The oviparous olm: Analysis &amp; refutation of claims for viviparity in the cave salamander Proteus anguinus (Amphibia: Proteidae)

Blackburn, Daniel G.

doi:10.1016/j.jcz.2019.05.004

Cited by 3 publications

(4 citation statements)

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“…Distinct evolutionary lineages of olms exist (Gorički & Trontelj, 2006), and it is therefore conceivable that these differ in their parity mode, similar to fire salamanders or reproductively bimodal lizards (Smith et al, 2001;Rodríguez et al, 2017;Recknagel et al, 2018;Recknagel & Elmer, 2019). On the other hand, individuals available to historical breeding collections belong to the same two lineages that are reliably reported to lay eggs (Sket & Velkovrh, 1978;Aljančič, 2019;Blackburn, 2019). Unless parity mode is plastic within these two lineages, previous reports on olm viviparity are implausible.…”

Section: Discussionmentioning

confidence: 99%

“…However, two species associated with caves, the cave-obligate olm (Proteus anguinus Laurenti, 1768) and Speleomantes sarrabusensis Lanza, Leo, Forti, Cimmaruta, Caputo & Nascetti, 2001, a salamander that is often found in caves, have been reported to be viviparous (Michahelles, 1831;Nusbaum, 1907;Kammerer, 1912;Lanza, 2006). Both cases are controversial, and more recent data suggest oviparity for both species as their natural parity mode (Lunghi et al, 2018;Blackburn, 2019).…”

Section: Reproduction In Cave Animalsmentioning

confidence: 99%

“…The reproduction of Proteus anguinus has been a long-standing mystery and debated vigorously in scientific literature (Aljančič, 2019). One of the most controversially discussed features -even today -is whether olms give birth to live young (viviparity), lay eggs (oviparity) or possess the ability to switch between the two parity modes (facultative oviparity/viviparity) (Aljančič & Aljančič, 1998;Blackburn, 2019;Nahm, 2021). The controversy partially stems from the lack of data on the biology of olms due to their subterranean lifestyle secluded from human sight and scientific observation.…”

Section: Historical Notes On Olm Reproductionmentioning

confidence: 99%

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Oviparity, viviparity or plasticity in reproductive mode of the olm Proteus anguinus: an epic misunderstanding caused by prey regurgitation?

et al. 2022

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Cave animals are biological models of fast evolutionary change induced by transition to extreme subterranean environments. But their concealed lifestyle makes it inherently difficult to study life-history changes. Therefore, currently very little is known on the reproduction of cave species, and even less is known on general patterns and potentially shared reproductive strategies. Theory predicts that the cave environment favours the production of a few well-developed offspring and live birth. For one of the most enigmatic cave animals, the olm (Proteus anguinus), it has been debated fiercely whether they reproduce by live birth (viviparity), egg-laying (oviparity) or facultatively. While successes in captive breeding after the 1950s report oviparity as the single parity mode, some historically older observations claimed viviparity. The controversial neo-Lamarckist Paul Kammerer even claimed to have induced changes in parity mode by altering environmental conditions. Here, we report on the feeding and regurgitation of fire salamander (Salamandra salamandra) larvae by olms. The salamander larvae showed clear teeth marks and other injuries on the head caused by the olm, yet one larva was still alive after regurgitation. We suggest that historical reports of olm viviparity could have been misled by regurgitated salamander larvae. Our data bring additional indications that at least some of Kammerer’s experiments were fraudulent.

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Section: Discussionmentioning

confidence: 99%

Section: Reproduction In Cave Animalsmentioning

confidence: 99%

Section: Historical Notes On Olm Reproductionmentioning

confidence: 99%

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Oviparity, viviparity or plasticity in reproductive mode of the olm Proteus anguinus: an epic misunderstanding caused by prey regurgitation?

et al. 2022

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“…It is widely known that P. anguinus may turn dark under conditions of light (e.g., von Chauvin, 1883; Schreiber, 1912), but a hereditary effect of such a treatment as reported by Kammerer remains to be confirmed. Moreover, Kammerer's observation that P. anguinus is facultatively life bearing has not been confirmed (Blackburn, 2019).…”

Section: Replicationmentioning

confidence: 95%

The Midwife Toad Challenge After (Half) a Century

Arntzen

2022

Front. Ecol. Evol.

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The evolutionary biologist Paul Kammerer (1880–1926) purportedly demonstrated that environmentally induced character states are carried over to the next generation(s), therewith providing evidence for Lamarckian evolution. Kammerer’s work is generally seen as contentious but has also been valued as daring and insightful, and Kammerer has been heralded as an academic forebear of epigenetics. Most of the more pertinent of Kammerer’s experiments on amphibians and the sea squirt have either been invalidated by replications that failed, or have been dismissed as virtually impossible. An experiment on color pattern change in the fire salamander stands out because it has been confirmed, but only with data for within a generation, so that Kammerer’s claim concerning the inheritance of acquired character states still awaits confirmation. To facilitate and encourage replicate studies, I draw attention to species and populations that would be most practical and promising to work with, for those that are into the challenge.

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