Larva

Question 1

Describe nauplius larva

Answer 1

1st and most commonly observed crustacean larval stage
1st 3 cephalic segments: antennules, antennae, mandibles
naupliar eye
swim using antennules and antennae

Question 2

Describe zoea larva

Answer 2

hatching stage in marine decapods
rostral spine 
pair of lateral eyes + naupliar eye
3 pairs of functional appendages 
segmented abdomen
swim using thoracic appendages

Question 3

Describe megalops larva

Answer 3

after zoea stage 
characteristic of marine decapods
fused cephalothorax
segmented abdomen
2 pairs of antennae
stalked compound eyes 
5 pairs of pereiopods (first 2 are chelate)
pleopods on abdomen
between planktonic and benthic = post larvae
swim using abdominal appendages

Question 4

Describe phyllosoma larvae

Answer 4

characteristic of spiny and slipper lobsters
transparent
flat
spindly (leaf bodies)
attach to jelly or hydromedusan with 4 pairs of legs
arrives in shallow waters - beings metamorphosis by discarding 3/4 of its body
hind end forms 1st stage of adult lobster

Question 5

Describe Bipinnaria larva

Answer 5

starfish larva
1st stage in larval development
body covered in cilia
as it grows cilia are confined to a narrow band looping over body surface
short stubby arms soon develop with ciliated bands
cilia used for locomotion and feeding

Question 6

Describe brachiolaria larva

Answer 6

starfish larva
marked by apperance of additional arms at the anterior end
bilateral symmetry
not all starfish have this stage
adult only develops from hind part away from sucker

Question 7

Describe Echinopluteus larva

Answer 7

Sand dollar/ sea urchin larvae
free swimming
4-6 pairs of ciliated larval arms supported by calcite rods
similar to starfish bipinnaria
lives for several weeks feeding in surface waters