MIDTERM 2

Question 1

Describe Flatworms

Answer 1

Platyhelminthes

• no respiratory/circulatory system
• digestive cavity has 1 opening
• simple nerve nets, most neurons in head (ventral)
• have sensory receptors in head-light and smell, but no eyes or organized sensory organs
• free living mostly predators (some parasitic eg tapeworms and flukes)

Question 2

Who is trochophore larva

Answer 2

Annelida

Question 3

What is protosome and who is is

Answer 3

bilateral, 3 germ layer, first opening is mouth

flatworms (platyhelminthes)

Question 4

Describe Ribbon Worms

Answer 4

Nemertea

• less than 20cm long
• have probiscis used in hunting, stored in digestive cavity (stylet)
• simple brain and pair of ventral nerve cords
• simple circulatory system - coelems, no gills-respire thru skin
• separate sexes-broadcast spawners
• most benthic (inc. deep sea), some pelagic
• parenchyma

Question 5

What is deuterostome and who is it

Answer 5

first opening is anus, nemertea (ribbon worms)

Question 6

Describe Round worms

Answer 6

Nematoda

• small, often meiofauna, adults 0.1-3 mm
• 1 sq meter of bottom mud can contain >1 million nematodes
• more than 5,000 species
• scavengers, nutrient turnover (consume detritis bacteria-some carnivores, parasites)
• no gills, simple fluid circulation
• no circular muscles

Question 7

Describe Segmented worms

Answer 7

Annelida

• bristle worms, christmas tree worms, hot vent tube worm
• includes all segments worms (polychaetes, earthworms, leeches)
• complex shared circulatory system of many organs, inc. simple gills (terrestrial via skin)
• complex shared circulatory system, gut and nervous system sensory organs
• body wall of collagen-a protein-can grow Chaeta (chitonous bristle) made of beta-chitin
• up to 10ft long
• soft bodies

Question 8

unique features of tube worms

Answer 8

have no gut, and gain nutrients from chemotrophic bacteria living inside them

Question 9

unique features of christmas tree worms

Answer 9

filter feeders, use palps as structure food harvesting and respiratory structures
feather like structure of palps called radioles

Question 10

describe bryzoans

Answer 10

• filter feeders-use crown of lophophore tentacles
• colonial - made up of zooids
• autozooids- feeding and excretion. other specialize in reproduction, defense, even locomotion
• cause disease in kelp
• eaten by many grazers, nudibranchs urchins

Question 11

described generalized autozooid

Answer 11

digestive tract, retractor muscle, gonads, and outer covering

Question 12

Who are hagfish

Answer 12

Myxini

Question 13

Who are lampreys

Answer 13

petromyzontida

Question 14

Who are cartilaginous fish

Answer 14

chondrichthyes

Question 15

Who are ray-finned fish

Answer 15

actinopterygii

Question 16

Who are colecantis

Answer 16

actinistia

Question 17

Who are lung fish

Answer 17

Dipnoi

Question 18

describe lampreys oral area

Answer 18

have oral disk and rasping tongue covered with horny dentacles to grasp prey, rasp hole in the bosy and suck out tissue and fluid

Question 19

describe lamprey reproduction

Answer 19

anadromous (return to fresh water to spawn) but males do not return to natal stream
males migrate up rivers and build nests, females arrive and attaches to the nest stone with oral sucker, male attaches to back of females, eggs and sperm shed

Question 20

what are lamprey larva called and describe them

Answer 20

ammocoetes, benthic, filter feeders, after 3-7 years they metamorphose into adults and return to sea

Question 21

describe the fin names

Answer 21

small/front-pectoral
left medium-pelvic
right-dorsal
left-anal 
back-caudal
small back-adipose, or 2nd dorsal

Question 22

describe cartilaginous fish

Answer 22

sharks, skates, rays, and chimaeras
skeleton of cartilage
posses jaws and paired fins
placoid covers skin

Question 23

what are the two main groups of cartilaginous fish

Answer 23

Holocephalans- chimaeras, or ratfish

Elasmobranchs- 2 body forms: streamlined eg sharks or dorsoventially flattened eg skates and rays

Question 24

list some holocephalans

Answer 24

rat fish, longnose chimaeras, elephant nose chimaeras, plough nose chimaeras

Question 25

describe chimaeras

Answer 25

large pointed head & long slender tails gills covered by operculum, water inhaled thru the nostrils rather than mouth have flat plates for crushing prey instead of teeth scales confined to a few dentacles, if they have scales they are placoid -no cloaca is have seperate anal and urogenital openings males have claspers on their heads and pelvic fins

Question 26

describe who has each type of scale

Answer 26

ctenoid-bass cycloid-salmon ganoid-gar placoid-shark

Question 27

describe reproduction in chimaeras

Answer 27

oviparity; fertilization internal, lay eggs, embryo has a yolk sac for nutrition ovoviviparity; fertilization internal, eggs hatch internally, embryos feed off yolk sac and uterine milk (mammals have viviparity utilizing placentas)

Question 28

list elasmobranches organisms

Answer 28

sharks & rays, ground & requiem sharks, mackerel sharks, carpet sharks, angel sharks, bullhead sharks, saw sharks & saw fish

Question 29

describe ground/requiem sharks

Answer 29

``` order carcharihiniformes (tiger, hammerhead, bull shark, black tip, blue) nictitating membrane (third eye that is translucent/clear) 2 dorsal fins, 1 anal fin 5 gill slits ```

Question 30

describe mackeral sharks

Answer 30

order lamniformes (great white, thresher, basking) no nicitaitng membrane 2 dorsal fins, 1 anal fin 5 gill slits

Question 31

describe carpet sharks

Answer 31

``` order orectolobiformes (whale, zebra) 2 dorsal fins, anal fin 5 gill slits ```

Question 32

describe angel sharks

Answer 32

(austrialian) 2 dorsal fns, no anal fin ovoviviparous

Question 33

describe bull head sharks

Answer 33

small spiracle (port jackson, horn) 2 dorsal fins with fin spines anal fin oviparous

Question 34

describe saw sharks and sawfish

Answer 34

5/6 gills 2 dorsal fins no anal 2 barbels on saw

Question 35

characteristics of saw sharks and sawfish

Answer 35

- cartilage skeleton - some 2 some 2 dorsal fin, some have dorsal spines - most have accessory, respiratory opening, the spiracle - can breathe via ram or buccal pumping - placoid scales - liver contains squalene - an oil - modified pelvic fin in males, claspers

Question 36

describe skates and rays

Answer 36

gill slits on ventral surface no anal fin pectoral fins usually fused to top of head eyes and spiracles on top of head (specialized gill slits located behind eyes) all skates and some rays are oviparous, other rays are ovoviviparous (aplacental) stingrays and relatives (eagle, manta)