Scientists discover second ‘super muscle’ in chameleon tongues

Scientists discover second ‘super muscle’ in chameleon tongues

by Alex Negro Science

Scientists have been investigating how chameleons’ tongues can shoot out of their mouths to such an extreme length for as long as anyone can remember. US biologists have now been able to solve another piece of the chameleon tongue puzzle.

In the study, experiments were carried out on 15 Veiled chameleons (Chamaeleo calyptratus). All 15 animals were first anaesthetised using overdosed gas anaesthesia and then killed by decapitation. The four tongue muscles were then dissected out and clamped in measuring devices. The muscles were stimulated with an electric current and the passive/active forces and various muscle lengths were measured. A series of calculations were then carried out and muscles were examined histologically. In addition, embryos previously obtained from eggs were analysed immunohistochemically to determine whether the tongue muscles develop from the same or two different muscle systems.

The results of the study are very interesting and focus primarily on the so-called sarcomeres of the muscles. A sarcomere is the smallest contractile unit of the muscle – i.e. the part that is responsible for the expansion and contraction of the muscles. At both ends of each sarcomere are the so-called intermediate discs (German “Zwischenscheibe”), abbreviated as Z-discs. Transverse striated muscles, i.e. the muscles that move the arms, legs and trunk of a vertebrate, can shorten to about half their resting length. In chameleons, however, there is a very special type of muscle, the so-called supercontracting muscle. By definition, this is a striated muscle that is able to shorten to less than half its resting length. The rectractor of the tongue, the hyoglossus muscle, is just such a muscle. In this muscle, perforated Z-discs on the sarcomeres ensure that it can stretch far better than normal striated muscles.

In the present study, it was found that a second supercontracting muscle is involved in the tongue shot: the sternohyoid superficialis muscle. In its counterpart, the sternohyoid profundus muscle, surprisingly, no perforated Z-discs could be detected at the sarcomeres. However, its length-tension ratio corresponded to the two supercontracting tongue muscles. This could be compensated for by the very broad attachment of the muscle to the hyoid bone. During tongue shooting, these areas of the hyoid bone are rapidly rotated, which could mechanically alter the sarcomeres.

Using immunohistochemistry, the biologists were also able to show in chameleon embryos that the two muscles develop from different origins, which is consistent with the different sarcomeres. Both the hyoglossus muscle and the sternohyoid muscles form a muscular unit, with one of the muscles even extending to the sternum. This means that the maximum length of the chameleon tongue when shooting is not only made possible by the special properties of the tongue muscles, but also by the overall length of the muscular unit. No other vertebrate in the world has ever been found to have two supercontracting muscles.

Feats of supercontractile strength: functional convergence of supercontracting muscle properties among hyoid musculature in chameleons
Nikole G. Schneider, Nicholas A. Henchal, Raul E. Diaz Jr., Christopher V. Anderson
Proceedings B of Royal Society Publishing, 2025
DOI: 10.1098/rspb.2025.0078

Figure: Schematic representation of the tongue muscles and hyoid bone in the Veiled chameleon from the aforementioned publication

Furcifer verrucosus discovered in the stomach of a snake

Furcifer verrucosus discovered in the stomach of a snake

by Alex Negro Beobachtungen Science

Biologists from the University of Michigan (USA) recently made a curious discovery: they analysed a snake of the species Langaha madagascariensis that had been prepared 31 years ago using dissection and microCT. The specimen had been largely untouched in the Zoological Museum of the University of Michigan since 1994. The snake was originally collected by R.A. Nussbaum in the extreme south of Madagascar, not far from Tolagnaro. Little is known about the diet of the leaf-nosed snake, only anecdotal case reports are known. Chameleons have now been added to the list of potential prey: An adult Furcifer verrucosus was found in the stomach of the female leaf-nosed snake examined.

