IN Amphibia, especially the CR modes are present.
Alternate mode: fish body-tail undulation are continued in Amphibia and are fully represented in the limb behavior. The Caudata (salamanders) and Caecilians (limbless burrowers) swim this way, although in frogs, whose front-to-back body compression
and skeletal torso rigidity designed for leaping allows only the larval tadpole can engage it.
Walking is alternate symmetrical in all the limbed species. The caecilian move on land with body-tail undulation, although they employ the wholly different concertina method in underground burrowing, like earthworms.
Alternate symmetric walking on land is performed by toads and tree frogs which quite efficiently walk on branches (see video).
Alternate symmetry has been discovered in the unusual swimming of Archeobatrachian (ancient frogs) suborder.
Anurans use the asymmetrical mode in such acts as grooming, where e.g., the front of hind limbs will synchronously or alternately groom (brush, wipe) their face or other body part while the legs or arms remain supporting the body either on land or i
n the trees. Holding themselves with the forelegs and with the hind legs alternately or in synchrony whipping nesting foam is the unusual practice of the African genus
Chiromantus among the Rhacophorid tree frogs.
Alternate symmetric swimming is also present in at least one modern frog family, the Ranidae, or "true frogs". This is noteworthy because it had been thought that typically frogs on land move by parallel jumps while toads crawl in alternate gait, and that i
n water both swim with arms at the sides and legs executing parallel strokes. However alternate leg propulsion in swimming has been reported "by some authors (e.g., Calow & Alexander, 1973"...but..."has been largely overlooked in previous work on anurans."
In 1999 a study by Abourachid et al. 1999, described how in two Archeobatrachian families, Leiopelma and Ascaphida,
alternate asymmetrical hind limb thrust occurs. These families belong to the more primitive of the two anuran suborders, making it seem that alternate mode swimming is also a primitive feature derived from the land crawling phase of the ancestral li
ne. Moreover it is unusual that these frogs also swim with anteriorly extended forelimbs. Apparently this is same CR configuration as we see in the landing of a jumping frog, where arms extend to absorb the landing impact.
More recently, in 2001, (Nauwelaerts...) workers in the field reported that
Rana esculenta in the Neobatrachian modern family Ranidae of common frogs exhibit not only typical anuran locomotory gaits listed above, but additionally employ
parallel symmetry in swimming, using all four limbs, and also
alternate symmtery when they swim using all four limbs as in walking.
Interestingly, it was also told that the species Rana esculenta employs forelimb movement when swimming in the general anuran parallel asymmetric mode, with the arms by the side and legs propelling. But, here on the return stroke, as the le
gs move apart, the arms also rotate out from the body and during the power kick phase, as the legs come together, they are repositioned close to the body. (see fig.000) This is evidence that the mechanism of CR parallel symmetry used in leaping is embedded
in Rana esculenta and so this drag generating action still manifests in swimming. The authors pint out that alternate leg swimming is less energy requiring and appears to be used at lower speeds. This agrees well with mammalian pattern of increase i
n speed when chnaging from run to gallop.
Parallel asymmetric mode is followed by frogs as they characteristically move on land by jumping, with arms held at the sides, but approaching the target site, the arms are synchronlously rotated forward for the landing, having thus chnaged into the
symmetrical mode. In swimming the anuran forelimbs are kept close to the body and the legs generate thrust in asymmetrical parallel action. When jumping into water the arms similarly remain unrotated, kept by to the body in position for swimming.
It can be noted while the four major modes of CR are represented in amphibian locomotion, the mixed mode does not occur.