tag:blogger.com,1999:blog-5821098719340852065.post5857447965028508894..comments2024-03-25T09:31:36.926+01:00Comments on Furahan Biology and Allied Matters: Explaining and animating how cloakfish swimSigmund Nastrazzurrohttp://www.blogger.com/profile/16449461215427527447noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-5821098719340852065.post-20996289616867116832021-04-04T02:23:54.815+02:002021-04-04T02:23:54.815+02:00I suspect the undulating ribbon could be fixed to ...I suspect the undulating ribbon could be fixed to the bladder (and the body probably wouldn't be hanging underneath like a gondala anyway) but the problem is how much mass can be devoted to the fin and associated muscles? Drag is proportional to the large cross-section but thrust is proportional to the smaller fin. That's the problem.<br /><br />Just to stay on the fishy topic of this post, that probably means the bladder needs to act as a lifting body so that more mass can be used to produce thrust. This is akin to sharks which need to keep moving to maintain lift from their pectoral fins.Abbydonhttps://www.blogger.com/profile/16752456316046971021noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-50562869081668386702021-04-02T19:21:48.143+02:002021-04-02T19:21:48.143+02:00Are the "fishes" air breathers or water ...Are the "fishes" air breathers or water breathers? are any just derived hexapods?cockzilla vs. dongnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-8502869091924339422021-03-31T17:14:42.983+02:002021-03-31T17:14:42.983+02:00Abbydon (22 March): Sorry about the delay. I was w...Abbydon (22 March): Sorry about the delay. I was working on a paper and that requires integrated concentrated working on the statistics, data handling, graphics and writing, so I tend to do nothing besides until it is done.<br /> Anyway, if the thrust in a ballont is prodeuced by an undulating ribbon, that need to not fixed to the 'cargo', but could also be fixed to the 'bladder', and perhaps more efficiently. Does that change matters?<br /><br />Odobeno... Interesting, and possible. Originally, I had cloakfish that had their cloaks arranged like a cross, with two vertical and two horizontal cloaks, while others had four diagonal cloaks. The latter disappeared from view. In such a 'mud wrestling escape' scenario, the latter would have it much easier, as they could rest on two cloaks at once, which should make a very large difference. Actually, if the vertical/horizontal types would attempt this, they would very probably keel over until they rested on two cloaks. They might feel uncomfortable in that position, though. <br /><br />Anthony / Abbydon /Anthony: I think we mean the same thing. Great minds...<br /><br />Sperm wheal / Anthony: there are six!Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-60017860218925231902021-03-23T06:59:27.610+01:002021-03-23T06:59:27.610+01:00offhand, I can think of...its either IV or VI..unl...offhand, I can think of...its either IV or VI..unless I'm wrong on both counts.<br /><br />-anthony docimo.<br /><br />ps: in hindsight, a tag search in the blog for "fishes" might have resulted in something useful.<br />Keenirhttps://www.blogger.com/profile/13529262864561571783noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-77714196894389979222021-03-23T06:30:25.329+01:002021-03-23T06:30:25.329+01:00How many clades of "fish" are on furaha?...How many clades of "fish" are on furaha?sperm whealnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-11086937806863483172021-03-23T01:12:35.170+01:002021-03-23T01:12:35.170+01:00good point. maybe then limit the inside-the-ballo...good point. maybe then limit the inside-the-balloon organs to scaffolding and air-generating tissues, and leave other things as outside-the-balloon organs, such as the cloak itself and the jaws.<br /><br />-anthony docimo<br />Keenirhttps://www.blogger.com/profile/13529262864561571783noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-13012196552776258102021-03-23T00:38:32.075+01:002021-03-23T00:38:32.075+01:00I just mean that the overall size is equivalent to...I just mean that the overall size is equivalent to a large fish but since most of that is just gas the available mass to provide other bodily functions is the same as a small fish. Effectively it would have the drag of a large fish but the thrust of a small fish. For example, the cloakfish images look a bit like a possible ballont but there would be a reduction in space inside for internal organs and muscles if it was full of gas.Abbydonhttps://www.blogger.com/profile/16752456316046971021noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-33010042165730871612021-03-22T20:01:36.523+01:002021-03-22T20:01:36.523+01:00>Simplistically, both thrust and drag are propo...