Standardized Maturity Stages for

Live-Bearing Sharks

Determining the maturity state of sharks in the field is difficult. The following summary is offered to help standardize observations and reportage of gonadal maturity in ovoviviparous and viviparous sharks. Once familiar with the stage categories proposed here, maturity state of sharks examined in the field can be determined accurately and scored quickly.

Males

Juvenile

claspers undeveloped sticks
gonads tiny, thread-like, and whitish
sperm ducts straight

Subadult

claspers formed but soft, flexible
testes enlarged
sperm ducts meandering

Adult

claspers fully formed and stiff
testes well rounded, reddish, and filled with flowing sperm
sperm ducts tightly coiled

Active

glans of claspers often dilated and swollen
sperm flowing from cloacal papilla under pressure applied to belly and/or present in clasper grooves

Females

Ovarian Stages

Juvenile

ovaries small, gelatinous or granulated
eggs not yet differentiated or evenly small and granular
uteri thread-shaped

Ripening

ovaries enlarged, walls transparent
eggs differentiated to various sizes
uteri thread-shaped

Ripe

ovaries large, well rounded
eggs enlarged, all about the same size so that they can be counted and measured easily

Uterine Stages

Developing

uteri well filled and rounded with unsegmented yolk content

Differentiating

uteri well filled and rounded with segmented content of yolk balls
embryos small, unpigmented, and with large yolk sacs, but can be counted

Expecting

embryos fully formed and pigmented, yolk sacs obviously reduced
embryos can be counted and measured easily

Postnatal

ovaries at resting stage, similar to Developing stage
uteri empty but still widened considerably in comparison with Developing and Differentiating stages