Comparative study of vitellogenesis of two African catfish species Chrysichthys nigrodigitatus (Claroteidae) and Heterobranchus 1ongifilis (Clariidae)Jésus Nuñez Rodriguez, Ziriga Josué Otémé and Saurin HemAquat. Living Resour., 8 4 (1995) 291-296DOI: https://doi.org/10.1051/alr:1995029