the nature of their scales
the position of the mouth
the position of gill slits
the kind of the tail fin
C. the position of gill slits
a shell
egg case of skate fishes
a colony of skate fishes
none of these
live at the bottom of rivers
live in shallow streams
are active swimmers
live in sea water
nostrils
mouth
gill slits
swimming bladder
Five pairs of gills covered with operculum
Homocercal tail
Eight pairs of gills
Any of these
Saurology
Traumatology
Torpedology
Ichthyology
Osteichthyes
Chondrichthyes
Dipnoi
Holocephali
sharks
rays
whales
lung fishes
pelvic fins
cloacal fins
anal fins
caudal fins
vitamin A
iron
calcium
vitamin B complex
Shark
Cod
Amia
Both (a) and (b)
cartilaginous fishes
bony fishes
both (a) and (b)
all fishes except sharks
mollusc
mammal
star fish
bony fish
teleosts
sharks
lung fishes
rays
anterior fins
ray fins
pectoral fins
paired fins
all types fishes
only cartilaginous fishes
only bony fishes
sea dwelling fishes
respiration
excretion
movement
none of these
Coelocanth
Diodon
Sturgeon
Labeo
Scoliodon
Electric ray
Whale
Lung fish
sound production
respiratory
locomotion
hydrostatic
Trygon
Torpedo
Chimaera
Sphynta
Placoid scales
Heterocercal tail fin
Ventrally placed mouth
Operculum
Dipnoi
Osteichthyes
Cyclostomata
Chondrichthyes
respiration
sound production
excretion
movement
Whale
Tadpole
Aquatic urodeles
Common Indian dog fish
Sharks
Stingray
Dogfish
Catfish
electric fish
saw fish
stone fish
dog fish
hippocampus
labeo
anabes
none of these
sharks
whales
lung fishes
rays
Placoid scales
Ventral mouth
Operculum
Five pairs of gill slits
olfactoreceptors
rheoreceptors
gustoreceptors
chemoreceptors