Phylogeny of Spiralia

AnnelidaMollusca

Ectoprocta

Lophotrochozoa

Pogonophora

Eutrochozoa Lophophorata

Spiralia

Practice Exam Essay

• Pretend that I am cookie monster and I ask you to explain the animal kingdom to me. In a 2-3 page essay describe the nature of the animal kingdom. Select 4 of the following themes and describe variations, patterns, similarities and differences across ALL of the phyla we have learned.

Protostome Phylogeny

sk. Eumetazoa

shed skin don’tshed skin

Ecydsozoa Locotrophozoa

Deuterostomeembryology

Protostome embryology

Etc. Rotifera, etc. Eutrochozoa

Lophophoratespgs. 451-457

especially Ectoprocta(also called Bryozoa)

Phylogeny of Lophotrochozoa

Platyhelminthes AnnelidaMolluscaRotifera Ectoprocta

Lophotrochozoa

Pogonophora

Eutrochozoa Lophophorata

Spiralia

Phoronida

Branchiopoda

LophophoreHickman Fig. 22-1, 22-2

feeding(a different species)

arc of ciliated tentacles for

feeding, respiration, and excretion

phylum Ectoproctacompare Hickman Fig. 22-4

• eucoelomate• lophophorates• Sessile, marine or freshwater• colonial,individuals microscopic• > 4,000 species, abundant

Ectoprocta Anatomyfig 22-2

lophophore

mouth

esophagus

coelom

intestineanus

zooid

zoecium

colony

retracted

extended

plant stem

21. Spiralia

Spiralia• “Spiralia” - all protostomes with spiral

clevage at the third division• Includes Lophotrochozoa, and

(separately) Rotifera and Platyhelminthes

• Lophotrochozoa should be a subdivision of Spiralia, which should be parallel to Ecdysozoa

Phylogeny of Spiralia

Platyhelminthes AnnelidaMolluscaRotifera Ectoprocta

Lophotrochozoa

Pogonophora

Eutrochozoa Lophophorata

Spiralia

Branching of Protostomes

• 3rd cleavage division– lophotrochozoans, rotifers, and flatworms

spiral– ecdysozoans superficial or other

3rd CleavageDivisioncompare

Campbell p. 163

basic deuterostome pattern

Spiralia pattern

Phylogeny of Spiralia

Platyhelminthes AnnelidaMolluscaRotifera Ectoprocta

Lophotrochozoa

Pogonophora

Eutrochozoa Lophophorata

Spiralia

“Water Bears”compare Hickman Fig. 21-13

phylumTardigrada

Tardigrade Characteristics

metameric appendages with clawschitinous cuticle, shed to growtiny, no respiratory or circulatory organsdieciousremarkable ability to dry out, freeze, etc.

Tardigrade Biology

eat cell contents of mosses or algae, or prey on small animals, using stylet~ 800 species in moss, soil, and pond and ocean sediments

Tardigrade Anatomy(fig 21-14)

hemocoel

Diecious Sexual Reproduction

shed skin holds fertilized eggs

previous cuticle of female

Cryptobiosiscompare p. 447

• adults live in suspended animation for years – lose most of their water– thicken the cuticle– protect cells with special proteins

Velvet Walking WormHickman Fig. 21-11

phylumOnychophora

• shed chitinous cuticle to grow, diecious• main body cavity is an unlined hemocoel• breathe by tracheal system• appendages are unjointed and have claws• metameric excretory sacs and pores• flexible antennae

Onychophora Biology

• carnivorous - entangle prey with slime • ~ 100 species in moist tropical forest litter• similar to Cambrian marine fossils

Onychophora Biology

Ecdysozoan Phyla for ZO 110• Nematoda• Tardigrada• Onychophora• Arthropoda

Ecdysozoa . . .

• have a non-living cuticle, shed to grow• have an unlined main body cavity

– pseudocoelom or hemocoel• lack cilia• are mostly diecious

Tardigrada vs. Nematoda ... 1

similarities– have pumping pharynx with stylets– produce resting eggs– adults capable of cryptobiosis

Tardigrades vs. Nematodes 2

differences– tardigrades have metameric nerves and

appendages • not reliant on pressurized body cavity

for locomotion– tardigrade gonads and excretory organ

(Malpighian tubules) attach to gut

Tardigrades and Onychophora

Similarities – chitinous cuticle– metameric appendages with claws– ventral nerve cord with segmental ganglia

Differences– tardigrades lack antennae, jaws and a

respiratory system– excretory systems are different

Relationships among Ecdysozoa

Tardigrada

OnychophoraNematoda

Arthropoda

Review!1. List two ecdysozoan phyla with

appendages that are not jointed.2. List two eutrochozoan phyla.3. List a phylum that is in the group

Spiralia but not in the subgroup Lophotrochozoa.

