TLACONETE: CHARACTERISTICS, HABITAT, REPRODUCTION, FEEDING - BIOLOGY - 2024

Tlaconete, whose scientific name is Bolitoglossa platydactyla, is an endemic salamander of Mexico that is also known by the name of the broad-footed mushroom tongue salamander.

It was described in 1831 by the English naturalist John Edward Gray (1800-1875) and is currently classified in the category 'near threatened with extinction', mainly due to the destruction of its habitat.

(c) 2010 Sean Michael Rovito, some rights reserved (CC BY-NC-SA)

-Species: Bolitoglossa platydactyla.

Morphology

Bolitoglossa platydactyla has a longitudinally elongated body. They are relatively large, reaching lengths that can range from 6 cm to approximately 9 cm.

They have a fairly characteristic coloration. The body is dark, either black or brown. On its dorsal surface, it has a wide golden yellowish stripe that extends across the surface, from the tail to the head. Here, the strip experiences a fork and splits in two. In the extremities it is possible to observe spots of the same color.

This salamander is quadruped, which means that it has four limbs, two front and two back. The number of fingers varies in each one. In the previous ones it has a total of four fingers, while in the later ones it has five.

The head is oval in shape and the eyes, which are quite prominent, stand out. They also have a reddish iris that can sometimes be orange.

On the ventral surface, at the end closest to the tail, there is a hole known as the cloaca, which is used for reproduction and for the release of waste substances.

Habitat and distribution

Bolitoglossa platydactyla habitat. Source: Pixabay.com

This species of salamander is endemic to Mexico. This means that the only place in the world where you are is in this country.

Now, in the interior of Mexico, this animal has a predilection for the south and central zone, being located mainly in the states of Chiapas, Veracruz, Oaxaca, Hidalgo and San Luis Potosí. Specimens have also been found in Tamaulipas, further north.

However, the habitat of these animals must meet certain characteristics for them to survive. Among these characteristics, the most important is related to humidity. It is important to remember that amphibians are a group of animals that require high levels of humidity, especially for their reproduction cycle. Bolitoglossa platydactyla is no exception.

Due to this, the habitat in which this animal is found is represented by tropical and subtropical forests, as well as humid savannas. The climate in these places is hot and humid, with temperatures around 24 ° C. Precipitation here is abundant, thus maintaining constant humidity.

In these ecosystems, Bolitoglossa platydactyla specimens have been found in places such as under rocks, logs, or leaves, in the vicinity of bodies of water such as streams, and at the foot of trees whose trunks are quite wide.

Feeding

As with all members of the animal kingdom, Bolitoglossa platydactyla is a heterotrophic organism, which indicates that it does not have the ability to synthesize its nutrients, so it feeds on other living beings or on the substances they produce.

In this sense, this salamander, like most amphibians, is carnivorous. This means that it eats other animals. Specialists who have been able to observe it in its natural habitat, have determined that it feeds mainly on the larvae of some insects, such as beetles. It also feeds on other insects, which has been evidenced in captive specimens.

Beetle larvae are the preferred food for Bolitoglossa platydactyla. Source: Ian Kirk from Broadstone, Dorset, UK

The main mechanism that these salamanders have to capture their prey is their long tongue, which is characterized by being very sticky.

When the animal identifies some prey, it approaches it stealthily and, only when it is close enough, does it unfold its tongue, capturing it and attracting it to engulf it directly. Importantly, Bolitoglossa platydactyla's prey are small in size compared to yours.

Digestion

Once the prey is ingested, the digestion process begins in the oral cavity. Here it comes into contact with the saliva of the animal, in which chemical substances known as digestive enzymes are dissolved. They contribute to the fragmentation of the food and transform it into smaller particles that are easier to digest.

From the oral cavity, food is sent to the stomach, through a muscular duct called the esophagus, which is short. Here the digestion process continues, with the action of digestive enzymes produced in the stomach. When leaving here, the food is already sufficiently prepared to be absorbed.

