Age Structure of a Spadefoot Toad Pelobates fuscus (Pelobatidae) Population

Eggert, Christophe; Guyetant, R.

doi:10.2307/1447991

“…8). These values differ from those reported by Eggert & Guyétant, (1999) for a Pelobates fuscus fuscus population in France, in which the males were younger (2.8 ± 0.8 LAGs, t = 2.43, P < 0.05), than females (5.0 ±1.7 LAGs, t = 2.43, P < 0.05), though, in any case, give a similar general overview, with animals showing quite a short life span. Males reach sexual maturity earlier than females, as can be observed from the difference in terms of inter-LAG zones, which are thicker before the l sl and thinner successively.…”

Section: Age Structurecontrasting

confidence: 98%

“…comm.). The age structure confirmed the data obtained by Eggert & Guyétant (1999, indicating that the species has quite a short life span, that the turn-over of adults is very fast, and that old populations may easily disappear and others may reconstitute.…”

Section: For a Conservation Which Conserves The Toads/supporting

confidence: 84%

See 1 more Smart Citation

On the edge of extinction? The spadefootPelobates fuscusinsubricus in the Po Plain, and a glimpse at its conservation biology

Andreone¹,

Bergò²,

Bovero³

et al. 2004

Italian Journal of Zoology

View full text Add to dashboard Cite

The Italian spadefoot toad, Pelobates fuscus insubricus, is said to be in decline throughout its range (Po Plain, N Italy), and for this reason it has been object of conservation campaigns and included in conservation papers and projects. We have reviewed its distribution, and compared historical and current findings. These data support only partly the idea of a decline in numbers over the past century. Most likely, the species has always been quite localised in northern Italy, and also difficult to detect: the inferred rarefaction is likely the consequence of growing anthropisation and rapid habitat destruction in some areas of the Po Plain. In any case, in light of the most recent findings, the species sometimes appears to be locally abundant. The most critical area in terms of presence and biodiversity is the central-eastern part of the Po Plain, as is the case for many other amphibians and reptiles. We also present migration and biometrie data regarding a population near Ivrea (Turin Province). Over a period of about 40 days, we captured more than 300 individuals using pitfall devices, which indicated that the population is particularly abundant (500-1000 individuals). The sex-ratio was approximately 2:1 in favour of males, which is in accordance with former literature. A skeletochronological analysis indicated an individual mean age of 338 ± 0.77 years in males, and 4.00 ± 0.77 in females. A review of conservation initiatives suggests that the campaigns were useful in terms of educating the general public, but much remains to be done with regards to habitat protection and conservation. Special importance is given to studies regarding several little known aspects of the life history of the Italian populations.

show abstract

“…In this case, the causes of inversion remain unknown. The occurrence of an isolated sex reversal event was suspected because of the abnormal age structure in a wild population of Pelobates fuscus [21,39]. Some protogyneous individuals under the supposed influence of a low male density in Hyperolius viridiflavus [40] or some proterandreous individuals under the supposed influence of "food castration" in Triturus alpestris [41] were observed in captivity.…”

Section: Sensitivity Of Sex Determination To Epigenetic Factorsmentioning

confidence: 99%

Sex determination: the amphibian models

Eggert

¹

2004

Self Cite

View full text Add to dashboard Cite

-We review and discuss current knowledge about sex determination in amphibians. The astonishing wide variety of mechanisms of genotypic sex determination is presented and discussed in an evolutionary context. We recall the natural occurrence of transitory juvenile hermaphroditism in some species. Our present knowledge of the mechanisms of sex determination in amphibians is compared to that in mammals. The influence of epigenetic factors, and especially temperature is highlighted. In amphibians, the influence of temperature on sexual differentiation, that can prevail over genotypic sex determination, remains poorly considered in publications. We suggest that studies on genetic and epigenetic factors of gonadal sex differentiation in amphibians could provide substantial information on the evolutionary process of sex determination mechanisms in current living vertebrates.sex determination mechanisms / sexual differentiation / hermaphroditism / epigenetic factors

show abstract

“…Up to now, information on age structure in P. fusctis was available regarding France (Eggert & Guyétant, 1999; and Austria (Wiener, 1997). The differences may be due to the lower mean rainfall rate for Piedmont and NW Italian sectors (see Andreone & Sindaco, 1999).…”

Section: Population Data From Migrai Ion and Age Analysismentioning

confidence: 99%

On the edge of extinction? The spadefootPelobates fuscusinsubricus in the Po Plain, and a glimpse at its conservation biology

Andreone

¹

,

Bergò

²

,

Bovero

³

et al. 2004

Italian Journal of Zoology

View full text Add to dashboard Cite

The Italian spadefoot toad, Pelobates fuscus insubricus, is said to be in decline throughout its range (Po Plain, N Italy), and for this reason it has been object of conservation campaigns and included in conservation papers and projects. We have reviewed its distribution, and compared historical and current findings. These data support only partly the idea of a decline in numbers over the past century. Most likely, the species has always been quite localised in northern Italy, and also difficult to detect: the inferred rarefaction is likely the consequence of growing anthropisation and rapid habitat destruction in some areas of the Po Plain. In any case, in light of the most recent findings, the species sometimes appears to be locally abundant. The most critical area in terms of presence and biodiversity is the central-eastern part of the Po Plain, as is the case for many other amphibians and reptiles. We also present migration and biometrie data regarding a population near Ivrea (Turin Province). Over a period of about 40 days, we captured more than 300 individuals using pitfall devices, which indicated that the population is particularly abundant (500-1000 individuals). The sex-ratio was approximately 2:1 in favour of males, which is in accordance with former literature. A skeletochronological analysis indicated an individual mean age of 338 ± 0.77 years in males, and 4.00 ± 0.77 in females. A review of conservation initiatives suggests that the campaigns were useful in terms of educating the general public, but much remains to be done with regards to habitat protection and conservation. Special importance is given to studies regarding several little known aspects of the life history of the Italian populations.

show abstract

Age Structure of a Spadefoot Toad Pelobates fuscus (Pelobatidae) Population

Cited by 17 publications

References 13 publications

On the edge of extinction? The spadefootPelobates fuscusinsubricus in the Po Plain, and a glimpse at its conservation biology

On the edge of extinction? The spadefootPelobates fuscusinsubricus in the Po Plain, and a glimpse at its conservation biology

Sex determination: the amphibian models

On the edge of extinction? The spadefootPelobates fuscusinsubricus in the Po Plain, and a glimpse at its conservation biology

Contact Info

Product

Resources

About