Ch. 7: Marine Animals Without a Backbone - PowerPoint Presentation

Ch. 7: Marine Animals Without a Backbone

Kingdom Animalia Heterotrophic- cannot make own food Eukaryotic and multicellularSome are autotrophs97% of all animal species are invertebrates

7.1 Sponges Phylum- Porifera “pore bearers” Aggregation of specialized cells Cells are independent from each other & do not form true tissues & organs Simplest multicellular animals

Nearly all are marine Sessile (don’t move) Variety of color, shape, and sizes Flexible skeletal frame gives the spongy texture If cells separated can even regroup and form new sponge

Ostia (tiny pores) allow water to enter and circulate through series of canals where plankton and organic particle s are filtered & eaten

Outer surface covered with flat cells called pinacocytes & pore cells (porocytes) which allows water to enter Water pumped into larger feeding chamber lined with collar cells (choanocytes) Each choanocytes has flagellum the creates currents and a thin collar that traps food particles, which is ingested by body of cell

Water leaves through osculum , large opening at top of sponge Type of suspension feeders that actively filter food particles (filter feeders) Marine sponges show more complex arrangement with collar cells are restricted to chambers connected to outer pores by a network of channels

Marine sponges have single osculum but have several oscula which serves as exit from many canals Helps meet higher demands for water flow for larger sponges Large sponges have spicules that are transparent made of siliceous or calcareous supporting structures of different shapes and sizes

Skeleton made of protein spongin Some may spicules, spongin, or both Wandering cells, amebocytes, secret spicules and sponging, transport and store food particles, and transform into other types of cells to quickly repair damage to the sponge

Reproduction of sponges Reproduce asexually If piece breaks off, it can form new sponge Reproduce sexually Specialized collar cells or amebocytes can turn into gametes Large nutrient rich egg and smaller sperm cell with flagellum Most are hermaphrodites Some have separate male and female organisms

Typically broadcast spawning Egg retained inside of body until fertilization Early development takes place inside Flagellated sphere of cells (larva) is calledparenchymula larva is planktonic & drifts with currents Settles & metamorphosis into juvenile

Live from the poles to tropics Largest number of species in shallow tropical waters

Types of Sponges Branching tubular volcano-like masses

Encrusting sponges are thin brightly colored growths on rocks

Glass sponges live anchored in deep water sediments & have siliceous spicules (lace-like)

Boring sponges bore thin channels through calcium carbonate such as oysters shells and corals

Sclerosponges (coralline sponges) calcium carbonate skeleton forms beneath body of sponge

Sponges Cont Some bath sponges are harvested in Gulf of Mexico and eastern Mediterranean The spongin are the fibers that remain after the death of a spongehttp://www.blueworldtv.com/webisodes/watch/the-biology-of-sponges

7.2 Cnidarians: Radial Symmetry Next evolutionary jump Have tissues that perform specific functions Sometimes called coelenterates include sea anemones, jellyfishes, and corals Radial symmetry If cut like pizza all resulting slices would be similarLook the same from all sides No head, front, or back

Cnidarians Cont. Oral surface and aboral (away from the mouth) surface Central mouth with tentacles Mouth open into a gut (only one opening—not a complete digestive tract)This means the entrance is also the exit! Where food goes in, waste goes out. Capture prey with nematocycts (stinging structures) found within tentacles

Cnidarian Life Cycle Two basic forms: Polyp and medusa

Polyp Medusa

Cnidarians Cont. Larva is called planula, ciliated stage with two cell layers Settles and metamorphoses into a polyp or develops into medusa Two layer of cells form body wall-one the epidermis and other gastrodermis Gelatinous middle layer is mesoglea - does not contain cells In medusa this layer expands to form gelatinous domed bell

Types of Cnidarians 1. Hydrozoans (class Hydrozoa) Feathery or bushy colonies of tiny polyps attached to Polyps may be specialized for feeding, defense, or reproduction Reproductive polyps produce minute, planktonic medusa

