Friday, October 30, 2020

Peptides in two Trinidadian frogs reveal antimicrobial resistance

 

Barbour's thin-toed frog (Leptodactylus insularum). Photo by Renoir Auguste


Frogs are vitally important to ecosystems, and to people. Their importance in ecosystems stems from the roles they play acting as predator and prey to a variety of animals. Their ecological importance also benefits people, as frogs prey on insects, including pests to crops and mosquitoes. However frogs also play an important role in medicinal values. In particular, the peptides in frog skin secretions have been used to treat diseases, for example diabetes. Trinidad and Tobago has at least 35 species of frogs (amphibians). Thus far, at least two frog species have shown to have peptides useful for medicine, including the paradoxical frog (Pseudis paradoxa), and the Trinidad leaf-nesting frog (Phyllomedusa trinitatis). Now, two more species can be added to the list. A recent published study by Barran and colleagues (2020) found antimicrobial resistant properties in two species. These are the Trinidadian thin-toed frog (Leptodactylus nesiotus), and Barbour's thin-toed frog (Leptodactylus insularum). Barran and colleagues' study further exemplifies the importance of conserving frogs in Trinidad and Tobago, and all citizens should do their part by learning more about them, and conserving them for generations to come. Citation: Barran, G.; Kolodziejek, J.; Coquet, L.; Leprince, J.; Jouenne, T.; Nowotny, N.; Conlon, J.M.; Mechkarska, M. Peptidomic Analysis of Skin Secretions of the Caribbean Frogs Leptodactylus insularum and Leptodactylus nesiotus (Leptodactylidae) Identifies an Ocellatin with Broad Spectrum Antimicrobial Activity. Antibiotics 2020, 9, 718. Link to paper here: pdf

Cryptic diversity, & a unique reproductive mode in a Neotropical water snake from Trinidad

A recent published study by Murphy and colleagues (2020) suggest that the number of water snakes in the genus Helicops has increased from 19 to 20 species based on morphology. Trinidad has one species (currently) in that genus - Helicops angulatus, known commonly as the brown-banded water snake, or to some locals as the "water mapepire" (seen in the photograph above by Renoir Auguste), because of its superficial resemblance to the Bothrops viper "Mapepire Balsain". This snake though, is not just another snake. It is believed to have a unique reproductive mode whereby females presumably lay eggs, like many other reptiles, but also gives birth to live young! This is sometimes referred to as facultative (viviparous) reproduction as they are able to do both. It is not certain as to what brings about the different choice (or lack thereof) in reproductive mode. Perhaps it is environmental related. However, the importance of conserving this unusual snake population, and its habitat is of paramount importance as we may be able to learn more about the evolution of this species, Squamates: lizards and snakes, and the potential benefits they may have to improving our knowledge of biodiversity conservation. Citation: Murphy JC, Muñoz-Mérida A, Auguste RJ, Lasso-Alcalá O, Rivas GA, Jowers MJ. 2020. Evidence for cryptic diversity in the Neotropical water snake, Helicops angulatus (Linnaeus, 1758) (Dipsadidae, Hydropsini), with comments on its ecology, facultative reproductive mode, and conservation. Amphibian & Reptile Conservation 14(3) [Taxonomy Section]: 138–155 (e261). Link to paper here: pdf

Wednesday, October 7, 2020

Brown vine snake (Horsewhip) from Trinidad and Tobago renamed after Mike Rutherford

 


The brown vine snake from Trinidad and Tobago locally known as Horsewhip has recently been re-described as a new species based on genetic and morphological data, compared to other specimens from across the Americas. The research was lead by Jadin and colleagues and published this year. The snake's scientific name is Oxybelis rutherfordi, or commonly Rutherford's vine snake.

The species has been named in honour of Mike Rutherford, who was the former Curator of the University of the West Indies Zoology Museum, for his contributions to Zoology and Natural History in Trinidad and Tobago. Persons from Trinidad and Tobago that have participated in the annual Bioblitz or with the Trinidad and Tobago Field Naturalists' Club will be familiar with Mike. Congrats, Mike!

No doubt, new species of reptiles and amphibians will continue to be described in the country, which makes for exciting opportunities for young naturalists to get involved and passionate about wildlife. 


Reference: 

Jadin et al. 2020. Not withering on the evolutionary vine: systematic revision of the Brown Vine Snake (Reptilia: Squamata: Oxybelis) from its northern distribution. Organisms Diversity & Evolution 

Sunday, August 16, 2020

Male bronze anole lizards square off!

