Some time ago, I went to Hainan on a business trip, and under the leadership of Teacher Tang, I tried sea fishing for the first time. I touched a lot of fish, and finally realized "touching fish at work"! （bushi）
Shuttle bean fish
Photography: Wu Haifeng
Lead-spotted multi-era pufferfish
Photography: Wu Haifeng
The best looking one is a purple sea pig fish.
Purple sea pig fish
Photography: Wu Haifeng
This fish looks quite normal, but in fact, many of its relatives are transgender fish! Today we're going to talk about animal transsexuality.
Sea Pig Fish: Really "Perverted"
At a glance, the sea pig fish has nothing to do with the "pig". But if it opens its mouth, it can see long "front teeth" and long "alkenes", like the fangs of a wild boar.
The teeth of the Sarsa's sea pig fish
Image credit: J.L. Gasparini and J.-C. Joyeux./semanticscholar.org
The fangs of wild boars are generally used for self-defense, and they are also used to compete and show off when looking for a partner. But the sea pig fish is not, and the fangs in front of it are mainly used to deal with prey. For example, if you catch a shelled shrimp crab or shellfish, you use these two pairs of fangs to get stuck, smash them on the stone, fall to death, smash them and eat them; If you don't have a shell of all kinds of small fish, you can eat them directly.
Often walking in the rivers and lakes, even if you can not be knifed, the sea pig fish will also be caught by other fish. Image credit: Loh Kok Sheng/wildsingapore.com
Sea pig fish are generally very good-looking, but to my shock, some species of sea pig fish can actually be denatured! When the sea pig fish is small, it is difficult to distinguish the sex, but in their bodies, there are two sets of reproductive systems, the first development is the female reproductive system, which is also the appearance of the female fish. As they grow, the strong individuals will become males, the ovaries degenerate, the spermatozoa begin to develop, and eventually become male bodies.
After the gender change, the body color will also become different. For example, the flower-finned sea pig fish, the female fish body is yellow, after becoming a male fish, the body becomes green, which is very distinguishable.
Flower-finned sea pig fish
Image source: Chinese Marine Fish
A situation like this one that starts out as a female and then becomes a male is called "female matures first", and such fish are mostly polygamous, and finally only the strongest female will become male, and only this male will "dominate" all wives.
Clownfish: My dad became my mom
Just mentioned that females mature first, so are there any animals that males mature first?
Of course there is, the clownfish is.
Nemo, is that you Nemo?
Image source: starbiz.com
The Double Sawfish is a clownfish found in China
Image source: snorkeling-report.com
Clownfish are social fish, and a large family lives in a small piece of anemone. The typical social structure is a female clownfish (the largest) with a male (the second largest), and many juveniles who do not show their sex.
Female clownfish are larger
See watermark for image source
When the female disappears or dies, the male slowly becomes aggressive, eats, and grows larger over a two-week period. At the same time, a series of changes are taking place in the male fish, testicular degeneration, ovarian development... Eventually becomes a female.
The more resources are tilted towards the female, the female will have better physical fitness and reproductive ability, and will be able to produce more heirs.
The denaturation cycle of clownfish
Image credit: youtube/BeckmanInstitute
What are the benefits of this transgender ability of clownfish?
The distribution of clownfish is closely related to the symbiotic anemone, and there is usually only one clownfish in a small piece of anemone. If the female clownfish is hung, it is difficult for a new female to swim in, and even if it swims, it may not be accepted by the anemone and the original clownfish. Transgender, on the other hand, ensures that there are always females and males in a clownfish population who can mate, which ensures sustainable population growth.
Nemo and Dad
Image source: Finding Nemo
Let's go back and forth to "Finding Nemo", so when Nemo's mother was eaten by a big fish, Nemo was captured, Nemo's father traveled thousands of miles to save Nemo, and when Nemo saw him, he should become... Nemo's mom?!
Oyster: Look at my seventy-two changes
The two situations mentioned above are the transition from one gender to the other, and both of these transformations are basically one-way irreversible. And oysters, yes, are the oysters you usually eat, and they can jump repeatedly between male and female. The reason may be related to the temperature of the sea, or it may be related to the nutritional status, and scientists have not been too clear.
So is this oyster you eat male or female?
Look at the gonads.
The literature says that the female gonads are yellowish in color, while the male gonads are white in color. But I didn't see it. Scientists also have a reliable method of resolution, extract a part of the gonads, drop a drop of water, put it under the microscope to observe, the female egg cells are granular, while the male sperm cells are not very visible.
Of course, the oysters you eat may not be able to distinguish between male and female at all, first of all because your skills are not good, and secondly, most of the oysters you eat have been passed by garlic fans. I don't believe that in the face of such delicious oysters, you are still in the mood to distinguish where the gonads are.
Is there really such a studious reader? Raise your hand and I'll take a look
There is also an important reason, the oysters on the market may be artificially bred triploid oysters, the degree of gonadal development is not high.
What's going on here?
Normal diploid oysters are male and female, and the nutrients accumulated in the body during the breeding season (the delicious part) will be turned to the reproductive system (not tasty), which you can understand as "the fattened oysters have run away, and the ducks that have reached the mouth have flown". So scientists use normal diploid oysters to cultivate tetraploid oysters, and then use the two to "hybridize" triploids, just like triploid "seedless watermelons", many of which are white and not fully developed seeds, so that oysters can concentrate on growing meat and satisfy your appetite.
👇
There are all sorts of strange things in the sea
Have you seen any of these?
In order to become a bigger oyster, it was almost neutered!
Written by | Wu Haifeng
WeChat Editor | What a cool