Medusae release gametes & fertilized eggs develop into free swimming planula larvae Each planula larvae settles and develops into a polyp The poylp divides repeatedly and develops into a colony Some lack poylp stage and develop into a medusae Few lack medusae stage and develop into gamete producing polyps

Types of Cnidarians 2. cyphozoans (class Scyphozoa) Larger jellyfish Large medusae are dominate stage in life cycle Polyps small & release juvenile medusae Few lack polyp stage Bell reach diameter of 2 m (6.6 ft) Bell diameter in deep water is 3 m (10 ft)

Cyphozoans Cont. Swim with rhythmic contractions of bell but easily carried by currents Some species stings range from a rash to fatalities Cubomedusae once classified as scyphozoa now own class Cubozoa Sea wasp (box jelly)

Types of Cnidarians 3. Anthozoans (class Anthozoa)Ex. Corals and Anemones

Anthozoans Cont. Solitary or colonial polyps that lack medusae stage (they stay in polyp stage for entire life!) Largest number of species Polyps more complex Gut contain septa increasing surface area for digestion of large prey Septa provide support for larger species Sea anemones have large polyps

Types of Cnidarians (Anthozoans Cont.) Corals Colonial anthozoans Carbonate skeletons Can occur in cold waters In tropical waters form coral reefs Gorgonians (sea fans) secrete branching skeleton made of protein

Black corals Secrete hard, black protein skeleton Used for jewelry

Biology of Cnidarians 1. Feeding and digestion Carnivores Use nematocysts to capture prey Each nematocyst contains fluid-filled capsule containing thread that is ejected Thread my be spines or long tube that wrap around preyToxic Extracellular digestion-out side the cells Intracellular digestion within cells lining gut

Pneumatacysts firing: https://www.youtube.com/watch?v=-Tp38DUjUnM

Behavior of Cnidarians Lack brain & true nerves Nerve cells interconnect forming nerve net that transmits impulses in all directions Sea anemones can tell if other member is from same clone Known to attack even kill anemones from other clones Some medusae have primitive eyes Medusae have statocysts to help with balance

Comb Jellies (phylum Ctenophora ) Comb jellies, ctemophores All marine (about 100 species) Gelatinous body with 8 rows of ciliary combs that beat in waves Beating of combs refracts light creating multicolor effect Body length few millimeters to 2 m Found in warm and cold waters https://www.youtube.com/watch?v=39qe0EajbIA

Comb Jellies Cont. Carnivores Swarms consume large numbers of fish larvae and other plankton Capture prey with long tentacles with colloblasts (sticky cells) Few have nematocysts

7.4 Bilaterally Symmetrical Worms Bilateral symmetry-only one way cut the body and get two identical halves Anterior where head with brain or accumulation of nerve cells and sensory organs like eyes Posterior where the bottom is Dorsal -back Ventral - belly

Bilateral symmetry Bilateral symmetry allows to organisms to actively pursue prey and develop sophisticated behaviors

Radial Vs. Bilateral Symmetry Draw bilateral and label parts!

Flatworms (phylum Platyhelminthes ) Yes, write the phylum! Simplest worms Bilateral symmetry allows for a more developed central nervous system Simple brain- aggregation of nerve cells Have several nerve cord running from brain through the length of body Nervous system coordinates movement of well developed muscular system

Flatworms Cont. Gut has one opening (not a complete digestive tract) Have middle layer of tissues, in developing embryos it is called mesoderm Mesoderm gives rise to muscles, reproductive system and other organs 20,000 known species Turbellarians most common have striking color patters Live in or on oysters, crabs, & other invertebrates

2. Flukes (Phylum trematodes ) Largest group 6,000 species All parasites Feed on tissues, blood, or intestinal contents Adult flukes live in vertebrates Larvae may inhabit like snails and clams or vertebrates like fish Larva must be eat by a vertebrate Common in fish, seabirds, and whales

