The reproductive system in Agama lizard is as follows.
[Photo credit: Sajjad Fazel]
The male Agama lizard possess two testes. The testes are located in the abdomen. One testis is found at the right side and the other at the left side.
The right testis is slightly higher in position than the left testis. Sperms are conducted from the testes called vasa epididymis (sperm duct), which lead the to the coiled epididymis located at the outer edge of the testis. The sperm cells are the passed on to the two protrusible penes. Each penis is hollow and cylindrical and both release sperms into the female for internal fertilization to occur.
In the female Agama reproductive system, the two ovaries are found in the abdomen in the same position, as the testes in the male. The eggs are released into the abdominal cavity. The eggs are then moved into the oviduct through the action of cilia. As they move down the oviduct, albumin and shell are deposited on the eggs. Fertilization occurs internally as mating occurs.
REPRODUCTIVE SYSTEM IN FISH
[Photo credit: NOZO]
Fertilization occurs externally in fishes, though they exhibit sexual reproduction. Fishes are unisexual. Their reproductive system is found in the abdomen.
For instance, in the case of Tilapia, the male reproductive system consists of two testes and a male duct which leads to the genital opening. The testes are suspended in the abdominal cavity. They are elongated structures and are joined in the posterior part of a single duct which opens to the outside as the genital opening.
In the female reproductive system of Tilapia, the female tilapia has two ovaries, which produce egg cells with a small amount of yolk. The ovaries are discharged into the body cavity and are wafted into the oviducts which open internally into the body cavity. The oviducts lead posteriorly and open again into the genital opening.
REPRODUCTIVE SYSTEM IN BIRDS
[Photo credit: Yann]
The reproductive system in domestic fowls is as follows.
In domestic fowls, the male reproductive system consists of two large and ovoid testes which are attached to the outer edges of the kidney. A vas deferens (sperm duct) leads to the hind end from each testis along the ureter.
Birds generally do not have penis. In many birds, the sperm ducts expand at their posterior ends to form seminal vesicles. Sperms accumulate here during copulation and are transferred from the male to the female when their cloca come in contact.
In the female reproductive system of domestic fowls, only the left ovary is functioning. The single ovary produces eggs in capsules attached to the ovary by short stalks. The ovary produces the yolk.
The infudibulum receives the yolk released by the ovary. Albumen and chalaze, which hold the yolk and germ cell in position are formed in the magnum. The two shell membranes and the shape of the egg are formed in the isthmus. The egg shell is finally formed in the uterus after which the egg is laid through the cloaca. Fertilization of the egg can take place as soon as the egg enters the oviduct when spermatozoa are present. Fertilization occurs before the formation of the albumen.
Recommended:
Reproductive System in Flowering Plants
Reproductive System in mammals
0 comments:
Post a Comment