What is a major difference between adult sea urchin and a larval sea urchin?
94030
This is what the larva looks like\nhttp://www.imagequest3d.com/catalogue/larvalforms/thumbnails/d004_jpg.jpg\nhttp://nai.arc.nasa.gov/library/images/news_stories/old/urchin_larva.jpg\n\nAnd these are the adults\nhttp://www.elasmodiver.com/BCMarinelife/images/green-sea-urchin.jpg\n\nI guess you can find several major differences.\nAnd I second the answer above :)
110483
Very true. Mollusc anatomy and physiology could fill a book.  Anatomy of a snail? A squid? A chambered Nautilus? A seahare? They are all molluscs yet very widely in their anatomy and physiology.\n\nThe books the above poster referenced are excellent college level texts that cover most invertebrate life.  I would also suggest for a more simple approach the Marine Biology Coloring Book. It is not a kids book, but has some good diagrams on a variety of molluscs.\n\nThere are a number of websites that have valid information as well. If you edit your questions, I can post some links to specific species informative web sites.
366521
In insects that exhibit paurometabolous or hemimetabolous metamorphsosis (an 'incomplete' metamorhphosis in which there is no pupal stage), the juvenile stage (between egg and adult) is known as a nymph.  In aquatic forms, like dragonflies or mayflies, it is also sometimes referred to as a naeid.\n\nBTW:  Why is this in Earth Science?
264616
The male sea horse has a pouch in to which the female lays her eggs. The male fertilizes the eggs and cares for them for 3 weeks he also nourishes the eggs through a capillary network with is own placental fluids,that why the male sea horse carry the young ones.
122470
Read the information on these sites and maybe you will find some of the answers to your questions.\n\nhttp://www.answers.com/echinoderm%20\nhttp://www.answers.com/topic/tube-foot?hl=echinoderm\nhttp://www.answers.com/Aristotle%E2%80%99s%20Lantern\nhttp://www.answers.com/main/ntquery?method=4&dsid=2222&dekey=Sea+urchin&gwp=8&curtab=2222_1&linktext=sea%20urchins
653958
They have a water vascular system which is unique to echinoderms (sea urchins, sea stars, etc) since they have a digestive system but no circulatory system.  They have an opening called a "madreporite" through which water flows into their bodies.  They have a system of canals within their bodies, and the flow of water transports nutrients.  It is also used for movement and respiration.
344675
Courtship, mating and reproduction : Like all snakes and lizards, male sea snakes have two penises. They are called hemipenes, but each is an autonomous independently functioning penis and only one is used during mating. Mating takes place for long periods and sea snakes must surface for air during that time. The female controls breathing and as she swims to the surface the male is pulled along attached via the hemipenis. At the surface the male needs to gulp for air or he has to wait til the next time the female comes up the the surface to breathe. Males are unable to disengage until mating is finished. \n\nIn species where courtship has been studied, eg olive and turtlehead sea snakes, one or more males follow the female very closely and occasionally prod the head and neck of females. \n\nAll sea snakes except the latidcaudids give birth to live young after gestation periods that range from four to eleven months, depending on the species. Most species reproduce every year. The timing of the reproductive cycle varies enomously between species and also differs between geographical locations for the same species. \n\nYoung are born underwater and must be independent immediately to swim to the surface to breathe. There is no parental care. In some species look quite different to the adults eg juvenile olive sea snake are strongly banded while the adults are not.
108081
Sea urchin belongs to a group of animals called: echinodermata (among them: starfish, brittle star and sea cucumbers). All echinoderms have a water-vascular system, a set of water-filled canals branching from a ring canal that encircles the gut. The canals lead to podia, or tube feet, which are sucker-like appendages that the echinoderm can use to move, grip the substrate, or manipulate objects. These tube feet are extended and retracted by hydraulic pressure in the water-vascular system. Pedicellaria are small, snapper-like skeletal elements that are used by the echinoderm to keep small organisms from settling on its body.
176452
Plankton are plants and animals that drift the oceans according to the currents. Animals in this class include\n\n* Amphipod\n* Copepod\n* Jellyfish\n* Salp\n* Polychaetes\n* Arrow worms\n\nThese animals are called holoplankton because they spend all of their lifes depending on the current. There are are also meroplankton which only spend the larval period as plankton. These include the larvae of sea urchins, starfish, crustaceans, marine worms, and most fish
236325
An invertebrate is any animal without a backbone. Invertebrates make up 95% of all species of\nanimals on the earth, and the variety of invertebrates is enormous. Scientists group or “clas\nsify” all of these different types of animals into broad categories called phyla, on the basis of\ntheir patterns of symmetry and on the basis of their overall body plan. There are 5 particularly important\ninvertebrate phyla (and another 23 or so less important phyla). The major invertebrate groups are classified as:\n· Phylum Cnidaria: sea anemones, corals, and jellyfish\n· Phylum Annelida: segmented worms\n· Phylum Mollusca: clams, snails, and squids\n· Phylum Arthropoda: lobsters, beetles, crabs, and flies and scorpions\n· Phylum Echinodermata: sea urchins, sea cucumbers, and starfish\n\nsee more info at:http://www.msc.ucla.edu/oceanglobe/pdf/Invertebrates/Inverts_Entire.pdf\n\nI hope this helps...\n\nDon
144263
Well, i'm not an expert, but as i understand it, the basic difference, besides the composition, is that cartilage is flexible. the human body uses cartilage to connect the bones to each other so that we have joints and can move in many different ways. It actually has many other functions too. here is a good link to learn more about cartilage:\nhttp://www.botany.uwc.ac.za/sci_ed/grade10/mammal/cart.htm\n\ncomparison of characteristics of both (kinda techinical)\nhttp://bms.brown.edu/curriculum/b189/Lectures/cart-bone-study.htm
517143
kingdom animalia\nsubphylum invertebrata\nphylum echinodermata\nclass : - asteroidea: starfish\n        - holothuroidea: sea cucumbers\n        - echinoidea: sea cucumbers
810850
Lake species of insects have larvae, as do many other animals. Lakes themselves do not have larvae, because lakes do not reproduce.
258574
a jellyfish is an invertebrete.\na cuttlefish is not a fish!! it is a cnidarian, henceforth an invertebrate\n\nan eel is a vertebrate
854809
Yes, there is a difference. One gives you natural cancer and the other one gives you just plain old cancer.
65611
Yes they are poisonous. As a diver I have been punctured and stung by sea urchins many times and have never experienced anything more than mild pain. Sea urchins have both spines which will puncture your skin, and some have Pedicellariea, which is an organ that delivers toxin, even after it breaks off from the sea urchin. Some species of sea urchins have been known to cause death. By the way, sea urchins are also good to eat. The edible part is the yellow roe inside their hollow body. This roe is called 'uni' on the sushi menu.
836347
Metamorphosis is the process in which an animal passes through different stages after being born or hatching.  It usually has three stages - larva, pupa, and adult.   The caterpillar becomes a pupa and then develops into the butterfly.\n\nThere is good information at these links.