Oh, ok... I saw he was from Michigan and wondered if it was a regional thing...beblondie;2946183; said:
Thanks.
The only behavior I think Cohazard missed is...
- Thread starter dbcb314
- Start date
Thanks.
don't feel like an ass cause i feel like one for spelling it like that for this long.
well i spelled it how i pronounce it.. i went back and checked and saw it's not spelled that way but i pronounce it that way.... when i googled it this came up its an old post from beblondie and the way i pronounce it i put in bold which would explain the misspelling i have done for sometime now.
WHY BICHIR?
When Europeans (French) discovered the genus Polypterus in 1809 it had already been known along the Nile since the time of the pharoahs. The local peoples referred to them as bichirs (unknown pronunciation and spelling). While unable to come up with an exact meaning for the word it was most likely a descriptive term (''whip'' has been suggested) for this type of fish.
The French most likely pronounced it as phonetically as possible to the orginal native word and came up with bee-sheer as a pronunciation and spelled 'bichir'. Since this would be the name of these fish for
several years until they were scientifically described and put into the proper family it became an accepted common name.
However the correct English pronunciation is up for grabs. Several dictionaries all have their own pronunciation including the below:
bee cher
beech er
biker
bercheer
bi cher
bir chir is common in England
Also known by the common name lobed fin pike,dinosaur eel.
The name Polypterus : poly=many + pterus=fins and is pronounced po-lyp'-terus.
p.s. sorry for the derailment.
well i spelled it how i pronounce it.. i went back and checked and saw it's not spelled that way but i pronounce it that way.... when i googled it this came up its an old post from beblondie and the way i pronounce it i put in bold which would explain the misspelling i have done for sometime now.
WHY BICHIR?
When Europeans (French) discovered the genus Polypterus in 1809 it had already been known along the Nile since the time of the pharoahs. The local peoples referred to them as bichirs (unknown pronunciation and spelling). While unable to come up with an exact meaning for the word it was most likely a descriptive term (''whip'' has been suggested) for this type of fish.
The French most likely pronounced it as phonetically as possible to the orginal native word and came up with bee-sheer as a pronunciation and spelled 'bichir'. Since this would be the name of these fish for
several years until they were scientifically described and put into the proper family it became an accepted common name.
However the correct English pronunciation is up for grabs. Several dictionaries all have their own pronunciation including the below:
bee cher
beech er
biker
bercheer
bi cher
bir chir is common in England
Also known by the common name lobed fin pike,dinosaur eel.
The name Polypterus : poly=many + pterus=fins and is pronounced po-lyp'-terus.
p.s. sorry for the derailment.
Cohazard;2946219; said:Good catch dbcb, King-eL also pointed out I didn't bring up activity levels. I can't really come up with an explanation for the difference between upper jaws and lower jaws.
Why don't we kick around some ideas on the subject?
Could it be a difference in the food they eat in the wild??
the lower jaws are bigger so it could be assumed they eat bigger prey in the wild so they rely purely on ambush hunting of say.. fish that swim by. . while the smaller guys eat more insects (like the sen they studied) and that involves more movement because you have to go to the surface?
completely guessing
dbcb314;2946675; said:
Exactly what I was thinking!
You have to have a solid hypothesis before you can prove anything right? Well, it's a logical idea supported by the fish's physiology, so I wouldn't be surprised if that were proved to be correct.
Hmmm...my Polys don't really do this as much. They just start munching away where the food is most of the time.
Tossing in my nickels worth.I asked Neale Monks does the size of the prey matter his
response below with an article he sent me -Anne
Yes, predators select prey size carefully. There's something called optimal foraging strategy that means animals will get food in the most profitable way, i.e., the most energy gained from prey compared to the most energy used up getting that prey. This applies equally to herbivores as well as carnivores.
Work done several decades ago on sunfish demonstrated that they will swim a small distance to catch small daphnia but a longer distance to catch bigger daphnia. Small daphnia at a far distance will be ignored if small daphnia closer by are present. Since small daphnia provide little energy, the sunfish will only expend a small amount of energy catching them. Bigger daphnia return more energy, so it's worthwhile swimming more to catch them. If less food is about, the sunfish becomes less picky, swimming further to take smaller prey. When food is abundant, the sunfish is more picky, and will swim shorter distances for smaller prey.
This is a classic piece of work and should be mentioned in most animal behaviour test books. Optimal foraging has been demonstrated again and again, so even though still a theory, it does appear that animals largely work in an optimal way. My own BSc dissertation was involved with demonstrating optimal foraging by starfish, animals that don't really have any kind of brain, yet still seem to select prey types depending on which is more profitable.
