The population of Furcifer labordi in Andranomena (Madagascar)

The population of Furcifer labordi in Andranomena (Madagascar)

by Alex Negro Science

After we already discussed a preprint on the habitat of the Labordes chameleon (Furcifer labordi) in Andranomena, Madagascar, last year, the final publication now followed after a long peer review. In fact, the focus of the paper was reconsidered and adapted.

Labordes chameleon (Furcifer labordi) has been known for several years as the world’s shortest-lived chameleon. Five scientists from Madagascar have recently investigated which factors influence the distribution and population size of the species. The study was carried out in the Andranomena Special Reserve, which is located around 30 kilometres north of the coastal town of Morondava in western Madagascar. The special reserve has various habitats used by the chameleons, such as intact dry forest with parts near and far from water as well as regrowing / heavily modified forest.

Distance sampling was used to estimate the population density of Furcifer labordi. For this purpose, each part of the forest was divided into three 50 metre transects over a width of 150 metres. At night, the chameleons were then searched for with a torch, their location measured and the animals themselves marked in colour with nail varnish. Faecal samples were collected and analysed. The following day, a 5 x 5 metre plot was marked around each site and at least 5 metres away along the transect line. In all plots, the degree of canopy cover in per cent, the thickness of the foliage layer on the ground and ground-covering plants in centimetres, the number of shrubs up to 1 m, the number of trees over 1 m and the number of felled and burnt trees were counted. Five days after the first count, chameleons were again searched for and counted at night. In addition, insects were counted and identified using light traps. Along a 1400 metre transect, observations of six species of birds of prey and four species of snakes were also counted as examples. Unfortunately, the exact species are no longer named.

Statistical analyses showed that more Furcifer labordi were found in forest sections where the canopy was denser, the foliage layer on the ground was thicker and there were more trees overall. In the parts of the forest where no chameleons were found at all, significantly more felled trees were counted. The predators observed or their presence did not appear to have any influence on the population density of the chameleons. Surprisingly, the suspected feeders present, mostly insects, also showed no effect on the distribution of the chameleon population. The height of the branches on which Furcifer labordi were found varied greatly over the observation period. However, no correlation was found between age and sex. Preferences in the choice of plants used could not be observed in the chameleons. Furthermore, the different age groups showed no clear preference in their choice of microhabitat.

The authors conclude that the declining population size is primarily due to habitat loss. Habitat loss in Andanomena is almost exclusively of human origin (deforestation for agriculture and cattle grazing, slash-and-burn).

Analyses spatiales de population de Furcifer labordi (Grandidier, 1972) dans la Réserve Spéciale d’Andranomena, Morondava-Madagascar
Philibertin Honoré Djadagna Ahy Nirindrainiarivony, Achille Philippe Raselimanana, Lily-Arison René de Roland, Willy Nathoo Veriza, Daudet Andriafidison
European Scientific Journal 20 (15), 2024,
DOI: 10.19044/esj.2024.v20n15p48
Informations about the preprint

The flap-necked chameleon on Serra da Neve (Angola)

The flap-necked chameleon on Serra da Neve (Angola)

by Alex Negro Verbreitung Science

The Serra da Neve inselberg is located in the province of Namibe in south-west Angola on the south-western edge of Africa. At 2489 metres above sea level, it is the second highest mountain in the country. The isolated location in the middle of savannahs makes the inselberg a refuge for biodiversity, but this has so far been poorly researched concerning herps. Scientists from the USA, Portugal and Germany have recently carried out a first survey study to inventory the amphibians and reptiles of the Serra da Neve.

Three expeditions have been carried out since 2016, each lasting a few days. Eight areas were selected to search for animals, including rocky areas as well as forest, open grassland and various altitudes. Pitfall traps, snares, rubber bands and manual searches by day and night were used to find the animals. The individuals found were all killed and prepared for storage and further examination in the museum.

A total of 59 species of reptiles and amphibians were found on the inselberg. Chamaeleo dilepis was found exclusively around the village of Catchi, located at 1590 metres. The village is surrounded by granite rocks and the Miombo forest area, which is dominated by Brachystegia and Julbernardia trees. The flat parts of the plateau surrounding the village are largely deforested. The land is used for grazing cattle or for growing cereals and maize. However, the steep slopes around the village are still forested. A small river also runs through the plateau.

