Lab 9:Animals II

Which animals have bilateral symmetry?

Which animals have bilateral symmetry?

All animals in the clade Bilateria. All animals except Porifera and Cnidaria

Which animals are triploblastic?

All animals in the clade Bilateria. All animals except Porifera and Cnidaria

coelom

The main body cavity that forms between the germ layers. Organs are suspended and protected in this cavity.

Which animals are acoelomate?

Porifera and Cnidaria and Flatworms (within the Bilateria).

Which animals have a pseudocoelom?

Roundworms (within the Bilateria). (Rotifers, which we did not discuss in lab, also are pseudocoelomates).

Which animals have a true coelom?

All Bilateria except flatworms and roundworms (and rotifers).

protostome

Organisms in which the blastopore becomes the mouth. "mouth first"

deuterostome

Organisms in which the blastopore becomes the anus. "mouth second"

Where are the two main groups of Bilateria?

Protostomes and Deuterostomes

What are the two main groups of the protostomes?

Ecdysozoa (roundworms, and Arthropoda) and Lophotrochozoa (flatworms, Mollusca, Annelida)

What is unique about the Ecdysozoa?

They secrete external skeletons (roundworms and Arthropoda)

ecdysis

shedding an exoskeleton (roundworms and arthropods) or old skin (reptiles).

molting

general term for the shedding of a body part such as skin (reptiles), feathers (birds), or hair (mammals) or exoskeleton (roundworms and arthropods)

Arthropoda

Bilateria, Ecdysozoa; has four main groups (Chelicerates, Crustaceans, Insects, Myriapods).

What are the main groups of Arthropods?

Chelicerates, Crustaceans, Insects, Myriapods

What kind of circulatory system to arthropods have?

Open circulatory system. Hemolymph flows through the hemocoel.

hemolymph

fluid that is made up of blood and interstitial fluid; found in animals with an open circulatory system.

What is the exoskeleton of arthropods made up of?

Layers of chitin and protein

Chelicerates (2 groups)

1. sea spiders and horseshoe crab, 2. Arachnida

chelicerae

Arthropoda, Chelicerates; feeding appendages, can be used as pinchers or fangs

pedipalps

appendages used for feeding, reproduction or sensing

horseshoe crab

Arthropoda, chelicerate

Arachnida

spiders, mites, ticks, scorpions (how many pairs of legs?)

spiders

Arthropoda, Arachnida (too few legs!!! not a spider)

Black widow spider

Arthropoda, Arachnida; note the red "hour-glass"

ticks

Arthropoda, Arachnida

scorpions

Arthropoda, Arachnida

What are the two main body parts of arachnids?

cephalothorax and abdomen

How many pairs of appendages do arachnids have?

6. chelicerae, pedipalps, and 4 pairs of walking legs.

What is a quick way to tell the difference between spiders and insects?

spiders have 4 pairs of walking legs; insects have 3 pairs of walking legs

Crustaceans (2 groups)

1. lobsters, crayfish, crabs, shrimp 2. copepods and barnacles

What are the two main body parts of crustaceans?

cephalothorax and abdomen

crayfish

19 including the antennae, modified mouthparts (maxillipeds)), claws (chelipeds), four pairs of walking legs, swimmerets on abdomen and telson (tail).

How can you tell the difference between male and female crayfish?

Males have enlarged first pair of swimmerets, to deposit sperm into the females seminal receptacle.

Find the external parts of a crayfish

abdomen, cephalothorax, antennae, feeding appendages, chelipeds, walking legs, swimmerets,

Find the internal parts of a crayfish

mouth, stomach, large digestive gland, intestine, anus

Insects

beetles, bees, flies, fleas, grasshoppers, butterflies, termites, true bugs, and others

What are the main body parts of insects?

head, thorax and abdomen

What are the appendages in insects?

modified mouthparts, antennae, 3 pairs of walking legs. (Wings are an extension of the cuticle, not a modified appendage).

