An electrophoretic study of genetic variation in the New Zealand frog genusLeiopelma

Abstract

Genetic variation at 33 loci in three species of Leiopelma was examined by cellulose acetate electrophoresis of liver enzymes. Heterozygosity is apparently comparable to levels detected in other amphibians. Genetic differentiation between species is extensive. L. hochstetteri is greatly divergent from both L. archeyi and L. hamiltoni, but these two are relatively similar genetically, in agreement with morphological, ecological, and developmental patterns. We tentatively estimate that the divergence of hochstetteri from the other two species occutrred during the Miocene, whereas that of archeyi and hamiltoni occurred during the Piiocl!ne. Implications of the genetic data for oonservation of these rare species are discussed.

Leiopelma pakeka,n. sp. (Anura: Leiopelmatidae), a cryptic species of frog from Maud Island, New Zealand, and a reassessment of the conservation status ofL. hamiltonifrom Stephens Island

“…2). L. hochstetteri is widely divergent from the other three species, confirming many previous studies, e.g., Stephenson et al (1972Stephenson et al ( , 1974, Bell (1978aBell ( , 1982a, Daugherty et al (1981Daugherty et al ( , 1982, Cree (1985), Green et al (1989).…”

“…Aspects of the habitat and life history of the new species of frog on Maud Island have already been described: anti-predator behaviour by Bell (1985b) and Green (1988c); demography by Newman (1977Newman ( ,1990, Bell (1994Bell ( ,1996Bell ( ,1997, Bell (1994), andBell (1995); diet by Kane (1980) and Bell (1995); ecological biogeography by Bell et al (1985); ecological management by Newman (1977Newman ( , 1990 and Bell (1985bBell ( , 1996; ecophysiology and water-balance by Cree (1985); habitat and climatic relationships by Crook et al (1971), Newman et al (1978), Newman (1990), Bell (1978aBell ( , 1985b, Bell (1994), andBell (1995); morphology by Barwick (1961), Stephenson (1960Stephenson ( , 1961, Bell (1978aBell ( ,b, 1982a, Worthy (1987) and Bell (1995); reproduction and early development by Bell (1977Bell ( , 1978aBell ( ,b, 1982aBell ( ,b, 1985a; systematics and genetics by Daugherty et al (1981Daugherty et al ( , 1982, Bell et al (1985), Green (1988b), Green et al (1989), Green & Cannatella (1993) and …”

“…Leiopelma is an endemic New Zealand frog genus including four extant and three sub-fossil species (Worthy 1987, Bell 1994 One of the extant species is confined to Maud Island, in the Marlborough Sounds, and is formally described here This Maud Island frog, first characterised by Stephenson (1961), was formerly regarded as a population of L hamiltoni, a species originally described from Stephens Island by McCulloch (1919) Subfossils in both the North and South Islands have also been regarded as L hamiltoni (Worthy 1987 - Fig 1) The extant species have been the subject of a series of genetic investigations (Daugherty et al 1981, 1982, Green 1988a,b, Green et al 1989, but L hamiltoni has previously been represented only by animals from the relatively abundant Maud Island population (ca 19 000 individuals on a 16 ha remnant patch of habitat Bell & Bell 1994) The Stephens Island population, restricted to <1 ha and numbering fewer than 300 individuals (Bell 1985b, Newman 1990, Brown 1994, has quite appropriately been considered at too great a risk for animals to be killed for research purposes However, a limited number of Stephens Island frogs have been held in captivity for behavioural and reproductive studies (Bell 1985a) One or two toes of 11 animals were used to provide tissue samples for genetic analysis, this did not require killing the animals The * School of Biological Sciences, Victoria University of Wellington, P O Box 600, Wellington, New Zealand ** Present address Department of Biology, Pennsylvania State University, PA 16802, U S A KEY TO SPECIES (after Worthy 1987 andBell 1994). The taxonomic status of subfossil L. hamiltoni requires clarification given our recognition of two taxa on islands in the Marlborough Sounds, and the possibility that northern populations may be L. archeyi (Bell 1994 …”

Retinal organisation in the native New Zealand frogsLeiopelma archeyi, L. hamiltoni, andL. hochstetteri(Amphibia: Anura; Leiopelmatidae)

“…On the basis of electrophoretic studies, L. archeyi and L. hamiltoni are more closely related to one another than either one is to L. hochstetteri (Daugherty et al, 1981). Stephenson (1960) suggested that relative degree of neoteny could be used to distinguish archeyi from hamiltoni, though this idea is rejected by Worthy (1987).…”

Distribution and abundance of Hochstetter's frog,Leiopelma hochstetteri

“…Moehau on the Coromandel Peninsula, and Dome Valley and Big Omaha near Warkworth ( Fig. 1) where frogs have been studied by Stephenson and Stephenson (1957), Bell (1978Bell ( , 1982, Daugherty et al (1981), Green (1988a,b) and others.…”