Sexual size and shape dimorphism in the Wushan salamander, Liua shihi (Liu, 1950) (Urodela: Hynobiidae)

Figures & data

Table I. Descriptive statistics of original morphometric characters (mm) in males and females of Liua shihi.

Variables	Female (n = 61)		Male (n = 55)
	mean ± SD	range	mean ± SD	range
snout-vent length	71.18 ± 7.69	57.89–90.72	76.46 ± 6.07	63.13–91.34
head length	21.14 ± 2.00	17.04–27.81	22.75 ± 1.97	18.34–28.30
head width	14.69 ± 1.38	11.20–19.70	16.10 ± 1.60	13.10–20.20
head height	8.89 ± 1.24	5.90–11.50	10.32 ± 1.83	7.20–18.30
snout length	4.63 ± 0.88	3.54–10.21	4.91 ± 0.50	3.83–6.42
tail length	66.42 ± 7.97	49.87–87.30	74.40 ± 8.01	59.54–94.96
tail height	11.04 ± 1.25	8.86–14.27	12.06 ± 1.64	9.02–16.30
tail width	8.37 ± 1.20	6.64–11.10	9.60 ± 1.58	7.37–13.41
interorbital space	3.43 ± 0.42	2.69–4.51	3.78 ± 0.55	2.78–5.27
eye diameter	4.26 ± 0.32	3.35–5.35	4.47 ± 0.28	3.92–5.54
internarial space	5.57 ± 0.52	4.35–6.87	5.94 ± 0.64	3.81–7.57
intercanthal space	5.60 ± 0.47	4.86–6.70	6.04 ± 0.57	4.90–7.48
length of forelimb	19.07 ± 1.43	15.81–23.07	21.04 ± 1.26	18.51–23.34
length of hindlimb	21.79 ± 1.78	17.90–26.30	23.45 ± 1.74	19.90–28.00
space between axilla and groin	33.32 ± 4.07	25.86–44.38	34.62 ± 3.67	26.80–44.53
forelimb width	3.68 ± 0.49	2.90–5.75	4.51 ± 0.58	3.34–6.18
hindlimb width	5.20 ± 0.71	3.85–8.43	6.25 ± 0.81	4.57–8.10

Table II. Factor loadings for the principal components (PC; eigenvectors), eigenvalues and proportion of total variance described by the first two components obtained from PCA on a correlation matrix. Results of analysis of covariance (ANCOVA) with PC1 scores as covariate tests for differences in morphological variables. All variables are log-transformed; df = 113.

Variables	PC1	PC2	F	P-value
head length	0.926	0.027	7.100	0.009
head width	0.744	−0.170	4.401	0.038
head height	0.810	−0.267	0.273	0.602
snout length	0.658	0.062	1.696	0.195
tail length	0.925	−0.087	0.021	0.886
tail height	0.701	−0.428	0.114	0.736
tail width	0.879	−0.361	0.491	0.485
interorbital space	0.793	0.063	1.401	0.239
eye diameter	0.608	0.449	0.173	0.678
internarial space	0.739	0.184	1.895	0.171
intercanthal space	0.864	0.099	0.989	0.322
length of forelimb	0.827	0.261	16.479	0.000
length of hindlimb	0.757	0.397	1.004	0.319
space between axilla and groin	0.736	−0.031	13.516	0.000
forelimb width	0.862	−0.081	29.004	0.000
hindlimb width	0.824	0.008	14.734	0.000
Eigenvalue	10.130	0.909
Proportion	63.310	5.685