13. Crustacea

Question 1

what is unique about crustaceans?

Answer 1

two pairs of antannae and biramous limbs

Question 2

name four species of crustaceans

Answer 2

shrimps, crayfish, crabs and barnacles

Question 3

what is special about the first pair of antannae and the second pair?

Answer 3

first pair is throught to be homologus to those in insects

second pair is only found in crustaceans. may be homologous to the fangs in archids (scorpians)

Question 4

what is special about the mouths of crustaceans?

Answer 4

have one pair of mandibles (lower jaw)

two pairs of maxilla (upper jaw)

Question 5

what is a carapace?

Answer 5

a part of the exoskeleton that is a hard shell which extends ventrally from the back of the head

Question 6

what is a biramous limb? what is the terminology

Answer 6

two branches of limbs - the branch on the ouside is an exopodite and the inside is an endopodite

Question 7

what is the exoskeleton made of in crustaceans and arthopods and what is one difference of the crustaceans exoskeleton compared to arthopods?

Answer 7

the exoskeleton is made of chitin. in crustaceans, both the epidcuticle and procuticle contain calcium carbonate which makes the exoskeleton stronger and less brittle than calcium carbonate on its own.

the exoskeleton epicuticle isnt waxy and waterproof like insects or arachnids

Question 8

define haemolymph

Answer 8

fluid equivilent to blood in most vertibrates

Question 9

define haemolglobin

Answer 9

the transporter - its a protein molecule (globin) in red blood cells. carries oxygen to the bod tissue in invertibrates

Question 10

define haemocyanin

Answer 10

the trasnporter of oxygen in the blood plasma in arthopods and molluscs. its a protein. haemocyanin is not bound to blood cells

Question 11

define what the haemocoel is

Answer 11

the body cavity of most invertibrates containing circuatory fluid. the haemocoel acts as a hydrostatic skeleton

Question 12

how do crustaceans breath? two points

Answer 12

they breath through their gills and the gas exchange system is closed (opposed to insects which is open)

Question 13

what happens during respiration (what happens to the oxygen - 2 points)

Answer 13

oxygen is diffused through the gills and is transported in simple solution in the haemolymph.

or

its is bount to blood pigments such as haemoglobin or haemocyanin

Question 14

what class is a crab in?

Answer 14

malaostaca

Question 15

what is the tagamata sequence of malaostraca? how many biramous limbs does each segement have?

Answer 15

5 segements in the head

8 segments in the thorax (each with a pair of limbs - maxillipeds)

6 segments in the abdomen (each with a pair of birmaous pleopods)

Question 16

what are the two orders that come from class malacostraca?

Answer 16

order decapoda (crayfish)

order euphausiacea (krill)

Question 17

what are the thorac limbs, pincers and pleopods used (in females) in the order decapoda?

Answer 17

thorac limbs used for walking

pincers used for offence and defence

pleopods in females used to carry eggs

Question 18

how to euphausiacea feed and swim?

Answer 18

filter feeding through the first 6 appendages of the thorax. the endopodites allow them to swim

Question 19

what type of clade are crustaceans? is there anythign that can be added to change this?

Answer 19

they are a paraphylectic clade (common ancestors but not including decendents). must include hexapods to make monophylectic (all decendents)

Question 20

give 5 facts about the class remipedia

Answer 20

no tagamataion behind head

two pars of antannae

live in deep oceans

blind

hermphroditc (male and female sex organs)

Question 21

what class are daphnia in?

Answer 21

branchiopoda

Question 22

what are three orders of malacostraca?

Answer 22

order stomatopoda (mantis shrimp)

order isopoda (parisitic)

cirripedia (stalk and stalkless)