>Simplistically, both thrust and drag are proportional to fluid density so that cancels out. The problem however is that the drag is due to the large balloon but the thrust is due to the small "fish" hanging underneath.<br /><br />Well, why not change it so the balloon and the fish are one and the same...or, if not the same, have the "fish" be extensions of the balloon -- the bits and pieces which couldn't be filled with gas or whatever. (like how in electric eels, all the vital organs are squished into what most people would assume is *just* the head of the eel)<br /><br />Or like in ctenophores and salps, the parts of the body that aren't for the fluid (air, water, whatever) or for the skin, are for the propulsive structures.<br /><br />just my two cents.<br /><br />-anthony docimo<br />Keenirhttps://www.blogger.com/profile/13529262864561571783noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-2096996527923109842021-03-22T13:19:03.962+01:002021-03-22T13:19:03.962+01:00Could ribbon fins become a slug-like "foot&qu...Could ribbon fins become a slug-like "foot" for a theoretical mudskipper like amphibious species? Just a thoughtOdobenodiabolus infernusnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-5069367550604090642021-03-22T11:37:00.276+01:002021-03-22T11:37:00.276+01:00I haven't finished Manton's book on arthro...I haven't finished Manton's book on arthropods yet and now I have another textbook to read... My bookshelf is looking quite varied these days. His "dinosaur speed calculator" shown on Wikipedia is interesting as it is invariant to gravity if you assume the organism linear size is inversely proportional to gravity (i.e. double gravity, half the hip height and stride length).<br /><br />Anyway, back on topic, my interest was how well fish modes of swimming could be applied to ballonts. Simplistically, both thrust and drag are proportional to fluid density so that cancels out. The problem however is that the drag is due to the large balloon but the thrust is due to the small "fish" hanging underneath.<br /><br />This means that there is some scale factor that reduces the speed of a ballont using fins relative to a fish. That presumably is dependent on the length or area of the fin depending on the swimming method used. I have a feeling that the undulating ribbon fin might be the best approach though the <a href="https://www.youtube.com/watch?v=sx7TEC_dYi8" rel="nofollow">Air Swimmers</a> radio controlled toys use the tail fin.Abbydonhttps://www.blogger.com/profile/16752456316046971021noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-60221216586699462162021-03-22T09:20:35.651+01:002021-03-22T09:20:35.651+01:00Noasaur; Aha! I met Joschua one at a Tetzoo confer...Noasaur; Aha! I met Joschua one at a Tetzoo conference. Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-88594546870132947672021-03-22T02:26:40.594+01:002021-03-22T02:26:40.594+01:00Sigmund-Nope. My profile picture is from a guy kno...Sigmund-Nope. My profile picture is from a guy known as Joschua knuppe...Noasaurhttps://www.blogger.com/profile/04311084551979795446noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-34731553658993479242021-03-21T17:12:42.669+01:002021-03-21T17:12:42.669+01:00Abbydon, No, I did not. I saw that one paper on ro...Abbydon, No, I did not. I saw that one paper on robotic undulatory swimming calculated forces for rectangular parts of the membrane and then went on to combine them all into a sumed force. That should not be too difficult for cloakfish, and perhaps I should do that to see whether they would jiggle about or would need to use their front wings to counter such forces.<br /><br />Otherwise, no. he books by the late Robert McNeill Alexander contain fairly digestible physics of moving animals. https://en.wikipedia.org/wiki/Robert_McNeill_Alexander. I think they are all easily found. <br />Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-77609776053951905592021-03-21T11:15:39.955+01:002021-03-21T11:15:39.955+01:00Out of curiosity, did you ever come across a paper...Out of curiosity, did you ever come across a paper (or papers) that provides approximate simple equations for the forces produced by different types of swimming? It would be helpful to use that to compare speeds for different body shapes but I suspect it is all far too complex for that unfortunately.Abbydonhttps://www.blogger.com/profile/16752456316046971021noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-43661464088394048782021-03-19T19:08:38.983+01:002021-03-19T19:08:38.983+01:00African...: in my mind's eye, i see cloakfish ...African...: in my mind's eye, i see cloakfish the size of orca's. On earth, filter feeders can obviously grow in size to become the largest animals in the history of the planet, so that mode of feeding will not restrict them. I cannot think of any mechanical reason why undulating membranes would only work up to a certain size either. In short, they could! <br /> Perhaps there should be a giant cloakfish in the documentary... Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-11118000358392875982021-03-18T07:48:31.068+01:002021-03-18T07:48:31.068+01:00How big can a cloakfish get? Would undulating memb...How big can a cloakfish get? Would undulating membranes work at like, blue whale size?African heffalumpnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-60988639422130050422021-03-15T13:40:05.355+01:002021-03-15T13:40:05.355+01:00Abbydon: The maximum size probably depends on the ...Abbydon: The maximum size probably depends on the choice of respiratory system. If you use tracheae, the animal probably will have to squeeze and relax rings to refresh the air. But if you provide it with an updated system, respiration should not be a big problem. The same goes for the exoskeleton; if you vary the degree of malleability, and equip the animal with internal attachments points for muscles etc., it could grow big. Exoskeletons do not have to be totally rigid nor exclusively external; they are not in many earth lineages.<br /><br />Noasaur; thank you! Nice site, by the way. Are the writer and the painter one and the same person? Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-85266125435878352662021-03-15T04:37:51.015+01:002021-03-15T04:37:51.015+01:00Bravo, Bravo. Love this blog. Helped me to make my...Bravo, Bravo. Love this blog. Helped me to make my own.Noasaurhttps://www.blogger.com/profile/04311084551979795446noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-50293652805586554222021-03-15T00:37:37.106+01:002021-03-15T00:37:37.106+01:00I have sometimes pondered what advantages/disadvan...I have sometimes pondered what advantages/disadvantages a limbless exoskeleton would produce and what the maximum size limit would be. I guess it would be a giant mealworm with ring segments covered in bristles/setae to help provide grip.Abbydonhttps://www.blogger.com/profile/16752456316046971021noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-24853376889315929342021-03-14T17:55:04.805+01:002021-03-14T17:55:04.805+01:00ed: I never envisaged anything with undulatory fin...ed: I never envisaged anything with undulatory fins as fast, but manta rays can jump out of the water, so they they must be able to generate considerable power. I guess that the 'long-sleeved ones will not be very fast, but that ones that evolve towards oscillatory fins can be a lot faster.<br /><br />Andrew Broeker: the papers on the robot fishes make the point that speed is directly related to the frequency of wave propagation, which makes sense, but the relation with the number of waves per cloak was more complex. <br /><br />Spooktober: than you. <br /><br />megapig: I never thought of that, and do not think their anatoy lends itself well to that. I'll keep them underwater, I think. <br /><br />Dugong: Interesting; I wonder whether limbless slitherers are a universal design. I might sneak one i=one into the background of a painting one day. <br /> Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-49883461567940971832021-03-13T03:10:51.403+01:002021-03-13T03:10:51.403+01:00Are there any limbless snake-like creatures on Fur...Are there any limbless snake-like creatures on Furaha? Perhaps a hexapod that lost all its limbs as it became a predator of burrowers?Dugong WITH LEGSnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-59623446809685382642021-03-13T02:09:22.807+01:002021-03-13T02:09:22.807+01:00Could a cloakfish-like aquatic species evolve to c...Could a cloakfish-like aquatic species evolve to come on land? what would an entire clade of land-cloakfish descendants be like and how could such fins become limbs?megapignoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-53838843146224497052021-03-11T18:26:57.777+01:002021-03-11T18:26:57.777+01:00Interesting, nice to see how this is coming alongInteresting, nice to see how this is coming alongSpooktobernoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-71239194517022591562021-03-11T03:48:40.276+01:002021-03-11T03:48:40.276+01:00It seems to me that the undulatory wavelength ough...It seems to me that the undulatory wavelength ought to vary considerably with swimming speed for best efficiency.Andrew Broekerhttps://www.blogger.com/profile/03455959935160897929noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-13660633603552926692021-03-10T01:48:06.600+01:002021-03-10T01:48:06.600+01:00are they fast? maybe there could be a dolphin-anal...are they fast? maybe there could be a dolphin-analogue called the torpoiseednoreply@blogger.com