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The function of the ear depends in part on its absolute size and internal proportions. Thus, in both young individuals and small species, the middle ear is expected to be allometrically enlarged despite its smaller absolute size. Here we aim to compare the ontogenetic allometry of relevant middle-ear structures as observed within gecko (gekkonomorph lizards) species, with the evolutionary allometry observed interspecifically. These observations also provide middle-ear data for future evaluation of variation in auditory sensitivity. The material comprised 84 museum specimens of geckos, representing nine species of three gekkonomorph subfamilies. The results of dissections and measurements show that different reports notwithstanding, the middle-ear ossicular chain is indeed structured as described for geckos by Werner and Wever (J Exp Zool 1972;179:1–16) and Wever (The reptile ear, 1978). Some sexual dimorphism is indicated, but this requires further study. During postnatal ontogeny, the allometric growth in the ratio of the columellar footplate area to body length differed between the intraspecific and interspecific levels, hence species differences in the middle ear do not merely result from animal size. The ratio of the tympanic membrane area to the columellar footplate area increased during ontogeny. In this, geckos resemble birds and probably also mammals. Similarly, when the comparison was among adults representing different species, the ratio of the tympanic membrane area to the columellar footplate area increased with body size. In this, however, the geckos differed from birds and mammals, in which this ratio varied taxonomically, irrespective of body size. It would thus seem that middle-ear proportions have evolved among geckos to produce small interspecific differences, but among amniote tetrapods they have evolved according to different principles in the classes reptiles, birds, and mammals. © 2005 Wiley-Liss, Inc.

In lizards and Sphenodon, often the fourth toes of individuals with intact tails have more subdigital lamellae on the right than on the left side, and the opposite situation frequently occurs in individuals with injured tails. The difference between intact and injured individuals in morphological directional asymmetry was statistically significant (P<0.05) in 11.4% among 193 species from various lizard families. Lizard families varied in extent and direction of association, but no phylogenetic constraints were detected within genera. Statistical significance was greater in samples from homogenous geographic origin than from heterogeneous ones. Among gekkonid species, the difference was stronger in those with cursorial (terrestrial) habits, than in those with scansorial (rupestral or arboreal) habits. In Scincidae, loss seems more often lethal in left-footed than in right-footed individuals. Statistically significant associations between morphological left-side dominance and tail injury exist also in three independent lineages with reduced limbs (Anguidae, Scincidae and Teidae). Hence such association is probably not a result of limb function. Rather, left-side dominance seems to be the symptom of an unknown, perhaps organism-wide, detrimental trait. Polymorphism in morphological dominance existed in all species, suggesting advantages and disadvantages in different situations to both phenotypes. We propose the hypothesis that an inversion of side dominance may occur in a single trait without systematic inversion of side dominance in all traits of the body. Inversion in a single trait causes incompatibility in multiple-trait functions. Such a mechanism, rather than cultural conventions, could increase accident proneness also in left-handed Homo sapiens, and could explain increased proneness to accident and warfare mortality in left-handed men, beyond the possible involvement of cultural factors.

The snakePsammophis schokari(Colubridae) occurs in Israel and Sinai, Egypt, in three pholidotically indistinguishable morphs: (1) striped, with four dark longitudinal stripes; (2) non-striped, plain or lightly dotted; and (3) rear-striped, dark stripes on the posterior part merge anteriorly (this pattern is first described herein). From 100 museum specimens it appears that the striped snakes occur mainly in the northern mesic parts of Israel, the non-striped mainly in the southern deserts, and the rear-striped mainly in a central belt. The distributions are correlated to rainfall, solar radiation and vegetation. This polymorphism may be maintained by crypsis, thermoregulation or both.

Using field observations and museum material, we compare environmental, morphological and biological aspects of some Peruvian and Israeli desert lizards (Reptilia: Gekkonidae). The rupicolous species Phyllodactylus reissi (Peru) resembles Ptyodactylus hasselquistii (Israel) whereas the psammophilous Phyllodactylus microphyllus (Peru) resembles Stenodactylus sthenodactylus (Israel). The similarities include habitat, activity timing, body size, body shape, scutellation, digit structure, eye size, sexual size difference and clutch size. Hence new world Phyllodactylus have radiated attaining a divergence paralleling that between very distinct old world genera.

Comparable auditory sound pressure level (SPL) and sound intensity level (SIL) threshold curves were determined in air and under water in Rana catesbeiana. Threshold curves were determined using chronic metal electrode implants which detected multi-unit responses of the torus semicircularis to incident sound. In terms of SPL, hearing thresholds in water and air are similar below 0·2 kHz. Above 0·2 kHz, the sensitivity under water falls off at about 16 dB/octave to reach an average loss of about 30 dB above 0·4 kHz. In terms of SIL, the organism is about 30 dB more sensitive under water than in air below 0·2 kHz and equally sensitive in air and water above 0·4 kHz. The relative merits of the two measures are discussed and an attempt is made to relate the results to morphology of the middle and inner ears. This report is the first to compare aerial and underwater hearing abilities in any organism using electrode implants.