 


Bronze Anole (Anolis aeneus). Photo by Renoir Auguste

Anolis lizards or Anoles are known to have fierce competition for territory and mates. The following short (20 second) YouTube video highlights a brief snapshot of what the square off looks like! Different displays include expanding and showing off their dewlap (yellow chin extension), tail taps, (which can be seen in the clip), head bobbing, and push ups. 

One can learn more about the behavior of these lizards found in Trinidad and Tobago in the Field Guide to the Amphibians and Reptiles of Trinidad and Tobago, available and sold by the Trinidad and Tobago Field Naturalists' Club locally (bookstores and directly from TTFNC) and abroad (by order).

Monday, July 27, 2020

Have you been hearing an odd animal noise in your home at night? It's probably a gecko

House gecko (Hemidactylus mabouia). Photo by John Murphy

For those of you living in Trinidad and Tobago, you may have heard an odd sound coming from your wall or roof at night. Chances are, it was an African House gecko (Hemidactylus mabouia).

Other common names include African wood-slave and twenty-four hours. (NB: A few different lizards are referred to as 24-hours in Trinidad, whereby when the lizard falls on you, you have 24-hours left to live - a common folklore in the country).

Here is a YouTube Link to what these geckos sound like: https://www.youtube.com/watch?v=7dP33YLo-KU (1 minute long, but can skip to 25 seconds). Have you heard this sound in your home? Let us know!

You can learn more about this lizard and the folklore of local reptiles in the "Field guide to the amphibians and reptiles of Trinidad and Tobago" available in most leading bookstores nationwide, or directly from the Trinidad and Tobago Field Naturalists' Club.

Tuesday, June 23, 2020

Hurricanes and Anolis lizards of the Caribbean

Leaf anole (Anolis planiceps) gripping onto a plant. Photo by Renoir Auguste
Hurricanes are a constant threat to all across the Caribbean and they are getting more severe because of climate change. Hurricanes not only have devastating effects on humans, but also animals as well. For example, the white-tailed sabrewing hummingbird was almost extirpated from Tobago after hurricane Flora passed over the island in 1963.

Some animals have shown the propensity to adapt to severe hurricane winds, allowing them to survive. One adept example can be seen in Anolis lizards or Anoles, which can be found on every Caribbean island.

Anoles are mostly small to semi-large lizards. They are found across the Caribbean and Americas and are important components of ecosystems, feeding on a variety of insects, and are food to a variety of birds and other animals. They are considered ideal organisms for studying biology, ecology, and adaptation (among other fields).

A study by Donihue et al. 2020 showed that Anoles have found a way to adapt to strong hurricane winds: by growing larger toepads! These toepads allow the small lizards to grip onto vegetation better, thus allowing them to not be blown away by strong winds. Not only are these lizards with larger toepads surviving hurricanes, for example hurricane Irma and Maria from 2017, their offspring are being born with large toepads as well (compared to other anoles not exposed to hurricanes).

It's amazing what we can learn from animals, such as anoles, about adaptation to global events. No doubt we can learn more from them, which hopefully will allow us to appreciate them more and improve our management of biodiversity conservation.

There are at least 8 types of Anoles in Trinidad and Tobago. To learn more about these Anoles found in T&T, do get yourself a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago, available from the Trinidad and Tobago Field Naturalists' Club.


Thursday, June 4, 2020

Why Glass Frogs have see through skin

Tobago Glass Frog (Hyalinobatrachium orientale tobagoense) seen from below - translucent. Photo by Renoir Auguste


Animals with transparent skin in nature are rare, and our understanding of the function of it is even rarer. One example of an animal with apparent transparent skin is the glass frog. They are found across Central and South America, as well as on the island of Tobago, north east of Venezuela. These frogs, as their name suggests, have skin where the organs, bones, and even eggs (in females) can be seen through their skin. However, only from their underside, and not their back (as seen in both photos in this post). Because of this, glass frogs are better defined as being translucent due to the dorsal pigmentation.

Scientists investigated whether the imperfect transparency (only the belly and not the back) acts as camouflage, and how effective it is. They found that the perceived luminance of the glass frogs changed depending on the background, which lowered detectability by predators, and increased survival, when compared to opaque (not able to see through) frogs. It also appears that the change was greatest for the legs, which surround the body at rest which hid the frogs even more, referred to as edge diffusion. No doubt this is probably why glass frogs are so difficult to find during the day when they are sleeping!

The Tobago Glass Frog shares these similar translucent features of other glass frogs across the region. To learn more about the local glass frogs in Tobago, including where to find them, check out the Field guide to the amphibians and reptiles of Trinidad and Tobago, available by the Trinidad and Tobago Field Naturalists' Club.


