Reproductive Terminology

Scientists can use this table of standardized reproductive terms and definitions to more effectively communicate about reproductive research.

An emerging issue in applied fisheries reproductive biology is the need for common terminology. Many of the terms used to describe reproductive concepts and developmental stages are often inconsistent and specific to a study, species or region. This makes communication and comparative analyses difficult for researchers. In an effort to address the need for a common vocabulary, a group of biologists developed a list of commonly used reproductive terms and definitions (view publication: Lowerre-Barbieri et al. 2011) and standardized terms to describe reproductive development (view publication: Brown-Peterson et al. 2011).

Reproductive Terms and Definitions

Term	Definition	References
Oogenesis	Development and growth of oocytes, from oogonia through maturation. Stages of oogenesis: oogonia (Oo); primary growth (PG); cortical alveolar (CA); vitellogenic (Vtg), also known as yolked (Yo); and oocyte maturation (OM).	Kjesbu 2009 Wallace and Selman 1981 Patiño and Sullivan 2002 Hunter and Macewicz 1985
Spermatogenesis	Morphological and physiological changes during development of male germ cells. Stages of spermatogenesis: spermatogonia (Sg), spermatocytes (Sc), spermatids (St) and spermatozoa (Sz).	Grier and Uribe-Aranzábal 2009 Nagahama 1983
Primary growth	Gonadotropin-independent growth of oocytes, characterized by basophilic staining. Stages include: single nucleolus, multiple nucleoli and perinucleolar.	Wallace and Selman 1981
Secondary growth	Gonadotropin-dependent growth of oocytes. Stages include: cortical alveolar (CA) and vitellogenic (Vtg). Vtg is often divided into three substages: primary vitellogenic (Vtg1), secondary vitellogenic (Vtg2) and tertiary vitellogenic (Vtg3).	Luckenbach et al. 2008 Abascal and Medina 2005 Matsuyama et al 1990
Oocyte maturation (OM)	Resumption of meiosis and achievement of oocyte maturational competence, ending in ovulation. OM includes two nuclear events: germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD). In some species, OM may also include: formation of large oil droplets, known as lipid coalescence (LC); yolk coalescence (YC); and hydration (H).	Grier et al. 2009 Jalabert 2005
Reproductive phases	Phases of gonadal development occurring in all fishes prior to, during and after spawning. Phases are defined as: immature (Imm); developing (Dev); spawning capable (SC), which includes the spawning (S) subphase; regressing (Rgs); and regenerating (Rgn).	Brown-Peterson et al. this 2011
Determinate fecundity	Recruitment of oocytes from primary growth to secondary growth occurs prior to an individual’s spawning period.	Hunter et al. 1992 Murua and Saborido-Rey 2003
Indeterminate fecundity	Recruitment of oocytes from primary growth to secondary growth continues throughout an individual’s spawning period.	Hunter et al. 1992 Murua and Saborido-Rey 2003
Batch spawner	Females capable of ovulating and spawning multiple batches of oocytes during the individual spawning period. Batch spawners can have determinate or indeterminate fecundity.	Murua and Saborido-Rey 2003
Total spawner	Females ovulate and spawn all developing oocytes in a single event or within a very short time period as part of a single episode.	Murua and Saborido-Rey 2003
Skipped spawning	Sexually mature fish that fail to spawn during a reproductive season. Failure to spawn can be recognized by a lack of ovarian development (vitellogenesis) or by massive atresia prior to the spawning period.	Rideout et al. 2005
Maturation	Synonymous with sexual maturity in both males and females, which is attained once in a lifetime.	Rideout et al. 2005

From Lowerre-Barbieri et al. 2011