Article: Dive dry with dr. Bill #492: A fish that's almost patriotic
- Thread starter drbill
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Sheri SGR
Contributor
Can you tell what sex they are by color markings like the sheephead or perhaps some other feature?
OP
Not that I'm aware of, Sheri. Color seems to be pretty consistent between the sexes as far as I can tell. They must use pheromones or other cues to tell the difference.
-=Striker=-
Registered
Sheri, as drbill said, the markings are consistent between both sexes, however you can tell their sex with nearly100% accuracy based on an external structure on their ventral surface directly posterior to their vent called "genital papillae". The shape of that papillae will define the sex of the individual. short, stubby and just as long as it is wide = female. Long, pointed and significantly longer than wide = male.
Sheri SGR
Contributor
Thanks Striker I will look closely next time and see if I can spot the differences.
OP
Sounds appropriate, Striker... wasn't aware of that but it certainly makes sense. I'll just have to get prescription lenses! Of course during mating it is pretty easy to distinguish them through behavioral differences.
Similar threads
