Cnidaria

•Phylum Cnidaria .
9400 species...4 classes..

•mainly marine

•free swimming and bottom dwelling

•microscopic to several meters

 

 

Cnidaria

•radially symmetrical with

•cells arranged into tissues

•posses tentacles and stinging cells

•2 layer body wall with non-living jelly-like wall containing elastic

•fibers to allow movements in between with digestive cavity

•no anus,

 

–    Hydrozoa, Scyphozoa, Cubozoa, and Anthozoa

 

 

 

Cnidaria

•2 distinct life history phases, free swimming Medusa and sedimentary polyp.  

 

 

 

 

Cnidaria

•Class Hydrozoa..most primitive Many consist of feathery or bushy colonies of tiny polyps.

•They are attached to pilings, seaweed, shells and other surfaces. The Siphonophores are hydrozoans in drifting colonies.

•Some polyps form floats, others form long tentacles to capture prey. Portuguese man-of-war is an example.

Cnidaria

• (Hydroids)

 

Cnidaria

• (Physalia )

 

Cnidaria

•Class Scyphozoa...jelly fish has digestive system is a set of radiating canals linking the central portion to a peripheral ring. Some mesogleas can expel heavy chemical ions and replace them with lighter ones to adjust buoyancy.

 

Cnidaria

•

 

 

Cubozoans

•     In the class Cubozoa, which includes box jellies and sea wasps

–    The medusa is box-shaped and has complex eyes

 

 

 

 

Cnidaria

•Class Anthozoa Corals and sea anemones only exist as polyps.

•The sea anemones always bear more than eight tentacles .

•Some burrow in mud but most dwell on a hard substratum, cemented there by secretions from a well differentiated disk.  

 

 

 

MOLLOSKS

•M

 

 

Cnidaria

•Subclass Zoantharia are hard corals whose polyps are encased in a rigid calcium carbonate skeleton. Most hard corals live in colonies which are composed of vast numbers of small polyps (about 5mm) but can be larger in solitary forms .

 

 

 

 

Cnidaria

•Most are subtropical or tropical in distribution. In colonial forms, the polyps are interconnected laterally forming a living sheet overlying the skeleton.

•Corals exhibit a great diversity in growth forms, ranging from delicately branching species to those whose massive skeletal deposits form the building blocks of the reef.  

 

Cnidaria

•On type, Meandrrina, the polyps are arranged continuously in rows, resulting in production of a skeleton with longitudinal fissures, a feature which accounts for its name, brain coral.

 

Cnidaria

•There is an order related to the hard corals without a skeleton that are anemones which can cover rock faces. The black or thorny corals form a slender, plant-like colonies arranged around a horny axial skeleton and possess numerous thorns

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cnidaria

•Octocorallian corals have eight featherlike tentacles and an internal skeleton like structure. These include the horny corals, sea whips and fans and red coral. Most of these have ancestral rod composed of organic material around which is draped the coenenchyme and polyps, the former containing spicules which impart a vivid coloration and form the spines of the red coral which is used in jewelry.  

 

Cnidaria

•To trap prey, cnidarians normally employ stinging cells which are discharged (under nervous control?) sometimes exposing barbs and frequently contain a toxin that can enter the body of the prey. Some are extremely potent (sea wasps ) and have killed humans...respiratory paralysis. Sea slugs are known to pirate Nematocysts (stinging cells) and use them for their own protection.

 

 

Cnidaria

•http://www.gotosnapshot.com/Ovate/ovate_catalog.html

 

Ctenophores

•Comb Jellies Phylum: Ctenophora

•About 90 species ...worldwide and marine distribution.

•4cm to 1m in size.

•.radial symmetry with eight rows of plates..fused cilia (comb) for locomotion.

 

Ctenophores

•Fewer than 100 species have been described. They are classified on the basis of their

•tentacles

•Body form

•oral lobes,

•gastrovascular divisions

•body compressions.  

