Ch 5 Protozoans and Major Invertebrate groups

Single celled animals, “tissue” organisms, and the animals

without backbones

Characteristics• Protozoans-single celled,

eukaryotic, heterotrophic (nonphotosynthetic), microscopic; asexual and sexual reproduction.

• Multicellular Animals- many cells, tissue level and system level organisms; heterotrophic; shape may be asymmetrical, radial or bilateral; asexual and sexual reproduction.

Globigerina

The "shell" is composed by a number of spherical chambers. Very common and abundant in pelagic plankton, even at the very deep.

Kingdom Protista Phylum

Sarcomastigophora Order Foraminiferida

Shells of Calcium carbonate

• The possession of photosynthetic symbionts by marine protozoa may make them important primary producers as well as being consumers.

• Thus the radiolarian protozoa, ACTINOPOD amoeba which live suspended in the euphotic* zone (that where there is enough light for photosynthesis) of warm seas, "farm" photosynthetic dinoflagellates* as symbionts in their cytoplasm* while also feeding phagotrophically* on other planktonic organisms.

• The siliceous skeletons of these organisms are objects of immense beauty; they sink to the sea bed forming the "radiolarian ooze".

Radiolarians Radiolarians are single-celled

protistan marine organisms that distinguish themselves with their unique and intricately detailed glass-like exoskeletons, silica. Skeleton commonly known as tests. Most contain many spines and holes that regulate a network of pseudopods useful in gathering food. Dead radiolarians accumulate in the ocean floor.

Tintinnid

Note the tintinnid ciliate lower left that has been suspension feeding on phytoplankton, visible in food vacuoles.

Ciliates

Ciliates are microscopic unicellular organisms, generally found in the plankton of rivers, lakes, seas and oceans. They are characterized by having hairy structures called cilia. These cilia can surround all the cell or part of it. They are used both for moving and for creating currents to carry food to their mouth.

How are they and what is their size?

Their shape can be spherical, ellipsoidal, conic or cylindrical and their size can vary between 10 and 200 µm. Some of them build a transparent shell around the cell called lorica (in tintinnida), while other are naked ciliates.

Characteristics• Protozoans-single celled, eukaryotic,

heterotrophic (nonphotosynthetic), microscopic; asexual and sexual reproduction.

• Multicellular Animals- many cells, tissue level and system level organisms; heterotrophic; shape may be asymmetrical, radial or bilateral; asexual and sexual reproduction.

Types of symmetry

• asymmetrical

• radially symmetrical

• bilaterally symmetrical

Porifera: The Pore animals

Porifera: “pre-tissue-level” animal Sponges are among the most

abundant and widely distributed marine animals.   A sponge can either be a single animal or a colony of animals.  They are incapable of locomotion and they attach themselves to rocks.   The living "tissue" is a soft, dark, slimy material that covers a soft, flexible skeleton.  The skeleton is what is left after the softer tissue has been cleaned off. 

                                

                             

Cnidaria: jellyfish,sea anemones, corals,

hydroids Although cnidarians vary

greatly in appearance, they do have common characteristics that separate them from other groups. A common characteristic that has given this group its name, are its stinging cells (cnidoblasts).

                                             

Polyp and/or Medusa

Cnidocysts (nematocysts) Stinging cells can even be

used for defense. However, most stinging cells are of insignificant strength to cause discomfort to man, but there are a few exceptions, like the lion´s mane jellyfish. A few specie can be very venomous. In Swedish waters only the stinging jellyfish can cause discomfort.

                                                         

Examples of Representatives

When touched they can discharge a barbed thread that is connected to a venom sac.   

Cnidarians use their stinging cells to incapacitate their prey. Large cnidarians like jellyfish and anemones are predators that can attack large prey.

                             

                                             

Moon jelly

Black Sea Nettle

Portuguese man-o-war

This colony of animals is found in the warmer regions of the Atlantic and Gulf can cause very painful injuries.

Box jellyfishseawasp

Along the beaches of Australia and Hawaii, signs are often posted warning for a special type of cnidarian, the box jellyfish. Injuries from box jellyfish can be lethal if medical attention is not acquired in time. Symptoms of a sting include stinging, burning, redness, swelling of lymph nodes and in cases of severe reactions may result in difficulty with breathing, symptoms of shock and cardiac arrest.

