Geometry.Net - Science: Mollusca

Mollusca In Germany - Snails, Clams And Other Mollusks
Here you can find info about molluscs (mollusca) and malacology (researchon molluscs). Members 1998. This page belongs to www.mollusca.net.
http://www.mollusca.net/

Extractions: Sprache Here you can find info about molluscs (mollusca) and malacology (research on molluscs). Members of the mollusca are snails and slugs (both gastropods, Gastropoda), clams and mussels (Bivalvia), squids and octopuses (Cephalopoda), chitons (Polyplacophora), tusk shells (Scaphopoda), and the less popular groups of Monoplacophora, Solenogastres and Caudofoveata. List of German land and freshwater mollusks Shell museum
Mollusca - Introduction
Unit mollusca, 1 Introduction. mollusca. The name mollusca (from theLatin mollis meaning soft), was first used by the French zoologist
http://www-biol.paisley.ac.uk/courses/Tatner/biomedia/units/moll1.htm
Biomedia - Zoology Museum
mollusca. Unit 1 Introduction. Unit 11 - Taxonomy - Classification of the Phylummollusca. CLASS Caudofoveata. CLASS Solenogastres. Example chitons^.
http://www-biol.paisley.ac.uk/biomedia/text/txt_mollusc.htm
Biol. Bull., December 1990. Laboratory Culture Of The Aeolid Nudibranch Berghia
Carroll D J and S C Kempf. Biol. Bull. 179 243253. (December 1990)
http://www.breeders-registry.gen.ca.us/Reprints/biolbull/v179/berghia_bb.htm

Extractions: 101 Cary Hal, Auburn University, Alabama 36849-5508 Abstract. Adult Berghia verrucicornis individuals lay white, spiral egg masses containing zygotes. Egg masses are easily cultured in aerated, Millipore-filtered, seasoned aquarium water. Development proceeds quickly, with the bilobed velum apparent by the end of the second day, and the larval shell appearing at the beginning of the third day after oviposition. Hatching occurs 11 to 12 days after oviposition (23.9 +/- 1.3C). If egg masses are incubated without aeration, poecilogonous development is observed; both larvae and juveniles hatch from the same undisturbed egg mass. The larvae metamorphose soon after hatching, losing the velum and larval shell. A habitat-specific inducer is not required for metamorphosis; but a factor associated with the sea anemone Aiptasia pallada appears to enhance a larva's tendency to metamorphose. Juveniles begin feeding on
Class Gastropoda
Overview of gastropod classification from the Animal Diversity Web.
http://animaldiversity.ummz.umich.edu/mollusca/gastropoda.html

Extractions: The University of Michigan Museum of Zoology Animal Diversity Web About us ... Glossary The Class Gastropoda includes the snails and slugs. Most gastropods have a single, usually spirally coiled shell into which the body can be withdrawn, but the shell is lost or reduced some important groups. Gastropods are characterized by "torsion," a process that results in the rotation of the visceral mass and mantle on the foot. The result is that the mantle cavity (including anus) lies in the anterior body, over the head and mouth, and the gut and nervous system are twisted. Torsion takes place during the veliger stage, usually very rapidly. Veligers are at first bilaterally symmetric, but torsion destroys this pattern and results in an asymmetric adult. Some species reverse torsion ("detorsion"), but evidence of having passed through a twisted phase can be seen in the anatomy of these forms. Many snails have an operculum, a horny plate that seals the opening when the snail's body is drawn into the shell. Gastropods have a muscular foot which is used for "creeping" locomotion in most species. In some, it is modified for swimming or burrowing. Most gastropods have a well-developed head that includes eyes, 1-2 pairs of tentacles, and a concentration of nervous tissue (ganglion).
Gastropoda
Overview of biology and taxonomy; species list for Montana.
http://www.esg.montana.edu/dlg/aim/mollusca/gastropd.html

