Marine Invert Exam 4

Phylum Tardigrada: Body?

• 100 um - 1mm

• Trunk

• 4 pairs of legs, “claws” disks

• Thick cuticle → molt

• Muscle bundles

Phylum Tardigrada: Habitat?

Algae, barnacles, interstitial

More in freshwater than marine

Phylum Tardigrada: Digestion?

Complete, Buccal tube (stylets)

• Cell fluid

Phylum Tardigrada: Circulation?

None

Phylum Tardigrada: Excretion?

Malpighian glands

Phylum Tardigrada: Respiration?

Diffusion

Phylum Tardigrada: Reproduction?

Dioecious

• Direct development, eggs in exuvium in some or free

Phylum Tardigrada: Nervous?

Dorsal ganglia

• ventral cord

• Ocelli

Phylum Tardigrada: Ecology?

Minor part of food web

• Cryptobiosis

  • Based on water

  • Can last years

Phylum Arthropoda: How many species?

Million + but that’s not even close!

Phylum Arthropoda: body?

• 100 um - several M

Phylum Arthropoda: Body: Exoskeleton -

• complex cuticle

  • Chitin + other minerals

Phylum Arthropoda: Body: Ecdysis -

• molting

  • Hormonal control

• Soft + Shell → expansion

• Stuck in molting stage

• Terminal molt

  • Fouling

Phylum Arthropoda: Body: Segmented body?

• Ancestral - many segments

• Derixed - few segments

  • Tagmata - head, thorax, abdomen

  • Cephalothroax - head + thorax fuse together

  • Carapace - covering head → thorax

Phylum Arthropoda: Body: Segmented appendages:

• Division by thin areas of exoskeleton

Phylum Arthropoda: Body: Segmented: Head -

• may or may not have antennae

  • Mouth parts of feeding

Phylum Arthropoda: Body: segmented body: Thorax -

• feeding, walking, wings

Phylum Arthropoda: Body: segmented body: Abdomen -

• Great variation

  • May or may not have appendages

Phylum Arthropoda: Body: segmented body: Muscle bundles -

• extensors

• Flexors

Phylum Arthropoda: Digestion:

• Complete, subdivisions

  • Digestive gland

Phylum Arthropoda: Circulation:

• open, long heart with Ostia

  • Arteries, sinuses

Phylum Arthropoda: Excretion:

Glands, named for exit area on body

Phylum Arthropoda: Respiration:

• diffusion - small forms

  • Gills - large forms

Phylum Arthropoda: Reproduction:

• Most dioecious

• Few monoecious

• Many larval stages

Phylum Arthropoda: Nervous:

• Dorsal ganglia

• Circumesophaqeal connectives

• Ventral cord

• Ganglia in segments

• “Eyes” - light sensor nerve endings

  • Simple

  • Complex

• Sensillae - hairs

  • Statocysts

Phylum Arthropoda

Subphylum Chelicerata: Everything

• No antennae

• Chelicera - first mouth parts

• Pedipalps

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Body?

• 30 - 70 cm

• Cephalothorax - prosoma

• Carapace

• Chelicera

• Pedipalps

• 4 pairs legs

• With gnathobase

• Chilaria

• Abdomen - opisthosoma

  • Genital operculum

  • Gill opercula → book gills

• Telson

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Habitat?

• Benthic, shallow, sand

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: what is this?

The Atlantic horseshoe crab (Limulus Polyphemus)

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Digestion:

• food groove, crop, gizzard

• Omnivores

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Circulation?

Arthropoda, blood → hemocyanin

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Excretion?

4 pairs coxal glands

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Respiration?

Book gills

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Reproduction?

• Dioecious

  • Males - smaller, hooked pedipalp

  • Mass spawn on beaches

  • Trilobite larva

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Nervous

• elongate ganglia

  • Light receptor system - includes

    • Simple + compound eyes

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Ecology?

Egg + shore birds

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Order Xiphosurida: Other?

Vision, medical testing

Bait, food

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: What is this?

Sea spiders

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Body: ?

Mm- few cm

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Body: Head?

• Proboscis, chelifores

  • Palps eyecone

• Head - thorax junction > ovigers

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Body: Thorax?

4-6 pairs of legs

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Body: Abdomen:

Small lump

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Habitat?

Many benthic: sand, algae, epizoic - sponges, corals, Bryozoa

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Digestion?

• Diverticula in legs

• Carnivores

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Circulation?

Arthropod

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Excretion?

Diffusion

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Respiration ?

Diffusion

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Reproduction?

Dioecious

• Males carry eggs on ovigers

• Protonymphon larva stage

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Nervous?

• Arthropod

  • Eyes

  • Palps

Phylum Arthropoda

Subphylum Chelicerata

Class Pycnogonida: Ecology?

• Minor part of food web

Phylum Arthropoda

Subphylum Crustacea: Body: Head:

1st antennae, 2nd antennae

(Anetennules). (Antennae)

Phylum Arthropoda

Subphylum Crustacea: Body: Mandible:

• 1st maxillae

• 2nd maxillae