Natural history notes: Langaha madagascariensis (Malagasy leaf-nosed snake)
Andressa L. Viol, Hayley L. Crowell, Justin L. Lee, Tristan D. Schramer
Herpetological Review 55 (2), 2025: 223-226.
DOI: not available

Photo: Furcifer verrucosus, photographed by Nick Newberry, CC BY 4.0

Veiled chameleon distributed over 12 new counties in Florida (USA)

Veiled chameleon distributed over 12 new counties in Florida (USA)

by Alex Negro Verbreitung Science

Introduced Veiled chameleons (Chamaeleo calyptratus) have been living in Florida (USA) since at least 2002. The first wild Veiled chameleons were found in Collier County, two years later animals were observed in Fort Myers in Lee County. This was followed by findings in Hendry, Miamia-Dade, Broward, St. Lucie, Palm Beach, Monroe, Alachua and Hillsborough County. Now an author in the Herpetological Review reports on 12 further populations in Florida: in Brevard, Charlotte, De Soto, Glades, Indian River, Lake, Manatee, Osceola, Pinellas, Polk, Sarasota and Seminole County.

He used data from iNaturalist and EDDMapS. The author suspects that most of the new finds could be due to so-called chameleon ranching. Chameleons are deliberately released into other habitats in order to later collect and sell the resulting juveniles. But even without prior release, collecting (‘harvesting’) animals for sale has become a source of income in Florida, which has also led to the fact that distribution data on new populations is rarely published. It is now a common recreational activity in Florida to search for Veiled chameleons at night. There are even commercial operators offering guided tours.

One problem is increasingly the owners of private property who feel disturbed by ‘chameleon tourism’. The impact on native wildlife in the USA is still unclear. Theoretically, Veiled chameleons could eat smaller mammals or young birds, but there have been no reports of such incidents in Florida to date.

It seems increasingly unlikely that it will be possible to get rid of the introduced Veiled chameleons. A one-year trial in Lake Worth Beach (Palm Beach) resulted in 1043 chameleons being caught during 71 collection campaigns, but not in the elimination of the population living there.

New County Records for the Veiled Chameleon (Chamaeleo calyptratus) in Florida, USA
Kevin M. Enge
Herpetological Review 55 (2), 2025: 223-226.
DOI: not available

Photo: Chamaeleo calyptratus, found and photographed in Fort Myers (USA) by Andrew Durso, CC-BY

New genomes of six chameleon species from Ethiopia

New genomes of six chameleon species from Ethiopia

by Alex Negro Science

A very brief publication by three scientists deals with the genome sequences of reptiles. Wild reptiles from a total of 101 different species were sampled in Ethiopia, Guyana, Mexico and the USA. Unfortunately, the authors do not state exactly how the sampling was carried out and whether whole animals or only tissue samples were taken. DNA was extracted using the Qiagen DNAeasy Kit and Illumina TruSeq kits were used for sequencing.

All genomes were deposited at Genbank. Genomes of one Chamaeleo dilepis (JBHLFC00000000000), one Chamaeleo laevigatus (JBIELG00000000000), one Trioceros affinis (JBHUPM00000000000), one Trioceros balebicornutus (JBHZFU00000000000), one Trioceros harennae (JBHRFO00000000000) and one Chamaeleo gracilis (JBINKK00000000000) were deposited. Several entries of these species already existed in GenBank.

The complete genome sequences of 101 species of reptiles
Timothy J. Colston, Stacy Pirro, R. Alexander Pyron
Biodiversity Genomes, 2025
DOI: 10.56179/001c.129597

Picture: Chamaeleo laevigatus, photographed by John Lyakurwa, Creative Commons Attribution 4.0 International

Chameleons in Marsa El Brega (Lybia)

Chameleons in Marsa El Brega (Lybia)

by Alex Negro Verbreitung Science

While other areas of Africa are regularly the subject of publications and expeditions, the herpetofauna of Libya has not been fully researched. Little is known about the reptiles of the coastal region of Marsa El Brega in particular. Marsa El Brega is located in the north of Libya directly on the Mediterranean Sea and therefore has a Mediterranean climate. The vegetation consists mainly of a desert-like landscape with low shrubs such as Nitraria retusa and small date palm oases in between.