Phylogeny of Spiralia

Platyhelminthes AnnelidaMolluscaRotifera Ectoprocta

Lophotrochozoa

Pogonophora

Eutrochozoa Lophophorata

Spiralia

Arthropoda

The Most Successful Phylum

Diversity of Arthropoda

• > 2,000,000 species (estimated)– our worst pests and valuable helpers

• Three subphyla and numerous classes, many of which are very diverse

Arthropod Characteristics

• chitinous cuticle thickened to exoskeleton

• metameric, jointed appendages – two or more adapted as mouthparts

• hemocoel as main body cavity– dorsal heart with open circulatory system

– coelom remnant in gonads

Cuticle

• mainly chitin– tough, flexible, glucose-amine polymer– stiffened with calcium carbonate in

crustaceans– permeable but resists chemicals– waterproofed with waxes in insects

• protection, support, muscle attachment

Exoskeleton Structurecompare Hickman 19-10

cuticle

Arthropod Tagmata

tagmata = metameres fused into functional units; singular is “tagma”

3 basic tagmata in all arthropods:• head, thorax, abdomen

– head + thorax = cephalothorax– thorax + abdomen = trunk

Segmentation and Anatomy

Metameres of an insect9 - 12 3

6

Mouthparts (Head Appendages)

• Modified legs• Uniramia and Crustacea

– antennae for sensing sound, touch, smell– mandibles for chewing– maxillae for tasting and handling food

• Chelicerata– Pedipalps and chelicera for tasting and

handling food

Arthropoda Classification• Subphyla:

– Chelicerata spiders, scorpions– Uniramia centipedes, millipedes,

insects– Crustacea shrimp, crayfish(a fourth, Trilobitomorpha, is

extinct)

Arthropoda Types

Trilobitomorphafossil

Crustacea

Chelicerata

Uniramia

Subphylum Chelicerata

Arthropods with Chelicera

Chelicerate Classes

• Merostomata horseshoe crabs– marine, only 4 species, benthic predators

• Pycnogonida (sea spiders) not required• Arachnida spiders, mites, etc.

– > 73,000 species– terrestrial and freshwater– many feeding types

Chelicerate Characteristics

• cephalothorax– mouthparts: chelicera, pedipalps– 4 pairs of walking legs– coxal glands for excretion (like

Onychophora)• abdomen

– ovipositors or spinnerets in some

MerostomataFig. 18.2

horseshoe crabs

Merostomate Anatomycompare Hickman Fig. 18-2

• Aranea– spiders

• Acari– ticks and mites

• Opiliones– daddy longlegs

• Scorpionida– scorpions

Class Arachnida

Aranea AnatomyFig. 18.6

pierce-&-suck carnivores - chelicera are poison fangs

Dangerous SpidersHickman Fig. 18-10

brown recluse

black widow

AcariAnatomy

parasites, detritivores, herbivores, predators

Acari Diversitycompare Hickman Fig. 18-16, 18-17

litter mites

mange, follicle, and dust mites

Dangerous Ticks

dog ticks deer ticks

after blood meal

Carry diseases:

• Rocky Mountain spotted fever

• Lyme disease

Scorpionida Anatomycarnivores (eat pieces of prey)

Opiliones Anatomy

carnivores and omnivores, eat particulate food

subphylum Crustacea

Arthropods with Crusty Exoskeletons - General

Characteristics

Chelicerate Characteristics

• cephalothorax– mouthparts: chelicera, pedipalps– 4 pairs of walking legs– coxal glands for excretion (like

Onychophora)• abdomen

– ovipositors or spinnerets in some

Crustacea(subphylum)

• about 40,000 species• mostly marine, but many freshwater

– terrestrial roly-poly “bug,” too• may be carnivores, herbivores,

detritivores, or parasites • widely variable in size and shape

General Crustacean Features• arthropods with biramous appendages• tagmata are (usually) cephalothorax

and abdomen• two pairs of antennae• mouthparts:

– mandibles– 1st and 2nd pairs of maxillae (marine,

benthic cephalo-carid)

External Crustacean Anatomy

compare Hickman Fig. 19-3

Internal Crustacean Anatomy

Hickman Fig. 19-5

• Biramous• Head: antennae (2 pr.),

mandible, maxillae (2 pr.)• Thorax: maxillipeds (3 pr.),

walking legs (5 pr.)• Abdomen: pleopods, uropod

Crayfish Appendages

gill

Exopod

Endopod

19-3

Crayfish Head

Appendages

19-4

Crayfish Thoracic

Appendages

Crayfish Abdominal

Appendages

Crustacean LarvaeLarva (definition): immature life stage

differing from adult in form and habits

• marine, benthic, decapod crustaceans have planktonic larvae

• entirely planktonic, copepod crustaceans have nauplius larvae

• however, amphipod and isopod crustaceans have direct development inside a marsupium– including marine species

