All the animals discussed so far had 'bilateral symmetry': like a loaf of bread, their bodies can be divided in left and right halves, mirror images of one another. Each half has distinguishable front and rear parts, as well as top and bottom parts. On Earth, animals such as jellyfish and starfish have 'radial symmetry', which means that instead of having two halves their bodies can be divided in more than two identical segments. Eight in the spidrids' case, so imagine their bodies as a round pie cut up in eight identical segments. On Earth, no animals with radial symmetry walk quickly. On Furaha, spidrids do, and here's one. It is the somewhat robust, or even rotund, 'beach ball'.

This one is the so-called Crown of Thorns. There are many species of spidrids, and their size varies from small enough to burrow under your toenails to large enough not to fit in your boots (like this one).
One of the more odd consequences of a radial build is that the animal does not have a front, nor a rear (it does have a top and a bottom though). The lack of a front means that it does not matter in which direction the animal moves, as it can move in any direction it wants to. They also do not need to turn their bodies to change direction.

crown of thorns
spidrid joints

This model shows the way the joints of spidrids work. One joint at the base of the legs (there are more than one closely-spaced joints there) serves to rotate the leg in a clockwise or antoiclockwise rotation, indicated by the vertical axis of the joint and th red arrow showing the direction of rotation; that type of movement is called 'promotion' and 'remotion', by the way. Furahan scientist copied the name from Earth crabs, whose legs are surprisingly like those of spidrids. Crabs do have a front side though, and 'promotion means the legs rotate forwards. In spidrids the animal has no front end, so 'promotion' came to mean 'anticlockwise'. It is likely that the scientists in question dodt not known the Latin for 'clockwise'.

The other diagram shows the muscles controlling all this. The promotor and remotor muscles, together with the flexor and extensor muscles, create a movement path. Legs sticking out sideways, at a cross angle to the direction of movement, derive most of their power form the promotor and remotor muscle, while the flexor/extensors muscles do not do much. The legs that are parallel to the movement direction face a different challenge: they mostly move through action of the flexor and extensor muscles. Complicated, isn't it?
For more explanations regarding the way spidrids move, search the Furaha blog for spidrids; this is a good post to start with.

spidrid muscles

Spidrid in 'clockwise walk' gait
With eight legs, there is an enormous number of possible gaits, and that holds for animals with bilateral symmetry as much as for those with radial symmetry: the legs can all be in a different phase of the cycle, or they can move in unison: for instance, the eight legs could move in four pairs of two legs, or in two quartets of four leg.
Here a simple 'walk' is shown, in which no two legs move in unison. The walking cycle is divided into phase differences of 12.5% for the eight legs. The spidrid shown here has such differences, but it is no that easy to find out what the order of movement is. In this gait the phases skip a leg for each phase offset. If the legs are numbered around a circle, like the hours on a clock, leg 1 is at phase zero, leg 3 gets phase 12.5, leg 5 phase 25.0%, leg 7 gets 37.5%, and then we go around again: leg 2 gets 50%, leg 4 gets 62.5%, etc.).
The diagram on the ground shows which legs are on the floor at any moment, and therefore forms a 'support diagram'. For a slow moving animal the centre of gravity should be poised over the support diagram, or else the animal will fall. As you can see, there are four ot five legs on the grond at any moment, so there is no risk of falling with this gait.

Spidrid in paired gait
The same spridrid is here shown with another gait. Now there are four pairs of two legs, each moving in unison. The pairs are 25% of a cycle apart in phase. The pairs consist of oppositely placed legs: legs 1 and 5 form a pair, as do 2 and 6, 3 and 7, and 4 and eight. By adjusting the phase differences between pairs the spidrid can adjust the support diagram. There are still four legs on the ground and the animal is unlikely to fall.

spidrid width

Spidrid with 'transverse predilection' gait
This animation shows a spidrid negotion height differences and making some turns. It is also clear that the animal's body does not turn while turning. There is another thing to note"for this spidrid, the promotion and remaotion muscles are stronger than the flexor and extensor muscles. That means that these muscles do better when they tickt out at right angles to the direction of moement, and the animal swings them that way to get the most out of its muscles.

Spidrid in 'longitudinal predilection' gait
Bt some other species have strong flxion and extension muscles, and they would prfit from turning the legs as fas as possible to be parallel to the direction of muscle. Well, in this animation the species is the same, but it is only a simple animation after all, not a field guide...

spidrid length