Mosquito bites may induce skin colour change

Mosquito bites may induce skin colour change

Tiermedizin Science

Sometimes science starts small: last year, someone posted a photo of a Calumma globifer with a mosquito sitting on it on the online platform iNaturalist. Right there you could see a black discoloration of the scales. I wonder if there was a connection?

A handful of curious people searched for more photos of mosquitoes on chameleons and found what they were looking for: On Facebook there were some of Veiled chameleons, on iNaturalist more of Furcifer minor and Furcifer nicosiai. However, there were also six observations of mosquitoes on chameleons that did not appear to have black spots.

To test the connection, scientists in Madagascar placed two Furcifer oustaleti and four carpet chameleons alone in an enclosure with 25 female Asian tiger mosquitoes (Aedes albopictus), which had not been fed for 24 hours beforehand. At the same time, all six chameleons were pricked in the skin with a needle to test whether this “trauma” would also trigger a color change in the skin. The results were surprising: in the four Furcifer lateralis, numerous black skin discolorations developed after mosquito bites, in the two Furcifer outaleti not a single one. The punctures with the needle remained without consequences in all six.

The authors of the recently published article propose three possible theories as to how the color change in the chameleon’s skin could come about: The mosquito saliva could contain a type of local anesthetic, nitric oxide or other proteins that cause the skin’s melanophores to become exclusively visible. Further research in this field would certainly be exciting!

Mosqito bite-induced color change in chameleon skin
Pablo Garcia, Raul E. Diaz Junior, Christopher V. Anderson, Tovo M. Andrianjafy, Len de Beer, Devin A. Edmonds, Ryan M. Carney
Herpetological Review 54(3), 2023, pp.353-358

Chameleons in Bobaomby (Madagascar)

Chameleons in Bobaomby (Madagascar)

Verbreitung Science

The Bobaomby complex is located at the northernmost tip of Madagascar, north and west of the largest coastal town in the north, Antsiranana (Diego Suarez in French). It consists of dry forest at sea level up to a maximum of 200 metres above sea level as well as extensive savannahs on karst rock and various rock formations. The area has not been protected to date.

Scientists from Madagascar conducted reptile counts in the Bobaomby complex in 2018. The counts were carried out in February and March, i.e. during the rainy season. Five different locations were analysed: Beantely, Antsisikala and Ambanililabe as examples of varying degrees of degraded dry forest, Anjiabe for its intact dry forest and Ampombofofo with relatively intact forest. To find animals, the visual survey was used on 25 days during the day and at night in selected transects, sometimes specifically in suitable habitats such as leaf axils or under dead tree trunks, and pitfall traps along erected fences were also used.

A total of 42 reptile species have been recorded. All of them, except one gecko species, originally only occur on Madagascar, while two other gecko species are now also found on neighbouring islands. There is a small novelty among the chameleons: the leaf chameleon Brookesia ebenaui was recorded for the first time in Bobaomby, more precisely in Beantely. Brookesia stumpffi and Furcifer petteri were found in Beantely, Anjiabe and Ampombofofo. Furcifer pardalis and Furcifer oustaleti occurred as expected throughout the whole Bobaomby complex.

The authors suggest that the Bobaomby complex – especially the three forests where most of the reptiles were found – should be protected to preserve the local herpetofauna.

Overview of reptile diversity from Bobaomby complex, northern tip of Madagascar
Randriamialisoa, Raphali R. Andriantsimanarilafy, Alain J. Rakotondrina, Josué A. Rakotoarisoa, Nasaina T. Ranaivoson, Jeanneney Rabearivony, Achille P. Raselimanana
Animals 13: 3396, 2023
DOI:  10.3390/ani13213396

Photo: Furcifer petteri, male, in the north of Madagascar, photographed by Alex Laube

Chameleons in the Montagne des Français (Madagascar)

Chameleons in the Montagne des Français (Madagascar)

Verbreitung Science

The Montagne des Français is a limestone massif with dry forest in northern Madagascar. It reaches up to 425 m above sea level and is within sight of the largest coastal town in the north, Antsiranana (French Diego Suarez). It has been a protected area since 2007. Scientists from Madagascar and the USA conducted counts of reptiles and amphibians in the Montagne des Français in 2014 and 2020.

