Ontogeny of Marine Turtle Gonads
217
Sperm ascend the oviduct with the aid of ciliary tracts (Solomon and Baird,
1979). They found nests of sperm in the glands at the junction of the shell-forming
zone and the vagina, near the base of the oviduct, but no spermatheca, which would
indicate storage. They also reported quantities of sperm in the aglandular zone. This
area is closer to the ovary than the magnum and is the last place during descent of
the oocyte through the oviduct where sperm could fertilize the oocyte without having
to penetrate albumen. Fertilization must occur either in the aglandular zone or in
the infundibulum.
The epididymis of a mature male is pendulous and extends from the body wall.
The seminiferous tubules are obvious within the testes, even in nonbreeding males.
In breeding males, the seminiferous tubules are distended and appear white because
they are filled with sperm. The entire epididymis is enlarged compared to that of
a nonbreeding male. The vas deferens is a whitish tube traversing the body wall
from the epididymis to the vicinity of the cloaca, where it becomes obscured by
other tissue.
For turtles in their foraging area, the adult reproductive system is in one of three
general states: quiescent, active, or regressive. The morphological expression of
these states is obvious in the female but is only indicated in the male. Because
marine turtles exhibit an iteroparous reproductive pattern, they do not all breed on
the same cycle (Hirth, 1980; NRC, 1990). Individual females exhibit variable intervals between reproductive episodes (Limpus and Limpus, in press); males do not
necessarily breed on the same cycle as females (Limpus, 1993).
7.6.4 QUIESCENCE
Female turtles that are in a quiescent reproductive period did not breed in the
immediately past season and will not breed in the next two seasons. They are
recovering the energy reserves used during their previous reproductive cycle, growFIGURE 7.11 Oviduct of adult female C. mydas on mesentery.
1123 book.book Page 217 Monday, November 11, 2002 11:11 AM
217
Sperm ascend the oviduct with the aid of ciliary tracts (Solomon and Baird,
1979). They found nests of sperm in the glands at the junction of the shell-forming
zone and the vagina, near the base of the oviduct, but no spermatheca, which would
indicate storage. They also reported quantities of sperm in the aglandular zone. This
area is closer to the ovary than the magnum and is the last place during descent of
the oocyte through the oviduct where sperm could fertilize the oocyte without having
to penetrate albumen. Fertilization must occur either in the aglandular zone or in
the infundibulum.
The epididymis of a mature male is pendulous and extends from the body wall.
The seminiferous tubules are obvious within the testes, even in nonbreeding males.
In breeding males, the seminiferous tubules are distended and appear white because
they are filled with sperm. The entire epididymis is enlarged compared to that of
a nonbreeding male. The vas deferens is a whitish tube traversing the body wall
from the epididymis to the vicinity of the cloaca, where it becomes obscured by
other tissue.
For turtles in their foraging area, the adult reproductive system is in one of three
general states: quiescent, active, or regressive. The morphological expression of
these states is obvious in the female but is only indicated in the male. Because
marine turtles exhibit an iteroparous reproductive pattern, they do not all breed on
the same cycle (Hirth, 1980; NRC, 1990). Individual females exhibit variable intervals between reproductive episodes (Limpus and Limpus, in press); males do not
necessarily breed on the same cycle as females (Limpus, 1993).
7.6.4 QUIESCENCE
Female turtles that are in a quiescent reproductive period did not breed in the
immediately past season and will not breed in the next two seasons. They are
recovering the energy reserves used during their previous reproductive cycle, growFIGURE 7.11 Oviduct of adult female C. mydas on mesentery.
1123 book.book Page 217 Monday, November 11, 2002 11:11 AM