Tobago Glass Frog seen from above - not translucent. Photo by Renoir Auguste



Reference: Barnett et al. 2020. Imperfect transparency and camouflage in glass frogs. PNAS.

Saturday, May 30, 2020

Venomous vs Poisonous difference examples using Trinidad herpetofauna

Figure and photos by Renoir Auguste.
On the left top & bottom: Cane Toad (Rhinella marina)
On the right top: Mapepire Balsain or fer-de-lance (Bothrops atrox)
On the right bottom: large coral snake (Micrurus diutius)
All species were photographed in Trinidad.

Saturday, April 4, 2020

A lizard pretending it is dead while being photographed

Trinidad hex-scaled lizard pretending to be dead while being photographed. Photo by Renoir Auguste
Death feigning (thanatosis) is an adaptive defensive behaviour seen in various animals, perhaps quite famously associated with opossums, but it has also been recorded in a variety of herpetofauna, including frogs, snakes and lizards.

A local example can be found here in Trinidad and Tobago with the hex-scaled lizard (Bachia trinitatis). This small (~ 6cm long) fossorial lizard is found in Trinidad and Tobago, mainly in leaf litter. Sometimes the small limbs may make persons confused this lizard for a worm.

In June 2016, one such individual was caught and brought back for closer inspection to photograph. While photographing it, the lizard rolled over to its side and pretended to be dead. After a couple minutes, and with the camera not too close, it put itself back upright. 

This may be the first documentation for this species exhibiting death feigning behaviour and it can be found here in Trinidad and Tobago. For more information about this lizard and other interesting facts about local wildlife, be sure to check out " A field guide to the amphibians and reptiles of Trinidad and Tobago". 


Source of information:
§  Auguste, R.J. 2019. Natural History Notes: Bachia trinitatis (Trinidad hex-scaled bachia). Defensive behavior. Herpetological Review 50(3):570.
Trinidad hex-scaled lizard (Bachia trinitatis) not playing dead. Photo Renoir Auguste


Tuesday, March 24, 2020

Trinidad's two types of Caiman

Spectacled caiman (with eye shine) from the Caroni Swamp. Photo by Renoir Auguste

Trinidad and Tobago has two species of caimans. The spectacled caiman (Caiman crocodilus). and the Cuvier's dwarf caiman (Paleosuchus palpebrosus). The following are some traits about each type of caiman and how to tell them apart.

Spectacled caiman
  • Typically grows to up to 2.3 m long. 
  • Males are larger than females. 
  • This species is widely distributed across the region, from Central America, to South America, and Trinidad and Tobago. 
  • They typically reside in brackish and freshwater environments and can be easily seen at night in swamps with their eye shine. 
  • Juveniles feed on aquatic invertebrates whereas adults feed on vertebrates such as fish, amphibians, birds, reptiles, and mammals. 
  • Juveniles do have a distress call and parental care is noted in crocodilians.
  • One of the key distinguishing features to tell the spectacled caiman apart from other caiman in the country is the bony ridge on the head behind the eyes.


Dwarf caiman
  • Typically grows to about 1.5 m long.
  • Males are slightly larger than females.
  • Distribution range is South American.
  • Habitat preference is for fast flowing streams in forests in cooler areas, compared to more open areas used by spectacled caimans.
  • Juveniles feed on insects, fish, frogs, whereas adults also feed on these but would include mammals to their diet.
  • Dwarf caimans are social and dominant individuals would have access to mates, food, nest sites.
  • Upper and lower jaw has dark and light spots. Also, the lack of a bony ridge anterior to the eyes distinguishes it from the spectacled caiman.

Dwarf caiman. Source: Wikipedia.

Source of information:
  • A field guide to the amphibians and reptiles of Trinidad and Tobago. Published by the Trinidad and Tobago Field Naturalists' Club. 
  • Ali SH, Rampersad-Ali N, Murphy JC. 2016. The discovery of Cuvier’s Dwarf Caiman, Paleosuchus palpebrosus (Reptilia: Alligatoridae) in Trinidad. Living World, Journal of the Trinidad and Tobago Field Naturalists' Club. 2016 Nov 30.