Crustacean Larvae

19-9

Crustacea in Mixed Plankton Sample

(Chesapeake Bay)

barnacle larva

crab larva

copepod

copepod

ostracod

cladoceran

Crustacean Diversity

Crustacea Taxa to Learnselected classes:• Branchiopodafairy shrimp, "water fleas"• Copepoda copepods• Cirripedia barnacles• Malacostraca large crustaceans

plus selected malacostracan orders:– Decapoda, Amphipoda, Isopoda

Branchiopoda

fairy shrimp(Anostraca)

Cladocera(“water fleas”)

Daphnia

19-16

Japanesespider crab

Mantis shrimp

Strange Crustacean Wonders

DaphniaHickman Fig. 19-16c

1 mm

parthenogeneticeggs

CladoceranParthenogenesis

Daphniaadult female

diploid egg

haploid egg

haploidadult male

diploidresting egg

spermparthenogenesis

sexual reproduction

meiosis

Copepodacompare Hickman Fig. 19-19

female copepod with eggs

1 mm

freshwater planktonic copepods

Copepod nauplius

larvaFig. 19-23

Cirripediacompare Hickman

Fig. 19-22

acorn barnacle anatomy

Barnacle Reproduction

Class Malacostracathe larger Crustacea

orders:– Decapoda: crayfish, shrimp, crabs, lobsters

– Amphipoda: sideswimmers or scuds– Isopoda: “roly-poly bugs,” sea lice

• Start here

MalacostracaAmphipoda

Decapoda

Decapoda

Isopoda

Some More Malacostraca

giant, deepwater amphipod cleaner shrimp

euphausiid

Economic Value of Decapods

• important seafoods– marine lobsters, crabs, and shrimp– freshwater prawns and crayfish

• major part of marine food webs– including baleen whales’

Whale Food Chain

diatoms

euphausiids

baleen whale

Parasitic Crustacea

copepods

isopod

Arthropods on Land

Subphylum UniramiaClasses Chilopoda and

Diplopoda

Uniramian Adaptations for Land

• cuticle waxed to hold water better• tracheal system to respire in air• excrete urea or uric acid

– Both are less toxic than ammonia, may be voided with less water loss

• insects evolved wings from dorso-lateral, thoracic ridges

Insect Tracheal System

Invasion of Land by Arthropods

• Cambrian invertebrates were all marine• Land arthropods first fossilized in Silurian

Period (Campbell Table 25.1)– About same time as plants, well before

chordates– Primitive spiders, then millipedes and insects– 3rd Period of Paleozoic Era, about 430

million years ago

plants

amphibians

arthropods

exclusivelymarine animals

compare Campbell Fig. 25.5

subphylum Uniramia• Class Chilopoda -

centipedes

• Class Diplopoda -millipedes

• “Class” Insecta

Centipedes are Carnivores

poison fangs

Head appendages:

* antennae

* (epistome)

* mandible

* 1st maxilla

* 2nd maxilla

Centipede Diversity

Head appendages:

* antennae

* labrum

* mandibles

* maxillae (1 pr.)

Millipedes are Detritivores

Millipede Diversity

(order namesnot required)

Millipedes Must Stay Moist

egg mound

Primitive InsectaResemble the Many-Legged

Uniramia

Wingless insects- microscopic, live in leaf litter and soil

Insect Mouth Partsmillipedescentipedes

(as secondmaxillae)

insects

Pop Quiz 7

1. What is the term for the fundamental pattern of Crustacea appendages?

2. List two, general ways that larvae differ from adults of the same species.

3. What is the most posterior mouthpart of Crustacea?

Insects

The Most Diverse Animals

Hickman Pg 411

Categories of Insects

phylum Arthropoda, subphylum Uniramia• “class” Insecta

– Wingless insects (several orders)– Winged insects:

• Incomplete metamorphosis (several orders)• Gradual metamorphosis (several orders)• Complete metamorphosis (several orders)

Wingless Insects

springtails

Incomplete Metamorphosis

• Wingpads visible in larvaedamselfly

mayfly

wing pads

wing pads

Gradual Metamorphosis

• larvae resemble adults without wings

cockroach

adult

Complete Metamorphosis

ant

larva pupaadult

adult

eggs

beetle

larvae pupa adultegg

Reproduction

• Diecious, usually sexual • Sometimes parthenogenetic

– e.g., some flies, wasps, and aphids– but does NOT produce resting eggs

Wings

• Usually, 2 pairs– 2nd & 3rd

thoracic segments

Unusual Wings1st pair forms wing covers

2nd pair converted to halteres

Abdominal Appendagescompare Hickman Fig. 20-13

• male claspers• female ovipositors

Flowering-Plant-Insect Coevolution

Most insects are phytophagous(= herbivorous)

Many insects are pollinators

Parasitoids

• biocontrol of pests• host-species-specific

Fig. 20-17

Insect Pests

• wood-eaters

More Insect Pests

• Blood-suckers

crab louse

mosquito

Hickman Fig. 20-18

Also:fleas, blackflies, horseflies, buffalo gnats, punkies, bedbugs

Social InsectsHickman Fig. 20-32

termites

honeybees and ants