An island in a sea of sand: A first checklist of the herpetofauna of the Serra da Neve inselberg, southwestern Angola
Mariana P. Marques, Diogo Parrinha, Manuel Lopes-Lima, Arthur Tiutenko, Aaron M. Bauer, Luis M. P. Ceríaco
ZooKeys 1201, 2024: pp. 167-217.
DOI: 10.3897/zookeys.1201.120750

Photo: taken from the aforementioned publication

Phylogenetics of African dwarf chameleons

Phylogenetics of African dwarf chameleons

by Alex Negro Science

The archives of museums and other zoological collections still contain a lot of single-gene fragment data. Although it is now relatively easy to decode entire genomes and prepare material for storage, this was not the case for a long time. Scientists at the University of Johannesburg (South Africa) have now investigated whether and, if so, which components of these single genes in dwarf chameleons can provide information on the entire genome with regard to the creation of phylogenetic family trees.

Samples were taken from 44 dwarf chameleons in the form of cut-off tail tips during various expeditions between 2010 and 2022. The sampled animals were captured and released in the Eastern Cape, KwaZulu-Natal, Limpopo, Mpumalanga, Northern Cape and Western Cape provinces. They belonged to the species Bradypodion barbatulum, caeruleogula, caffrum, damaranum, gutturale, melanocephalum, ngomeense, occidentale, pumilum, setaroi, taeniabronchum, thamnobates, transvaalense, ventrale, venustum as well as candidate species from Greytown, Kamberg. Karkloof Forest and Gilboa Forest in KwaZulu-Natal. An existing mitogenome of a Chamaeleo chamaeleon was used as a reference genome. In addition, the mitogenomes of seven other genera were loaded from GenBank for comparison.

DNA was extracted from all samples and phylogenetically analysed using Geneious Prime and IQ-Tree, among others. A total of 22 different alignments were created: a complete mitogenome alignment (without tRNA), 15 alignments of individual loci, the short fragment of 16S, a frequently used COI fragment, a concatenation of 16S fragment with ND2, a concatenation of ND2 and ND5, a concatenation of the two ribosomal subunits and a concatenation of all protein-coding genes (PCG). A statistical analysis of the data followed.

The results showed that the complete mitogenome topology is largely consistent with the previously published phylogenies of African dwarf chameleons from ND2-16S concatenations. The phylogeny based on the ND2 fragments proved to be more stable and even closer to the mitogenome. These gene fragments are therefore well suited to phylogenetically classify a genome and thus a chameleon species. However, there were also a few differences to the previously published phylogenies. The mitogenome topology considers Bradypodion setaroi and Bradypodion caffrum to be sister taxa. Furthermore, Bradypodion ngomeense possibly belongs genetically to the Bradypodion transvaalense clade instead of being a sister taxon of it.

The efficacy of single mitochondrial genes at reconciling the complete mitogenome phylogeny – a case study on dwarf chameleons
Devon C. Main, Jody M. Taft, Anthony J. Geneva, Bettine Jansen van Vuuren, Krystal A. Tolley
PeerJ 12:e17076, 2024
DOI: 10.7717/peerj.17076

Picture: Bradypodion transvaalense, photographed by Ryan van Huyssteen, Creative Commons Attribution-Share Alike 4.0 International

Five new Rhampholeon species

Five new Rhampholeon species

by Alex Negro Neubeschreibungen Science

There is still a lot to discover about the small, brown pygmy chameleons on the African mainland. After new species were discovered in the Rhampholeon uluguruensis/moyeri complex in Tanzania two years ago, international scientists have now taken a closer look at the Rhampholeon boulengeri complex. And as expected, new species have been discovered!

The pygmy chameleons from this complex inhabit various habitats along the Albertine Rif). This 6000 km long chain of mountains and rifts stretches from Lake Albert in Uganda to Lake Tanganyika. It crosses the Democratic Republic of Congo, Rwanda, Burundi and Tanzania. In the genus Rhampholeon, the species hardly differ externally, but often live in very different habitats or can be easily distinguished from each other genetically. The authors analysed over 130 pygmy chameleons from more than 20 different locations as well as the lectotypes (the holotype no longer exists) of the species Rhampholeon boulengeri. Using genetic analyses, they were able to identify five new Rhampholeon species.

The already known species Rhampholeon boulengeri, described by Grauer in 1908, occurs exclusively in its type locality according to the current data. This is the Itombwe Plateau in the Democratic Republic of Congo, at altitudes between 2100 and 2470 metres.

