Thanks for that. I didn't know about the blackness on the bottom, or yellowness, or that the personality and activity can be the pointers.
What I have read and heard rather consistently is that the RTC sexing is unknown from external features.
I have been raising 9 RTCs in one of the 4500 gal for 2-3 years now and I noted that there are two distinct groups.
One kind has a broader and flatter top of the head, hence bigger mouth, and grows faster or maybe just grows larger, and these are the most active at hand-feeding times. There are 3 of them and these are all currently 3'-3.5'.
The other kind has a relatively narrower and more sloping top of the head and they are all smaller than the other kind, currently at 2.5'-3', less active at feeding. There are 6 of those.
I see no consistency in the coloration between the two groups, of the top or of the bottom, or in the amount of the redness.
If I go by what you said, the first group then must be the females and the second are the males.
I thought the opposite because fishermen state that in general male catfish have a broader head and a female would tend to have a larger tummy girth. People seem to state that about the North American fish they catch, like channel, blue, and flathead. IDK about bullheads.
You are a fisherman. You should know.
I vaguely recall reading that this rule may be general and apply to other catfish and other continents. That the females have a larger girth is understandable as they need to house larger reproductive organs and the eggs take up a lot more space than the male's milt. But the head is what's intriguing to me. If males have a bigger head and bigger mouth, is it for display, intimidation, fighting? Kind of like among some hooved animals the males have horns while females horns are reduced or absent.
What I have read and heard rather consistently is that the RTC sexing is unknown from external features.
I have been raising 9 RTCs in one of the 4500 gal for 2-3 years now and I noted that there are two distinct groups.
One kind has a broader and flatter top of the head, hence bigger mouth, and grows faster or maybe just grows larger, and these are the most active at hand-feeding times. There are 3 of them and these are all currently 3'-3.5'.
The other kind has a relatively narrower and more sloping top of the head and they are all smaller than the other kind, currently at 2.5'-3', less active at feeding. There are 6 of those.
I see no consistency in the coloration between the two groups, of the top or of the bottom, or in the amount of the redness.
If I go by what you said, the first group then must be the females and the second are the males.
I thought the opposite because fishermen state that in general male catfish have a broader head and a female would tend to have a larger tummy girth. People seem to state that about the North American fish they catch, like channel, blue, and flathead. IDK about bullheads.
You are a fisherman. You should know.
I vaguely recall reading that this rule may be general and apply to other catfish and other continents. That the females have a larger girth is understandable as they need to house larger reproductive organs and the eggs take up a lot more space than the male's milt. But the head is what's intriguing to me. If males have a bigger head and bigger mouth, is it for display, intimidation, fighting? Kind of like among some hooved animals the males have horns while females horns are reduced or absent.
