Male spiny frogs enter the underwater battlefield with loose skin exhibiting enhanced penetration of capillaries into the epidermis

Table 1 Skin and erythrocyte variables expressed as mean ± SD for the three groups

Variable	Breeding male	Non-breeding male	Breeding female
Capillary penetration extent	0.71 ± 0.09	0.88 ± 0.09	0.82 ± 0.10
CD (dorsal head; capillaries/mm)	12.2 ± 2.6	5.8 ± 2.7	4.8 ± 2.5
MDPL (dorsal forearm; μm)	16 ± 9	29 ± 8	23 ± 8
MDPL (dorsal distal hindlimb; μm)	13 ± 8	21 ± 8	16 ± 7
Erythrocyte area (μm²)	180 ± 24	150 ± 17	178 ± 30
Erythrocyte length (μm)	21 ± 2	19 ± 1	20 ± 2
Erythrocyte width (μm)	11 ± 1	10 ± 1	11 ± 1
Erythrocyte length/width ratio	2.0 ± 0.2	1.9 ± 0.2	1.9 ± 0.2
Stratum compactum thickness (μm)	56 ± 19	66 ± 18	47 ± 15
Total skin thickness (μm)	174 ± 54	187 ± 50	155 ± 56

Capillary penetration extent: ratio of the average minimum diffusion path length of perfused subepidermal capillaries (MDPL) to the average epidermal thickness; CD: density of perfused subepidermal capillaries. The skin variable values were based on the 10 sampled body regions if not specified

ISSN: 2056-306X