Rhampholeon plumptrei was named in honour of the English zoologist Andrew Plumptre. As chairman of the Wildlife Conservation Society, he has been campaigning for species conservation along the African Rift Valley for almost 20 years. The species lives in montane and submontane rainforest at altitudes of 1203-2269 metres, although they are most commonly found at 1200 to 1700 metres. The distribution ranges from the east of the Democratic Republic of Congo with the Kahuzi-Biega National Park to the west of Kenya to the Kakamega Forest National Reserve. In between, Rhampoleon plumptrei can be found in Bwindi Impenetrable National Park, in Mabira and in Kalinzu Central Forest Reserve in western Uganda. It has a clearly visible nasal appendage and a slightly shorter tail than Rhampholeon boulengeri. Rhampholeon plumptrei grows up to 60 mm in size. The males have a white colouration on the throat and belly and one or two diagonal dark stripes on the body. Most chameleons of this species have a dark-coloured tubercle on the back of the neck.

Rhampholeon nalubaale was named after the Luganda word for ‘goddess’, which is also the native name of Lake Victoria, the largest lake in Africa. So far, only the females of this species are known, males have not yet been found. Rhampholeon nalubaale occurs in submontane rainforest at altitudes of 513 to 1506 metres. It is most common in the Kibale National Park in Uganda, but can also be found in the Budungo Central Forest Reserve in the same country and in the Kahuzi-Biega National Park and the Itombwe Natural Reserve in the Democratic Republic of Congo. Rhampholeon nalubaale grows up to 56 mm long. One of the animals found was illuminated with UV light and some of the tubercles in the face fluoresced blue, as is already known from other chameleons – but this is new for the genus Rhampholeon. The species occurs together with Trioceros johnstoni and Kinyongia tolleyae.

Rhampholeon bombayi was named after the waYao explorer Sidi Mubarak Bombay. He was born in 1820 on the border between Tanzania and Mozambique and was sold to India as a slave at an early age. He later returned to Africa and made a name for himself on expeditions by British explorers in East Africa. Rhampholeon bombayi grows up to 55 mm long. It lives in montane forests at altitudes of 1450 to 2330 metres in Rwanda and the Democratic Republic of Congo. It has so far been recorded in Kahuzi-Biega National Park, Kabobo Natural Reserve, Itombwe Natural Reserve and Nyungwe Forest National Park. Trioceros johnstoni and Trioceros schoutedeni also live in the same forest. The animals have two or three dark lines diagonally on the body, the tail and extremities are often darker brown than the trunk.

Rhampholeon msitugrabensis was named after the Albertine Rift. The Swahili word for forest, msitu, and the German word for rift, Graben, were combined. This ground chameleon grows up to 49 mm in size. It inhabits forest edges near Mpishi close to Kibira National Park in Burundi. Rhampholeon msitugrabensis is also described from Mount Bigugu in Nyungwe Forest National Park in Rwanda, so that its occurrence extends from 1986 to 2699 metres. In the Nyungwe Forest, Rhampholeon msitugrabensis occurs allopatrically with Rhampholeon bombayi, more precisely in the Kamiranzovu swamp area at 2000 to 2330 m altitude. Other chameleons that share a habitat with Rhampholeon msitugrabensis are Trioceros ellioti, Chamaeleo dilepis and Kinyongia rugegensis.

Rhampholeon monteslunae was named after its habitat, the Rwenzori Mountains on the border of the Democratic Republic of the Congo and Uganda. This mountain range, where the Nile rises, was described by Ptolemy as ‘Lunae Montes’ as early as 150 AD. Rhampholeon monteslunae occurs at altitudes of 1655 to 2360 metres and is most common in the Rwenzori Mountains National Park near the entrance to Nyakalengija. Another population can be found in the Bururi Forest Nature Reserve in Burundi. This ground chameleon grows up to 47 mm long. Kinyongia carpenteri, Kinyongia xenorhina, Kinyongia tolleyae, Trioceros ellioti, Trioceros johnstoni and Trioceros rudis are also found in the same forests.

