Abstract:
Histological analysis of the gonads of 25 Manila catfish (Arius manilensis), an
endemic fish thriving in the waters of Laguna de Bay, was performed. The female A.
manilensis specimens revealed the presence of basophilic cells around and within stage
IV and V oocytes, highly vacuolated immature oocytes, and unidentified masses of
brown cells interspersed and or aggregated within the ovarian connective tissue stroma.
The male A. manilensis testis showed the separation of the spermatogenic cells from the
basement membrane of the seminiferous tubules. Disintegration of the tubular walls was
also observed in some testes These abnormalities may suggest a decreased number of
viable oocytes and spermatogenic cells, and may consequently decrease the fecundity of
A. manilensis.