Zoology Exam 3

Metamerism

repetition along anterior-posterior axis of similar body segments

-annelids, arthropods, chordates

Peritoneum

forms dorsal and ventral mesenteries

Annelida circulatory system

closed circulatory system

Phylum Annelida Respiration

through skin, gills, or parapodia

Phylum Annelida

Class Errantia

Wandering worm

Phylum Annelida

Class Sedentaria

tube worms

• reduced parapodia

• reduced setae

Phylum Sipuncula

Sister to Phylum Annelida

Polychaetes Locomotion

Parapodia

Polychaetes

mostly marine

• sedentary

• errant

Polychaetes:

Fanworms

use tentacle crown to feed

• food moved from radioles to mouth

Polychaetes Reproduction

Sexes are separate

• Gametes are shed into coelom

• Gonads are temporary

Polychaetes

Palolo worms

“caviar are south pacific”

• gametes filled epitokes that burst at dawn releasing eggs

Echiuridea

“Spoon worms”

• spoon shaped proboscis

• weird sex determination

Phylum Annelida

Order Clitellata

“Oligochaetes” and Hirudinea

• Clitellum with cross-fertilization

• monoecious

Phylum Annelida

Order Clitellata

Family Hirundinidae

ectoparasite, rarely predatory

• oral and posterior suckers

• clitellum only during breeding season

Phylum Sipuncula

Peanut worms

• non segmented worms

• large coelom u-shaped gut

• trochophore larvae

Cuticle

non-living, noncellular, outer layer secreted by epidermis

• restricts growth

Ecdysone

regulation of molting under hormone control

Ecdysozoa

have an exoskeleton - nonliving part of body

• no shared body plan

Phylum Nematoda

“Roundworms”

• parasites for nearly all animals/plants

• cuticle shed between each juvenile stage

• hydrostatic skeleton

Collagen

Primary protein in cuticle

Hydrostatic Skeleton

Longitudinal muscles constrict compressing the cuticle forcing opposite side to expand

Phylum Nematoda Reproduction

Dioecious with males smaller than females

• males have copulatory spicules

• sperm lack flagella **

Ascaris lumbricoides

Parasitic Roundworms

• lay up to 200,000 eggs a day

• juveniles burrow through intenstine wall

Enterobius vermicularis

Pinworms

• most common worm parasite

• females migrate to the anus at night to lay eggs on skin

Filarial Worms

vector: mosquitos

• female mosquitoes release live young microfilariae into blood/lymph

Phylum Nematomorpha

“Horsehair worms”

• endoparasite that attack invertabrates

• juveniles are parasites of arthropods

• Paratenic host **

Paratenic Host/ Transport Host

Not necessary for development

Phylum Kinorhyncha

body is divided into the introvert head, neck, and trunk, with external segments

• scalids

• live in marine/mud

Phylum Priapulida

Carnivorous marine worms

• occur in cold water both hemispheres

• burrow head up

Phylum Loricifera

Most recent discovered groups of Metazoas

• body can retract into circular lorica

• scalids

Scalids

recurved spines function in locomotion

Panarthropoda

coelom reduces

open circulatory system and triploblastic

Phylum Onychophora

“velvet worms”

• 14 to 43 pairs of legs/lobopods

• oral papilla produces slime glands for prey capture

• not hard cuticle

Phylum Onychophora Reproduction

Dioecious

• viviparous birth in some

• bizarre mating behavior

Tagamata

fusion of metameric segments into specialized functional groups

Trachea and Spiracles

found in insects, millipedes, centipedes and rarely some spiders

Phylum Tardigrada

“water bears”

• live in film of water around mosses and lichens

• stylet mouthparts for piercing

• Tun

• Cryptobiosis

Tun

dormant life stage

Cryptobiosis

survive extreme dehydration from 85% to only 3%

• resistant to harsh conditions

Phylum Arthropoda

Jointed appendages - allows them to move in directed motion

• segmented bodies

• chitin in cuticle

• open circulatory system

Phylum Arthropoda Success

• highly developed sensory organs

• complex behavior patterns

• segmentation and appendages

Phylum Arthropoda

Subphylum Chelicerata

• no mandibles or antennae

• two tagmata

• six pairs appendages

• respiration with book gills or book lungs **

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

“Horseshoe Crab”

• cephalothorax completely covered w/ large carapace

• book gills

• blue blood

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida

“Sea Spiders”

