squid are attracted to. Many commercial and
government docks now use yellow/orange lights and these do not seem to attract
the squid. Scientist need to do more research to find out why. A good site
you can write to to find out more information is The Cephalopod Page at:
http://is.dal.ca/~ceph/TCP/index.html The squid in your area is likely Loligo
opalescens (this is the most common squid ranging from British Columbia to
Mexico), for a picture and description, check out the following field guide: "The
Audubon Society Nature Guides: Pacific Coast".
Q: Why does an Octopus have three hearts? A: Basically an octopus has three hearts because it needs them for blood circulation and gas exchange. The octopus has one main heart that drives the blood in its body. But here comes the interesting part. Octopi have something called a booster heart (branchial heart) that pumps blood into the capillary networks of the Ctenidia where gas exchange takes place. Basically the extra hearts of the Octopus are for assisting in the uptake of oxygen and the releasing of carbon dioxide. Without these extra hearts the Octopus might not be able to breathe properly.
Q: Hello I was wondering if Octopus have teeth, what they eat and if they can grow back tentacles that were cut off? A: he Cephlapods from which the octopi
are a part of tend to eat crustaceans, other molluscs (cephlapods are from
the phylum mollusca) and fishes. Q: What is the function of the jet tube of a squid ? A: Squid use the jet tube as a form of jet propulsion to move around the ocean. Squid move by sucking water into their bod |
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TO 
A.
Clams are bivalve molluscs, meaning that they are closely related
to chitons, snails, octopus, squid and other soft bodied invertebrates.
The clam has two calcareous valves which are commonly referred
to as the shell, which protects the animal's soft parts. Inside
of the shell is the soft part of the animal, including the siphons,
long tubes that the animal uses for feeding and respiration.
Clams often burrow deep in the sand to prevent them from being
dislodged from the substrate or grabbed by potential predators.
These animals are filter feeders, feeding on particulate matter
that is present in the water. The clams extend their muscular
siphons (they may have one or two) up to the surface of the sand
and use it like a straw to suck in large quantities of water.
Water flows in through one siphon, the incurrent siphon, and
passes over a series of gill filaments. The gills are covered
with millions of little sticky hairs called cilia that trap organic
particles in the water and then move those particles to the mouth
of the clam. The filtered water is then pumped out of the excurrent
siphon and away from the animal. Clams have to filter large quantities
of water in order to make their living. Sometimes when you walk
on the beach you can see little holes in the sand. These are
often the burrows of clams, the places where the siphons stick
up through the sand, waiting for the tide to come in and with
it, dinner! The picture shown is of a small clam, Protothaca
staminea, but it illustrates the siphons really well.
a
whole bunch of websites that don't really help you out. Instead
of using the common name "abalone" in search engines
you want to use the scientific name, which for abalone the genus
name is "Haliotis". If you type in "Haliotis" in
any search engine I guarantee you will find tons of information
on abalones. Another great place to search for information is
at your local library. Look for books on Invertebrates (animals
without backbones) and Molluscs (abalones, sea snails,and their
relatives).
is
the Japanese Abalone and it's scientific name is Haliotis
kamtschatkana. It can reach a maximum length of 15cm (6 inches)
and a width of 10.8cm (4.5 inches). This species is found from
Alaska to central California. They are found living on rocks
and crevices in the subtidal, usually in areas where there is
quite a fast current or lots of waves. Abalones are usually red
or pink in colour because of the incrusting algae that grows
on their shell. The shell under the encrusting algae is greyish
to white in colour. Abalones are grazers and feed on tiny animals,
algae, and sponges that grow on rocks or kelps. Abalone feed
by using a specialized "tongue" called a radula. The
radula has many teeth on it, and these teeth are great for scraping
food off the rocks.
