Phylum Annelida

Question 1

What Classes/sub-phylums can be found in Annelida?

Answer 1

Original: Polychaeta, Oligochaeta, Hirudinia
Now: Echiuria, Sipunculida
New possible sub-phylums: Vestimentiferans and Pogonophorans

Question 2

Symmetry

Answer 2

Bilateral

Question 3

Coelom?

Answer 3

Eucoelom - body compartments covered by peritoneum

- Originates in Mesoderm

Question 4

What is metameric segmentation?

Answer 4

Serial repetition of segments

Each called a metameer

Question 5

Muscle characteristics?

Answer 5

Circular and Longitudinal

Question 6

Organ systems

Answer 6

Circulatory, respiratory (skin, gills, parapodia), Excretory (nephridia), Nervous (Brain, metameric ganglia, sense organs)

Question 7

Functions of Coelomic compartments

Answer 7

• Circulation of nutrients and gases
• Hydrostatic skeleton
• Excretion and osmoregulation
• Storage of gametes

Question 8

What is the locomotory form of Oligochaetes?

Answer 8

Peristalsis (similar to how food moves through an esophagus

Question 9

Annelid reproduction

Answer 9

• Monoecious, or Dioecious
• Trocophore Larva
• Some reproduce asexually by budding

Question 10

Size range of polychaetes

Answer 10

> 1mm-3m

Most 5-10cm

Question 11

Which is the largest class in phylum annelida?

Answer 11

0Polychaeta

More than 10,000 species

Question 12

Describe segments of Polchaetes

Answer 12

Segments have parapodia, some with setae and cirri

Question 13

What are parapodia?

Answer 13

Paired paddle-like appendages for locomotion

Question 14

What is a prostomium?

Answer 14

First segment with eyes, palps, and tentacles

Question 15

What is a peristomium?

Answer 15

Second segment surrounding mouth, may bear setae, palps, or chitinous jaws

Question 16

Habitat of polychaetes

Answer 16

Typically marine

Question 17

Polychaete sex organs

Answer 17

Gonads are a temporary swelling of peritoneum

No permanent sex organs

Question 18

What are Errantia?

Answer 18

Free-living crawlers, burrowers, swimmers

: Predatory or vegetarians

Question 19

What is sedentaria?

Answer 19

Burrowers or tube dwellers

: Filter or deposit feeders

Question 20

What is Arenicolidae?

Answer 20

Lug worm, deposit feeder polychaete

Question 21

Polychaete reproduction

Answer 21

Some monoecious: asexual budding
Most dioecious: sexual reproduction
External fertilization in most, copulation and internal in some (swarming common)
Trochophore larva produced

Question 22

Polychaete Habitat

Answer 22

All marine, Mainly benthic, on or in hard or soft substrate

Infauna or epifauna

Question 23

Ecological Value of polychaetes

Answer 23

• Important food source for benthic predators like fish and crabs
• Contribute to recycling of nutrients
• Structure sediments & provide habitats

Question 24

Example of important ecological interactions of polychaetes

Answer 24

• Shifted ecology from amphipods to polychaetes

- Moved Grey whales out b/c not enough amphipods left to eat

Question 25

What is a Clitellum?

Answer 25

A specialized region of the epithelium that secretes a cocoon where embryos develop in Oligochaetes

Question 26

What is the common name of Oligochaete?

Answer 26

Earthworms (some aquatic, freshwater)

Question 27

Oligochaeta characteristics

Answer 27

- Lack parapodia, possess setae - Have a clitellum - Prostomium lacks conspicuous sensory structures such as eyes and tentacles

Question 28

What is Class Hirudinea?

Answer 28

Leeches

Question 29

Hirudinea characteristics

Answer 29

- Lack parapodia - Lack prostomium sensory structures - Have Clitellum - Hermaphrodytic - Terrestrial (or aquatic freshwater)

Question 30

What are the differentiating characteristics between Oligochaetes and Hirudinea?

Answer 30

- Lack setae (hairs) - Body not compartmentalized by septa - Posess anterior and posterior suckers - Parasitic: Ectoparasites on invertebrates and vertebrates

Question 31

Leech locomotion

Answer 31

'Looping' using anterior and posterior suckers

Question 32

Why are leeches used medicinally?

Answer 32

Maintain bloodflow into re-attached limbs, or restricted bloodflow areas - Also cosmetics and as tissue building

Question 33

What is the Family Siboglinidae (in Class polychaeta)?

Answer 33

- Skinny deep-water burrowing 'Bearded' Worms, differentiated segments (cephalic lobe, trunk, opisthosoma), no guts, segmentation in opisthosoma

Question 34

What are the Sub-families in Siboglinidae?

Answer 34

Frenulata and Vestimentifera

Question 35

Sub-family Frenulata?

Answer 35

Have symbiotic chemo-autotrophic bacteria in 'trophosome'. | Ex-pogonophoran

Question 36

Sub-family Vestimentifera?

Answer 36

Giant vent worms at deep sea vents Symbiotic sulfide-oxidizing bacteria in trophosome Large fused tentacles to transfer sulphides to and oxygen through blood w/ hemoglobin

Question 37

What do the bodies of Vestimentifera have?

Answer 37

Tentacles, vestimentum, obturaculum, trunk, opisthosome | - No digestive system

Question 38

Class Echiura (ex-phylum)

Answer 38

Spoon/Innkeeper worms - all marine - unsegmented adults, may have segmentation as embryos - molecular data links to annelids - ventral nerve cord - one pair of setae - proboscis and ciliated funnel - deposit and suspension feeders - Trochophore larva

Question 39

Class Echiura Developement

Answer 39

Metameric pattern of neuronal cell bodies along developing ventral nerve cord

Question 40

What is a Urechis?

Answer 40

Innkeeper worm | - Called such because of other creatures that live in the worm burrow

Question 41

How do Innkeeper worms feed?

Answer 41

A mucous net filters and captures food, the worm then eats the net

Question 42

Characteristics of Class Sipunculida

Answer 42

- All marine - Unsegmented always - Deposit feeder - No setae - Eucoelom - Schizoceol - Trochophore larva - Anterior eversible introvert - U-shaped gut - Hydraulic compensation sacs for tentacles - Molecular link to annelids

Question 43

What is the common name of class sipunculida?

Answer 43

Peanut worm