Extractions: Snails. The largest and most diverse group of mollusks. The phylum Mollusca in a ancient group that is second in size only to the arthropods. There are over 50,000 living species and about as many fossil species known. Mollusks are unsegmented, coelomate protostomes with a ventral muscular foot, a shell-secreting mantle, and a radula as the feeding organ. They have a trochophore larval stage similar to the annelids and a later veliger larval stage. The circulatory system is open and excretion is by metanephridia. Gastropods make up 70% of all mollusks and they are well represented in marine, freshwater and terrestrial habitats. About 500 species, 350 prosobranchs and 150 pulmonates, in the freshwaters of North America, north of Mexico. Mollusks with increased cephalization and an asymmetrical, univalved, usually spiral shell serving as a retreat rather than a shield. The class is characterized by torsion, a 180 degree counterclockwise rotation of the body behind the head. Marine forms have a free-swimming veliger larva, freshwater forms usually pass that stage within the egg and miniature adults emerge. Pulmonates are monoecious, copulation usually involves mutual sperm transfer, but it can be one-way only or they can be self-fertile. Freshwater prosobranchs are dioecious, except for Valvatidae. Some are parthenogenetic, some are egg brooders, some are both. Mating and egg laying may be seasonal or occur throughout much of the year. The species may be semelparous or iteroparous. Individuals of some species may live for several years. The life cycle is non-emergent.
BIOSIS | Resource Guide | Mollusca
Systematic information and extensive links about mollusks.Category Science Biology Flora and Fauna Animalia mollusca Conferences. Index to Organism Names. Search. mollusca. General (malacology, conchology).Journals. Organizations. Aplacophora (vermiform, shellless mollusks).
http://www.biosis.org/zrdocs/zoolinfo/grp_moll.htm

Extractions: Pull Down for Destinations BIOSIS Previews Zoological Record MethodsFinder Index to Organism Names Internet Resource Guide for Zoology User Support Search Sitemap Index Help with this Site Introduction About the Resource Guide Awards Latest Additions ... Search General (malacology, conchology) Journals Organizations Aplacophora (vermiform, shell-less mollusks) Bivalvia (clams, oysters, mussels) Cephalopoda Gastropoda (snails, slugs, limpets) Monoplacophora (rare shell-bearing mollusks) Polyplacophora (chitons) Scaphopoda (scaphopods, tusk shells) Contact: webmaster@york.biosis.org About News Products ... Contact
Order Archaeogastropoda
Images and brief description. Species accounts for Haliotis kamtschatkana (Northern Abalone) and H. rufescens (Red Abalone).
http://animaldiversity.ummz.umich.edu/mollusca/gastropoda/archaeogastropoda.html

Extractions: Accounts marked with a p contain pictures, t contain narrative text (student authored), a contain anatomical still/QTVR images, and s contain digitized sound clips. Haliotis, shell. These primitive mollusks have a linear series of perforations rather then a slit for the exhalant mantle cavity currents. Haliotis is an important commercial mollusk; there is a world demand for its meat. Pleurotomaria This primitive gastropod has a slit in its mantle and shell to facilitate the excurrent water leaving the mantle cavity. This is a primitive solution to the sanitation problems caused by torsion (having the mantle cavity with the anus, nephridiopores and gonopores located over the head). Unbonium, shells - genetic diversity. The shells in any population of Umbonium are highly polymorphic.
BIOSIS | Resource Guide | Mollusca - General
mollusca General.
http://www.biosis.org/zrdocs/zoolinfo/moll_gen.htm

Extractions: Pull Down for Destinations BIOSIS Previews Zoological Record MethodsFinder Index to Organism Names Internet Resource Guide for Zoology User Support Search Sitemap Index Help with this Site Introduction About the Resource Guide Awards Latest Additions ... 2nd Catalogue of Malacology A N van der Bijl, dealer in new, secondhand and antiquarian books, periodicals and reprints/offprints/separates on recent and fossil Mollusca Animal Diversity Web University of Michigan Museum of Zoology
Class Scaphopoda
http://animaldiversity.ummz.umich.edu/mollusca/scaphopoda.html

