Biology 2 Lara

• Phylum: CALCAREA, SILICEA (paraphyletic)
• lack true tissues, have choanocytes (collar cells-flagellated cells that ingest bactera and tiny food particles)

Water passes through pores and food particles are trapped in mucosa of collar cell projections of choanocytes; phagocytosis of particles and/or passed on to amoebocytes

• Diploblastic;
• Radially symmetrical;
• Gastrovascular cavity (digestive comparment with a single opening ass and mouth)

1 Hydrozoa- (port man-of-wars, hydras) Most marine, a few freshwater; BOTH POLYP and MEDUSA STAGES in MOST species; polyp stage often COLONIAL

2. Scyphozoa- (jellies)- All marine; POLYP STAGE absent OR reduced; free-swimming; medusae up to 2 m diameter

3. Cubozoa- (box jellies, see wasps) All marine; BOX SHAPED MEDUSAE; complex eyes; potent venom

4. Anthozoa- (sea anemones, most corals) - All marin; MEDUSA STAGE COMPLETELY ABSENT- ONLY POLYPS!

(Flatwoms)- Dorsoventrally flattened, unsegmented, acoelomates (no body cavity); have a gastrovascular cavity or no digestive tract

Classes of Platyhelminths (flatworms) phylum:

• Turbellaria (free-living flatworms),
• Monogenea (monogeneans),
• Trematoda (trematodes, or flukes),
• Cestoda (tapeworms)

• CLADE: Lopotrochozoa
• PHYLUM: Platyhelminths
• CLASS: Turbellaria
• Mostly marine, some freshwater, few terrestrial
• Predators and Scavengers
• Ciliated body surface

• CLADE: Lopotrochozoans
• PHYLUM: Platyhelminths
• CLASS: Monogenea
• Marine and freshwater parasites
• Most infect external srufaces of fishes
• Life history simple
• Ciliated larva starts infection on host

• CLADE: Lophotrochozoans
• PHYLUM: Platyhelminths
• CLASS: Trematoda (flukes)
• parasites of mostly vertebrates;
• two suckers attach to host;
• most life cycles include intermediate and final hosts

• CLADE: Lopotrochozoa
• PHYLUM: Platyhelminths
• CLASS: Cestoda (tapeworms)
• Parasites of vertebrates
• Scolex attaches to host
• Proglottids produce eggs and break off after fertilization
• NO head or digestive system
• Lifecycle with one or more intermediate hosts

• Lophotrochozoa clade
• Pseudocoelomates with alimentary canal (digestive tube with mouth and anus)
• Jaws (trophi) in pharynx
• Head with ciliated crown

Lophophore is a crown of ciliated tentacles that surround the mouth and function in feeding

Phyla Ectoprocta and Brachiopoda (Coelomates)

Coelomates with three main body parts (muscular foot, mantle, and visceral mass)

• CLADE: Lophotrochozoa
• CLASSES:
• Polyplacophora (chitons)
• Gastropoda (snails, slugs)
• Bivalvia (clams, mussels, scallops, oysters)
• Cephalopoda (squids, octopuses, cuttlefishes, chambered nautiluses)

• CLADE: Lophotrochozoa
• PHYLUM: Mollusca
• CLASS: Polyplacophora (chitons)
• Marine
• Shell with eight plates
• foot used for locomotion
• radula
• no head

• Marine
• Freshwater or terrestrial
• Head present
• a symmetrical body, usually with a coiled shell
• shell reduced or absent
• foot for locomotion
• radula

• CLADE: Lophotrochozoan
• PHYLUM: Mollusca
• CLASS: Bivalvia (clams, mussels, scallops, oysters)
• Marine and freshwater
• Flattened shell with two halves
• Head reduced
• Paired gills
• No radula
• Most are suspension feeders
• Mantle forms siphons

• CLADE: Lophotrochozoa
• PHYLUM: Mollusca
• CLASS: Cephalopoda
• Marine
• Head surrounded by grasping tentacles, usually with suckers
• Shell external, internal, OR absent
• Mouth with OR without radula
• Locomotion by jet propolsion using siphon formed from foot