The absorption process occurs at the level of the intestine, which is quite simple. In this, the important nutrients pass into the animal's circulation, while what is not absorbed remains in the intestine. Finally, what is not used by the animal's body, is released to the outside, through the hole known as the cloaca.

Reproduction

Bolitoglossa platydactyla is a dioecious organism. This implies that there are female individuals and male individuals. Similarly, it is important to clarify that the type of reproduction that this species of salamanders has is sexual. Through this, the new individuals are the product of the fusion of the male gametes (sperm) with the female gametes (ovules).

Mating rite

As with a wide variety of species in the animal kingdom, Bolitoglossa platydactyla also exhibits specific behavior that is intended to arouse interest in individuals of the opposite sex.

However, specialists have not yet managed to elucidate exactly what are the specific mechanisms that make up the mating rite of this species of salamanders. However, it has been established that they can be guided by olfactory or tactile signals to be able to identify themselves.

The synthesis and release of pheromones also seems to have a leading role in these rituals. These are nothing more than chemical substances whose function is to attract individuals of the opposite sex for the sole purpose of reproducing.

Well, in this species of salamander, it is most likely that they use the release of pheromones, being produced by both sexes. In the case of males, they are produced by the abdominal gland, while in the female, pheromones are synthesized by glands that are found at the level of the cloaca and it is believed that also at the level of the skin.

Fertilization and egg laying

Fertilization in Bolitoglossa platydactyla is internal, which means that the sperm fertilize the ovules inside the female's body. However, between them there is no copulation process as such.

What happens here is that the male releases the sperm into the ground in a structure known as the spermatophore. However, specialists have not yet agreed on the way in which the spermatophore is introduced inside the female's body.

Some argue that the female takes the spermatophore and introduces it into the cloaca, while others consider that a kind of dance begins between the female and the male, in which the male drags the female so that she walks on the spermatophore and so you can get it into your cloaca.

Regardless of how it is, the important thing is that the spermatophore is introduced into the cloaca of the female and fertilization occurs.

Once the eggs have been fertilized, the female lays them on the ground, specifically in places protected from possible predators, such as under rocks or even on decaying tree trunks.

One of the distinctive elements of these eggs is that they have a resistant, leathery-type cover, which has the function of protecting them from drying out as a result of environmental conditions.

After laying, the eggs do not remain unprotected, but rather one of the parents, generally the mother, stays with them, ensuring that they are not eaten by a predator.

Development and birth

Inside the egg, the embryo develops. As already mentioned, Bolitoglossa platydactyla is triblastic, which means that all the tissues that will make up the adult animal are formed and developed from the three germ layers.

However, unlike most amphibians, Bolitoglossa platydactyla does not present a metamorphosis stage. The animals that emerge from the eggs, once they hatch, present the characteristics of an adult salamander.

The only difference is size, as young salamanders are much smaller than adult ones. For all this it is affirmed that Bolitoglossa platydactyla presents a direct development.

References

1. Curtis, H., Barnes, S., Schneck, A. and Massarini, A. (2008). Biology. Editorial Médica Panamericana. 7th edition.
2. Farr, W., Sosa, G., Ugalde, J. and Vite, A. (2016). Geographic distribution; Bolitoglossa platydactyla (Broad-footed Salamander). Mexico: Tamaulipas. Herpetological Review 47 (2).
3. Hickman, CP, Roberts, LS, Larson, A., Ober, WC, & Garrison, C. (2001). Integrated principles of zoology (Vol. 15). McGraw-Hill.
4. Lemos, J. (2015). Amphibians and Reptiles of the US - Mexico border States. Texas ARM University Press. First Edition.
5. Ramírez, A., Mendoza, F., Hernández, X. and Tovar H. (2004). Bolitoglossa platydactyla technical data sheet. In: Arizmendi, MC (compiler). Status and conservation of some amphibians and reptiles of Mexico. Iztacala Faculty of Higher Studies, Unit of Biology, Technology and Prototypes (UBIPRO), National Autonomous University of Mexico. SNIB-CONABIO databases. Project No. W043. Mexico DF
6. Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, ​​Spain; Gland, Switzerland; and Arlington, Virginia, USA.