Ctenophora

The rainbow colors on ctenophores are not bioluminescence. They are merely diffraction acting on the ambient light. This shallow-dwelling species, Beroe forskalii, produces a bright luminescent display when disturbed. (Approx size 10 cm).

                            

Ctenophore, Pleurobranchia

• tentacles armed with colloblasts capture food

• four external bands of cilia called ctenes that provide propulsion

                                                 

Platyhelminthes: the flatworms

• Endoparasitic and ectoparasitic

• Free-living• Three groups:

1. flukes

2. tapeworms

3. turbellarians

Nemertina: benthic ribbon or bootlace worm

This is a Ribbon Worm, or Bootlace Worm. They can grow very long and can change shape from being a short, fat worm to being an extremely long thin worm. Unlike most worms, it does not have a mouth at the end of its body, but has a long proboscis which can shoot out from a pore about a quarter of the way down the body.

Gastrotricha

Usually less than 1 mm, these worms they often go unnoticed. They live in the sand and mud deposits in shallow marine water and feed on detritus, diatoms, and other small animals

Nematoda: the round worms

• Round worms are separately sexed (males and females)

• Probably the most abundant group of organisms on Earth.

• Free-living and parasitic

Mollusks

Soft-bodied animals, having a muscular foot, mantle that may produce a shell. Shells may be internal or external and vary in number of pieces (valves or plates). Most exhibit cephalization and many have a radula, a rasping tonguelike organ.

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Chiton

Early Americans ate chitons in times of extreme hunger.

Known for their 8 plates that appear as a ribbon shell when animal tissue dies away.

Molluscan parts…

• heart• intestine• radula• shell• foot• stomach• mouth• eyes on stalks

Chambered nautilus

The chambered nautilus is a cephalopod with a beautiful external shell

Squid or Cuttlefish?

Cuttlefish

The cuttlefish looks like a flattened squid and has an internal skeleton-the cuttle bone (below) that is often used as a supplement for birds.

Scallop

Bivalve

Able to move by a “clapping” motion

Octopus

• shy, timid and not aggressive

• average size is about three feet from head to end of arms

• mate one time, female cares for her eggs without eating, and she dies as the eggs hatch

Giant Octopus The octopus has eight tentacles that sometimes stretch 4.8 m across in a 45 kg specimen. The octopus is a mollusk that is related to the squid, oyster, clam and snail. The giant Pacific octopus is the major species on the west coast and also the world's largest. It is illegal to use jigs, gaffs, spears, rakes or any other sharp-pointed instrument to take octopus.

Giant squid

Estimated 100 feet long and weighing 2 tons

Chaetognatha

• Arrowworms are torpedo-shaped planktonic carnivores.

• The tiny reflection in wet beach sand are probably the chaetognath, Sagitta.

                                         

           

Annelids the segmented worms

This phylum includes earthworms, leeches and marine worms, the Polychaetes.

Many are tube-dwelling and have filtering structures resembling feathers.

Arthropoda: the jointed legs, segmented bodied animals

Widely distributed on the planet earth, these animals have exoskeletons composed of chitin. Their size varies from microscopic copepods and other marine crustaceans to crabs several feet across.

Shrimp, crab and lobster

Blue crab

                                                                                          

Female and male crab

Growth rateMust molt to grow; females and males sexually mature at 100 and 150 mm, respectively (2-3 yr); males reach legal size (165 mm) at 3-4 yr; females seldom reach legal size.

                                                                                                  

                            

Limulus-horseshoe crab These animals have aqua

blue blood. Although horseshoe crabs look dangerous, they are not. And they are really not crabs at all; they are distant relatives of the spider.

                                               

Gender: Male or Female? Several distinct variations between males and females occur in

horseshoe crabs. Upon reaching maturity at 9-10 years old, the female horseshoe crab will molt one or two more times unlike the male crab that stops molting. As a result, the female crab is considerably larger than the male. Also, the mature male horseshoe crab will develop a modified first pair of walking legs. The new legs (pedipalps) have a hooklike structure that resembles a boxing glove. The male horseshoe crab uses the modified legs to clasp onto the shell of the female during spawning. Prior to reaching maturity males and females are identified by the shape of their genital pores. The pores can be found behind the first gill cover at the base of the first pair of book gills. On a male, the genital pores are firm pointed structures and white in color. Differing from the male, the females genital pores are broad convex structures similar in appearance to small bumps.

