Free guestbook - Furaha - MyGB.nl - Get your free guestbook now!

The owner of this guestbook has (temporarily) disabled adding new messages.

01:27 11-11-2011 Evan Black: That's a good point, Sigmund; I hadn't thought of the feeding squid.

23:53 10-11-2011 SN: Jan, Evan,

I'm with Evan on this one. In speculative biology there seems to be a tendency towards perfection, i.e. organisms that are supernormal in every respect. Have a look at life on Earth: do all organisms follow that rule? Better still, does any? Why do humans have an utterly inferior sense of smell, have a blind spot, or not have a simple reflective layer behind the retina allowing us to see in the dark, etc., etc.? The answer is probably that the current state of affairs is good enough to allow propagation of the species. That's about it.

Cloakfish do not need to outwit smarter predators as long as enough of them survive to procreate. That was the idea behind their original somewhat dumb filter-feeding body plan, and the main reason for reconsidering it was that I hadn't considered a mechanism to collect 'krill' and shove it into an oesophagus.

Evan: regarding a chameleon-type of tongue under water, please consider how squid feed: they've got two raptorial tentacles that can suddenly shoot out and capture prey. That's a close analogue, I should think.

'FB': thank you, and welcome.

19:38 08-11-2011 Evan Black: But do cloakfish need to be more effective predators? I mean, if they're doing just fine in Darwinian terms by meandering around and gobbling up clouds of krill then there isn't a whole lot of reason to develop long range weapons or more effective pursuit mechanisms. Poisons, finned maneuverability, or perhaps even some kind of armored skin can keep them alive as they take their time moving from one drifting patch of food to another.

I'm curious: could a frog-like or chameleon-like tongue underwater? I wonder about hydrodynamic issues and Newton's laws...

21:37 06-11-2011 Jan: Well, wrong again. The cuttlefish is not the only and probably not even the best example of animal swimming like cloakfish. Knifefish or flatworms do this also
http://www.youtube.com/watch?v=m3QkRFfY5hU&feature=related
http://www.youtube.com/watch?v=SxEFSOwG8J0&feature=related
http://www.youtube.com/watch?v=zCH37KI_R_E&feature=related
I still think that combination of the maneuvrability of fins and some sort of long range weapon would create more effective predator.

20:48 05-11-2011 Jan: The water predators weaponry is quite diverse http://www.youtube.com/watch?v=pDU4CQWXaNY

20:45 05-11-2011 Jan: SN: Predators do not need to be faster than they prey, but they have other ways to catch them. Crustaceans have their claws, squids have tentacles, dragonfly nymph extendable labium, conus and ther predatory molluscs proboscis. It would be logical to see something similar in cloakfish, for example chameleon-like tongues.

20:09 05-11-2011 SN: Jan (1): You are right, there is always more to know. For instance, I had not realised the big differences between filter feeders that can take in water at one end of their body and let it pass out another, and those that cannot. Sharks can let in water through their mouths and out thrpugh their gills, but whales have no gills, so for the it is one giant mouthful and then the water has to leave through the mouth again. No continuous filter feeding for them.

Spugpow: were you talking about the cloakfish? If so, I am still playing with different possibilities.

Jan (2): Do not forget that you can be a slow predator! Whales that feed on krill do not need to be fast, nor does nay predator that feeds on slow predator. In fact, for predators, you only have to be faster than your prey, not fast in an absolute sense.

Evan: In part the same answer applies, but big cloakfish might be a nice prey themselves, so they indeed ought to have a bit more manoeuvrability. The fins are indeed the obvious choice. If someone were to make a film of Furahan underwater life, cloakfish would not feature in scenes of animals cutting waves and jumping from the surface. Theirs is a more sedate lifestyle. Perhaps I ought to make some of them poisonous, allowing various types of mimicry...

03:36 05-11-2011 Evan Black: I think that their form of propulsion can achieve quite high speeds; it's maneuverability that concerns me. Perhaps in more predatory niches, those four fins toward the front of the body can be used for more dynamic steering.

17:59 04-11-2011 Jan: Just a question, the cloakfish has some resemblance to cuttlefish, right? It does not seem to be build for speed, so how do the predatory species hunt? Feeding tentacles of cuttlefish seem to be quite efficient http://www.youtube.com/watch?v=dF-jHp-5XfU

06:47 30-10-2011 Spugpow: Huh, I notice the gill inlet configuration is different. What led you to make the change?

Furahan taxonomy: there's still a lot to be revealed, though. For example, I'd be interested to know how closely related rusps and groulliards are to hexapods, and to one another.

23:26 29-10-2011 Jan: Some interesting facts about feeding behaviour in water
http://en.wikipedia.org/wiki/Aquatic_predation
http://www.marietta.edu/~biol/biomes/feed.htm
http://en.wikipedia.org/wiki/Feeding_behaviour_of_fish#By_feeding_behaviour
It seems that there is more to that than "open the mouth - close". I did not think about it before.

22:57 29-10-2011 Wout Conijn: Beste Gert,

We zijn een speelfilm aan het voorbereiden en zouden graag voor researchdoeleinden contact met je opnemen. Hoor graag van je.

Met vriendelijke groet,
Wout Conijn, producent
David Verbeek, scenarist/regisseur

11:23 29-10-2011 SN: William: about your tree/neuron: this is a clever idea, but what you haven't explained yet is its purpose from an evolutionary perspective. What I mean by that is that there ought to be a reason for such a feature to come into being in the first place, as well to keep evolving it. An example of such reason might be the evolution of flying squid: there is a rood reason for them to jet out of the water, but what reason is there for them to take the path further and develop longer and longer flight?

Spugpow (on taking in water): I am afraid that taking in a fairly large mass of water would act as such a powerful brake that the animal would descend back into the water. A small intake would have less braking effect, but would brake for a longer time...

Jan and Spugpow: I wouldn't mind writing such a post, but part of it has already been published: http://planetfuraha.blogspot.com/2010/11/furaha-swamp-scene-ii.html

If you look carefully, you will see that the anatomy of Fishes IV has changed miraculously since I made that sketch a long time ago...

http://planetfuraha.blogspot.com/2010/11/furaha-swamp-scene-ii.html

Berichten: 271 t/m 285 van de 930.
Aantal pagina's: 62
Nieuwer 16 17 18 [19] 20 21 22 Ouder

Free guestbook of MyGB.nl