Subphylum with:

2 body regions

No antennae

4 pair of walking legs

Have chelicerae but no mandibles

Order with..

5 pair of walking legs

telson: rights animal

eats polychaetes

Subclass Xiphosura (horseshoe crabs)

Subclass Xiphosura anatomy (5)

gnathobases: for chewing food

crop and gizzards present

flabellum: last pr. of legs for cleaning

chilaria: coxae of degenerate last appendages

6 pair of abdominal appendages (all but 1st are BOOK GILLS)

Circulatory system w/ hemocyanin (useful for neurological study)

Excretory coxal glands

Dioecious: migrate to shallow water to mate, large female lays eggs, male fertilizes

Subclass Eurypterida

water scorpion 

oldest merostomatan

have paddles: last pair of legs

Have slit sense organs

Malphigian tubules

Order Scorpiones

sensory pectines on 2nd abdominal segment

reproduction: male places spermatophore on ground, female picks it up

shorter abdomen than Scorpiones

Order Uropygi anatomy

whip scorpion

1st legs sensory

repugnatorial glands: produce acidic fluid that burns

2 body regions

chelicerae have poison glands

displays, dances, nuptial gifts (keeps fem. distracted and satiated)

female guards eggs; may carry young on abdomen

prosoma and abdomen not obviously seperated

little visible segmentation

can have carapace

3 groups of Acarina

Chiggers: larvae on skin

Feather mites: lays eggs in skin

Ticks: suck blood, drop off (have carapace)

Up to 12 long legs

segmented body

Usually in cold seas

Intestine extends into legs

No gas exchange or excretion organs

Superclass Crustacea anatomy (4)

Mandibles and maxillae

2 pair of antennae

2 or 3 body regions that may be fused

stalked eyes

Respiration: Gills

Excretion: antennal or coxal glands

Larval stage includes nauplius

Class Cephalocarida (horseshoe shrimps) anatomy

(4)

Most primitive Crustacean 

Head +19 segments

2 pair of antennae

Mandible w/ 2 pr. maxillae

Food groove

3 pair of head appendages (mouthparts)

Hermaphroditic

Blind cave-dwellers

Class Branchiopoda (brine shrimp and water fleas) antomy

(4)

May have carapace

Food groove

Swim by using legs or jerking antennae

Fish eat them

eat algae

bivalved carapace

spines at the end of abdomen

Sexually dimorphic

Parthenogenesis in ephemeral habitats

Branchipoda reproduction

Can have direct development or parthenogenesis

Drought resistant eggs

Uniramous 1st antennae

Naupliar eye

Caudal rami

Free-living or parasites

Copepod respiration?

No gills

Class Cirripedia (barnacles) reproduction

Nauplius --> cypris --> settles, cements by glands in 1st antenna --> adult with plates

hermaphroditic

Primitive = Stalked barnacle= Pollicipes

Attached = Balanomorph

Parasitic Cirripedes

Parasatize crabs

Nauplius penetrates crabs

Largest group of crustaceans

14 segments, often fused, and telson

Scaphocerite: scaled 2nd antenna

Well-developed carapace

5 pair pleopods, 1 pair of uropods

Male gonophores on 6th thoracic segment

Female gonophores on 8th thoracic segment

Order Stomatophoda (mantis shrimps) anatomy

triramous antennae

small carapace

large stalked eyes - keen vision

telson may have spines

gills on abdomen

very territorial

courtship

female tends eggs and larval stages

biramous pereopods

female often w/ brood pouch

NO CARAPACE

Sessile eyes w/ no stalks

3 pair of pleopods, 3 pair of uropods

May have subchelate appendages

No carapace

Some segments may be fused with telson

Sessile eyes

In FW AND SW

Nearly direct development

Gills on abdomen

Have carapace

Stalked eyes

No brood pouch

No maxillipods

Carapace

No brood pouch

Stalked eyes

3 pair mxpds, 5 pair pereopods

2nd abdominal segment doesn't overlap 1st

1st 3 pr. of pereopods have chelae

Female doesn't carry eggs

All SW

2nd abdominal segment overlaps 1st

Female carries eggs

Only 1st 2 pereopods have chelae

heavy calcified abdomen; can flip tail

pair of heavy chelae, 2 pair of smaller ones

phyllosoma: larval stage

Palinura anatomy

If chelae present, long and thin

Rarely w/ strong chelae

5th pereopods modified to hold shell or dig

one pr. of antennae lateral to eyes

autotomy

5th pereopods for locomotion

FW, SW, terrestrial

on land

at least 12 segments w/ at least a pair of legs per seg.

uniramous legs

1 pair of antennae

sessile eyes

Malphigian tubules

At least 21 segments (1 pr. legs/seg.)

2 pr. maxillae, 1 pr. forms fangs (predators)

gonopore on next-to-last segment

court by palpating each other

male builds web, puts spermatophore in web, female removes spermatophore, self-fertilizes and may guard eggs

diplosegment: 2 spircales, 2 pair of legs

sessile eyes