ECHINODERMS

PHYLUM ECHINODERMATA

CHARACTERISTICS

• Radial symmentry
• Several arms (5 or more,mostly grouped 2 left-1 middle-2 right)radiating from a central body.
• Body consist of equal segments,each containing a duplicate of various internal organs.
• no brain nor heart
• with eyespots on each arm
• mouth situated on the underside and anus on the top(except feathers stars,sea cucumber and some urchins).
• contains tube feet with suction pads controlled by water vascular system.
• some are carnivorous while others are detritus foragers 
• reproduction is through release of sperms and egg into the water
• capable of regeneration and fragmentation.

TYPES OF ECHINODERMS

• Class Asteroidea
• Class Ophiurodea
• Class Echinoidea
• Class Holothuroidea
• Class Crinoidea

1.CLASS ASTEROIDEA

• Carnivorous and feed on sponges and mollusks some are specialized feeders.(crown of thorns)
• doesn't have hard mouth parts to help them capture prey



CROWN OF THORNS (ACANTHASTER PLANCI)

Crown of thorns ( Acanthaster planci)
• one of the largest and the most venomous starfish
• size reaches up to 50cm. in diameter
• 10-20 spiny arms with formidable thorn like toxic spines
• feed on coral polyps
• Predators: Triton shell and some puffer fish

2.CLASS OPHIUROIDEA

• close relatives of sea stars
• have five snakelike arms which highly flexible
• no replication on internal organs,just one set in the central disk
• smaller central disk and no anus



SERPENT STARS



• arms  of brittle stars are fragile. (defense mechanism)
• most active and fastest moving echinoderms
• feed on plankton but also on detritus

3.CLASS ECHINOIDEA

Sea Urchins:

• external chitinous skeleton and a centrally located jaw
• some have spherical bulb like cloaca
• movable spines are attached to the body,some are venomous

• locomotion by tube feet but also by movement of the spines on the underside of the body
• generally nocturnal
• most are algal grazers but some feed on the sponges and detritus

4.CLASS HOLOTHUROIDEA

• dont have radial symmetry but are bilateral
• cucumber shaped with elongated muscular,flexible body with mouth at one end anus on the other 
• tentacles present in mouth for food collection 

• feed on rich organic film coating sandy surfaces
• crawl over the bottom and ingest sand
• move by means of tube feet
• releases its digestive tract when threatened (defense  mechanism)

5.CLASS CRINOIDEA

• radial symmetry
• cup-shaped body
• numerous feathery arms project from a central disc
• have 5 up to 200 arms(pinnules)
• nocturnal
• usually cling to sponges

FEATHER STARS

Reporters: 

⚬Ma. Fe Camacho

⚬Merielette Joven

⚬Florencio Angcay

BIRDS

EVOLUTION OF BIRDS

• Birds are thought to have evolved from a group of bipedal dinosaurs called theropods. The ancestor of birds was probably similar to theropod called Deinonychus which is presented by the sketch.

• Fossils of Deinonychus were the first identified in 1960s.This was an extremely important discovery. It finally convinced most scientist that birds had descended from dinosaurs, which had been debated for almost a century.

• Deinonychus is the genus name of an extinct dinosaur that is considered to be one of the closest non-bird relatives of modern birds. It lived about 110 million years ago in what is now North America.
  
• Theropods - a carnivorous dinosaur of a group whose members are typically bipedal and range from small and delicately built to very large.

THE ORIGIN OF BIRDS

• The discovery that birds evolved from carnivorous dinosaurs of the LATE JURASSIC was made possible by recently discovered fossils from China, South America, and other countries, as well as by looking at old museum specimens from new perspectives and with new methods.

• The hunt for the ancestors of living birds began with a specimen of Archaeopteryx, the first known bird, discovered in the early 1860s. Like birds, it had feathers along its arm and tail, but unlike living birds, it is also had teeth and a long bony tail. Futhermore, many of the bones in Archaepteryx hands, shoulder girdles, pelvis, and feet were distinct not fused and reduced as they are in living birds.

