A Histological Study of Ovarian Development in the Giant Red Shrimp Aristaeomorpha foliacea (Crustacea: Decapoda: Aristeidae) from the Southern Tyrrhenian Sea (Western Mediterranean)

Table 4

Histological description of ovarian maturity stages in Aristaeomorpha foliacea, with their relative GSI (mean ± s.d.).

Maturity stage		Histological description	GSI
(MEDITS Instruction Manual v.5.0, 2008)
1	Immature	Oogonia (Og) and early primary oocytes (Ep) scattered in the connective stroma. Late primary oocytes (Lp) occasionally present.	0.11±0.08; (𝑛=11)
2a	Virgin developing	Germinative zone containing Oo and Ep. Maturative zone containing Lp, organized into tubule-like structural units.	0.53±0.13; (𝑛=10)
2b	Recovering	The same as 2a.	1.17±0.69; (𝑛=59)
2c	Maturing	Maturative parenchyma containing a single batch of early vitellogenic (Ev) oocytes, organized into tubule-like structural units. Germinative islets populated by Oo and Ep oocytes.	5.07±1.64; (𝑛=14)
2d	Mature	Maturative parenchyma containing late vitellogenic oocytes (Lv), piled up in tubular units. The most advanced specimens contain post-vitellogenic oocytes (Pv). Germinative islets populated by Oo and Ep oocytes.	9.29±2.51; (𝑛=11)
2e	Resting	Proliferation and hypertrophy of mesodermal cells lining tubular units. The latter are populated by Lp oocytes at an initial stage of atresia (Ao), among which some residual Pv oocyte could be detected.	2.17±0.47; (𝑛=9)