Tapeworms (cestodes ) Parasitic Have long body with repeating units Live in intestine of most species of vertebrates Head attaches to walls of gut by suckers and hooks Lack gut or mouth Absorb nutrients from host across body wall Found in invertebrates and vertebrates Longest recorded in sperm whale was 50 ft

tapeworms

tapeworms

B. Ribbon Worms (phylum Nemertea ) yes, write phylum! Ribbon or nemertean worms More complex than flatworms Complete digestive tract (mouth, gut, anus) Have circulatory system Proboscis-long flesh tube to capture prey Inverted in cavity above mouth

Ribbon Worms Cont. Feed of worms and crustaceans 900 species mostly marine Found in all oceans most common in shallow temperate waters Some nocturnal, some brightly colored found under rocks at low tides Elastic, and proboscis may extend to a meter or more beyond body length Longest invertebrate reaches 100 ft

Nematodes (phylum Nematoda ) Yes, write phylum Round worms Hardly ever seen Found in large numbers in rich organic sediments Many are parasitic found in most marine organisms Adapted to live in sediment or tissues of other organisms Typically pointed at both ends

Roundworms Anisakis and few related inhabit seals and dolphins Larvae found on flesh of many types of fish and may infect humans who eat raw or poorly cooked fish Often larvae are vomited or coughed up without further complications Sometimes penetrate into walls of stomach or intestine causing symptoms similar to ulcers

Feed mostly on bacteria and organic matter Anus lies within body cavity filled with fluid that transports nutrients Layer of muscle in the tough but flexible body pushes and squeezesagainst the fluid which acts as hydrostatic skeleton that provides support and aids in locomotion 10,000 to 25,000 species and estimates that half a million still undiscovered

Roundworms A risk all sashimi and ceviche lovers take

Segmented Worms (phylum Annelida ) Yes, write PHylum 20,000 species Series of similar compartments (segmented) Gut through all segments and lies in cavity known as coelom Coelom fluid filled & divided by partitions Segments acts as hydrostatic skeleton contracting in sequence by muscles in body wall Efficient crawlers & burrowers

Types of Segmented Worms 1. Polychaetes (class Polychaeta) Body segments of most have a pair of flattened extensions or parapodia Parapoda have stiff sharp bristles (setae) Have closed circulatory system Muscular contractions help circulation of blood Small organisms oxygen in water can easily move across body wall to all tissues Large organisms have gills on parapodia Gills thin wall extensions of body that have capillaries where gas exchange takes place

Polychaetes (class Polychaeta ) Cont. Have plantonic larval stage-trochonphore Biologist compare larvae stage of polychaetes with other invertebrates to examine evolutionary relationships Typical length is 5 to 10 cm Many crawl hiding under rocks Nereis (sandworms) carnivores Have several pairs of eyes & other sensory organs

Polychaetes (class Polychaeta ) Cont. Use proboscis with jaws to capture prey Others are deposit feeders Many live in temporary or permanent tubes made from mucus, proteins, bits of seaweed, cemented mud particles, sand grains, or tiny fragments of shells

Polychaetes (class Polychaeta ) Cont. Some are plantonic (Tomopteris) use flat parapodia to swim The Palolo worm break off & the posterior half swims up to surface to spawn (swarming) Timed with phases of the moon Some places people gather the worms for food Live on external surface of sea stars & sea urchins, in burrows of other invertebrates, and shells of hermit crabs

2. Beard worms (pogonophorans ) Highly specialized lack gut and mouth Tuft (thousand long tentacles) absorb nutrients in dissolved water Some have symbiotic relationship w/bacteria Bacteria use the nutrients to manufacture food for worm

Beard Worms Cont. Mostly restricted to deep water Length from 4-7 ft Related vestimentiferans grow larger and found at hydrothermal vents