5 MAJOR CHARACTERISTICS OF BIRDS

FEATHERS- are the defining characteristic of Aves, found on every living species of bird and no other class of animal. 

• made of keratin, the same substance that forms hair and nails in other animals and are highly modified scales.
• feathers are critical not only for flight but also for warmth and protection against the elements and many species 
• feathers for males used to attract mates
  

WINGS- all birds have wing, although not all birds can fly. Nor are wings confined to Aves: bats are flying mammals and most insects have wings.

        

BEAK-all birds have beaks or bills, made of a bony core surrounded by a thin layer of keratin.

• Birds do not have true teeth, but many have species have tomia
• sharp ridges along the edge of their beaks
• birds do not chew food
• grind or rip into pieces small enough to swallow
• shape of birds beak indicates the birds general diet
• meat eaters like hawks and owls have sharp, hooked beaks for ripping and tearing
• strong cone-shapes beaks help seed eaters break through shells.
• ducks and geese have broad,flat beaks for straining food out of water
  

EGG-all birds lay eggs,some very colorful or covered with spots.Eggs are not unique to eggs,of course fish,reptiles,amphibians and insects also lay eggs.

SKELETON-most birds have lightweight skeleton with hollow bones.

• keeps them light enough for flight
• fused bones including the collarbones or wishbones make birds skeleton rigid
• sternums or breastbones are large,providing sturdy attachment points for powerful wing muscles
  

DIVERSITY OF MODERN BIRDS

BIRDS are one of the most recognizable and diverse group of modern vertebrates.Over the past two decades, a wealth of new fossil discoveries and phylo genetic and macro evolutionary studies has transformed our understanding of how birds originated and became so successful.

The phylogeny shows where birds fit into the larger vertebrate family tree and the relationships of the earliest birds and their closest dinosaurian relatives (based on and other studies cited therein)

AMPHIBIANS

Origin and Evolution of Amphibians

Lobe – finned fish

• Bone structure within their fins allowed for them to function as “legs”
• Modified pouches in digestive tract evolved into lungs of the lungfish and swim bladder of modern fish
• Amphibians also share skull and vertebral column

Lobed – finned fish: Coelocanth

Oldest amphibian fossils were dated to 360 m.y.a

Between 359 – 299 m.y.a amphibians split into two main evolutionary lines

Modern amphibians

Ancestors of reptiles

Classification

Domain: Eukarya 

Kingdom: Animalia 

Phylum: Chordata 

Subphylum: Vertebrata

Class: Amphibia, 4500 species

Order Anura, largest order contains the frogs and toads

Order Caudata, contains salamanders

Order Gymnophiona, contains caecilians

1. Order Anura

• Frogs and toads (squat bodies, shorter legs, skin not as smooth as frog)
• Found in a variety of moist habitats
• Adults are carnivorous
• Reproduction
• Amplexus
• Metamorphosis

Life Cycle

• Fertilization takes place
• Eggs hatch, tadpole lives off yolk stored in its body
• Tadpole grows larger, three gills develop
• Mouth opens, begins to feed on algae
• Tadpole grows slowing changing from an aquatic larva into an adult
• May vary depending on species

Metamorphosis

Process of change from an egg to larva to adult

Triggered by the hormone thyroxine that is produced by the thyroid gland

2. Order Caudata

• Salamanders, newts, mudpuppies
• Elongated tails, and smooth, moist skin
• Lay eggs in water or moist places
• Both young and adult are carnivorous
• Hatchlings are small versions of parent except young have gills

3. Order Gymnophiona

• Caecilians
• Legless amphibians
• Live in tropical areas, burrow in the soil, also aquatic
• Lay eggs or young are born alive

Characteristics of Amphibians

• Five key characteristics; legs, lungs, double – loop circulation, 3 - chambered heart, cutaneous respiration
• Live in moist habitats
• Mostly external fertilization

