Parental care in fishes ranges from simple nest building to carrying eggs and live birth. Some common types of parental care seen in fishes are nest building like bubble nests and weed nests. Other fishes attach eggs to their bodies like pipefish and sea horses where males carry fertilized eggs in brood pouches. Mouth brooding is also common where parents incubate eggs in their mouths. Some sharks and rays enclose eggs in leathery mermaid's purses. The highest level of care is viviparity where young develop internally and receive nourishment from a placenta.

1. parental care of fishes

2. Introduction
• The nursing of eggs and youngones by parents is called parental care.
• It is an instinctive behavior. fishes which produce large number of offspring's shows
less parental care.
• Fishes which produce limited number of youngones show high degree of parental care.
Types:
• Nest Builders
• Fishes that attached the eggs on their body
• Mouth breeding
• Mermaids purse
• Viviparity

3. Nest builders
•Bubble nest
•Weed nest
•Pit nests

4. Bubble nest
• Some fishes makes bubbles of air on the
surface of the water and lays the eggs
inside the bubbles.
• E.g.: Chinese paradise fish, Macropodus
(males guarded the nest)

5. Weed nests
• Etroplus suratensis(Pearl spot) built a nest in over hanging weeds, submerged in water. When
youngones develop, they put them in small pit and the female guard them.
• Amia during breeding season, these fishes move to the area where there is abundance of weeds. It
swims round and round among the weed until the eggs hatch.
• Gasterosteus ( stikle-back) during breeding season, males develop beautiful coloration in the body.
Then the male starts building the nest with aquatic weeds. Then the male attracts the female into
the nest. The female lays the eggs which are fertilized by the male the male then drives away the
females and brings in another female to the nest to get a treasure of eggs. The male guards the eggs
until they hatch.

6. Pit nests
• Slmon digs a small hole in the gravel bottom of the hill streams and lays the eggs
• Lepidosiren makes pits under the ground level. The eggs are deposited in “L” shaped
nests built underground.
• Cyclopterus builds a nest in pits in the rocks and lays eggs. The eggs are usually
attached to the rocks. The males guard the eggs and aerate them by creating a flow of
water by moving its pectoral fins.

7. Breeding habit of Rhodeus
• It is a small cyprinid found in the rivers of central Europe. It lays the eggs
inside the tubular siphon of freshwater mussel. For this purpose the oviduct of
the female develops into a tubular ovipositor.
• The ovipositor passes the eggs into the siphon and immediately the male
sheds the sperm and the fertilization takes place.

8. Fishes that attached the eggs on their body
• Mystus aor( Giant River cat fish): this fish builds nests of
circular depression in the bottom and eggs are laid by the
females in the nest.
• The males attach the eggs to the abdomen by pressing
against them and carry them all they get hatched.
• The nurse male even feeds the young ones with a milky
secretion of the abdominal wall.

9. • Pholis(butter fish): this fish is in the habit of rolling the eggs into a mass.
afterwards, one of the parents guard the eggs by coiling round the eggs.
• The egg masses are laced safely on holes made by boring molluscs.
• Kurtus: the male is provided with a bony hook projecting from the forehead.
The mass of eggs is produced in two bunches connected by a string. This gets
attached to the hook in such a manner that one bunch of eggs lies on either
side of the male as he swims.

10. • Hippocampus(sea horse): in sea horses, the male has a
brood pouch in the trunk, at the breeding season this
pouch becomes thickened and well supplied with
blood vessels. The female lays the eggs in the brood
pouch of the male. The eggs are incubated there until
hatching. The brood pouch is the modified pelvic fin.

11. • Pipe fishes: in the pipe fishes, the care of the egg is always undertaken by the male fish.
• After the eggs are fertilized the oviduct of the female is thrust into the small opening at the front
end of the males brood pouch. The eggs remain in the pouch until hatched.
• The egg are carried in a special brood pouch situated on the underside of the trunk.

12. Mouth breeders
• Many of the cichlids protect their eggs by carrying them in
their mouths. Normally this duty is performed by the
mother.
• Arius: it is a brackish water cat fish of north and South
America. It lays only a few eggs which are about 17-18mm
in diameter. The eggs are carries in the mouth by the male
until they are hatched. The male does not feed while
carrying the eggs.
• Tilapia: after fertilization the females keep the eggs inside
the buccal cavity. Even after hatching the yougones remain
near the mother and if there is any disturbance they enter
the buccal cavity for shelter.

13. Mermaids purse
•Some of the sharks and rays produce a special type of
leathery case called mermaids purse.
•It is a protective hard shell secreted by the shell
glands present in the oviduct. The shape of the purse
varies in different species. Generally, it is rectangular
in shape. The corners of the shell are drawn out into
four long twisted elastic filaments which serve to
attach the purses to sea weeds. The development is
completed within this purse.

14. Viviparity
•The highest degree of parental care is found in viviparous fishes
where youngones develop within the oviduct of the female.
•The youngones gets its nourishment from the yolk sac placenta. Eg.
Gambusia, Sword tail, Scoliodon, etc.,