Thalassoma amblycephalum Sexual Dimorphism... dichromatism    3/21/07 Hi, <Hello.> What are the identifying characteristics to look for in distinguishing a male Paddlefin wrasse from a female?  There is one at my LFS that has a blue head with a yellow band behind its head with a red body that has a faint white stripe that runs horizontally along its body. Is this a male or female?  Someone told me that the females have this white horizontal stripe, but someone else told me that the males have white vertical lines across their bodies and that they are more colorful than the females.  Can you please help me in knowing which is which.  Some pics of males vs. females would be very helpful. <Please read here: http://www.wetwebmedia.com/thalassoma.htm...will answer your question and contains pics too.  For what it's worth males are easily distinguishable and females/juvies are not imported as much.  The one in the store from description alone is surely a male.> Thanks, Gary <Adam J.>

Thalassoma Lucasanum Bob, <<Actually, JasonC today...>> I have two female Thalassoma lucasanum. One of them is going through a sex change from female to male (it's really very interesting). <<Indeed.>> Is there any chance that they will mate? <<Certainly a possibility, but not guaranteed - the right conditions may not exist in a captive system.>> If so, is there anything I can do to help insure the survival of the offspring? <<Probably not... I'm not sure that there's ever been any success at breeding these in captivity.>> I also have a yellow tang, a maroon clown, and an assortment of damsels (blue fin, blue devil and green Chromis) in my aquarium. Thanks, Rich <<Cheers, J -- >>

- Sex Changing Wrasse - Hello to all at WWM: About three months ago a bought a FEMALE Thalassoma lucasanum, (AKA Rainbow Wrasse, Paddlefish Wrasse, Cortez  margarita Wrasse). However, now almost 3 months later, it has changed to the  male coloration, maybe into an actual male. I did not know these fish would or  even can change from the female coloration to the male coloration.  Just curious if anyone at the Crew has heard or seen of such a thing. <There are many wrasses as well as several other groups of fish that have this remarkable ability. It ensures the continuation of the species. What a planet!> Either way I like both color forms. By the way, Scott Michael's Marine Fishes pocket guide  has great photos of this fish on page 319. As always, thanks for all your time and effort. Gene
<Cheers, J -- >