Development and growth of long bones in European water frogs (Amphibia: Anura: Ranidae), with remarks on age determination

Abstract

Differentiation and development of long bones were studied in European water frogs: Rana lessonae, R. ridibunda, and R. esculenta. The study included premetamorphic larvae (Gosner Stage 40) to frogs that were 5 years old. Femora, metatarsal bones, and proximal phalanges of the hindlimb exhibit the same pattern of periosteal bone differentiation and the same pattern of growth. Longitudinal and radial growth of these bones was studied by examination of the diaphyses and epiphyses, particularly where the edge of periosteal bone is inserted into the epiphysis. The periosteum seems to be responsible for both longitudinal and radial growth. Investigation of the formation, length, and arrangement of lines of arrested growth reveals that the first line is present only in the middle 25-35% of the length of the diaphysis of an adult bone; therefore, only the central portion of the diaphysis should be used for age estimation in skeletochronological studies. Comparison of the shapes and histological structures of epiphyses in the femur, metatarsal bones, and phalanges revealed that epiphyseal cartilages are composed of an inner and outer part. The inner metaphyseal cartilage has distinct zones and plugs the end of the periosteal bone cylinder; its role in longitudinal growth is questioned. The outer epiphyseal cartilage is composed of articular cartilages proper, in addition to lateral articular cartilages. Differences in the symmetry of the lateral articular cartilages of distal epiphyses of the femur and toes may reflect adaptations to different kinds of movements at the knee and in the foot.

Altitudinal variation in body size and age structure of the Sauter’s frog Rana sauteri in Taiwan

“…For each of the phalanges, the mid-diaphyseal part was cut into 10-to 20-μm-thick transverse sections with a freezing microtome (Rozenblut and Ogielska 2005). The sections were immediately stained with Ehrlich's hematoxylin for 15 min, rinsed with distilled The values were taken from the six sampling sites in southwestern Taiwan.…”

“…Each slide with the label covered was read twice by the observers (Morrison et al 2004;Lai et al 2005). The endosteal resorption from the inner surface of the bone could completely destroy LAGs, resulting in age determination error (Sagor et al 1998;Rozenblut and Ogielska 2005). Following the protocol of Lai et al (2005), we compared the major axis of the innermost LAG of each section with the mean of juveniles' LAG without resorption.…”

Age structure and body size of two populations of the rice frogRana limnocharisfrom different altitudes

“…All fingers were collected during the breeding seasons after emergence from hibernation, so we counted the outer margin of the bone as an additional LAG. Endosteal resorption of long bones starts from the inner surface of the bone, enlarging the marrow cavities and eroding a portion of LAGs when frogs have completed their hibernation (Rozenblut & Ogielska 2005). Following the protocol of Khonsue et al (2000), we measured the diameters of the innermost portion of the periosteal bone (resorption line) and of the first LAG to confirm LAG endosteal resorption.…”

Further Data on Sesamoid Identity from Two Anuran Species

“…The size of the specimens was used as a proxy of the development rate of the specimens (Dickson, 1982). However, this criterion should be considered with caution because a direct relationship between age and size has not been proven in anurans (Rozenblut and Ogielska, 2005). The stages of individuals were determined according to the relative percentage of the maximum length, which corresponds to the length of the adult specimen of each studied species (Table 1).…”