Taxonomy of the Rhampholeon boulengeri Complex (Sauria: Chamaeleonidae): Five new species from central Africa’s Albertine Rift
Daniel F. Hughes, Mathias Behangana, Wilber Lukwago, Michele Menegon, J. Maximilian Dehling, Philipp Wagner, Colin R. Tilbury, Trisan South, Chifundera Kusamba, Eli Greenbaum
Zootaxa Vol. 5458 4, 2024, pp. 451-494
DOI: 10.11646/zootaxa.5458.4.1

Photo: From top left to bottom right Rhampholeon boulengeri, Rhampholeon plumptrei, Rhampholeon nalubaale, Rhampholeon bombayi, Rhampholeon msitugrabensis und Rhampholeon monteslunae from the mentioned publication

New data on the international trade in chameleons

New data on the international trade in chameleons

by Alex Negro Science

Researchers from several universities recently analysed the international trade in chameleons. The focus was on Tanzania in East Africa. Tanzania is currently home to 41 of the 228 known species, making it the country with the second-highest number of chameleon species after Madagascar.

The study was based on the publicly accessible CITES trade database and the annual reports of the countries participating in the Washington Convention on International Trade in Endangered Species of Wild Fauna and Flora. Chameleons exported for scientific or non-commercial purposes were excluded. In addition, the most frequently clicked websites on the Internet in the form of English-language sales platforms, social media and forums were searched for sale and purchase adverts for chameleons using Google and “[species] for sale”. A total of 14 websites of commercial sellers, two online forums, two advertising websites, four social media sites and seven closed groups in social media were analysed. As a third pillar of the study, villagers in the Eastern Arc Mountains in Tanzania were interviewed using a questionnaire with eleven questions.

The general result of the study is that the international trade in chameleons fell rapidly between 2000 and 2019. At the same time, the number of chameleons bred in captivity increased. The number of “ranched” chameleons, i.e. chameleons bred on a farm in the country of origin for export, fell slightly. The largest export factor was commercial trade, with almost all species being exported directly from their countries of origin and not via other intermediaries in other countries. From 2000 to 2019, a total of 327,522 chameleons were legally traded. Only six countries accounted for 91% of exports: Tanzania, Madagascar, Mozambique, Uganda, Ghana and Cameroon. Tanzania was the country from which the most chameleons were traded, accounting for 34% of all exports. The country to which most chameleon exports went was the USA with 46%. The USA thus received almost half of all chameleons traded under CITES worldwide between 2000 and 2019. Other countries with relatively high numbers of chameleon imports were Japan (13%) and Germany (10%).

Six chameleon species from Tanzania were particularly sought after. Together they accounted for 85% of the trade in chameleons in the period mentioned. Kinyongia fischeri and Kinyongia tavetana were exported most frequently, followed by Trioceros werneri, Trioceros deremensis and Trioceros fuelleborni. Of the 42 species occurring in Tanzania, 35 were found for sale on online platforms and 29 were regularly on sales lists.

The on-site surveys in Tanzania revealed that only two out of three mountain ranges observed had participated in the trade in chameleons (East Usambara and Uluguru). As Tanzania has suspended its exports indefinitely since 2016, the majority of respondents stated that there is currently no longer any trade in chameleons. Interestingly, the villagers stated that they had collected 13 species for trade, but 7 of these species never appeared on the official exports for Tanzania. The answers to the question of how many chameleons of which species were traded also differed significantly from the official figures in the perception of the local population: While locals reported “thousands” of chameleons with one horn as supposedly collected annually, only very isolated ones of these were actually exported. There may also be a strong divergence here due to a lack of species differentiation.

Trade routes in Tanzania could be traced quite well through the interviews. In general, traders from Muheza and Morogoro came to the Usambaa and Uluguru mountains and gave the villagers a desired number of certain species (selected according to “one horn, two horns, three horns or giant”). A time limit was set, after which the traders returned and transported the collected chameleons to Dar es Salaam for export. One trader was questioned more intensively and stated that his father had already traded in chameleons. He had also never seen a collection permit, even though his clients always emphasised that they had one. The middlemen and collectors had no interest in what the collected chameleons were to be used for, only what was paid for them. Even a middleman only received 0.4 US dollars per chameleon.