 

Ctenophores

•1. These are a group of bi-radial jellyfish called comb jellies because of the presence of ciliated comb plates used in locomotion. Their

•continuous beating refract light creating a prism-like multicolor effect. Each row is a series of small paddles and each paddle is

 

 

 

Ctenophores

•composed of thousands of tiny cilia. Collectively, the cilia produce a color spectrum in much the same way as a diffraction grating or the surface of a compact disk. Entirely marine and mostly pelagic or planktonic...some can creep.

•2. Only body cavity is the gastrovascular cavity in the form of canals.

 

 

 

Ctenophores

•3. The body wall is composed of an epidermis, layer of collenchyme, and a gastrodermis. Collenchyme contains amoebocytes,  connective tissue and true muscle cells, so its more advanced than the mesoglea in cnidarians.

•4. Most ctenophores possess on their tentacles adhesive cells called colloblasts. The tentacles are used for catching prey and

 

 

Ctenophores

•balancing organs (nematocysts in cnidarians and only one ctenophore).

•5. Skeletal structures and excretory and respiratory organs are lacking.

•6. Varied shapes

•7. Well developed statocyst at pole and a nerve net system in epidermis

 

 

 

 

 

 

 

 

 

 

Ctenophores

•Comb jellies are virtually all true plankton (drifters)-dwellers whose almost invisible transparent bodies drift in the oceans trailing tentacles like fishing lines.

•These are armed with lasso cells that explode and ensnare their microscopic prey.

 

Ctenophores

•Phylum Ctenophora

–Class Tentaculata with tentacles

–Order Cydippida Pleurobrachia

•Order Lobata Mnemiopsis

•Order Cestida Velamen

•Order Platyctenea Ctenoplana

–Class Nuda without tentacles

•Order Beroida Beroe  

 

 

Worms

•LOPHOPHORATES

•Three phyla of marine animals, Ectoprocta, formally Bryozoa, Brachiopdoa and Phoronida, are characterized by a lophophore, a circular or U-shaped ridge around the mouth bearing either one or two rows of ciliated, hollow tentacles.

 

Worms

•Because of this unusual feature, they are thought to be related to one another.

•The coelomic cavity of them lie within the lophophore and its tentacles and the anus is always elsewhere.

•The lophophore functions in these animals as a food collection organ and as a surface for gas exchange.

Worms

•They are attached to the substratum or move slowly, using the cilia of the lophophore to capture the plankton on which they feed.

 

Worms

•Phylum Phoronida resemble common tube worms seen on dock pilings.

•Look like polychaete worms.

•They secrete a chitinous tube within which it lives out its life and they also extend tentacles to feed and quickly withdraw them when disturbed but that's where the resemblance to the tube worm ends.

 

Worms

•The Phoronida is one of the smallest and least familiar phyla; there are about twelve or so living species in two genera, Phoronis and Phoronopsis. However, phoronids -- or "horseshoe worms," as they are sometimes called -- may be abundant in shallow marine sediments at certain localities.

Worms

•Phoronids are elongated and worm- shaped, but the gut loops and ends close to the mouth, instead of passing straight through the body as in annelids and many other wormlike organisms

 

 

Worms

•There is no straight tube within a tube but a U-shaped gut within a sac.

•Only 12 species are known ranging in length from a few mm to 30 cm.

•Some lie buried in sand and others attach to rocks signally or in groups.

 

Worms

•Phylum Ectoprocta (Bryozoa) look like tiny short versions of the phoronoids ..small .5mm and colonial and called moss animals.

•The new name, ectoprocta refers to the location of the anus (proct) which is external to the lophophore.

 

Worms

•4000 species include marine and freshwater forms..only non-marine lophophores.

• Most live in shallow water but some live at 18,000 feet.

Worms

•Individuals secrete a tiny chitinous or limestone chamber, ZOECIUM, attached to other members of the colony and to rocks.

•Individuals communicate chemically through pores between chambers.

 

Worms

•Their taxonomy depends on the sizes shape, and organization of the colonies.

