How does a tick pass through its uterus? - briefly
Fertilized eggs move through the oviducts into the uterus, where they mature and are then expelled through the genital pore as a batch of eggs. The process is completed shortly after the tick finishes feeding.
How does a tick pass through its uterus? - in detail
Ticks reproduce through internal fertilization. During copulation, the male inserts his spermatophore into the female’s genital aperture. The spermatophore is guided to the spermatheca, a storage organ located near the posterior part of the abdomen. Sperm remain viable in the spermatheca for weeks, allowing the female to control fertilization timing.
The ovaries lie anterior to the spermatheca and release mature oocytes into the common oviduct. Each oocyte is coated with a proteinaceous layer and then moves posteriorly toward the uterus. The uterus is a tubular cavity that runs along the ventral side of the abdomen, connecting the oviducts to the genital opening.
Passage through the uterus involves several steps:
- Contraction of uterine muscles propels the oocyte forward.
- Peristaltic waves synchronize with the release of yolk nutrients from accessory glands.
- The oocyte’s outer membrane contacts the uterine epithelium, where additional chorionic layers are secreted, forming a protective shell.
- After shell formation, the now‑embryonic egg continues its journey toward the distal end of the uterus.
At the terminal end, the uterus opens into the genital pore, which is surrounded by the anal plate. The fully formed egg is expelled through this pore onto the host or into the environment, depending on the tick species. In many ixodid ticks, the female remains attached to the host while laying a batch of eggs, depositing them in a protected site after detaching.
The entire process—from spermatophore insertion to egg expulsion—occurs within a single reproductive cycle that may span several weeks, with temperature and host availability influencing the rate of uterine transit and egg deposition.