ASPECT OF BIOLOGY OF Chrysichthys nigrodigitatus (Lacepede 1802) FROM EPE, LAGOS, AND BADAGRY LAGOONS, SOUTH-WEST NIGERIA.

• B. E. Emmanuel

  Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka – Yaba, Lagos.

  Author

• A. J. Momodu

  Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka – Yaba, Lagos.

  Author

The morphometric characteristics, length-weight relationship, condition factor, and diet composition of Chrysichthys nigrodigitatus from the Badagry, Epe, and Lagos Lagoons were studied from November 2017 to April 2018. The chemical parameters of Epe, Badagry, and Lagos Lagoons showed that pH was 6.60 ±1.04, 6.68±0.60, and 6.85±0.19 respectively, and salinity was 1.66 ±2.80 ‰, 0.68 ±0.12 ‰, and 2.72 ±2.60 ‰ respectively. Total lengths of Chrysichthys nigrodigitatus obtained from Epe, Badagry, and Lagos lagoons were 23.7±4.3 cm 22.7±18.6 cm, and 24.8±4.8 respectively. Some morphometric parameters tested against total length revealed a strong positive correlation, except the mouth gape that showed weak positive correlations. The length-weight relationships of Chrysichthys nigrodigitatus from the lagoons showed negative allometric growth. The condition factor (K) of the combined sexes of the Chrysichthys nigrodigitatus from Epe, Badagry, and Lagos Lagoons was 0.76 ±0.18, 0.77 ±0.18, and 0.69 ±0.31 respectively. The condition factor of Chrysichthys nigrodigitatus from the three lagoons showed that the values were all less than 1. This reflects poor physiological and environmental conditions; it indicates that the fishes are not healthy and does not do well in the waterbodies. The fish stomach content showed that 32%, 4%, and 17% had empty stomachs from Epe, Badagry, and Lagos lagoons respectively. Items identified from the fish gut from the Lagoons include molluscs, sand grain, fish, shrimp, and some unidentified materials. Chrysichthys nigrodigitatus from the three Lagoons are omnivorous. Sand grains observed in the fish stomach indicated that the species is a bottom feeder. This study confirmed that C. nigrodigitatus can survive in different habitat with different environmental factors include temperature, food, pollutants, population density, sound, light, and parasites.

1. B. E. Emmanuel, Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka – Yaba, Lagos.

   Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka – Yaba, Lagos.

2. A. J. Momodu, Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka – Yaba, Lagos.

   Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka – Yaba, Lagos.

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