MOVEMENT

Skeleton

• Strong endoskeleton
• Vertebrae of the spine is interlocked to form a rigid structure
• Limbs support body           

Forelimbs attach to the pectoral girdle (shoulder)

Hind limbs attach to the pelvic girdle

Transfers body weight to the limbs

Frogs, lower limbs are fused into a single bone

Forelimb (radio – ulna) and hind limb (tibiofibula)

Response

• Sense Organs
• Lateral line as larvae
• Sight, sound, smell
• Nictitating membrane
• Transparent membrane that covers eyes
• Tympanic membrane
• Eardrum

Respiration

• Gills, most loose as adults
• Skin serves two important functions – respiration and protection

            Cutaneous respiration

            Diffusion

            Mucous glands

• Pulmonary respiration

Pulmonary Respiration

• Pump air into lungs in a process called positive – pressure breathing
• Frog breathes by changing the volume and pressure of air in its mouth while either opening or closing its nostrils

Circulation

• Three chambered heart and double – looped circulation
• Increase pressure and speed of delivery for oxygen rich blood to organs
• Divided into two separate loops

Two separate loops

• Pulmonary circulation
• Carries deoxygenated blood from the heart to the lungs and back to the heart
• Systemic circulation

  Carries oxygenated blood from the heart to the body and back to the heart

  
  

Three chambered heart

• Right and Left Atrium (septum divides)
• Ventricle (spongy surface and contraction)

  Deoxygenated blood enters from the body, right atrium

  Oxygenated blood enters from the lungs, left atrium

  Contraction of the atria forces blood into a single ventricle

  Ventricle contracts pushes all of the blood into the conus arteriosus, which directs the blood to the lungs or the body

MAMMALS

MAMMALS

There many groups (classes) of animals. Mammals is just one group.

All mammals share some traits:

• Mammals have body hair that protects them from colds or sun.
• Mammals have 3 middle ear bones that helps give them good hearing.
• Females have milk to feed their young.
• Mammals take care of their young.
• Mammals are warm blooded.

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WARM BLOODED VERTEBRATES

• Birds and mammals are two classes of vertebrates that are said to be warm blooded. They possess various mechanisms to ensure that their body temperature is fairly constant, (unaffected by, and usually warmer than, their surroundings), so that they can function more efficiently and reliably.

Warm & Cold Blooded

• Warm blooded-only two kinds of vertebrates birds and mammals are warm blooded.Their blood and body stay the same temperature no matter how cold or hot their surroundings.These animals become ill or die if their body temperature change very much.
• Cold Blooded-Almost all animals are cold-blooded. The temperature of their blood and body changes when their surroundings became warmer or colder.

EVOLUTIONARY PRESSURES

 

FISH

FISHES

• a limbless cold-blooded vertebrate animal with gills and fins and living wholly in water. "the sea is thick with fish"

Chordata: Subphylum Vertebrata

• Vertebrates constitute the vast majority of living chordates, and they have evolved an enormous variety of forms.

• possess a backbone (aka vertebral column spine)
• vertebrae=Dorsal row of hollow skeletal elements(usually bone)
• nerve cord=spinal chord,protected by vertebrae.(part of nervous system)ends in brain
• bilateral symmetry,endoskeleton

AGNATHANS(AGNATHA)

• It is came from the Greek word[4] ἀ-γνάθος "no jaws") is a superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present (cyclostomes) and extinct (conodonts and ostracoderms) species.

• Agnathan, (superclass Agnatha), any member of the group of primitive jawless fishes that includes the lampreys (order Petromyzoniformes), hagfishes (order Myxiniformes), and several extinct groups. 