Extractions: The University of Michigan Museum of Zoology Animal Diversity Web About us ... Glossary The scaphopods, or tusk shells, are a small group of marine forms (around 350 species are known). They are sedentary animals with a slender, tubular shell open at both ends. The mantle cavity is large, and the mantle wraps around the viscera to form a tube. Scaphopods have a well-developed foot located at the large end of the shell. The foot is used for burrowing. Club-like tentacles also extend from the large end of the shell. A radula is present; the head is rudimentary; and eyes are lacking. There is no heart. Scaphopods feed on detritus and protistans, which are captured in mucus secreted by the foot and tentacles. Source Hickman, C.P. and L. S. Roberts. 1994. Animal Diversity . Wm. C. Brown, Dubuque, IA.
Malacology In Latvia / Malakologie In Lettland
Malacology in Latvia / Malakologie in Lettland.
http://www.mollusca.from.lv/
Introduction To The Scaphopoda
Information about biology of the tusk shells, with illustrations and links.
http://www.ucmp.berkeley.edu/mollusca/scaphs/scaphopoda.html

Extractions: The Scaphopoda are a distinctive group of molluscs commonly known as the "tusk shells" because their shells are conical and slightly curved to the dorsal side, making the shells look like tiny tusks (see the photos below). The scientific name Scaphopoda means "shovel foot", a term that refers to the "head" of the animal, which lacks eyes and is used for burrowing in marine mud and sediments. The most distinctive feature of scaphopods is that the tubular shell is open at both ends, not just one end as in most molluscs. Scaphopods live their adult lives buried in sand or mud, with their head-end pointed downwards. Only the narrow posterior end of the shell sticks up into the seawater for water exchange and waste expulsion. Gills have been lost in the scaphopods, so the mantle tissue not only produces the shell, but also serves the function of gills in obtaining oxygen from seawater. The mantle is fused into a tube that surrounds the body of the animal, but it is open at both ends. Water is circulated around the mantle cavity by the action of numerous cilia . When the dissolved oxygen runs low, the water is ejected through the top end of the shell by contraction of the foot.
Mollusca
mollusca. Prosobranchs Pulmonates Bivalves Cephlapods. INFORMATION Recent andongoing projects on Molluscs Staff expertise Who's who in mollusca?
http://zoology.nmgw.ac.uk:591/Museum/mollusca.htm
Class Aplacophora
http://animaldiversity.ummz.umich.edu/mollusca/aplacophora.html

Extractions: The University of Michigan Museum of Zoology Animal Diversity Web About us ... Glossary These organisms lack shells and are worm-like in body form. They have calcareous scales or spicules in their integument. Aplacophorans lack nephridia. All are marine; around 320 species are known, mostly from the deep oceans. They can be divided into two groups (sometimes separated as Classes Caudofoveata and Solenogastres); caudofoveates are burrowers that feed on detritus and bottom-dwelling microorganisms, while soleonogasters, which also live on the bottom, feed on cnidarians. Source
Mollusca HOW TO SEARCH
DESCRIPTION OF THE DATABASE FIELDS. You are connected to a FileMakerdatabase. Here are some important things you should know FileMaker
http://zoology.nmgw.ac.uk:591/Museum/mollusca_how.htm

Extractions: DESCRIPTION OF THE DATABASE FIELDS Here are some important things you should know: FileMaker has free text retrieval, it will find any word or part of a word in all those fields that are open to you. This can help you because Species name gender endings:- you need not enter the full name of a species you can find alba, albus or album by entering alb or alb* only. Geographic localities:- if you cannot remember exact spellings simply enter the first few letters. SEARCHABLE FIELDS Superfamily Family and Subfamily fields are provided for searching across higher taxon levels. Searching on these alone will produce extensive lists and cost you time. Current name and Original label name These are groups of four fields each
Class Monoplacophora
http://animaldiversity.ummz.umich.edu/mollusca/monoplacophera.html