•The arrangement of the zooids on the colonies is also highly variable. Some are important as pests as they can foul up piers, pilings, buoys and ship hulls.

Worms

•PHYLUM BRACHIOPODA or lampshells

•Bottom dwelling clamlike organism that are permanently attached to the substrate and possess a complex lophophore, which consists of two spiral ciliated tentacles resembling arms.

•Classification key http://paleo.cortland.edu/tutorial/Brachiopods/brachclass.htm

 

 

 

 

Worms

•The LOPHOPHORE is a circular or U-shaped ridge around the mouth bearing either one or two rows of ciliated, hollow tentacles

Worms

•The lamp shells resemble clams because they have two shells but these shells are hinged so that one shell covers the top and the other its bottom side (dorsal and ventral whereas the clam its the left and right side.

Worms

•Many species attach to rocks or sand by stalks that protrude from within the shell, a contractile muscle called the PEDUNCLE, while others become cemented by shell secretions to the substratum.

Worms

•These shells feed on particles suspended in the water, the cilia creating water currents sweeping food particles onto the lophophore which lies within the shell (as opposed to others that are outside).

Worms

•There are only 300 species of brachiopods existing today but more than 30,000 species are known as fossils with the genus Lingula having fossil records back to 500 million years.

Worms

•Worms... Nematode sea worms are the most numerous of all sea or land animals with an estimated population of 40 septillion.

 

•The convoluta worm feeds only once in its life feeding off a special algae and is sustained by starches made through photosynthesis by the algae it swallowed.

 

 

Most modern reports say that Convoluta roscoffensis needs the algal cells (Platymonas convoluta) to survive. The algae cells inside the worm are rounded and hardly look like an algal cell. However when they are released into the sea water the quickly change shape and swim to nearby flatworm eggs where they burrow inside the eggs and grow and multiply inside the developing flatworm embryo. Another species, Convoluta paradoxa is thought to have photosynthetic diatoms in its tissues.

Biology of the acoel flatworm Convoluta roscoffensis

Sheltered sandy beaches of the bretonic coast (near Roscoff, Carantec, Carnac, La Trinite sur mer) are  well-known habitats of the acoel flatworm Convoluta roscoffensis (order: Acoela, phylum: Platyhelminthes) which can be found there in summer time on a massive scale.

 

 

 

©  All photos and information kindly provided by:Arthur Hauck, Germany

 

 

During low tide, when water puddles form at sandy beaches, Convoluta roscoffensis gather together at the surface of these warm floodlit pools to provide optimal photosynthetic conditions to their symbiont Tetraselmis convolutae, a green alga living inside the flatworm's body.

 

 

 

At first glance the green coloration of sea water puddles seems to be caused by massive accumulations of algae. However, at closer observation color is obviously due to millions of tiny green flatworms (up to 15 mm in length) continuously moving around.

 

 

 

 

In Convoluta roscoffensis up to 25.000 algae per individuum have been counted. After entering the adult phase, crucial anatomical changes such as loss of a functional pharynx and mouth, demonstrate that the worms now completely rely on their endosymbionts. They have become photoautotrophic organisms consuming sugars provided by the symbiontic algae.

 

 

 

 

The relationship between Convoluta roscoffensis
and Tetraselmis convolutae shows typical
features of a true symbiosis that are
depicted on this flow scheme.

 

 

Worms

•Phylum Platyhelminthes...flatworms...3 layers, organs, no anus. They are the only worm like creature without an anus, use cilia on the bottom to glide along the surface and have muscle contraction in the body walls.

•These animals are worm like...tapeworms, planaria flukes and marine flatworms.

Worms

•There is a free-living flat worm that lives in the book lungs of a horseshoe crab, a tapeworm in the digestive system of the whiting fish some live on the beards or threads of mussels and one lives on the sandy beaches in France...bright green!

Worms

•Phylum Nemertea...ribbon worms...900 species..most marine. Like flatworm but has one way digestive system and circulatory system . Usually very highly colored and found burrowing in sand and mud on the shore or in crevices of rocks. Some can swim and most capture their prey.

