Central African armored crocodile

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Central African armored crocodile
Central African armored crocodile (on a snake farm in Tanzania)

Central African armored crocodile
(on a snake farm in Tanzania)

Systematics
without rank: Sauropsida
without rank: Archosauria
Order : Crocodiles (crocodylia)
Family : Real crocodiles (Crocodylidae)
Genre : Mecistops
Type : Central African armored crocodile
Scientific name
Mecistops leptorhynchus
( Bennett , 1835)

The Central African armored crocodile ( Mecistops leptorhynchus ) is a medium-sized species of crocodile that is widespread in central Africa. The distribution area extends from the coast of Gabon and the catchment area of Sangha and Dja in the west over the Congo Basin to Lake Tanganyika and the Malagarasi in the east and from the Uelle in the north to Lake Mweru and its tributaries in the south. In the east and south of the range, in Tanzania and Zambia, the species may now have become extinct.

features

The Central African armored crocodile reaches a length of 3.5 meters, a few specimens can possibly also grow a little larger. The color is very variable. Most specimens are light yellowish-brown with dark brown or blackish broad bands or spots on the back. Some are also completely black on the back. On the coast of Gabon there are relatively many very light, yellowish or orange-colored animals and in the Mpassa river on the Batéké plateau there are individuals with a very light, "blonde" coloration without pattern. The belly is almost monochrome whitish or cream-colored with some dark spots or bands on the edge. The underside of the tail is whitish with some large, black spots that only reach the cloaca in front , but never to the torso. The extent and intensity of these spots decrease with increasing size of the animals and they can only be seen indistinctly in adult specimens, but this is also due to the increasing darkening of the color in adult animals. The eyes are light, yellowish green or bronze in color . The tongue is usually light cream to yellow in color and unpatterned.

In contrast to the Central African armored crocodile, the West African armored crocodile has spots on its lower jaw.

In contrast to that of the West African armored crocodile, the lower jaw of the Central African armored crocodile is usually monochrome and unpatterned. Only on Epulu and Ituri in the Democratic Republic of the Congo do the Central African armored crocodiles have some spots on the lower and sometimes also on the upper jaw. However, they cannot be seen as clearly as in the West African armored crocodile. The head and skull of the Central African armored crocodile are slightly narrower than that of the West African armored crocodile and the front edge of the premaxillary is much more frequently perforated by the first pair of lower jaw teeth than that of the West African armored crocodile.

Habitat and way of life

The Central African armored crocodile lives in medium and large rivers, in lakes, in flooded forests, in papyrus swamps and other flooded areas. On the coast it also occurs in lagoons with low salinity and in river mouths, but avoids beach areas with open sea access. It occurs only in wooded areas or on rivers that are accompanied by gallery forests e.g. B. at Mpassa on the Batéké plateau. The Central African armored crocodile is highly aquatic and cannot reach isolated wetlands.

The Central African armored crocodile feeds mainly on fish. The stomach contents examined consisted of 80% fish remains, including catfish of the Claroteidae family , tetras and cichlids . In addition, they found mouse deer , snakes, crustaceans (shrimp from the family Palaemonidae and crabs from the family Thelphusidae ) and grasshoppers . One specimen has been seen trying to eat a red-backed softshell turtle ( Cycloderma aubryi ), and an adult specimen has been seen attempting to capture a red pelican in Loango National Park on the Atlantic coast of Gabon . For reproduction, the Central African armored crocodile piles up nest mounds measuring 125 × 45 cm at the base of large trees. They are almost always under a closed canopy of leaves and often hidden in the vegetation and are guarded by the female after they have laid eggs. The breeding season begins at the end of the dry season in November or December and it takes about 100 days from the egg-laying to the hatching of the young. The clutches are relatively small and contain 13 to 21 eggs. In Gabon and the Democratic Republic of the Congo, newly hatched young animals were observed in April and May at the end of the rainy season at the highest water level.

Danger

Little is known about the endangerment status of the Central African crocodile populations. The Central African armored crocodile is believed to be around 70% of the population in Gabon. In the south, southeast and east of the distribution area, at the Luapula , at Lake Tanganyika and at Lake Mweru, the species may now have become extinct. From there, however, observations of the species are still available from the 1990s and from the Malagarasi from the year 2000. The population of the species in Gabon, the Republic of the Congo and the Central African Republic is still considered safe.

Systematics

The Central African armored crocodile was first described in 1835 by the English doctor and zoologist Edward Turner Bennett and was then assigned to the genus Crocodylus . It was later synonymous with Crocodilus cataphractus . In 1844 John Edward Gray introduced the genus Mecistops . Only one species of armored crocodile was recognized throughout the 20th century. DNA comparisons and detailed investigations of the skull morphology show, however, that there are two - externally indistinguishable or barely distinguishable - species ( cryptospecies ) that were found 7.5 to 6.5 million years ago through the emerging Cameroon line , a volcanic mountain range in Central Africa, isolated from each other ( allopatric speciation ). One species lives west of the Cameroon Line in Upper Guinea , the other southeast of it in Lower Guinea and in the Congo Basin . Because of these differences, the Central African armored crocodile has been differentiated from the West African armored crocodile ( Mecistops cataphractus ) since 2018 .

literature

  • Matthew H. Shirley, Amanda N. Carr, Jennifer H. Nestler, Kent A. Vliet, Christopher A. Brochu: Systematic revision of the living African Slender-snouted Crocodiles (Mecistops Gray, 1844). In: Zootaxa . 4504, 2018, p. 151, doi: 10.11646 / zootaxa.4504.2.1 .

Individual evidence

  1. a b c Shirley, Vliet, Carr & Austin (2018). Page 179.
  2. Shirley, Vliet, Carr & Austin (2018). Page 174.
  3. a b Shirley, Vliet, Carr & Austin (2018). Page 176.
  4. Shirley, Vliet, Carr & Austin (2018). Page 177.
  5. Shirley, Vliet, Carr & Austin (2018). Page 180.
  6. Shirley, Vliet, Carr & Austin (2018). Page 181.
  7. Shirley, Vliet, Carr & Austin (2018). Page 172.
  8. Shirley, Vliet, Carr & Austin (2018). Page 153.
  9. ^ MH Shirley, KA Vliet, AN Carr, JD Austin. Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation. Proceedings of the Royal Society B: Biological Sciences, 2013; 281 (1776): 20132483, doi: 10.1098 / rspb.2013.2483 .
  10. Shirley, Vliet, Carr & Austin (2018). Page 151–193.