Extractions: The University of Michigan Museum of Zoology Animal Diversity Web About us ... Glossary Living representatives of this Class were not discovered until 1952, although Paleozoic fossil monoplacophorans had been known for some time. At present, 11 species are known. Most live at great depths and all are marine. Monoplacophorans are small and have a single, caplike shell, giving them a limpet-like appearance. A number of their organs (nephridia, heart, etc.) are repeated serially, making them resemble metamerically-arranged species such as annelids and arthropods. Whether this resemblance indicates a close relationship between monoplacophorans and phyla exhibiting true metamerism is an open question. Source Brusca, R. C., and G. J. Brusca. Invertebrates . 1990. Sinauer Associates, Sunderland, MA. Neopilina galatheae , top (dorsal) view. Neopilina is peculiar because of the replication of various of its organs and organ systems, reminiscent of metameric animals. The class Monoplacophora is well known as fossils, and until 1952 all of its members were believed to have been extinct since the Devonian period, about 350 million years ago. [This shell, relatively thin, was damaged while being dredged.] Neopilina galatheae , bottom (ventral) view.
Mollusca (BMLSS Information)
mollusca. mollusca. Latin molluscus = soft Soft bodied animals witha hard external shell (mussels, winkles, snails), or an internal
http://ourworld.compuserve.com/homepages/BMLSS/molluscs.htm

Extractions: Latin molluscus = soft Soft bodied animals with a hard external shell (mussels, winkles, snails), or an internal shell (sea hares, cuttlefish) or have lost their shell in the course of evolution (nudibranchs). Molluscs have a mantle that secretes the calcium carbonate that makes up the shell. They inhabitat numerous different environments with a large number living in the sea. Octopuses and squids have evolved to intelligent mobile forms with complex behaviour. British species of molluscs found in the seas and estuaries around these islands Chitons
The Mollusc Page
This page lists links for the phylum mollusca which contains cephalopods,snails, clams, chitons and scallops. The Mollusc Page. Phylum mollusca.
http://www.dal.ca/~ceph/TCP/mollusca.html

Extractions: Molluscs include the familiar snails, garden slugs, and beautiful sea slugs (class Gastropoda), the clams, oysters, scallops, and mussels (class Bivalvia), the active octopuses, squid, cuttlefish and Nautilus (class Cephalopoda) as well as some less familiar groups such as the classes Aplacophora (shell-less worm looking things called solenogasters), Caudofoveata (small shell-less deep-sea worm like things), Monoplacophora (living fossils - only 8 or so species), Polyplacophora (chitons) and Scaphopoda (tusk shells). In terms of numbers of species, Mollusca is the second largest phylum of invertebrates (Arthropoda is the largest). Molluscs are one of the most noticeable groups of invertebrates as well - their attractive shells are collected and many species are consumed as food (hungary yet?).
Seaslug Mollusca Opisthobranch Nudibranch
primary mission of Seaslug.com is to provide bibliographic resources for scientificand medical research relating to seaslugs (mollusca, Opisthobranchia) and
http://www.seaslug.com/
Mollusca
encyclopediaEncyclopedia mollusca, mulus'ku Pronunciation Key. mollusca, taxonomic name for the one of the largest phyla of invertebrate
http://www.factmonster.com/ce6/sci/A0833641.html

Extractions: Pronunciation Key Mollusca , taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,000 fossil species dating back to the Cambrian period. Mollusks are soft-bodied, and most have a prominent shell. The members of this highly successful and diverse phylum are mostly aquatic and include the familiar scallop clam oyster mussel ... chiton , and a variety of others. Mollusks occupy habitats ranging from the deep ocean to shallow waters to moist terrestrial niches. Certain mollusks, such as clams, squids, and scallops, constitute important food staples, and molluskan shells are highly valued by collectors. In times past these shells were used as money and today are used ornamentally for such items as buttons and jewelry. There are six classes of mollusks. Sections in this article:

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