• CLADE: Lophotrochozoan
• CLASSES:
• Oligochaeta (freshwater, marine, and terrestrial segmented worms) reduced head; no parapodia, but chetae present
• Polychaeta (mostly marine segmented worms)
• -Many have a well-developed head
• -Each segment usually has parapodia with many chetae
• -Free-living
• Hirudinea (leeches)
• -Body usually flattened, with reduced coelom and segmentation
• -Chaetae usually absent
• -Suckers at anterior and Posterior ends
• -Parasites, predators, and scavengars

• Nematoda (roundworms)
• Arthropoda (crustaceans, insects, spiders)

Bilateria Protostome falling into the Ecdysozoa clade

• Cylyndrical, UNSEGMENTED, pseudocoelomates with tapered ends
• NO circulatory system
• Undergo ecdysis

• Arthropoda (crustaceans, insects, spiders) are Coelomates. Success due to;
• Segmented body
• Jointed appendages
• Exoskeleton made of protein and chitin

• Cheliceriforms- Body having or or two main parts; six pairs of appendages (chelicerae, pedipalps, and four pairs of walking legs); Mostly terrestrial or marine
• Myriapoda (millipedes and centipedes) Distinct head bearing antennae and chewing mouthparts; terrestrial; millipedes are herbivorous and have two pairs of walking legs per trunk segment; centipedes are carnivorous and have one pair of walking legs per trunk segment and poison claws on first body segment
• Hexapoda (insects, springtails) Body divided into head, thorax and abdomen; antennae present; mouthparts modified for chewing, sucking, or lapping; three pairs of legs and usually tow pairs of wings; mostly terrestrial
• Crustacea (crabs, lobsters, crayfishes, shrimps) Body of two or three parts; antennae present; chewing mouth parts; three or more pairs of legs; mostly marine and freshwater

Body having or or two main parts; six pairs of appendages (chelicerae, pedipalps, and four pairs of walking legs); Mostly terrestrial or marine

Diplopoda (millipedes) and Chilopoda (centipedes)

• Distinct head bearing antennae and chewing mouthparts;
• Terrestrial; millipedes are herbivorous and have two pairs of walking legs per trunk segment;
• Centipedes are carnivorous and have one pair of walking legs per trunk segment and poison claws on first body segment

• Body divided into head, thorax and abdomen;
• Antennae present;
• Mouthparts modified for chewing, sucking, or lapping; Three pairs of legs and usually two pairs of wings;
• Mostly terrestrial

• Body of two or three parts;
• Antennae present;
• Chewing mouth parts;
• Three or more pairs of legs;
• Mostly marine and freshwater

• Both deutoerostomes so they develop by way of radial cleavage (in line) and formation of the mouth at the end of the embryo opposite the blastopore.
• Both are coelomates
• (Deuterostomia is defined primarily by DNA similarities---not developmental similarities)

• Phylum Echinodermata (sea stars, sea urchins)
• - Coelomates with bilaterally symmetrical larvae and five-part body organization as adults
• - Unique water vascular system
• - Endoskeleton

• Classes:
• 1. Asteroidea (sea stars) -
• -Star shaped body with multiple arms;
• -Mouth directed to substrate

• 2. Ophiuroidea (brittle stars)
• - Distinct central disk
• - Long , flexible arms
• - Incomplete digestive system

• 3. Echinoidea (sea urchins, sand dollars)
• - Roughly spherical or disk-shaped
• - No Arms
• - Mouth ringed by omplex, jaw-like structure
• - Five rows of tube feet, enabling slow movement

• 4. Crinoidea (sea lilies, feather stars)
• - Feathered arms surrounding upward pointing mouth
• - Suspension feeders

• 5. Holothuroidea (sea cucumbers)
• - Cucumber-shaped body
• - Five rows of tube feeat around the mouth are modified as feeding tentacles
• - Reduced Skeletons
• - NO SPINES