Sexing the Horseshoe crab

Male female

“blue blood”?

Why is the Horseshoe Crab the original “blue blood”? A horseshoe crab’s blood has a blue to blue-green color when exposed to the air. The blood is blue because it contains a copper-based respiratory pigment called hemocyanin.

HORSESHOE CRAB BLOOD

The blood of the horseshoe crab is not only unique but it provides a valuable medical product critical to maintaining the safety of many drugs and devices used in medical care. A protein in the blood called Limulus Amebocyte Lysate (LAL) is used by pharmaceutical and medical device manufacturers to test their products for the presence of endotoxins, bacterial substances that can cause fevers and even be fatal to humans.

OTHER MEDICAL BENEFITS Horseshoe crabs have also been proven to benefit cancer

research. Endotoxins are known to inhibit the growth of cancer cells. Therefore, the ability of the LAL test to detect cancer cells may lead to a new type of cancer therapy using endotoxins. Another substance found in horseshoe crab blood may have the potential for diagnosing leukemia. This substance reacts with red and white human blood cells, including cancerous white blood cells in leukemia patients. Furthermore, a New Jersey Sea Grant project has recently discovered a rare protein in horseshoe crab blood that traces and binds with vitamin B12. These findings led to the development of an accurate, cost-efficient testing kit for detecting vitamin B12-related deficiencies and diseases, which may include pernicious anemia, gastric and intestinal damage, and even mental disorders.

Barnacles

Copepods

Although most of the approximately 8,500 species of copepods are marine, some live in freshwater lakes and ponds.  One of the most important and abundant components of aquatic food chains, copepods feed on unicellular phytoplankton (photosynthesizing protists).  Lacking a carapace, copepods have cylindrical, tapering bodies with forked tails. In contrast to other crustaceans, copepods lack gills and abdominal appendages. The female copepod shown in the image (appropriately named Cyclops) carries eggs inside of two attached egg sacs.

Mysid These small organisms show a very

strong seasonal pattern with highest abundances in the summer and fall of the year when they reach mean densities of 300-700 per sample and peak at over 2000 in a single sample, but may be completely absent from samples during other times of the year. Their value is a food resource for fisheries species. Mysids are highly motile and can migrate vertically although they are primarily a bottom dwelling group

Euphausiid • Euphausiid's are harvested mainly as a feed supplement for both fish farms (gives salmon their "pink" color) and humans consume them.

• Swimming appendages are too small to enable them to swim effectively against the currents, so they are common and widespread along the coast.

• Krill undergo a daily "diurnal" cycle, where they spend the daylight hours in the twilight depths of the ocean (100 meters or 300 feet), and during the night or cloudy days they come closer to the surface. Intertidal at over 100 meters subtidal depth to 60 meters.

Brine shrimp

Brine shrimp are branchiopod crustaceans that live in waters with high salt contents (like Death Valley, Great Salt Lake, etc.).   They often produce resistant eggs as an adaptation to drying in temporary pools.  When the rains come and the eggs are rehydrated, they  hatch into tiny brine shrimp.  It is these eggs that are sold in dehydrated form for aquarium fish food as well as for culturing so-called "sea monkeys".   

The Echinoderms

All members of this phylum live in a marine environment. Representatives include sea stars, brittle stars, sea urchins and sand dollars, sea cucumbers, feather stars and sea lilies.

Brittle star

Brittle stars have delicate arms that quickly regenerate from the central disk when broken.

Sea Urchin

HabitatRocky substrates, especially ledges and crevices; locate near or in giant or bull kelp beds and other brown algae in areas of moderate to swift currents; larvae drift and feed in plankton; juveniles settle near kelp beds, often associate with aggregations of adults, remain under adult spines until they reach 40 mm.

The Invertebrate Chordates Chordates exhibit at

sometime their life history: – notochord (cartilage), – dorsal nerve cord, and – paired gill slits.

Common reps considered invertebrate chordates include the tunicates (lancelets) and sea squirts)

TUNICATA (Urochordata

CEPHALOCHORDATA (Lancelets)

Lancelet

Invertebrate food from the sea

Name the phyla represented

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