Home›Glossary›YGlossaryyolkEdit this pageSubstance in an animal egg consisting of protein and fat that nourishes the developing embryo.Used in 114 species profilesAmatitlania myrnaeAmatitlania nanoluteaAmatitlania nigrofasciataAncistrus ranunculusAncistrus sp.Ancistrus triradiatusAll 114 →