Status and trends in the international wildlife trade in Chameleons with a focus on Tanzania
Maxim Conrad Isaac, Neil D. Burgess, Oliver J.S. Tallowin, Alyson T. Pavitt, Reuben M. J. Kadigi, Claire Ract
PLoS ONE 19(5), 2024.
DOI: 10.1371

Picture: Kinygonia tavetana, photographed by Elizabeth Dougherty, Creative Commons Attribution 4.0 International

Chameleons as prey of Compsophis infralineatus

Chameleons as prey of Compsophis infralineatus

by Alex Negro Beobachtungen Science

Some interesting observations were recently made in central eastern Madagascar. Two snakes of the species Compsophis infralineatus were observed trying to devour chameleons as prey. Overall, not much is known about these snakes, but they were long thought to be primarily frog and egg eaters. An observation from 2018 already reports an attempt by another Compsophis species to eat a chameleon, which was regurgitated.

The current observations were made in the private rainforest of Vallombre Natiora near Mandraka. During night walks, an adult Compsophis infralineatus was discovered eating an adult Calumma gastrotaenia. The entire process of consumption was not observed, the snake had disappeared on return to the site, as had the chameleon. The authors assume that the chameleon was successfully devoured. On the same night, another snake of the same species was seen attempting to eat an adult Calumma crypticum. The chameleon was still alive and tried to free itself from the snake’s coils, but seemed unsuccessful first. Later, the same snake was seen again, hanging with its mouth in the back of the chameleon, which was apparently still alive but no with the snake wrapped around it. In the photo, it appears that the chameleon is still alive.

Predation on the chameleons Calummy crypticum Raxworthy and Nussbaum, 2006 and C. gastrotaenia (Boulenger, 1888) by the snake Compsophis infralineatus (Günther 1882) near Mandaka, Madagascar
Devin A. Edmonds and Samina S. Sam-Edmonds
Herpetology Notes (17), 2024: pp. 327-328
DOI:  not available

Picture: from the above-mentioned publication, CC BY-NC-ND 4.0

Sex chromosomes in chameleons

Sex chromosomes in chameleons

by Alex Negro Science

Which sex chromosomes are present in chameleons has so far been studied rather sparsely. The Madagascan chameleon genus Furcifer is known to have Z and W chromosomes, although sometimes several Z chromosomes occur, so-called neo-sex chromosomes. Recently in the Czech Republic, scientists examined this deeper.

Blood and tissue samples were taken from 13 chameleons to isolate DNA. The animals sampled included one male and one female each of the species Brookesia therezieni, Calumma glawi, Calumma parsonii, Chamaeleo calyptratus, Furcifer campani, Furcifer labordi, Furcifer lateralis, Furcifer oustaleti, Furcifer pardalis, Furcifer rhinoceratus, Furcifer viridis, Kinyongia boehmei and Trioceros johnstoni. Only in Furcifer oustaleti were two females sampled. Subsequently, the Z1 chromosomes of the panther chameleons and the Z and W chromosomes were analysed by microdissection. Gene coverage analyses were performed for carpet and panther chameleons. In addition, qPCRs were performed to compare the homology of the Z chromosomes.

The results show that the morphology of the Z1 chromosomes of panther chameleons corresponds to the Z chromosome of the entire genus Furcifer. The Z1 chromosome of panther chameleons thus corresponds to the Z chromosome of Furcifer oustaleti. The Z2 chromosome of panther chameleons, on the other hand, is a neo-sex chromosome. Both the Z and W chromosomes in Furcifer oustaleti are probably pseudautosomal. 42 genes have been described as specific for the W chromosome.

A total of 16,947 genes were identified in Furcifer lateralis and 16,909 genes in Furcifer pardalis. The ratio of the number of genes between females and males is 0.35 and 0.65 for the two species. In panther and carpet chameleons, most of the genes on the W and Z chromosomes were found to be the same, with relatively few genes found only on the W chromosome. This finding is surprising, as the researchers had actually expected that the heterochromatic W in Furcifer species would have lost most of its genes compared to the Z chromosome.

The sex chromosomes of the genus Furcifer probably evolved at least 20 million years ago, which roughly corresponds to the time when the species Furcifer campani split off from the other Furcifer species.

Heteromorphic ZZ/ZW sex chromosomes sharing gene content with mammalian XX/XY are conserved in Madagascan chameleons of the genus Furcifer
Michail Rovatsos, Sofia Mazzoleni, Barbora Augstenová, Marie Altmanová, Petr Velenský, Frank Glaw, Antonio Sanchez, Lukáš Kratochvíl
Scientific Reports 14, 2024: 4898.
DOI: 10.1038/s41598-024-55431-9

Potential new distribution areas of the European chameleon

Potential new distribution areas of the European chameleon

by Alex Negro Verbreitung Science

The European chameleon (Chamaeleo chameleon) was historically found in some small areas of the Mediterranean and Central Asia. Today, however, it is much more widespread. It is now assumed that the animals were brought to their new distribution areas by humans and were able to reproduce there due to the favourable climatic conditions. Scientists have now investigated where there are further suitable habitats for the European chameleon and how the existing populations could develop over the next 50 years.