Saturday, March 14, 2020

The Bushmaster/Mapepire Zanana (Lachesis Muta), A Unique and Highly Specialized Pit-Viper Living In Trinidad’s Forests

Lachesis muta (Mapepire Zanana or Bushmaster) in-situation and in habitat  
(Photo by Rainer Deo)

           Strewn across the globe are highly venomous snakes that stand out to herpetologists and civilians alike. Some of these include the King Cobra from Asia (the largest venomous snake in the world), the Black Mamba from Africa (considered the fastest snake in the world), the Inland Taipan from Australia (the most venomous terrestrial snake in the world) and the Atlantic Bushmaster, locally known as Mapepire Zanana, from South America (the largest pit-viper in the world). Only two viper species can be found in Trinidad and it should be said with pride, that the Bushmaster is one of them.

What makes the Bushmaster such a unique and highly specialized snake?

1.        Oviparous (Egg-laying): When compared to close relatives, such as the Mapepire balsain (Bothrops cf), Bushmasters stand out as being the only documented genus of new world pit-vipers to lay eggs, as opposed to retaining eggs and giving “live birth” (ovoviviparity). The mother lays her eggs in the burrows created by agouti, lappe and armadillos or in holes under the buttress roots of trees such as the Mora (Mora excelsa). She coils around them to provide insulation, since their habitat is usually very cool and courageously guards them until they hatch.

2.        Big snake, small prey: It is typically believed that the larger a snake grows, the larger the prey it would hunt and be able to consume. This however, is not applicable to a number of groups, including the Bushmasters. They are known to feed primarily on small forest mammals with the Trinidad spiny-rat being one of their favourite local preys. Inexperienced keepers would be left baffled when a large Bushmaster (8-10 ft long) would bite and kill a rat but refused to eat it because it was simply too big.

3.        Intolerant of hot environments: It might be assumed that it is typically always warm and sunny in the tropics. However, Bushmasters are found most frequently in the hilly and mountainous areas of Trinidad where the environment gets very moist and cool. Deep within some of Trinidad’s forests, nights and early mornings may have temperatures that drop to as low as 19 degrees Celsius. These wet and cold conditions are essential for the survival of the Bushmaster which can accommodate multiple small prey in its lengthy body. If the environment and the snake become too warm, bacteria found within its prey would begin to multiply rapidly, resulting in the poisoning and almost certain death of the snake.

4.        Fossorial (Burrowers): Bushmasters are semi-fossorial which means they spend a significant amount of time underground in holes and burrows. In Trinidad, the Bushmaster is referred to as Mapepire Zanana, a name with French Creole and Carib origins. It translates to “Pineapple snake”, an appropriate comparison considering how bumpy and serrated some of the scales are. The roughness of the skin is an evolutionary feature which aids the snake in excavating its burrows. 
Closer look at scales on the Bushmaster. Photo by Rainer Deo

To learn more about the Bushmaster or other snakes in Trinidad, feel free to contact the Trinidad and Tobago Field Naturalists’Club (TTFNC) Herpetology Group, and get yourself a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago – published by the TTFNC!

This post was written by Rainer Deo – TTFNC Herpetology Group member.

Friday, March 6, 2020

T&T Lizard, Frog, Snake, Turtle, Caiman Identification and Awareness

Beebe toad in hand. Photo by R. Auguste

Chances are you have come across a lizard, snake, turtle, caiman, &/or frog at some point in time while living here in Trinidad and Tobago. However, you either have been told what the local name is, or sometimes you do not know. But you are curious. You want to know.

However for most people, they dislike frogs and reptiles, and rather not know. Yet, there are some that do and it is always beneficial to know about them, even if you dislike them. Perhaps you know someone who is, or your child is fascinated with frogs and reptiles despite your feelings towards them. However, for most, (maybe you) you have already convinced yourself that you will never change your mind about liking snakes, lizards, and/or frogs. OK - but maybe your child does like them. Your child wants to learn more about them. It helps them be more creative with their school work giving a local real example. It also helps build national pride in our native fauna.

If that is the case, you can reach out to us (Trinidad and Tobago Field Naturalists' Club) anytime for information on local frogs and reptiles. Whether it is simply asking for an identification, or perhaps you want to know some quick facts about them - what does it eat? is it poisonous/venomous?  how beneficial is it to me, society, economy and the environment? You'd be surprised that frogs and reptiles offer economic and social benefits to people! We also carry out field trips annually to locations across the country to look for reptiles and frogs and photograph them. Beneficial to persons interested in seeing them in their natural habitat and learning how to identify them.

If you are a parent or teacher, then you can get a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago. Appropriate for all ages. Young children can enjoy the colourful photographs, whereas older ones and young adults can read up on the scientific information, which also includes folklore details and habitat information.

The more children learn and appreciate animals around us, the better society, economy and the environment will prevail for all.

Harmless mangrove snake (non-venomous) on hand. Photo by R. Auguste