 

 

 

 

Worms

•The most distinctive feature is a proboscis, a long fleshy tube to entangle prey . Though common, some are nocturnal and not usually seen, and others are found under rocks at low tide. They are very elastic. They are of little economical or ecological importance.

 

 

Worms

•Phylum Nematoda or round worms usually found in sediments , especially rich organic matter. Many can even live nicely in tissues of other organisms. The actual number is debatable 10-15,000 but maybe more like 1/2 million.

 

Worms

•Phylum Annelida segmented worms 13,000 species mainly the Polychaetes make up the marine annelids. (6,000 species) They have short extensions or parapodia with stiff sharp bristles or setae often with gills on them for respiration. The life cycle includes a trochophore larval feeding stage...like other groups of invertebrates.

 

Worms

Worms

 

 

 

 

 

•     In 1900, a strange tube-dwelling worm was dredged from deep waters around Indonesia. While somewhat resembling tube-dwelling annelids, it lacked obvious segmentation; even more strangely, it also lacked a mouth, gut, or anus.

 

•     About 80 pogonophoran species are known today, with new species still being discovered. One of the most spectacular zoological discoveries of recent years was the finding in 1977 of giant pogonophoran worms, 1.5 meters long, growing in heated, sulfur-rich water around warm-water vents in the Pacific Ocean, 2600 meters below the surface

 

 

 

•     How do pogonophorans feed with no mouth or gut? Some nutrition is provided by absorbing nutrients directly from the water with the tentacles. But most of a pogonophoran's nutrition is provided by symbiotic bacteria living inside the worm, in a specialized organ known as the trophosome that develops from the embryonic gut.

 

•     Inside the trophosome, these bacteria oxidize sulfur-containing compounds such as hydrogen sulfide, which pogonophorans absorb through their tentacles -- the bright red color of rift-dwelling pogonophoran tentacles is due to hemoglobin, which absorbs both sulfides and oxygen for the use of the bacteria. The bacteria derive energy from sulfur oxidation, which they use to fix carbon into larger organic molecules, on which the pogonophoran feeds.

 

 

 

 

Worms

•They include sandworms, bloodworms, fanworms or featherduster worms, palolo worms and a variety of tube dwelling worms. These can make tubes from mucus, protein, mudgrains, bits of seaweed, shell fragments etc..

 

 

Worms

•Worm

Rock…

 

 

 

 

 

 

•     Sabellariid Worm Reefs

•     The low mounding structures that form living reefs along Florida’s coast are made by numerous tiny marine bristle worms of the family Sabellariidae (sa - bell- AIR - id - ee). Each worm settles onto a hard, durable surface and begins to construct a protective tube out of the surrounding sand.

 

•     The Sabellariid worms attach their tubes to their neighbors’ tubes, forming large colonies which grow into massive mounding reefs. These reefs are sometimes exposed at low tide, creating tide pools and providing habitat for many marine organisms. An outstanding example of this type of reef is found at Bathtub Reef Park on Hutchinson Island, just 3 miles south of the Florida Oceanographic Society, and just north of the St. Lucie Inlet

 

 

 

•     The species of Sabellariid worm found in our area is called Phragmatopoma caudata. The Adult worms are up to 2 inches long and 1/8 inch in diameter, although most worms are closer to Ύ inch long. These worms can be found building their reefs on limestone and coquina formations, jetties and pilings from Cape Canaveral to the south end of Biscayne Bay.

 

•     Many different species of marine organisms live around these reefs. This makes them excellent places to go snorkeling on calm days.

 

 

•     These worms build sand hoods over their tubes to protect themselves from drying out in the sun at low tide. Walking on a living worm reef crushes these hoods into the tubes, sealing them, and killing the worms. People should never walk on, scrape, or break pieces off the worm reefs.

 

Worms

•Feeding methods relate to the locomotion and many are either suspension feeders/deposit feeders or just plain carnivores.