Potential new distribution areas of the European chameleon

Potential new distribution areas of the European chameleon

by Alex Laube 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.

Oddity: Use of chameleon powder in Algeria

Oddity: Use of chameleon powder in Algeria

by Alex Laube General topics

Dried bodies of Chamaeleo chamaeleon have always been used in traditional medicine in Algeria. In the El Oued region, extracts and powders from common chameleons are still regularly used today for the therapy of various diseases and various superstitions. An Algerian biochemist has now tried to prove the benefits of chameleon powder in a somewhat curious way.

Allegedly exactly 1000 users of the powder as well as 100 hunters and sellers were questioned for a maximum of 10 to 15 minutes by means of questionnaires or interviews. The evaluation of these was not published. However, the author states that according to the interviews, chameleons are only hunted by “experienced persons”. However, the breeding season is left out, so no damage to the chameleon population is to be feared.

In addition, an unspecified number of wild Chamaeleo chamaeleon were captured and killed in Algeria. The organs were removed, the chameleons washed, salted and dried at 35 to 40°C for over a week. The dried bodies were then washed again and re-dried in an oven at 45°C. The chameleons were then killed using mice. Then the chameleons were ground using a mortar to obtain powder. Dry matter, ph values, protein, carbohydrate, fat, calcium, magnesium, sodium, potassium and ash contents of the powder were examined. A relatively high phosphorus content of 14.01% stood out, and traces of iron, zinc and copper were also detected. A relatively high concentration of vitamin E (19.23 mg/100 g powder) was noticed, as well as vitamin B1 (21 mg/100 g powder). Under laboratory conditions, the powder proved capable of scavenging radicals. Also in the laboratory, the powder as an extract at 100 mg/ml showed some efficacy against various bacteria. In a chicken chorioallantoic membrane (CAM) assay, angiogenesis was tested around a powder disc inserted into a fertilised chicken egg.

Several groups of laboratory rats were treated with carbimazole in the drinking water. Afterwards, one group was freely injected into the abdomen with a solution containing chameleon powder, one group was fed chameleon powder in various mixtures, another was given levothyroxine in the drinking water, another nothing at all and a final group was injected with water in the abdomen. After the experimental period, blood was taken and then all the rats were killed and dissected. The rats showed no reaction to the chameleon powder, while treatment with levothyroxine, not surprisingly, resulted in various changes in blood count and blood chemistry.

The author interestingly concludes from all these experiments that the use of dried chameleon powder is safe for use in humans and can treat tonsillitis, coughs, skin diseases such as vitiligo, scorpion stings, urinary tract infections, leukaemia (!) as well as thyroid diseases. However, none of his studies provides any proof of this and so this “study” remains more of an absurd curiosity.

Physicochemical composition and evaluation of biological activities of Chamaeleo chamaeleon
Ouafa Boudebia
Thesis TD571/007/01 der Universität von Eloued, 2023
DOI:  none

Genetics: Karyotype in the Veiled Chameleon

Genetics: Karyotype in the Veiled Chameleon

by Alex Laube Science

It has been known for some time that the sex of the Veiled chameleon (Chamaeleo calyptratus) is genetically determined. The species has an XX/XY system. Scientists from Russia, Great Britain, Italy, and Thailand have now studied the karyotype of the species, i.e. the characteristics of the chromosomes.

The probably most original karyotype of all chameleons is 2n= 36. This “primal chameleon” had six pairs of metacentric macrochromosomes and twelve pairs of microchromosomes, particularly small chromosomes. The Veiled chameleon, on the other hand, has a smaller number of chromosomes, namely only 2n=24. Using various genetic investigation methods, the researchers in the present study found that this karyotype probably arose through fusions. Microchromosomes apparently fused with each other twice, and micro- and macrochromosomes fused no less than four times. The latter, the so-called heterogeneous fusion between chromosomes of different sizes, is unusual for vertebrates. Normally, macro- and microchromosomes are located at different locations in the cell nucleus and are transcribed and replicated at different rates. However, this phenomenon is already known from alligators and turtles – for chameleons it is new.

Until now, it was also unclear which pair of chromosomes in the Veiled chameleon is actually responsible for the sex. In Chamaeleo chamaeleon, the second largest chromosome pair codes for sex. However, initial speculation suggests that in the Veiled chameleon the fifth chromosome pair (CCA5) may instead be the sex chromosome pair. The conjecture still needs to be validated by further research. It is also still up for discussion which gene is actually predominantly responsible for the development of the sex organs in the embryo – the researchers identified at least three possible genes on CCA5.

Identification of Iguania ancestral syntenic blocks and putative sex chromosomes in the Veiled Chameleon (Chamaeleo calyptratus, Chamaeleonidae, Iguania)
Katerina V. Tishakova, Dmitry Yu. Prokopov, Guzel I. Davletshina, Alexander V. Rumyantsev, Patricia C. M. O’Brien, Malcolm A. Ferguson-Smith, Massimo Giovannotti, Artem P. Lisachov, Vladimir A. Trifonov
International Journal of Molecular Sciences 23, December 2022
DOI: 10.3390/ijms232415838