Authors

Policarpo L. Openiano, Jr.

Author

Henry E. Dejarme

Co-author

Alex B. Apongan

Co-author

Alita E. Openiano

Co-author

Mindanao State University at Naawan, 9023 Naawan, Misamis Oriental, Philippines

*Corresponding author: *@gmail.com

ABSTRACT

Observations on the abundance and certain aspects of the biology, ecology, and fishery of the cross-barred grunt Mesopristes cancellatus in Mandulog river, Iligan Citywere carried out in 1991 to obtain necessary information for the development of culture technology of the species. Data were gathered from two study stations, Hinaplanon and Bayug, representing the upstream and downstream portions of the river. Biological aspects of the fish investigated were sex ratio, sexual maturity, fecundity, and gut content. Physico-chemical description of the river included water salinity, turbidity, velocity, pH, D.O. and substrate characteristics. A description of M. cancellatus fishery in Mandulog river was also undertaken in the study. Results indicate that M. cancellatus exhibiteds easonal abundance apparently influenced by flooding and lunar phase. The fish occurred abundantly in the months of April to September but were not observed between January and March and between October and November. A total of 125 fish were collected within the period with weights ranging from 25-700g, dominated by medium sized individuals with body weight ranging from 261-420g (64%) while small individuals (25-100g) occurred at a relatively lower frequency (27.4%). Sex ratios generally showed higher number of female than male fish, and gonadal maturity appeared to peak between April and May. Fecundity ranged from as low as 16,800 eggs to as high as 2,078,000 eggs per fish, depending on gonadal size and maturity. Large, mature (Stage IV) females with weight range of 350-560g had a mean fecundity of 1,186,420 eggs. Moderate levels of ambient physico-chemical conditions and abundant plankton populations make Mandulog River an ideal habitat for this economically important species.