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West African slender-snouted crocodile

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West African slender-snouted crocodile
Temporal range: MioceneRecent, 11.6–0 Ma[1]
West African slender-snouted crocodile at the porte dorée aquarium in Paris, France
CITES Appendix I (CITES)[3]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Crocodylidae
Genus: Mecistops
Species:
M. cataphractus
Binomial name
Mecistops cataphractus
(Cuvier, 1825)
Synonyms[4]
  • Crocodylus cataphractus Cuvier, 1825
  • Mecistops bennettii Gray, 1844

The West African slender-snouted crocodile (Mecistops cataphractus), or slender-snouted crocodile, is a critically endangered species of African crocodile.[5] It is one of five species of crocodile in Africa, the other four being the Central African slender-snouted, Nile, West African and dwarf crocodiles.

The slender-snouted crocodile (M. cataphractus) was thought to be distributed across west Africa and into central Africa but the central African species has been separated as the Central African slender-snouted crocodile (M. leptorhynchus) based on studies in 2014 and 2018 that indicated that both were distinct species. The name cataphractus is retained for the West African species as that species was described first based on specimens from western Africa.[6] The two species diverged about 6.5–7.5 mya, living in different river drainage zones that were geographically separated from each other by the Cameroon Line.[7]

Etymology

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The genus name Mecistops is most probably derived from the Ancient Greek words μήκιστ (mēkist) meaning "longest" and ὄψις (ópsis) meaning "aspect" or "appearance". The species name cataphractus is thought to be derived from the Greek word κατάφρακτος (katáphraktos) meaning "armoured" or "shielded".[6]

Description

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As with its relative, the West African slender-snouted crocodile has a very long, slender snout that it uses to catch fish and small aquatic invertebrates.[8] As with all crocodilians, larger animals may feed opportunistically on larger prey if it becomes available.[8] They are relatively medium-sized, but large males can exceed several other species of crocodilians in size. Three individuals measuring 2.31 to 2.62 m (7 ft 7 in – 8 ft 7 in) and weighing 50–95 kg (110–209 lb) had a bite force in the range of 1,704–2,447 N (383–550 lbf).[9] Adult males typically reach 3 to 4 m (9 ft 10 in – 13 ft 1 in) in length.[10][11] Large males can reportedly grow up to 4.5 m (15 ft) in length.[12] They generally weigh between 125 and 325 kg (276 and 717 lb).[13] The body mass of the largest males have been estimated to reach up to 667 kg (1,470 lb).[14]

Status

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This species is relatively poorly known with few studies of the wild populations. Consequently, it was rated as Data Deficient by the IUCN in 1996. Following a review in 2014, it was moved to Critically Endangered, although this includes both the Central African and West African species.[2] Their declining populations are attributed to the loss of their habitats, hunting, depletion of their prey,[15] and illegal consumption of them through bush-meat markets.[16] It appears to have been entirely extirpated from several countries where formerly present and declined elsewhere.[2] Recent conservation efforts are in effect as project faux gavial works towards lessening the hunting and commerce of the slender-snouted crocodile.[16] In its native range, it is extremely rare and on the verge of disappearing.[7] There have been implemented protected wildlife preserves in Ghana, one of their main habitats, to help protect the species, though it has been largely ineffective.[15] A study in 2015 that included 24 captive slender-snouted crocodiles in six US zoos (more than 50% of the slender-snouted crocodiles in AZA zoos) found that all were of West African origin, indicating that captive breeding may be important for conservation of this species.[17] Captive breeding is currently being used by one zoo, the Abidjin zoo, who have already begun releasing captive breed individuals when they reach around 3–4 years old.[18]

Distribution

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West African slender-snouted crocodile occurs widely in West Africa (Benin, Burkina Faso, southern Senegal, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, southern Mali, Nigeria, Sierra Leone, and Togo) and extends into Cameroon in Central Africa.[4] They prefer to live in dense, vegetated bodies of water that are away from human settlements.[15] Their distribution is currently being monitored by drone surveillance[19] and prerecorded calls to attract them.[20]