Counts were made in January and May, i.e. during and at the end of the rainy season. In 2014, the focus was on the region around Andavakoera, while in 2020 it was on Sahabedara, Ampitiliantsambo, and Andavakoera. In order to find animals, the search was conducted during the day and at night along predefined paths, partly in suitable habitats, and partly in pitfall pits.

A total of 20 amphibian and 50 reptile species were recorded. Four new amphibians and one reptile were found for the first time in the Montagne des Français. The snake Langaha pseudoalluaudi was discovered again for the first time since 2007. Among the chameleons, there were minor new discoveries. Brookesia stumpffi could only be found in 2014, but no longer in 2020 – however, due to the relatively wide distribution of the species, this should not be a problem for the entire population. Brookesia tristis, one of the smallest chameleons in the world, was also only seen in 2014. Here, the body size, which makes it very difficult to find, and the time of year (May is relatively late for this species) could play a role. Brookesia ebenaui was detected in Andavakoera in 2014 and in Sahabedara in 2020. The two tree dwellers Furcifer oustaleti and Furcifer pardalis were found in both years in Andavakoera and Ampitiliantsambo. Furcifer petteri, on the other hand, was present at all the sites surveyed in both years.

Amphibians and reptiles of the “Montagne des Français”: Update of the distribution and regional endemicity
Herizo Oninjatovo Radonirina, Bernard Randriamahatantsoa, Rabibisoa Harinelina Christian Nirhy, Christopher J. Raxworthy
Preprint
DOI: 10.20944/preprints202306.1499.v1

Photo: Furcifer petteri on Madagascar, photographed by A. Laube

Introduced chameleons in Florida

Introduced chameleons in Florida

Science

The “Sunshine State” Florida in the southeast of the USA has long been known for a variety of introduced reptiles. Students at the University of Florida recently published a small brochure on the current status of chameleon species introduced there.

As early as the late 1800s, a non-native reptile was documented to have found its way to Florida by ship: an anole. Since then, some 150 introduced species have been documented in the US state, including eight species of chameleons. Three of them are now spread over the entire southern half of the peninsula and even reproduce: the Yemen chameleon Chamaeleo calyptratus, the Malagasy Giant chameleon Furcifer oustaleti, and the panther chameleon Furcifer pardalis.

Current known distribution of Panther, Veiled, and Malagasy Giant Chameleons in Florida.

All three species are thought to have come into the country with increasing pet trade and private keeping of chameleons. Furcifer oustaleti has been in Florida since at least the year 2000. At that time, the first findings became known in an avocado plantation located in the immediate vicinity of the buildings of a former importer in Miami – Dade County. Chamaeleo calyptratus was first recorded in Fort Myers on a vacant lot only a little later, in 2002. Furcifer pardalis followed in 2008.

The question of whether any of the three species mentioned should be considered invasive is difficult to answer so far due to a lack of data. A species is considered invasive if it is non-native, has been introduced by humans, and has been proven to cause damage to native flora and fauna. The last point, however, is debatable. While Jackson’s chameleons in Hawaii have been shown to consume endangered native snail species, among others, the same is not yet known from Florida. There, the animals are currently considered more of a nuisance, but with the potential to threaten the native invertebrate fauna.

The problem is that chameleons are still being released – sometimes they escape unintentionally, but sometimes they are deliberately released in order to collect and sell the offspring later. For the latter, you need a permit in Florida. Interesting to note: Anyone is allowed to kill introduced chameleons on their own property “in a humane way”. In some places, chameleons are already being collected to be sold to private owners.

The students call for observations of chameleons in Florida to be reported on the internet via IveGot1.org or via the app of the same name. So far, not all populations are known, as much information is only passed on by hand. Furthermore, they ask that chameleons that have become a nuisance should not be abandoned, but handed into the Exotic Pet Amnesty Program of the Florida Fish and Wildlife Conservation Commission. The surrender there is free of charge, and the EPAP is ultimately looking for new keepers for the animals.

Florida’s introduced reptiles: Veiled Chameleon (Chamaeleo calyptratus), Oustalet’s chameleon (Furcifer oustaleti), and panther chameleon (Furcifer pardalis)
Max Maddox, Karissa Beloyan, Natalie M. Claunch, Steve A. Johnson
Veröffentlichung des Wildlife Ecology and Conservation Department, Universität of Florida
DOI: 10.32473/edis-UW501-2022