Zoology Test Study 2

Protostome

an animal whose mouth is formed from the blastopore

Deuterostome

blastopore becomes anus

pseudocoelomate

internal organs float within body cavity

- Nematoda

coelomate

true body cavity

mesentaries

allow locations for networks of blood vessels, alimentary canal more independent in function

- used as hydrostatic skeleton

Phylum Mollusca

- second most diverse phylum

- marine, freshwater, terrestrial

- variety of feeding methods

- intermediate hosts

Organisms in the Phylum Mollusca

- giant clam

- giant squids

- giant octopus

Mantle

- skin sheath

- between mantle and visceral mass

- opening: siphon (modified into tentacles)

Larvae of Mollusca are named

veliger

Class Caudofoveata

very ancestral - worm-like burrowers

Class Solenogastres

worm-like, lack shell

Class Monoplacophora

have a single shell to cover multiple gills and other organs

Class Scaphopoda

tusk shells

- water pulled through from above

- gills in mantle cavity

Class Polyplacophora

chitons

- all marine

Class Gastropoda

snails and slugs

- herbivourous

- single nephriudium

- sexual reproduction

- statocysts

- chemoreceptors

Genus Conus use _____ to capture prey

conotoxins

Nudibranchs

Slugs

Sea hares

Limpets

Abalones

Snails

Torsion

act of twisting; stress due to twisting forces exerted on a body

Sinistral

left-handed

Dextral

right-handed

operculum

A protective flap that covers the gills of fishes

Ctenedium

gills in mantle cavity

- in Gastropoda

Respiration in Gastropoda

- vascular area in mantles

- oxygen exchange in the mantle cavity

Prosobranchs

- Gastropods

- marine and some freshwater

Opisthobranchs

nudibranchs, sea hares

- can incorporate ingested toxins into body wall

Pulmonates

air breathing snails

Invasive species of Gastropoda

Giant African land snails

Class Bivalvia

- 2 shells

- mussels, clams, scallops

- water taken in through siphon

- cillia on gills (lamellae) to put food into mouth

Class Bivalvia labeled

Larva of Class Bivalvia

glochidium

- useful for dispersal

How are pearls formed?

Grains of sand get on nacre and organism wraps irritant in nacre layer.

Byssus threads

Filaments secreted by Phylum mollusca Class Bivalvia These threads help them attach to surfaces.

Invasive species in Class Bivalvia

Zebra mussels

Class Cephalopoda

"head-foot"

- marine

- move by expelling water through siphon

- closed circulatory system

- carnivorous

- predators

Ammonites

- Class Cephalopoda

- gone extinct at K-T event

Nautiloids

cephalopods whose body is covered by a shell

- 6 shelled

Nautilus

Only cephalopod with an external shell

- gas chambers: bouyancy

What class has the largest brain of any invertebrate?

class Cephalopoda

How can Cephalopods change colors?

have chromatophores in mantle

Class Cephalopoda Reproduction

males produce spermatophores

What are the 5 major groups of Cephalopodas

Octopuses, Squids, Cuttlefishes, Neutiloids, Vampire squids

Phylum Annelida

- segmented worms separated by septa

- 2 part head: prostomium and peristomium

- freshwater, marine, terrestrial

The Phylum Annelida are separated by narrow rings called

annuli

Pygidium

the end segment of an annelid that contains the anus

Sipuncula

peanut worms

- marine

Polychaeta

seaworms

- marine

- bottom dwellers

- larva: trochophore

Clitellata

earthworms, leeches

Parapodia

paired appendages on each body segment

- setae on each

Tubeworms

specialized mouthparts for capturing drifting food

List the sensory organs in Prostomium (Polychaeta)