I'd caution against using optimal foraging theory as an excuse to mix small fish with big predators though. While I've seen it done with, for example, piranhas in big tanks with guppies, it isn't 100% reliable. In an aquarium fish will adopt learned behaviours, connecting the presence of humans with the appearance of food. That's probably going to override their optimal foraging programming.
Cheers, Neale
Optimal Foraging and the Size Selection of Prey by the Bluegill Sunfish (Lepomis Macrochirus)
Earl E. Werner and Donald J. Hall
The bluegill sunfish, Lepomis macrochirus, is known to select prey on the basis of size. We present evidence that this size selection is related to the optimal allocation of time spent searching for, and handling prey. A model relating search and handling time to energy return is constructed to determine the optimal breadth of diet. Prey are permitted to differ in size and relative abundance. All elements of the model are estimated from experiments with the bluegill feeding on populations constructed from size classes of Daphnia magna. Relative visibility of the different prey sizes markedly affects relative encounter rates or "effective" proportions. Effective proportions are determined empirically from feeding experiments and theoretically from reaction distance in order to correct for this bias. Search time is then manipulated by varying absolute abundance of prey. At low absolute abundance, prey of different size are eaten as encountered. As prey abundance is increased, size classes are dropped sequentially from the diet in accordance with the theory. Search and handling times are estimated from these experiments and quantitative comparisons with the model indicate these changes in diet maximize return with respect to time spent foraging.
See full-text article at JSTOR
Cited by
Erica B. Young, John Janssen. (2009) Symposium 7 Ecological Processes across the Salinity Divide. Contrasts and Comparisons in Marine and Great Lakes Ecosystems. Bulletin of the Ecological Society of America 90:1, 115-133
Online publication date: 1-Jan-2009.
Citation . Full Text . PDF (1756 KB)
Márcio S. Araújo, Paulo R. Guimara~es Jr., Richard Svanbäck, Aluisio Pinheiro, Paulo Guimara~es, Sérgio F. dos Reis, Daniel I. Bolnick. (2008) NETWORK ANALYSIS REVEALS CONTRASTING EFFECTS OF INTRASPECIFIC COMPETITION ON INDIVIDUAL VS. POPULATION DIETS. Ecology 89:7, 1981-1993
Online publication date: 1-Jul-2008.
Abstract . Full Text . PDF (1263 KB)
Rick A. Relyea. (2003) PREDATORS COME AND PREDATORS GO: THE REVERSIBILITY OF PREDATOR-INDUCED TRAITS. Ecology 84:7, 1840-1848
Online publication date: 1-Jul-2003.
Abstract . Full Text . PDF (203 KB)
James R. Lovvorn, Cheryl L. Baduini, George L. Hunt Jr.. (2001) MODELING UNDERWATER VISUAL AND FILTER FEEDING BY PLANKTIVOROUS SHEARWATERS IN UNUSUAL SEA CONDITIONS. Ecology 82:8, 2342-2356
Online publication date: 1-Aug-2001.
Abstract . Full Text . PDF (182 KB)
Mark A. McPeek, Margaret Grace, Jean M. L. Richardson. (2001) PHYSIOLOGICAL AND BEHAVIORAL RESPONSES TO PREDATORS SHAPE THE GROWTH/PREDATION RISK TRADE-OFF IN DAMSELFLIES. Ecology 82:6, 1535-1545
Online publication date: 1-Jun-2001.
Abstract . Full Text . PDF (152 KB)
T. E. Lankford Jr., T. E. Targett. (1997) SELECTIVE PREDATION BY JUVENILE WEAKFISH: POST-CONSUMPTIVE CONSTRAINTS ON ENERGY MAXIMIZATION AND GROWTH. Ecology 78:4, 1049-1061
Online publication date: 1-Jun-1997.
Abstract . Full Text . PDF (161 KB)
response below with an article he sent me -Anne
Yes, predators select prey size carefully. There's something called optimal foraging strategy that means animals will get food in the most profitable way, i.e., the most energy gained from prey compared to the most energy used up getting that prey. This applies equally to herbivores as well as carnivores.
Work done several decades ago on sunfish demonstrated that they will swim a small distance to catch small daphnia but a longer distance to catch bigger daphnia. Small daphnia at a far distance will be ignored if small daphnia closer by are present. Since small daphnia provide little energy, the sunfish will only expend a small amount of energy catching them. Bigger daphnia return more energy, so it's worthwhile swimming more to catch them. If less food is about, the sunfish becomes less picky, swimming further to take smaller prey. When food is abundant, the sunfish is more picky, and will swim shorter distances for smaller prey.
