Ontogeny of Marine Turtle Gonads
207
7.3.2 T ESTIS
In histological cross section, the cortex of the testis is differentiated into flattened,
squamous cells positioned next to the tunica albuginea (Figure 7.4). The medulla
is filled with seminiferous tubules with germinal cells situated near the inner
membrane. The space contained in the lumen of the tubules appears about the
same as that occupied by the surrounding tissue.
TABLE 7.2
Characteristics of Hatchling Gonads
Region
Female
Male
Gonad
Medulla
Dense, without tubules
Tubular
Cortex
Columnar epithelium
Squamous epithelium
Paramesonephric duct
Developed with lumen
Undeveloped, without lumen
Inner epithelium columnar
Inner epithelium absent
With long, thin shaft
Without long, thin stalk
Sources: From Miller, J.D. and Limpus, C.J. 1981. Incubation period and sexual differentiation in
the green turtle, Chelonia mydas L. Pp. 66–73. In: Proceedings of the Melbourne Herpetological
Symposium (C.B. Banks and A.A. Martin, eds.). Zoological Board of Victoria, Parkville, Victoria,
Australia; and Merchant-Larios, H., Villalpando, I., and Centeno, B. 1989. Gonadal morphogenesis
under controlled temperature in the sea turtle Lepidochelys olivacea . Herpetol. Monogr. 3:128–157.
With permission.
FIGURE 7.2 Gonad and paramesonephric duct in hatchling C. caretta . A. Gonad, B. Paramesonephric duct.
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