insect tracheal system

insect respiratory system- tubes that air is conducted through

spiracles

insect respiratory system - openings in the exoskeleton that allow air to enter the trachea

complete metamorphosis

insects - developmental larval stages that look different from the adult such as caterpillars (moths have cocoons and butterflies have a chrysalis)

gradual metamorphosis

insects - developmental stages that grow gradually into adults that look like the early stages (grasshoppers )

beetles

Arthropoda, Insecta

bees

Arthropoda, Insecta

flies

Arthropoda, Insecta

fleas

Arthropoda, Insecta

grasshoppers

Arthropoda, Insecta

butterflies

Arthropoda, Insecta

termites

Arthropoda, Insecta

true bugs

Arthropoda, Insecta

Myriapods

centipedes and millipedes

centipedes (Myriapoda)

carnivores; each segment has one pair of walking legs

millipedes (Myriapoda)

detritivores; segments are fused so that each segment has two pairs of walking legs.

detritivore

derives nutrition mainly through decaying leaves and plant matter

carnivore

derives nutrition mainly from animal tissue (through predation or scavenging)

Mollusca

Bilateria, Lophotrochozoan; the Chitons, Gastropods, Bivalves, Cephalopods

What kind of circulatory system do molluscs have?

Mollusca have an open circulatory system (except in cephalopods) with a few large vessels and a heart.

Do molluscs have shells?

Most molluscs have shells secreted by a specialized epidermal layer. Some have a large external shell (e. g., snails, clams), some have a remnant internal shell (e. g., the pen of the squid) and some do not have a shell (e. g., octopi)

What are the main body parts of molluscs?

a visceral mass of organs, a muscular foot for locomotion, a calcium-based shell, and a mantle that secretes the shell

Visceral Mass (Mollusca)

Mollusca- A mass made up of the organs; the guts. Have you ever had a visceral feeling, a feeling that "comes from the gut"?

muscular foot

Mollusca- for locomotion

calcium-based shell - Mollusca

Mollusca- Some have a large external shell (e. g., snails, clams), some have a remnant internal shell (e. g., the pen of the squid) and some do not have a shell (e. g., octopi)

Mantle (Mollusca)

Mollusca- secretes the shell

Chitons

Mollusca,

Are the rows on the chiton segments?

No, chitons are not segmented, but they do have a shell made up of eight dorsal overlapping plates. They can curl into a ball.

Gastropods

Mollusca; snails and slugs

snails

Mollusca, Gastropoda

slugs

Mollusca, Gastropoda (no shell)

Bivalves

Molluscs, clams, oysters, mussels; the shell is divided into two (bi) with a hinge.

clams

Mollusca, Bivalve

umbo

Mollusca, Bivalve, clam E is the umbo. Can you find anterior and posterior?

What are the three layers of the shell of the clam?

periostracum (outer brown), prismatic layer(middle layer of calcium carbonate), nacre (mother of pearl, iridescent inner layer).

parts of the clam

mantle, gills, labial palps (guide food), muscular foot), intestine.

What is unique about the heart of the clam?

the intestine runs through the heart before reaching the anus

oysters

Mollusca, Bivalve

mussels

Mollusca, Bivalve

Cephalopods

Mollusca, squids, octopi, nautilus

squids

Mollusca, Cephalopod

Pen (squid)

Mollusca, Cephalopod, squid- the chitinous endoskeleton or inner shell. Runs the full length of the animal.

radula

Mollusca, a feeding structure. Has tiny teeth used to scrape food off of a surface.

beak (squid)

used to rip or tear up prey in the squid.

heart (squid)

the blue (filled with blue latex) circles over the internal organs.

diverticulum (squid)

the ink sack of a mollusc, you saw one in the squid.

octopi

Mollusca, Cephalopod

nautilus

Mollusca, Cephalopod

Which cephalopod has an external shell?

Nautilus

Annelida

Bilateria, Lophotrochozoa, the Earthworms and leeches

What kind of circulatory system do Annelids have?

closed circulatory system; the bloods is retained within the vessels.

earthworms

Bilateria, Lophotrochozoa, Annelida

leeches

Bilateria, Lophotrochozoa, Annelida

septae (annelids)

In Annelida, the divisions between the segments

setae (earthworm)

also called chaetae- the chitinous bristle on each segment of the earthworm. You can feel these.

clitellum (earthworm)

series of larger segments through which copulating worms exchange sperm.

How many hearts does an earthworm have?

It has five segments of the aortic arch, each of which functions as a "heart".