Vitelluses, a term used in biology to describe the nutrients stored in an egg yolk, may also be referred to as yolk or ooplasm. These terms are commonly used in the study of embryonic development, as the nutrients stored in the egg yolk provide essential nourishment for the growing embryo. Additionally, the term vitellus may be used interchangeably with yolk, as both are used to describe the yellow, nutrient-rich substance found in eggs. Regardless of the terminology used, a thorough understanding of the composition and function of vitelluses is crucial to the study of reproductive biology and embryonic development.