Fig. 1From: Optimizing selection of sexually mature Barbus altianalis for induced spawning: determination of size at sexual maturity of populations from Lake Edward and Upper Victoria Nile in UgandaCross section of female gonad. a Stage I gonad with oogonia (OO), chromatin nucleolar oocytes (CN), and perinucleolar oocytes (PN). The three types constitute primary growth oocytes (PG). b Stage II gonads with cortical alveolar oocytes (CA), primary vitellogenic oocytes (Vtg1), and secondary vitellogenic oocytes (Vtg2). c Stage III constituted all other oocyte types with tertiary vitellogenic oocytes (Vtg3) and mature oocytes (MO). d Stage V with primary growth oocytes (PG), old post ovulatory follicles (POF), and degenerating atretic oocytes (AT). (H&E)Back to article page