The three subspecies studied were Chamaeleo chamaeleon chamaeleon, Chamaeleo chamaeleon musae and Chamaeleo chamaeleon reticrista. The former is known from the southern edge of Portgual and Spain as well as from southern Italy, Algeria, Egypt, Libya, Malta, Morocco, Tunisia, the western Sahara and Yemen. The second subspecies is currently found in Jordan, Israel and Egypt. The third subspecies occurs between Greece and Turkey, in Cyprus, Israel, Lebanon and Syria, but is actually native to northern Africa and the Middle East. It was probably introduced by people in southern Spain and Portgual, but is now considered a native species there.

For the study, the existing literature, sampling by the author himself, OpenStreetMaps and information from the Global Biodiversity Information Facility (GBIF) were used, statistically processed and analysed. Climate, topography, habitat of the sites and connections of existing populations were used to predict potentially suitable new habitats.

A total of 553 Chamaeleo chamaeleon findings were included in the study. 22% of the finds could be assigned to urban areas, 21% to scrubland and 18% to agricultural land. Most of the finds were made at altitudes of 0 to 100 metres above sea level. Not surprisingly, the areas currently colonised by Chamaeleo chamaeleon proved to be very suitable habitat. Potential well-suited new distribution areas in the future could be the Iberian Islands between Murcia and the Algarve in Portugal, Sicily, Calabria, Apulia and Sardinia in Italy, Morocco, Tunisia, Libya, the region between Israel and Lebanon in the Middle East, Cyprus and all coasts and islands of the Aegean Sea. Overall, a progressive increase in all existing habitats of the European chameleon is expected over the next 50 years. The only exceptions to this are probably some regions in Tunisia and Turkey. Further habitat losses are assumed on the Aegean coast in Turkey and Israel. In Spain and Portgual, the distribution area could shift westwards.

Habitat suitability and connectivity modelling predict a latitudinal-driven expansion in the Mediterranean basin for a historically introduced reptile
Davide Serva, Viviana Cittadino, Ilaria Bernabò, Maurizio Biondi, Mattia Iannella
European Journal of Wildlife Resarch 70 (27), 2024
DOI: 10.1007/s10344-024-01780-9

The two graphics are both from the publication mentioned.

New hope for Calumma tarzan

New hope for Calumma tarzan

by Alex Negro Verbreitung Science

Calumma tarzan, the Tarzan chameleon, was only described in 2010. It was named after the place where it was found, Tarzanville, a small village in the Anosibe An’Ala region in the centre-east of Madagascar. Due to the previously assumed very small distribution area, the species was immediately classified as “critically endangered” on the IUCN Red List.

In 2020 and 2021, Malagasy scientists searched for the species in many other places in eastern Madagascar – and promptly found it, as a recent publication reports. They searched 46 transects, each one kilometre long, in 23 different forest fragments. A further 28 transects, each 200 metres long, were examined in order to assess the population density. Calumma tarzan was found in 14 of the 23 forest fragments analysed. None of these occurrences were previously known. The species occurred at altitudes of 604 to 1048 metres. Population density estimates varied greatly. In some areas there are only 25 chameleons per hectare, in others more than three times as many, namely 78.

Only a few of the forest fragments are currently protected. This study therefore emphasises how urgent it is to establish further protected areas in Madagascar’s eastern rainforests. This is the only way to save the Tarzan chameleon.

New distribution records and population density of the critically endangered Tarzan chameleon (Calumma tarzan), eastern Madagascar
Alain J.V. Rakotondrina, Raphali R. Andriantsimanarilafy, Hanta J. Razafimanahaka, Achille P. Raselimanana, Rikki Gumbs, Caleb Ofori-Boateng, Jody M. Taft, Fanomezana M. Ratsoavina
African Journal of Herpetology, 2024
DOI: 10.1080/21564574.2023.2291358

Mosquito bites may induce skin colour change

Mosquito bites may induce skin colour change

by Alex Negro 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