This is a classic piece of work and should be mentioned in most animal behaviour test books. Optimal foraging has been demonstrated again and again, so even though still a theory, it does appear that animals largely work in an optimal way. My own BSc dissertation was involved with demonstrating optimal foraging by starfish, animals that don't really have any kind of brain, yet still seem to select prey types depending on which is more profitable.
I'd caution against using optimal foraging theory as an excuse to mix small fish with big predators though. While I've seen it done with, for example, piranhas in big tanks with guppies, it isn't 100% reliable. In an aquarium fish will adopt learned behaviours, connecting the presence of humans with the appearance of food. That's probably going to override their optimal foraging programming.
Cheers, Neale
Optimal Foraging and the Size Selection of Prey by the Bluegill Sunfish (Lepomis Macrochirus)
Earl E. Werner and Donald J. Hall
The bluegill sunfish, Lepomis macrochirus, is known to select prey on the basis of size. We present evidence that this size selection is related to the optimal allocation of time spent searching for, and handling prey. A model relating search and handling time to energy return is constructed to determine the optimal breadth of diet. Prey are permitted to differ in size and relative abundance. All elements of the model are estimated from experiments with the bluegill feeding on populations constructed from size classes of Daphnia magna. Relative visibility of the different prey sizes markedly affects relative encounter rates or "effective" proportions. Effective proportions are determined empirically from feeding experiments and theoretically from reaction distance in order to correct for this bias. Search time is then manipulated by varying absolute abundance of prey. At low absolute abundance, prey of different size are eaten as encountered. As prey abundance is increased, size classes are dropped sequentially from the diet in accordance with the theory. Search and handling times are estimated from these experiments and quantitative comparisons with the model indicate these changes in diet maximize return with respect to time spent foraging.
See full-text article at JSTOR
Cited by
Erica B. Young, John Janssen. (2009) Symposium 7 Ecological Processes across the Salinity Divide. Contrasts and Comparisons in Marine and Great Lakes Ecosystems. Bulletin of the Ecological Society of America 90:1, 115-133
Online publication date: 1-Jan-2009.
Citation . Full Text . PDF (1756 KB)
Márcio S. Araújo, Paulo R. Guimara~es Jr., Richard Svanbäck, Aluisio Pinheiro, Paulo Guimara~es, Sérgio F. dos Reis, Daniel I. Bolnick. (2008) NETWORK ANALYSIS REVEALS CONTRASTING EFFECTS OF INTRASPECIFIC COMPETITION ON INDIVIDUAL VS. POPULATION DIETS. Ecology 89:7, 1981-1993
Online publication date: 1-Jul-2008.
Abstract . Full Text . PDF (1263 KB)
Rick A. Relyea. (2003) PREDATORS COME AND PREDATORS GO: THE REVERSIBILITY OF PREDATOR-INDUCED TRAITS. Ecology 84:7, 1840-1848
Online publication date: 1-Jul-2003.
Abstract . Full Text . PDF (203 KB)
James R. Lovvorn, Cheryl L. Baduini, George L. Hunt Jr.. (2001) MODELING UNDERWATER VISUAL AND FILTER FEEDING BY PLANKTIVOROUS SHEARWATERS IN UNUSUAL SEA CONDITIONS. Ecology 82:8, 2342-2356
Online publication date: 1-Aug-2001.
Abstract . Full Text . PDF (182 KB)
Mark A. McPeek, Margaret Grace, Jean M. L. Richardson. (2001) PHYSIOLOGICAL AND BEHAVIORAL RESPONSES TO PREDATORS SHAPE THE GROWTH/PREDATION RISK TRADE-OFF IN DAMSELFLIES. Ecology 82:6, 1535-1545
Online publication date: 1-Jun-2001.
Abstract . Full Text . PDF (152 KB)
T. E. Lankford Jr., T. E. Targett. (1997) SELECTIVE PREDATION BY JUVENILE WEAKFISH: POST-CONSUMPTIVE CONSTRAINTS ON ENERGY MAXIMIZATION AND GROWTH. Ecology 78:4, 1049-1061
Online publication date: 1-Jun-1997.
Abstract . Full Text . PDF (161 KB)
my fish do the same only when the food items are large.
my guess is that with small food items they swallow fast at the spot.
but with bigger food items it takes a while to get it down,while getting it down theres a possibility of other fish snatching the food.
my guess is that with small food items they swallow fast at the spot.
but with bigger food items it takes a while to get it down,while getting it down theres a possibility of other fish snatching the food.