• four pairs of walking legs

• some males have legs to carry legs (ovigers)

• Abdomen reduced

Phylum Arthropoda

Subphylum Chelicerata

Class Arachnida

external segmentation reduced

• cephalothorax and abdomen

Phylum Arthropoda

Subphylum Chelicerata

Class Arachnida

Order Araneae

“Spiders”

• chelicerae function as fangs

• 6 or 8 simple eyes

• silk glands and spinnerets

• book lungs and trachae

Phylum Arthropoda

Subphylum Chelicerata

Class Arachnida

Order Scorpionida

“Scorpions”

• pedipalps capture, chelicerae shred prey

• cephalothorax and abdomen

• well developed young

Phylum Arthropoda

Subphylum Chelicerata

Class Arachnida

Order Opilicones

“Harvestmen”

• single pair of eyes

• legs easily shred

• no venom

Phylum Arthropoda

Subphylum Chelicerata

Class Arachnida

Order Acari

“Ticks and Mites”

• cephalothorax and abdomen completely fused

• mouth parts on capitulum

• transmit diseases

Maratus

Genus of jumping spider - “Peacock spider”

Phylum Arthropoda

Subphylum Myriapoda

Two tagmata - head and trunk

• one pair of antennae

• between 10-750 uniramous legs

Phylum Arthropoda

Subphylum Myriapoda

Class Chilopoda

“Centipedes”

• venomous

• one pair legs per segment

• eyes consists of groups of ocelli

Scutigera coleoptrata

House centipede

• harmless to humans

Phylum Arthropoda

Subphylum Myriapoda

Class Diplopoda

“Millipedes”

• Detritivores/Herbivores

• body cylindrical

• glands secrete various hallucinogenic compounds

Phylum Arthropoda

Subphylum Crustacea

• Three tagmata (Head, thorax, abdomen)

• biraous appendages

• two pairs antennae

Crustacea Sensory Organs

Stalked compound eyes

• Panoramic mosaic view

Crustacea Reproduction

Separate sexes with sexual dimorphism

Crustacea Life Cycles

Larval stages: Nauplius then Zoea

Molt through intermediate larval stages

Phylum Arthropoda

Subphylum Crustacea

Class Brachiopoda

“Brine shrimp, tadpole shrimp”

• flattened leaf-like legs

• freshwater zooplankton

Phylum Arthropoda

Subphylum Crustacea

Class Maxillopoda

“Barnacles, ostracods, copepods”

• reduced abdomen

• lack appendages

Phylum Arthropoda

Subphylum Crustacea

Class Malacostraca

“Isopods, amphipods, krill, decapods”

• largest class

• gills on thoracic appendages

Phylum Arthropoda

Subphylum Hexapoda

• six walking legs

• body with three tagmata

• respiration via trachea and spiracles

• one pair of antennae, madibles, maxille

Phylum Arthropoda

Subphylum Hexapoda

Class Entognatha

• primitively wingless

• no metamorphosis

• mouthparts retracted in head

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

like ectognata but with external mouths

• 28 extant species

• only flying invertebrates

• metamorphic development

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Thysanura

Silverfish

• wingless

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Odonata

Dragonflies and Damselflies

• aquatic larvae

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Ephemeroptera

Mayfly

• aquatic larvae

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Orthoptera

Grasshoppers, crickets, locusts, katydids

• thickened forwings

• jumping legs

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Blattodea

Cockroaches and Termites

• social behavior

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Mantodea

Mantids

• predators

• raptorial forelimbs

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Phasmatadoa

Walking sticks

• elongated bodies, herbivores

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Dermaptera

Earwings

• hind wings folded under short forewings

• forceps like cerci

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Hemiptera

True bugs, hoppers, aphids

• sucking, tubelike mouthparts

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Neuroptera

Lacewings, antlions

• predators

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Hemiptera

Suborder Heteroptera

Brown stink bugs

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Hemiptera

Suborder Homoptera

Spotted Lantern Fly

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Coleoptera

Beetles and Weevils

• largest order of animals

• diverse environments

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Hymenoptera

Bees, wasps, ants

• pollinators

• biocontrol of pests

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Diptera

Flies, mosquitos, maggots

• two wings with hind legs

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Siphonaptera

Fleas

• Ectoparasites

• body laterally compressed

Phylum Arthropoda

Subphylum Hexapoda

Class Insecta

Order Lepidopetera

Butterflies and Moths

• Large showy wings

• fluid feeders