Segmented Worms Cont. 3. Oligchaetes Small found in mud and sand feeding on detritus Lack parapodia 4. Leeches Blood sucking found attached to fishes & invertebrates Distinguished by suckers & no parapodia

E. Peanut Worms (phylum Sipuncula ) Soft unsegmented bodiesBurrow in muddy bottoms, rocks, corals, and empty shells All are marine living in shallow waters Deposit feeders Long anterior portion of body contains mouth &set of small lobes or branching tentacles Tentacles can be pulled into remaining body, become compact 1-35 cm length

F. Echiurans (phylum Echiura )Soft segmented sausages buried in mud or in coral Look like peanut w/ out spoon-like or forked proboscis Deposit feeders that use proboscis to gather organic matter Urechis caupo lives in U-shaped tubes in mud

7.5 Molluscs : The Successful Soft Body

Phylum Mollusca 200,000 species More species in ocean than of any other animal group Soft body enclosed by calcium carbonate shell soft body covered by mantle Bilateral symmetry Ventral muscular foot used for locomotion Head that includes eyes & other sensory organs

Some have radula -ribbon of small teeth used to grasp food from surfaces Radula made of chitin Paired gills Potion of body maybe coiled and asymmetrical Occupy all marine environments-rocky shores to hydrothermal vents

A. Types of Molluscs 1. Gastropods (class Gastropoda ) = stomach footed Snails, limpets, abalones, and nudibranchs Coiled mass of vital organs enclosed by a dorsal shell resting on a foot Snails, limpets, & abalone use radula to scrape algae Mud snails are deposit feeders

Limpet

abalone

Whelks, oyster drills, and cone shells are carnivores that prey on clams, oysters, worms, & small fishes Violet snail has thin shell & produces a bubble raft out of mucus to float Sea hares whose shells are small, thin & buried in tissue graze on seaweeds

Whelk

Oyster Drill Snail

Cone Shell Snail

Nudibranch

Nudibranchs

Nudibranchs (sea slugs) No shell Have colorful branches of the gut & gills Prey on sponges, hydroids, & other invertebrates Produce noxious chemicals or retain undischarged nematocystshttps://www.youtube.com/watch?v=cJE-LPcwtP8

2. Bivalves (class Bivalvia ) Clams, mussels, & oysters Body laterally compressed & enclosed with two parts (valves) No head or radula Gills expanded & folded used to obtain oxygen, filter & sort small food particles from water

Inner surface of shell lined w/mantel so whole body lies in mantle cavity Strong muscles used to close valves Clams burrow in sand or mud & water drawn in and out of mantle by siphons Siphons allow clam to feed & obtain oxygen while buried Mussels secret byssal threads that attach them to rocks & other surfaces

Oysters cement their left shell to hard surface & other to another oyster Pearls are formed when oyster secretes shiny layers of calcium carbonate to coat irritating particles or parasites lodged between the mantle and the iridescent inner surface of the shell

scallops Some can swim by rapidly ejecting water from mantle cavity https://www.youtube.com/watch?v=_2iXHBuSIJY Giant clam can grow 3 ft Bore in coral, rock, or wood Shipworm bores in mangroves, driftwood, & pilings Have symbiotic w/bacteria in the gut that digest the wood Valves lie at the inner end of tunnel lined w/calcium carbonate & tiny siphon protrudes from entrance at other end Fouling organism=settles on bottoms of boats, pilings, & other submerged structures

Clam moving https:// www.youtube.com/watch?v=48_MU9NH2rc Clam licking salthttps://www.youtube.com/watch?v=irF5sBTVniIGiant Clamhttps://www.youtube.com/watch?v=Z-32RfYNbOY

3. Cephalopods (head-footed) Predators specialized in locomotion Octopuses, squids, cuttlefishes Agile swimmers w/complex nervous system and reduction or loss of shell All marine Head toward foot that is modified into arms and tentacles Tentacles usually have suckers Large eyes on side of head