Swordtails' Mysterious, Magical Sex Change
Many many months ago, I bought what I thought was 1 male and 3 female Pineapple Swordtails (Xiphophorus Helleri) from my local fish stores. The lone male was small but had a really long "sword" and was incredibly aggressive towards the others. After about a month, his aggression was resulting in severely stressed out tankmates so I couldn't bear to continue housing them all together. I took out the aggressive male (after half an hour of netting struggles) and put him in my 50 gallon.
All was well. All the fish started acting less stressed out and were generally happy after the mean bully was relocated.
 |
| Female Pineapple Swordtail (notice the triangle shaped anal fin and huge belly) |
Until 2 months after the relocation...
After one of the youngest females gave birth, I noticed that the 2 other "females'" tails were getting pointier. And their anal fins were changing from a "triangle" to a "stick" shape. Wtf?
Usually you can sex platies and swordtails by looking at their anal fin. Females have a triangle shaped anal fin and have rounder bellies whereas males are longer and thinner and have a gonopodium (sexual organ).
 |
| Male Pineapple Swordtail with Gonopodium |
Well, imagine my surprise when a few weeks after I noticed the females' pointier tails, the tails grew out almost overnight and BADABOOM - They turned into males.
Well, some of you may say they were probably males to begin with and just were too young to develop their "swords". Wellllll....mayyybe. But highly unlikely. These "shemales" were fully grown - almost 3.5 inches when I bought them. They were huge! How could they possibly be that big and not have developed even a small tail yet? Also, these "shemales" had very round bellies. And they had a triangle anal fin.
I am still puzzled to this day. I thought maybe it was just some weird freaky accident. But I recently purchased a DEFINITE female pineapple sword. Mature. 4 inches. Triangle anal fin. The experienced shop owner even said she was the "old mother". Said she had lots of babies.
I brought her home maybe 2? weeks ago. She has already started developing a "Sword" and her triangle changed into a gonopodium!! Freaky!!
I brought this up when I saw the owner of my local fish store and she said sometimes when there's a dominant male, it will try to fight (and maim) other males in order to try and mate with the female(s). Male-male aggression is especially bad when there's only 1 female (as was my case). So as a defence mechanism, sometimes males will "hide" their "swords" during development and pretend to be a female in order to avoid harassment. Perhaps that's the answer...except male swordtails harass females too....Just to a lesser extent. I guess male-male harassment is more lethal because they are trying to show off their dominance whereas male-female harassment only involves endless chasing and wooing.
What a conundrum. If any of you out there knows what's going on or have speculations, please, I'd love to hear about them!
On another note, I purchased 3 gorgeous "Red Neon Painted Platies" this afternoon at Aquariums West. They are all males and have adapted perfectly to my tank. I would just fall right off my chair if these 3 males turned into females for some reason.
I keep my swordtails and platies in my 36 gallon (76-78F, 7.5-7.8 pH)
That's all for now folks.
Chesmok
No comments:
Post a Comment