Shoaling: species number, behaviors, and science
- Thread starter Tifftastic
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I think that question can best be answered this way:
Schooling is the motion of moving together in a group. A true schooling species, like the videos of marine fish you see on documentaries will always school.
Shoaling is more staying together for safety or foraging reasons, but some shoaling species will exhibit schooling behaviors. So, if the species schools temporarily, like say during flight from a predator, the closeness of the group and their ability to move in unison may relax when the stimulus relaxes. However, this largely depends on species and the unique situation as well as (in some) cases the age class, size, gender and individual personality syndromes of the fish involved.
Shoaling/schooling are incredibly complex behaviors and I honestly think your question is one that a lot of the research I am looking at is trying to determine.
Schooling is the motion of moving together in a group. A true schooling species, like the videos of marine fish you see on documentaries will always school.
Shoaling is more staying together for safety or foraging reasons, but some shoaling species will exhibit schooling behaviors. So, if the species schools temporarily, like say during flight from a predator, the closeness of the group and their ability to move in unison may relax when the stimulus relaxes. However, this largely depends on species and the unique situation as well as (in some) cases the age class, size, gender and individual personality syndromes of the fish involved.
Shoaling/schooling are incredibly complex behaviors and I honestly think your question is one that a lot of the research I am looking at is trying to determine.
That makes sense. And it is still avoiding what I wanted to know a little bit. Let me rephrase with the new knowledge of extra terms you just put out there.
The really true schooling species in the ocean (the hundreds, or thousands of individuals in a group) that always school have to eat sometimes. How do they eat? My thinking is that they either open mouth, don't ever break formation and hope for the best (pretty stupid even for a fish). Or, that it is impossible to actually observe them eat, because they are too scared to eat when anything is too close (like a diver with camera). This option is probably too far fetched which would leave one viable option that comes to my mind: the school is opportunistic fish (which I believe every fish to some point be opportunistic) and they eat all the time, with individuals breaking out of unison all the time. Statistically those movements may never be detected as breaking unison and may just get filtered out as noise.
Food for thought (pun intented), or possible new research if it hasn't been done.
The really true schooling species in the ocean (the hundreds, or thousands of individuals in a group) that always school have to eat sometimes. How do they eat? My thinking is that they either open mouth, don't ever break formation and hope for the best (pretty stupid even for a fish). Or, that it is impossible to actually observe them eat, because they are too scared to eat when anything is too close (like a diver with camera). This option is probably too far fetched which would leave one viable option that comes to my mind: the school is opportunistic fish (which I believe every fish to some point be opportunistic) and they eat all the time, with individuals breaking out of unison all the time. Statistically those movements may never be detected as breaking unison and may just get filtered out as noise.
Food for thought (pun intented), or possible new research if it hasn't been done.
So, from what I have read the active foraging behavior includes schooling as leaders who are informed of a location of food will lead the uniformed members to a location. Now here's where individual requirements/desires will come into play. The desire to eat/need for food has to outweigh the benefit of safety that the individual is gaining from schooling. So, a small number of individuals will leave the central area of the school where it is safest and make their way to the periphery where they are less safe, but can adequately forage within proximity of the food.
You can see if you watch this video close enough that the fish in the center are packed very tight while those on the periphery are less close together. What I would speculate from reading is that the fish on the outside are prioritizing some need over the need (and it is a genetically determined inherent desire) to school. The fish on the periphery could also be those that are less social, more bold or more informed of a food source.
Now, I a friend of mine is working on publishing a paper that deals with the use of baited passive trapping gear to actually select for bolder individuals (accidentally). Because what happens is that bolder individuals are more likely to leave a school (break formation) to look for food, but will come back and lead the group to a food source. These fish are more likely to be trapped and more likely to encourage the more social followers to be trapped by showing them where food is, and also because these ones are less likely to break from the school even while feeding.
In short, its incredibly complicated behavior and a lot of leaving the center of the school to the periphery to feed (though they do forage as a group, its one of the benefits of schooling) has a lot to do with individual personality syndromes and priorities of the fish itself. But a lot of the question is still "how often do they do it, as well as why, and what makes these fish more likely to do that?"
You can see if you watch this video close enough that the fish in the center are packed very tight while those on the periphery are less close together. What I would speculate from reading is that the fish on the outside are prioritizing some need over the need (and it is a genetically determined inherent desire) to school. The fish on the periphery could also be those that are less social, more bold or more informed of a food source.
Now, I a friend of mine is working on publishing a paper that deals with the use of baited passive trapping gear to actually select for bolder individuals (accidentally). Because what happens is that bolder individuals are more likely to leave a school (break formation) to look for food, but will come back and lead the group to a food source. These fish are more likely to be trapped and more likely to encourage the more social followers to be trapped by showing them where food is, and also because these ones are less likely to break from the school even while feeding.
In short, its incredibly complicated behavior and a lot of leaving the center of the school to the periphery to feed (though they do forage as a group, its one of the benefits of schooling) has a lot to do with individual personality syndromes and priorities of the fish itself. But a lot of the question is still "how often do they do it, as well as why, and what makes these fish more likely to do that?"
