Sal

Abstract

The evolution of adaptive innovations carries strong eco-evolutionary implications, allowing organisms to explore novel ecological opportunities, which facilitates lineage diversification. The remarkable diversity of reproductive strategies in amphibians provides a natural laboratory for identifying ecological mechanisms driving evolutionary novelties. In viviparous salamanders, the transition from larviparous (i.e., live bearing of aquatic larvae) to pueriparous (i.e., live bearing of fully terrestrial juveniles) reproduction is hypothesized to represent an adaptation to the absence of water for larval deposition, in what is known as the dry-climate hypothesis. This work aimed to identify the ecological drivers of independent evolutionary transitions to pueriparity and test the dry-climate hypothesis.

Main Conclusions

Reproductive transitions to pueriparity in salamanders were consistently associated with scarcity of surface water driven by steep topography and karstic geology, providing the most unambiguous support for the dry-climate hypothesis to date and supporting convergent evolution of terrestrialisation in salamanders for most pueriparous lineages. Climatic, hydrological (i.e., soil moisture and vapour pressure deficit) and habitat factors appear to be comparatively less relevant drivers of reproductive shifts, yet may have played a role in specific transitions to pueriparity, especially at the intraspecific level. We also found key differences in the use of available habitat between reproductive modes, with pueriparity representing a more specialised strategy likely restricted to areas with strong selective pressure against aquatic breeding.

This is a recent article that describes some details on the reproductive biology of Bolitoglossa pandi. I found it interesting to see how the eggs are deposited as clutches among leaf litter.

The article also includes this nice image of Bolitoglossa hatchlings:

A new species of salamander from Costa Rica, Bolitoglossa chirripoensis, has been described!

KLANK, JEREMY, et al. "A new species of salamander of the genus Bolitoglossa (Caudata: Plethodontidae) from the highest massif of the Cordillera de Talamanca, Costa Rica." Zootaxa 5642.5 (2025): 427-450.

Research Gate Link

There are a few people out there self-dosing with snake venom. The posted article is based on a study on the blood of one of these guys, Tim Friede, who has developed very effective antivenom in his blood after 20 years of self-dosing with a diverse array of snake venoms.

Vice did a few documentaries on Steve Ludwin, who is also self-immunizing. In one of these he answers questions about how he began and his motivation for doing what he does. In addition to producing anti-bodies he also believes that snake venoms have medicinal and anti-ageing properties - but these beliefs do not appear to be supported by any animal-based data as far as I can tell: https://www.youtube.com/watch?v=AcbqB0pFRPA

Self-dosing with snake venom is not something I would recommend. Generally a bad idea. But it is interesting to see the results and to learn about what motivates someone to do something like this.

Abstract

Bolitoglossa digitigrada Wake, Brame and Thomas, 1982 was described from a few kilometers upstream from the Rio Santa Rosa, Ayacucho Region, Peru, at 1000 m a.s.l. in the Eastern Amazonian Montane Forest. Besides the type specimens, no additional collections or sightings of B. digitigrada had been reported for 43 years, and there is no information about its phylogenetic position inside its group. During a field expedition conducted in October 2022, we found four individuals of B. digitigrada in a corn and banana field near the community of San Jose, approximately 2.7 km from the type locality. Here, we provide information about living specimens, update description of coloration in life, elevation, and evaluate the phylogenetic relationships of B. digitigrada with a molecular phylogeny based on a 16S rRNA sequence.

This is a Trachycephalus typhonius, formerly Trachycephalus venulosus, from Yucatan.

These frogs secrete a sticky and irritant milk-like fliud through its skin when bothered. Several years ago I got some some of that fluid into my eyes by accident - that hurts similar to scratching one's eye after touching a spicy pepper. So, they are not terribly toxic but I certainly do not recommend the experience.

Funnily enough I just ran a search and found a publication of someone who describes a similar but worse experience: https://www.thebhs.org/publications/the-herpetological-bulletin/issue-number-152-summer-2020-1/3101-09-a-caution-on-handling-i-trachycephalus-venulosus-i-anura-hylidae-toxic-effects-of-skin-secretion-on-human-eyes/file

You may notice that the finger pads of this frog look green. That's because its bones are green! A characteristic feature of this species. Here is a photo (not mine) of a skeleton of one of these : https://www.pybio.org/wp-content/uploads/2008/06/t-ven31.jpg

A new paper on a Bolitoglossid showed up in my alerts today! 🥳

It is a one-pager and comes with a beautiful photo of a foraging arboreal salamander 😄

Found this Imantodes cenchoa sleeping on top of a leaf in Punta Laguna, Quintana Roo.

Here is a photo of where it was sleeping:

There are a few different snakes of the genus Imantodes in Yucatán. What sets this species apart is that the row of scales on its back consists of enlarged scales. Here is a closeup emphasizing that row of scales. The green arrow points at an enlarged mid-dorsal scale, the blue arrow at a regular scale.

In comparison, here is a photo from an Imantodes tenuissimus that I took back in 2009 in Mérida, Yucatán (with a less sharp camera), and a closeup of its mid-dorsal scales that does not show this enlargement.

One of my favorite frogs! Spent some time specifically looking for it. Managed to find two near Cobá, in Quintana Roo (in the Yucatán peninsula). This frog hides in holes in lime stone and tree trunks, and makes use of its flat head to block the entrance. This type of defense is known as phragmosis.

Some other shots:

Found this anole in Yucatan. I am not sure of its exact species - probably an Anolis sp..

Anoles often sleep at the tips of leaves and twigs. My guess is that this is a strategy to prevent nocturnal predators sneaking up on them through the branches without making its bed vibrate. When woken up they can quickly drop down.

Found many of these frogs under a wet trash bag in a back yard in Mérida, Yucatán. I made use of a handheld flash with a remote trigger for lighting, and a Sigma 105 mm as my macro lens.

These frogs do not seem to match with any of the local frogs reported in Julian C. Lee's field guide to the amphibians and reptiles of the maya world.

From a reverse image search, I mostly found images of the green house frog Eleutherodactylus planirostris. Eleutherodactylus planirostris is native to Cuba and the Bahamas, and is often introduced with plants that come from green houses in those areas. These frogs go from tadpole to frog while still inside of the egg, which explains why the baby frogs are so small.

The visual aspect, the incredibly small baby frogs, and the fact that they were found in a back yard in the city with greenhouse plants, all lead me to conclude that it is likely Eleutherodactylus planirostris.