A Hungarian herpetologist has investigated the reptile populations in Marsa El Brega during two expeditions. Unfortunately, the exact procedure for finding animals is not mentioned in the article. All animals found were photographed and species phenotyped according to existing field guides.

The author found a total of 25 reptile species in the Marsa El Brega region, including two Chamaeleo chameleons, one each two days apart. The coordinates given for the find site are in the outskirts of the town of Brega, right next to the garden of a bed’n’breakfast facing the beach. The author cites stray dogs and cats as the greatest potential threat to the local herpetofauna. In addition, the coastal area investigated was heavily littered.

Some reptiles from Marsa El Brega, Libya (Reptilia: Chamaeleonidae, Gekkonidae, Phyllodactylidae, Lacertidae and Scincidae)
Attila Haris
Natura Somogyiensis 45: 17-26, 2025
DOI: 10.24394/NatSom.2025.45.17

The microbiome in the gut of South African dwarf chameleons

The microbiome in the gut of South African dwarf chameleons

by Alex Negro Science

The term microbiome has been on everyone’s lips for some years now. In the intestine, this refers to the entirety of all microorganisms, especially bacteria, that colonise the mucous membrane. Now a group of researchers in South Africa has for the first time studied the gut microbiome in chameleons and how it changes in different habitats.

Three species of dwarf chameleons were searched for at night in the province of KwaZulu Natal with the help of torches: Bradypodion melanocephalum, Bradypodion thamnobates and Bradypodion setaroi. All animals were kept in containers for 24 hours and then released at the site. For each species, 10 buccal swabs and 10 faecal samples were collected in a natural and an urban habitat, resulting in a total of 120 samples. In the laboratory, DNA was extracted from the samples, amplified by PCR and then sequenced. Phylogenetic trees were created and statistical comparisons were made between the samples.

The samples were also analysed for zoonotic pathogens such as salmonella. However, only Campylobacter, Escherichia and Serratia were detected in human pathogens in the faeces. The authors conclude that the zoonotic potential of the microbiome of dwarf chameleons is very low.

In total, almost 350 different bacterial species were detected in the microbiome of the dwarf chameleons, which corresponds to other reptiles such as anoles and turtles. Proteobacteria, Firmicutes and Bacteroidota were most abundant in all samples. Overall, the microbiome was very similar in both buccal swab and faecal samples with only a few exceptions and slightly different depending on the species. The differences in the microbiome between natural and urban habitats were much smaller than expected. The microbiome of the buccal swab of Bradypodion melanocephalum living in urban environments showed more Caulobacteraceae and less Enterococcaceae than that in natural habitats, and Desulfovibrionaceae were more common in the faeces of urban animals. The microbiome of Bradypodion thamnobates showed more Ruminococcaceae and Akkermanisaceae in the faecal samples of urban chameleons. A striking feature of dwarf chameleons is the difference between the microbiota in the mouth and rectum, which has not yet been observed in other vertebrates. It remains to be seen whether chameleons in the animal kingdom have a specialized microbiome that could explain these differences.

Anthropogenic reverberations on the gut microbiome of dwarf chameleons (Bradypodion)
Matthew G. Adair​, Krystal A. Tolley, Bettine Jansen van Vuuren, Jessica Marie da Silva
PeerJ 13, 2025
DOI: 10.7717/peerj.18811

Photo: Bradypodion melanocephalum, photographed by Marius Burger

Namaqua chameleons discovered in Namibe (Angola)

Namaqua chameleons discovered in Namibe (Angola)

by Alex Negro Verbreitung Science

Western Angola has increasingly become the focus of herpetologists in recent years. However, the reptile population of the Iona National Park on the border with Namibia still raises some questions. Whilst searching for the dwarf puff adder Bitis peringueyi, an international research team also found Chamaeleo namaquensis. The survey of reptile populations was carried out in the coastal area, in the sand sea and in the shifting sand dunes of the gravel plains.

A total of 27 reptile species were discovered – although the dwarf puff adder was not among them. Chamaeleo namaquensis was found along the EN100 road about 50 kilometres south of Moçamedes. A second site was found around 10 km north of Salondjmba, the entrance to the Iona National Park in Ponta Albina.

