Bio Lab Exam 2

Nematodes classes

classes Enoplea and Chromadorea

Nematode traits

Lack segmentation (difference from annelids)

Complete digestive system

No specialized circulatory or respiratory system Dioecious

Parasitic, only 1 host or multiple

Ecdysis (sheds its cuticle)

Female Ascaris (roundworm)

Male Ascaris (roundworm) curled tail / spicule at the end

Phylum annelida classes

Polychaeta, Oligochaeta, Hirudinida

Annelid Characteristics

Means segmented

complete digestive system

closed circulatory system

Nervous system: ventral nerve cord

parapodia

Annelid (segmented)

Polychaetes

(marine bristle worms) well differentiated head, parapodia, many setae

Sandworm

Earthworms reproduction

monoecious (hermaphroditic)

Earthworm (oligochaetes)

Class Hirudinida

(leeches)

most are fluid feeders

(blood suckers , terrestrial feed on insect larvae with oral sucker and pharynx, or active predators scavengers with extendable proboscis)

Arthropoda classes

classes Insecta and Malacostraca

arthropods Subphylum

Myriapoda, Chelicerata, Crustacea, Hexapoda

Myriapoda

centipedes and millipedes

Chelicerata

spiders, scorpions, mites, ticks

Crustacea

crayfish, crabs, barnacles, shrimp, lobsters

Hexapoda

insects

trilobite

Arthropoda Characteristics

Tagmosis and specialization of
appendages (serial homologs)
• Ecdysis
• Exoskeleton: cuticle made of
chitin (not to be confused with
chiton)
• Open circulatory system
• Closed digestive system
• Pair(s) of antennae
• Respiratory system: via “book”
gills/lungs or trachea

Gas exchange

terrestrial and aquatic

Terrestrial

book lungs and trachea

Aquatic

gills

aquatic arthropods excretory systems

saccate nephridia or maxillary glands/ filtration kidneys with end sac and tubule

terrestrial arthropods excretory systems

malpighian tubules excrete ur acid waste and also retain water

Subphylum Chelicerata mouth

mouth parts called chelicerae

subphylum hexapoda characteristics

6 legs, unbranched appendages, one pair antennae, includes class insecta

Class insecta Head

1 pair antennae

various mouthparts

eyes

thorax

3 segments each with pair of legs

typically 2 pairs of wings

abdomen

9-11 segments

Insect Mouthparts

siphoning, lapping, biting and chewing, sponging, piercing and sucking,

Siphoning (butterfly)

lapping (bee)

chewing (cockroaches, grasshoppers, locusts, termites, wasps, book and bird lice, earwigs, dragonflies)

sponging (houseflies feeding on liquid foods)

piercing and sucking (blood or fluid/ mosquitoes, sand flies, biting midges, lice)

Subphylum crustacea

class Malacostraca (crayfish, crabs, lobsters, and shrimp)

Subphylum crustacea traits

biramous (branched appendages

two pair antennae

Subphylum myriapoda classes

classes chilopoda (centipedes) diplopoda (millipede)

phylum: arthropods

subphylum: myriapoda

class: diplopoda

phylum: arthropoda

subphylum: myriapoda

class: chilopoda

Grasshopper

Grasshopper identification

phylum: arthropoda

subphylum: hexapoda

class: insecta

female grasshopper

V shaped ovipositor (burrows into soil to deposit eggs)

Crayfish

Crayfish identification

phylum: arthropoda

subphylum: crustacea

class: malacostraca

male crayfish vs female

male: large swimmerets (middle part above tail)

female: none / smaller overall size

Phylum echinodermata and chordata

deuterosomes

anus first mouth second

protosomes

mouth first anus second

Echinodermata traits

“Spiny Skin”
• No distinct brain (circumoral ring and radial nerves)
• Complete digestive system
• No circulatory system, uses coelom
• Gas exchange via dermal branchiae or other specialized systems
• Endoskeleton made of calcium carbonate ossicles
• Bilateral symmetry in larvae but pentaradial in adulthood
• Exclusively marine

echinoderm larvae

free swimming/ bilateral symmetry

phylum echinodermata

class echinoidea

(sea urchin larvae)

phylum: echinodermata

class: asteroidea

(sea star larvae)

phylum echinodermata traits

pentaradial symmetry (5 pieces)/ regeneration

echinodermata classes

Crinoidea, asteroidea, ophiuroidea, echinoidea, holothuroidea

Class asteroidea

sea star

top

bottom

Special characteristics of asteroidea

water vascular system hydraulic pressure, tube feet, locomotion for capturing prey

Class ophiuroidea (brittle stars)

Class Echinoidea (sea urchins, sand dollars)

Regular echinoids

radial symmetry, hemispheral shape, medium to long spines, tube feet, sea urchins

irregular echinoids

secondary bilateral symmetry, short spines, move with spines, sand dollars, heart urchins

Class holothuroidea (sea cucumbers)

sea cucumber feeding

tentacles around mouth for deposit feeding

sea cucumber gas exchange

respiratory trees/ cloaca pump water in and out of

Class Crinoidea (sea lilies, feather stars)

Phylum Chordata

subphylum’s in Phylum Chordata

subphylum’s Urochordata and Cephalochordata

Chordata Characteristics

dorsal nerve cord, notochord, pharyngeal slits, endostyle, post-anal tail

Notochord

Dorsal tubular nerve cord

Pharyngeal pouches and slits

postanal tail

Endostyle or thyroid gland

Subphylum Urochrodata (or Tunicata)

filter feeders/ sessile adults free swimming larvae/ siphons for gas exchange/ hermaphroditic

subphylum cephalochordata

lancelet larvae(amphioxus) free swimming , adults spend most time burrowed in sand/ oral cirri (buccal cirri) for filter feeding/ complete digestive/ closed circulatory/ excrete waste through nephridia