Social Sciences, asked by ashrafkhannijaz3731, 1 year ago

Structure reproduction , life history of balanoglossus

Answers

Answered by petty1
1
Balanoglossus performs both asexual and sexual reproduction

ASEXUAL REPRODUCTION :
Gilchrist described the asexual reproduction. In summer season its posterior end is divide into a number of bits. Each bit will develop into a new individual.

SEXUAL REPRODUCTION
In these sexes are separate. so, sexual dimorphism is absent. The gonds is simple. Both sperms and ova are realized in water. So, external fertilization is take place.
DEVELOPMENT,
Fertile egg contain some yolk called MESELECITHAL EGG.
This stage is called HOLOBLASTIC CLEAVAGE.
It includes MOGULS AND BLAST STAGE.
It undergoes invalidation two layered GLATRULA IS formed.
At last all one item will develop like ectoderm and endoderm and coleom is formed.
This is called TORNARIA LARVA STAGE.

TORNARIA LARVA
It was proposed by MULIER as FXHINODERM LARVA.
METACOFF first discovered this larva in Balanoglossus.
This larva will swim and is oval in shape , it is transparent and digestive tract. will develop in it from mouth to anus.
TORNARIA take micro organisms as a food in sea water.
There are two eye spots and nerve cell is present.
The larval stage is finished and they now become adult called METAMORPHOSIS.

METAMORPHOSE STAGE
Here the eye spots and collated bands will reduce.
There will appear three parts are,
a) Anterior part probosis
b) Middle part collar
c) Posterior part trunk
The trunk region will grow faster than other two parts.
Pharynx gills and in intestine HEPATIC CALCAE, HEART AND BLOOD VESSELS AND ALSO GLONURUKI develop.
In coleom there are 5 cavities will present.



That the reproduction of Balanoglossus. is done.
There is some special cases like in Balanoglossus Kowaiowseles development is direct . So, no larval stage is occur in life history.



Similar questions