Placoid scales
Heterocercal tail fin
Ventrally placed mouth
Operculum
D. Operculum
Pterois
Fistularia
Gambusia
None of these
a shell
egg case of skate fishes
a colony of skate fishes
none of these
hippocampus
labeo
anabes
none of these
Shark
Cod
Amia
Both (a) and (b)
Primates
Aves
Crocodiles
Pisces
Sharks
Stingray
Dogfish
Catfish
respiration
excretion
movement
none of these
Placoid scales
Heterocercal tail fin
Ventrally placed mouth
Operculum
lungs
air bladders
cartilaginous skeleton
fins
sharks
rays
whales
lung fishes
cat fish
dog fish
flying fish
seahorse
Osteichthyes
Chondrichthyes
Dipnoi
Holocephali
Trygon
Torpedo
Chimaera
Sphynta
nostrils
mouth
gill slits
swimming bladder
anterior fins
ray fins
pectoral fins
paired fins
Five pairs of gills covered with operculum
Homocercal tail
Eight pairs of gills
Any of these
the nature of their scales
the position of the mouth
the position of gill slits
the kind of the tail fin
Endoderm
Mesoderm
Ectoderm
Integument
dorsal
ventral
caudal
pelvic
pelvic fins
cloacal fins
anal fins
caudal fins
Placoid scales
Ventral mouth
Operculum
Five pairs of gill slits
cartilaginous fishes
bony fishes
lung fishes
paleontological fishes
pharyngeal gills
paired fins
dermal scales
all of these
cartilaginous fishes
bony fishes
both (a) and (b)
all fishes except sharks
Dipnoi
Osteichthyes
Cyclostomata
Chondrichthyes
all types fishes
only cartilaginous fishes
only bony fishes
sea dwelling fishes
sharks
whales
lung fishes
rays
Oxygen
Carbon dioxide
Fish food
Decoration
sound production
respiratory
locomotion
hydrostatic
live at the bottom of rivers
live in shallow streams
are active swimmers
live in sea water