- eyes, tentacles, sensory palps, nuchal organs, jaws

foregut vs midgut vs hindgut

Epitokes

free swimming reproductive segments

- in Clam worms

Notopodium and neuropodium

notopodium: dorsal

neuropodium: ventral

clam worm

bobbit worm

scale worms

fireworms

tubeworms

lugworms

fanworms

parchment worms

Subclass Echiura

- Polychaeta

- Proboscis scoops sediment and brings it to mouth

- Proboscis is not retractable, but can be rolled into scoop shape

- Setae

- Generally in burrows

Clitellum

Band of thickened, specialized segments in annelids that secretes a mucus ring into which eggs and sperm are released

- In Class Hirudinida

Describe a double circulatory system

- coelomic fluid circulates some nutrients

- closed blood system powered by a heart

How many aortic arches does an earthworm have?

5

- serve to maintain blood flow

How species obtain oxygen if they lack a respiratory system?

oxygen obtained through skin- vascularized

metanephridium

a type of excretory tubule with internal openings called nephrostomes that collect body fluids and external openings called nephridiopores.

Tubifex worms

sensitive to concentrations of heavy metals

Which side of the leech is the head?

the side opposite of the sucker

Proboscis

the long snout of an animal; a nose, especially a prominent one; a tubular organ

- in Hirudinea

Hirudin

the anticoagulant secreted by leeches into the wound they create to prevent clotting

Leeches nervous system

- have 2 brains: one in head, other at posterior end

- double ventral nerve cord

Hirudotherapy

leech therapy

- remove excess blood, promote healing by maintaining flow of freshblood

What big problem can leeches cause?

- venous congestion due to inefficient venous drainage

- blood can clot, and arteries that bring tissues nourishment will become plugged

- tissues will die

Leeches double the success rate of __________________

transplanted tissue flaps

Ecdysozoa characteristics

- all have cuticle

- outer non-living layer

- secreted by epidermis

Ecdysis

periodic molting

Nematodes

roundworms

- moist environment

- over 25,000

- breakdown of glycogen = obtain O2

Nematoda labeled

Do most of Ascaris eggs survive?

No. they produce tons of eggs that are resistant.

What is the advantage of Nematodes living environment?

they can live under extreme hypoxic conditions and therefore can live where there is little competition

spicule (Nematoda)

sperm cells pass out of the male tract during copulation (intercourse), and a __________ holds the female reproductive organ in place while the sperm cells pass into the females

Which Nematoda species are important in agriculture and medicine?

Globodera restochiensis

Ascaris lumbricoides

Phylum Nematoda vs. Phylum Nematomorpha

Nematoda:

Nematomorpha:

- horsehair worms, gordian worms

- lack respiratory, circulatory, and excretory system

Snout worms

Phylum Kinorhyncha

- 11 trunk segments

- introverted head

- feed on bacteria, diatoms, and algae in sediment

Penis worms

Phylum Priapulida

- live on bottom or in sand

Nematodes are different from flatworms because

When nematodes get into the wrong host, they wander until they find an exit leading to the destruction of internal structures. When flatworms get into the wrong host, they immediately die

Phylum Loricifera

- 5 body regions (mouth cone, head, neck, thorax, abdomen)

- marine

Phylum Onychophora

- velvet worms

- 70 species

- have 14-43 pairs of short unjointed legs

- soft exoskeleton

- moist leafy debris

- feed on insects, snails, and worms

Phylum Tardigrada

- water bears

- 900 species

- thin film of water on mosses

- trunk has 4 pairs of unjointed legs

- mouth = stylet

stylet

feeding tube in Targidrada

Cryptobiosis (Tardigrada)

State of extreme hibernation, slows metabolism

- form on anhydrobiosis

Describe the Phylum Tardigrada's evolution with moss

- mosses tolerate complete dehydration

- Tardigrades date back to the Cambrian period

- co-evolve together

Describe the Cambrian period

Appearance of many types of relatively large, mobile animals with hard skeletal tissues

Dracunulus medinensis

Guinea worm

- used to be in middle of Africa, then after time fewer and fewer cases occur. There is a related species in dogs that makes it difficult to fully eliminate these.