Table 1 Classification of maturity stages for female B. altianalis

Stage I (immature): Strand-like reddish gonads (dominated by oogonia and primary growth oocytes)

Stage II (developing): Minute off-white speckles (cortical alveolar oocytes) are observed within the ovary. Few Vtg1 and Vtg2 are also observed

Stage III (spawning capable): Early stage; clear gonads with batches of off-white and pale yellow eggs. This stage is dominated by Vtg1 and Vtg2 oocytes. But still enlarging in size

Stage III (spawning capable): Spawning stage; clear gonads with batches of off-white and pale yellow eggs parked in the ovary. The observed oocytes are largely dominated by Vtg3 and mature oocytes with some POFs. But all oocytes types are present qualifying it as a batch spawner

Stage IV (regressing): Flabby gonads with observed residual eggs. Residues are degenerating atretic oocytes

Stage V (regenerating): Same as II but slightly bigger. Old POFs, melano microphage centers, and OO and PG oocytes are observed