Growth and body size in populations of mink frogs Rana septentrionalis from two latitudes

Abstract

R. J r and Laurin. G. 1996. Growth and body size in populations of mink frogs Runu seprenfrionulis from two latitudes. -Ecognphy 1 9 296-304.Age. longevity, and growth in mink frogs Runa srprenfriunulis from two latitudes in Quebec, Canada, were assessed by skeletochronological and backcalculation methods in order to document proximate causes for intraspecific variations in adult body size. In both study sites, females grew faster and were on avenge 11% larger than males. Mean age and maximal longevity were significantly higher in females than in males only in the southern populations. There was thus an interpopulation diference in the relative contribution of age and growth to sexual size dimorphisms. Sex-ratio also Favored females (males suffering higher mortality) only in the southern populations. Specimens from the northern population had higher mean ages (but not higher longevities) and were 17% larger than specimens from the southern populations. Annual growth rate appeared similar at the two study sites despite a shorter growing season at the northern locality. Maturity was reached by both sexes after 1 yr of post-metamorphic life (PML) in the southern populations but after 2 yr of PML in the northern population. There are indications that tadpoles metamorphose at larger body size at the northern locality after a prolonged larval period. It is concluded that growth rate, delayed maturity, greater mean ages. and eventually size at transformation, all contribute to the larger size of adult mink frogs at northern localities.

Ageing and growth of the endangered midwife toad Alytes muletensis

“…Greater longevity values for females have previously been reported for some species of anurans (Cherry & Francillon-Vieillot 1992, Leclair & Laurin 1996, Guarino et al 2011, and this result is generally interpreted as the consequence of a delayed sexual maturity (Kyriakopoulou-Sklavounou et al 2008) or a lower predation pressure on females (Cherry & Francillon-Vieillot 1992). In the case of Alytes muletensis, the first interpretation is convincing, because age at maturity is higher in females than in males.…”

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

“…It has been observed in R. septentrionalis (Leclair & Laurin 1996), R. temporaria (Miaud et al 1999), R. perezi (Esteban et al 1996), R. sylvatica (Sagor et al 1998), R. luteiventris (Reaser 2000), R. nigromaculata (Khonsue et al 2001), R. porosa (Khonsue et al 2002), R. epeirotica (Tsiora & Kyriakopoulou-Sklavounou 2002), R. ridibunda (Yilmaz et al 2005) and R. muscosa (Matthews & Miaud 2007). Sexual size dimorphism may be consequences of differences in age and partially to differences in growth rates for both sexes (Monnet & Cherry 2002).…”

Adult body size = f (initial size + growth rate × age): explaining the proximate cause of Bergman’s cline in a toad along altitudinal gradients

“…(1) Two distinct size patterns along latitudinal or altitudinal gradients have been identified among anuran species (review in Ashton 2002): some conform to Bergmann's rule (e.g. Leclair and Laurin 1996;Lai et al 2005;Lu et al 2006;Ma et al 2009a;Liao and Lu 2010a;Gillespie 2011), whereas others do the opposite (Ryser 1996;Eaton et al 2005;Matthews and Miaud 2007;Cvetković et al 2009;Ma et al 2009b;Sinsch et al 2010). This offers opportunities to assess relative roles of the size-related parameters in shaping the direction and degree of geographic size clines.…”