In sharks, the scales are
placoid
cycloid
ctenoid
rhombiod
Correct Answer :
A. placoid
Related Questions
The flying fish Exocoetus belongs to the class
Dipnoi
Osteichthyes
Cyclostomata
Chondrichthyes
Heterocercal tail fin is a characteristic of which group of fishes?
cartilaginous fishes
bony fishes
both (a) and (b)
all fishes except sharks
Which of the following is not characteristic of chondricthyes ?
Placoid scales
Heterocercal tail fin
Ventrally placed mouth
Operculum
A muscular fin, aiding in propulsion is
dorsal
ventral
caudal
pelvic
Chondrichthyes differs from Osteichthves in
having gills not covered by operculum
presence of lateral line system
presence of large scales
presence of terminal mouth
Which of the following is not true about bony fishes ?
Five pairs of gills covered with operculum
Homocercal tail
Eight pairs of gills
Any of these
Anandromous fishes are those which
live in sea water and migrate to fresh water rivers and lakes for breeding
live in fresh water and migrate to sea for breeding
both (a) and (b)
none of these
Which of the following does not have lateral line organs ?
Whale
Tadpole
Aquatic urodeles
Common Indian dog fish
A group of cartilaginous fishes specialised for bottom dwelling is
sharks
whales
lung fishes
rays
Chondricthyes is not characterised by the presence of
Placoid scales
Ventral mouth
Operculum
Five pairs of gill slits
The oldest living fish is
Coelocanth
Diodon
Sturgeon
Labeo
Salmon is an example of
anandromous migration
catadromous migration
cartilaginous fish
none of these
The fish used to control spread of malaria is
Pterois
Fistularia
Gambusia
None of these
Fish scales originate from one of the following?
Endoderm
Mesoderm
Ectoderm
Integument
The saw fish Pristis is a member of the class
Osteichthyes
Chondrichthyes
Dipnoi
Holocephali
An anamniote group is
Primates
Aves
Crocodiles
Pisces
Water into the gills of fishes passes through
nostrils
mouth
gill slits
swimming bladder
Sharks and rays can be distinguished by
the nature of their scales
the position of the mouth
the position of gill slits
the kind of the tail fin
Which fish is famous for cod liver oil ?
Shark
Cod
Amia
Both (a) and (b)
Fishes swim in water because they have
lungs
air bladders
cartilaginous skeleton
fins
Which one of the cartilaginous fishes posses an operculum over the gill ?
Trygon
Torpedo
Chimaera
Sphynta
Air bladder in fishes does not help in
respiration
sound production
excretion
movement
Cod liver oil is a rich source of
vitamin A
iron
calcium
vitamin B complex
Fillibranch gills are present in
all types fishes
only cartilaginous fishes
only bony fishes
sea dwelling fishes
A well developed swim bladder is seen in fishes which
live at the bottom of rivers
live in shallow streams
are active swimmers
live in sea water
Which of the following fishes lack claspers, used for internal fertilization in cartilaginous fishes ?
Sharks
Stingray
Dogfish
Catfish
Parental care by males is found in
hippocampus
labeo
anabes
none of these
Mermaid purse is
a shell
egg case of skate fishes
a colony of skate fishes
none of these
In Scoliodon, the thermoreceptors are
ampullae of lorenzini
lateral line system
stato-acoustic organs
neuromast organs
Torpedo is a name for
sawfish
seahorse
electric ray
sucker fish