• 6. Concentricyloidea (sea daisies)
• - Armless, disk-shaped body ringed with small SPINES
• - Incomplete digestive system
• - Live on submerged wood

Phylum Chordata (Lancelets tunicates, vertebrates)

Derived traits

• Coelomates with
• -notochord
• -Dorsal, hollow nerve cord
• -Phryngeal slits
• -Post-anal tail

notochord

pharyngeal cleft

pharyngeal slit

Dorsal, Hollow Nerve cord

Tunicates

• chordates with a head
• two Hox gene clusters, neural crest

• Craniates:
• Myxini (hagfish and relatives)
• Petromyzontida (lampreys)
• Chondrichthyes (sharks, rays, skates, ratfishes)
• Actinopterygii (ray-finned fishes)
• Actinistia (coelacanths --fish)
• Dipnoi (lungfishes)
• Amphibia (salamanders, frogs, caecilians)
• Reptilia (tuataras, lizards and snakes, turtles, crocs and birds)
• Mammalia (monotremes, marsupials, eutherians ( placental mammals such as rodents primates))

• Vertebrates are craniates with a backbone
• Dlx genes duplication, backbone of vertebrae

• Vertebrates:
• -Petromyzontida (lampreys)
• -Chondirchthyes (sharks, rays, skates, ratfishes)
• -A
• -A
• -D
• -A
• -R
• -M

Gnathostomes are vertebrates that have hinged jaws and four Hox gene clusters

• From Chondrichthyes (sharks, rays skates, ratfishes) on down
• NOT Lampreys or Hagfishes. They are jawless.

• Tetrapods are gnathostomes that have;
• Four limbs, neck, and fused pelvic girdle

• Amphibia (salamanders, forgs, caecilians)
• Reptilia (tuataras, lizards and snakes, turtles, crocs, AND birds)
• Mammalia (monotremes, marsupials, eutherians)

Amniotes are tetrapods that have a terrestrially adapted egg and rib-cage ventilation

• Includes;
• Reptilia (tuataras, lizards and snakes, turtles, crocs, and birds)
• Mammalia (monotremes, marsupials, and eutherians (placental mammals such as rodents, primates)

Adapted for flight, larger brains proportionally compared to other amphibians that don't have the acuity of senses for flight. High metabolism. NO bladder, gonads small except during mating season, females have one ovary, toothless.

Synapsids

• Mammals are amniotes that have hair and produce milk
• Evolved from synapsid ancestors
• Include egg-laying monotremes (echidnas, platypus)
• Pouched marsupials (such as kangaroos, opossums)

Haikouella resembled a lancelet and was likely a suspension feeder. Had characters of craniates in that it had a large and well formed brain, small eyes, and muscle segments along the body as do the vertebrate fishes. Haikouella did NOT have a skull or ear organs, suggesting that these characters emerged with further innovations to the chordate nervous system.

• Began as mineralized cartilage
• transition of feeding mechanisms likely influenced mineralization. End of darvonian period jawless armored bodied verts disappeared
• Jaws and teeth or mineralized mouth parts began to show in in early vertebrates (conodont dental elements) which was probably due to their larger size and ability to now become scavengers and predators.
• Mineralized fin rays may have helped swimming abilities.

Petromyzontida (lampreys)

• Chondrichthyes (sharks, rays, skates, ratfishes) traits include;
• Hinged Jaws,
• Four Hox gene clusters
• Aquatic gnathostomes; have cartilaginous skeleton secondarily evolved from an ancestral mineralized skeleton

• OSTEICHTHYES (actinopterygii) Ray finned fish
• have bony skeletons

cloaca

operculum

Sarcopterygii --Lobe-fins (lineage of ostei)

lateral line system

Gnathostomes (Chondrichthyes "sharks" to mammals) have hinged jaws, four hox gene clusters

Tetrapods (amphibia, reptilia, mammalia) are gnathostomes that have four limbs (from modified fins), neck, fused pelvic girdle (boney skeleton)

Amniotes (repitlia and mammalia) have amniotic eggs, and rib-cage ventiliation

lizard in drag