Kingdom:Animalia

Phylum:Chordata

Subphylum:Vertebrata

Superclass:Cyclostomata

Class:Myxini

Order:Myxiniformes

Family:Myxinidae

HAGFISH :(order Myxiniformes)

• Hagfish, of the class Myxini (also known as Hyperotreti), are eel-shaped, slime-producing marine fish (occasionally called slime eels). They are the only known living animals that have a skull but no vertebral column, although hagfish do have rudimentary vertebrae.
• Hagfish are widely considered the most disgusting animals in the ocean, if not on earth. The eel-shaped creatures use four pairs of thin sensory tentacles surrounding their mouths to find food—including carcasses of much larger animals.
• The estimated 76 species of hagfishes live in cold waters around the world, from shallow to as deep as 5,500 feet (nearly 1,700 meters).
• Hagfish can absorb nutrients straight through their skin.
• They are sometimes called “slime eels”—but they are not eels. They are in the class Agnatha, designated for fish without jaws (around 100 species in total).

CLASS CEPHALASPIDOMORPHI

• Cephalaspidomorphs are a group of jawless fishes named for Cephalaspis of the osteostracans. Most biologists regard this taxon as extinct, but the name is sometimes used in the classification of lampreys, because lampreys were once thought to be related to cephalaspids. 

Scientific name: Cephalaspidomorphi

Extinction status: Extinct Encyclopedia of Life

Rank: Class

Higher classification: Craniate

Phylum: Chordata

LAMPREY: (order Petromyzoniformes)

• Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes, placed in the superclass Cyclostomata.
• The sea lamprey is a fish that is eel-like in appearance. 
• It has a skeleton made of cartilage and lacks a jaw.
• This species has seven gill openings, two fins along its backs, and no side fins. 
• The sea lamprey has a large, round mouth with sharp, curved teeth
• Ocean-dwelling sea lamprey can grow up to 47 inches (120 cm) in length. Freshwater sea lamprey can grow up to 25 inches (64 cm) in length.

GNATHOSTHOMES

• Jawed vertebrates with teeth develop from modication of skeletal rods between pharyngeal gill slits.
• other features of gnathothomes:

1. additional duplication of hox genes
2. enlarged forebrains-enhanced sense of vision and smell.

*Leteral line system-rows of microscopic organs sensitive to vibrations in the water.

Example:sharks,rays,ray finned and lobe finned fish.

 *SHARK:

*RAYS FISH

*RAY FINNED FISH

*LOBE FINNED FISH

TWO EARLY GROUPS OF GNATHOSTHOMES:

*class chondrichthynes

*class osteichthynes

Chondrichthyes: Cartilaginous Fishes

-Chondrichthyes consists of sharks, rays, and skates, together with sawfishes and a few dozen species of fishes called chimaeras, or “ghost,” sharks.

-Chondrichthyes are jawed fishes that possess paired fins and a skeleton made of cartilage.

-Most sharks are carnivores that feed on live prey.

-Sharks have well-developed sense organs that aid them in locating prey, including a keen sense of smell and electroreception. 

• Rays and skates comprise more than 500 species and are closely related to sharks. 
• sharks, rays and skates have a cartilaginous skeleton.
• Most species are marine and live on the sea floor, with nearly a worldwide distribution.

Osteichthyes: Bony Fishes

-the Osteichthyes, also called bony fish, are characterized by a bony skeleton. The vast majority of present-day fish belong to this group, which consists of approximately 30,000 species, making it the largest class of vertebrates in existence today.

-A few groups of Osteichthyes, such as sturgeons and paddlefish, have primarily cartilaginous skeletons, but retain some bony elements. 

-bony fish have a lateral line system that detects vibrations in water.

• Bony fish are further divided into two extant clades: Actinopterygii (ray-finned fish) and Sarcopterygii (lobe-finned fish).

-Actinopterygii, the ray-finned fish include many familiar fish, such as tuna, bass, trout, and salmon, among others. 

- Sarcopterygii are fleshy and lobed, supported by bone. Early Sarcopterygii evolved into modern tetrapods, including reptiles, amphibians, birds, and mammals.

Actinopterygii and Sarcopterygii