FISH AND GENDER ROLES
Vocabulary
Cortez rainbow wrasse: male with blue
head and yellow saddle; females with
the horizontal yellow and red stripes
Hermaphrodite—having both male and female reproductive organs
Synchronous hermaphrodites—male and female at same time
Sequential hermaphrodites—change from one gender to the other
Protandric hermaphrodite—male to female
Protogynous hermaphrodite—female to male
Bi-directional (or alternate) hermaphrodites—can change
between genders several times
Polygamy—having multiple partners or spouses
Polygyny—dominant male with multiple females
Polyandry—dominant female with multiple males
Fish Stories
Hermaphroditism in the fish world is a common thing. In fact, a lot of deep
sea fish are either synchronous hermaphrodites or have parasitic partners.
The anglerfish female (pictured right) can have several smaller males (circled)
fused to her body so she always has sperm available.
The snook is one such fish that is hermaphroditic. All snook hatch with the
beginning gender of male. Between one to seven years however, the majority
switch to females. Clownfish are also protandric hermaphrodites, with the
largest of the pair as the female. If the female dies, the reproductive male will
change into female and find another fish to be its male.
Opposite of those are the protogynous hermaphrodites which start out as female and develop into males.
Species of wrasse, angelfish, grouper, goby, and parrotfish exhibit this biology. Wrasses are very
interesting with their polygynous harems, or a dominant male over several female and some males. When
the dominant male dies, the largest wrasse in the harem will turn male.
Oysters, while not fish, are hermaphrodites. The majority are protandric hermaphrodites, however they
can change gender between male and female several times throughout a lifespan.
http://myfwc.com/media/195824/eastern_oyster.pdf; http://www.dfs-pet-blog.com/2010/05/wrasse/; http://www.merriam-webster.com/; www.fishbase.org; http://www.flmnh.ufl.edu/fish/
gallery/descript/snook/snook.html