Noteworthy herpetological notes from Naimbe Province, Angola
Javier Lobón-Rovira, Pablo Sierra, Rubén Portas, Pedro Vaz Pinto, Fernando Martínez-Freiría
Herpetology Notes Vol 18: 99-105
DOI: nicht vorhanden

Picture: Daniel S. Katz, Creative Commons Attribution 4.0 International

Utilisation of flap-necked chameleons at urban markets in South Africa

Utilisation of flap-necked chameleons at urban markets in South Africa

by Alex Negro Science

Scientists from the African Amphibian Conservation Research Group have analysed the existing literature on the subject. Fortunate M. Phaka also visited six municipal markets in Durban, Johannesburg, Petermaritzburg, Polokwane and Pretoria. At the markets, he searched for amphibians and reptiles sold for medicinal purposes and the names given to them by the vendors. He was able to interview 11 traditional health practitioners in Limpopo, Gauteng and KwaZulu-Natal in detail, from nine of whom he was allowed to take samples of the amphibians and reptiles sold for species identification.

In total, 33 species of reptiles and one species of amphibian used for traditional medicine were identified. Nine of these were found and identified on site during the market visits. The traditional healers interviewed stated that they had either hunted the animal parts themselves, bought them from hunters or taken them from roadkill. Fat and internal organs are removed, the carcasses are rubbed with ash or salt and dried in the sun. Usually, the healers’ customers do not buy complete carcasses, but only small parts of the reptiles on offer. Of the 111 animal samples taken, sufficient DNA to identify the species was obtained from 90 of them. 23% of the samples tested were incorrectly named by the healers.

Chamaeleo dilepis was among the reptile species utilised. No complete chameleon could be found at the markets visited. At the Warwick Muthi Market in KwaZulu-Natal, however, several reptile parts were sampled which, according to DNA comparisons, came from lobed chameleons. Chameleons in general were not identified to species level by the healers. The IsiZulu word unwabu stands for any chameleon.

Barcoding and traditional health practitioner perspectives are informative to monitor and conserve frogs and reptiles traded for traditional medicine in urban South Africa
Fortunate M. Phaka, Edward C. Netherlands, Maarten Van Steenberge, Erik Verheyen, Gontran Sonet, Jean Hugé, Louis H. du Preez, Maarten P.M. Vanhove
Molecular Ecology Resources Vol 25(2), 2025
DOI: 10.1111/1755-0998.13873

Chamaeleo gracilis in Nechisar (Ethiopia)

Chamaeleo gracilis in Nechisar (Ethiopia)

by Alex Negro Verbreitung Science

Over the last hundred years, humans have reduced Ethiopia’s forest cover from around 40% to just 2.36%. Despite this, little is still known about the country’s herpetological fauna in some places. Scientists from Egypt, the USA and Ethiopia recently carried out a survey study in a national park.

Necisar National Park is located in south-west Ethiopia on the line of the Great Rift Valley, more than 500 kilometres south of the capital Addis Ababa. Necisar covers an area of 514 square kilometres, bordered to the north and south by two lakes, to the east by the Amarao Mountains and to the west by the town of Arbaminch. Nechisar is very hot all year round with very little rainfall.

A total of two expeditions were carried out during the rainy season and two during the dry season. Transects with a total length of 290 km and a width of nine metres were covered, 230 km of which were in grassland and stony terrain, 60 km in the forest and along the lakeshore. In addition to manual searches with the naked eye, small pitfall traps and cover plates were used.

A total of 34 species of reptiles were found, including Chamaeleo gracilis. The species was discovered twice. Both chameleons were found near different rivers, one in the scrubland and one in the forest.

Survey of reptiles in Nechisar National Park, Southern Ethiopia
Samy A. Saber, Fikirte Gebresenbet, Afework Bekele, Eman N. Salama
Russian Journal of Herpetology 31(5): 291-301
DOI: 10.30906/1026-2296-2024-31-5-293-301