Fibrous and Cystic Lesions in the Ovaries of Aged Atlantic Cod (Gadus morhua): a Preliminary Report

Abstract

Ovarian stromal fibrosis occurred in four Atlantic cod (Gadus morhua L.) from the northeastern Gulf of St. Lawrence (49°07′N, 59°18′W) and off Fox Harbour, Labrador (52°18′N, 55°52′W), with accompanying cystic lesions in two specimens.Externally the ovaries varied. Specimen 1 (115 cm fork length, age 18 years) possessed clear areas (0.5–1.5 mm) where the underlying stroma was relatively thin. Specimen 2 (107 cm, 19 years) possessed scattered cream or yellow nodules (< 1 mm) and coalesced nodules (1.5–2.0 mm). Specimen 3 (118 cm, 19 years) had many colourless fluid-filled cysts (1.5–2.0 mm) and a few larger cysts (5.0 × 7.5–7.0 × 12.0 mm), the latter confined to the tapering posterior regions of the ovary. Specimen 4 (99 cm, 16 years) possessed large (up to 8 mm) multilocular cysts anteriorly.Stromal fibrosis occurred to varying degrees in each specimen, containing predominantly fibrinoid as identified by Mallory's PAH, Weigert's fibrin test, and retention of a PAS-positive reaction after incubation in alkaline trypsin. Widespread degeneration of ovigerous lamellae occurred in specimens 3 and 4.The condition of specimens 3 and 4 suggests involutional ovarian stromal fibrosis, but the endocrine studies necessary to confirm this opinion were not performed.