Females are usually considered to be more choosy than males when seeking a mating partner, resulting in the evolution of attractive males. When males are the limiting resource for receptive females, however, the females may become brightly coloured.

we investigated sexual size dimorphism in the tree frog, hyla savignyi using 33 males and 22 females from the western and northwestern regions of kermanshah province, western iran. out of sixteen measured morphometric characters, four were significantly larger in females than in males. these characters were nostrileye length, brachium length, elbowlongest finger length and hind limb length.

we collected 60 adult males and 85 adult females of trapelus lessonae de filippi, 1863 in early may 2008 from central iranian plateau to study sexual dimorphism in morphological traits as well as female reproductive traits. size-related sexual dimorphism occurred in all the compared body dimensions. the largest female was 83.88 mm in snout-vent length, and the largest male was 73.12 mm. as well...

The Japanese quail has been utilized as a research species in establishing the genetic relationships that may also be present in other species. Divergent phenotypic selection for 4-wk BW was conducted for three generations in high (HW) and low (LW) lines. Within each line, 50 females and 25 males were selected among 600 birds, based on 4-wk BW. Mean BW at 4 wk of age in the base generation was ...