References

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  1. ^ Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
  2. ^ a b c Shirley, M.H. (2014). "Mecistops cataphractus". IUCN Red List of Threatened Species. 2014: e.T5660A3044332. doi:10.2305/IUCN.UK.2014-1.RLTS.T5660A3044332.en. Retrieved 19 November 2021.
  3. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  4. ^ a b Mecistops cataphractus at the Reptarium.cz Reptile Database. Accessed 30 January 2020.
  5. ^ Brochu, C. A.; Storrs, G. W. (2012). "A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity of Crocodylus in Africa". Journal of Vertebrate Paleontology. 32 (3): 587. Bibcode:2012JVPal..32..587B. doi:10.1080/02724634.2012.652324. S2CID 85103427.
  6. ^ a b Shirley, M. H.; Carr, A. N.; Nestler, J. H.; Vliet, K. A.; Brochu, C. A. (2018-10-24). "Systematic revision of the living African Slender-snouted Crocodiles (Mecistops Gray, 1844)". Zootaxa. 4504 (2): 151–193. doi:10.11646/zootaxa.4504.2.1. ISSN 1175-5334. PMID 30486023. S2CID 54146247.
  7. ^ a b Shirley, M. H.; Vliet, K. A.; Carr, A. N.; Austin, J. D. (2014). "Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation". Proceedings of the Royal Society B: Biological Sciences. 281 (1776): 20132483. doi:10.1098/rspb.2013.2483. PMC 3871313. PMID 24335982.
  8. ^ a b "Crocodilian Species - Slender-snouted Crocodile (Mecistops cataphractus, Crocodylus cataphractus)".
  9. ^ Erickson, Gregory M.; Gignac, Paul M.; Steppan, Scott J.; Lappin, A. Kristopher; Vliet, Kent A.; Brueggen, John D.; Inouye, Brian D.; Kledzik, David; Webb, Grahame J. W. (14 March 2012). "Insights into the Ecology and Evolutionary Success of Crocodilians Revealed through Bite-Force and Tooth-Pressure Experimentation". PLOS ONE. 7 (3): e31781. Bibcode:2012PLoSO...731781E. doi:10.1371/journal.pone.0031781. PMC 3303775. PMID 22431965.
  10. ^ "Slender-snouted Crocodile | San Diego Zoo Animals & Plants". animals.sandiegozoo.org.
  11. ^ "West African Slender-snouted Crocodile". EDGE of Existence.
  12. ^ J Milan, R Hedegaard (2010). Interspecific variation in tracks and trackways from extant crocodylians. New Mexico Museum of Natural History and Science Bulletin. pp. 15–29.
  13. ^ "African Slender-snouted Crocodile". The Maryland Zoo.
  14. ^ Michael J. Lynch, Stephen F. Pires (2019). Quantitative studies in green and conservation criminology : the measurement of environmental harm and crime. Abingdon, Oxon: Taylor & Francis. p. 96. ISBN 9780429844232.
  15. ^ a b c Amoah et al. A Survival Blueprint for the conservation and management of the West African slender-snouted crocodile, Mecistops cataphractus in the Jimi River (Obuasi) and Tano River (Tanoso), Ghana. An output from the EDGE of Existence fellowship, Zoological Society of London, 2019.
  16. ^ a b Arrowood, H., & Mvele, C. (2017). Projet Faux Gavial reduces commerce of slender-snouted crocodile in Gabon. Oryx, 51(1), 13-14. doi:10.1017/S003060531600140X
  17. ^ Shirley, M. H.; Villanova, V. L.; Vliet, K. A.; Austin, J. D. (2015). "Genetic barcoding facilitates captive and wild management of three cryptic African crocodile species complexes". Animal Conservation. 18 (4): 322–330. Bibcode:2015AnCon..18..322S. doi:10.1111/acv.12176. S2CID 82155811.
  18. ^ Bradford, Carol; Eschenbrenner, Matt (2017). "HEALTH SURVEY INCLUDING SELECTED BLOOD PARAMETERS IN THE AFRICAN SLENDER SNOUTED CROCODILE (MECISTOPS CATAPHRACTUS) AT THE ABIDJAN ZOO IN CÔTE D'IVOIRE". Journal of Zoo and Wildlife Medicine. 48 (2): 510–513. doi:10.1638/2016-0006R3.1. ISSN 1042-7260. JSTOR 26805649. PMID 28749270.
  19. ^ Aubert, Clément; Moguédec, Gilles Le; Assio, Cindy; Blatrix, Rumsaïs; Ahizi, Michel N’dédé; Hedegbetan, Georges Codjo; Kpera, Nathalie Gnanki; Lapeyre, Vincent; Martin, Damien; Labbé, Pierrick; Shirley, Matthew H. (2021-06-17). "Evaluation of the use of drones to monitor a diverse crocodylian assemblage in West Africa". Wildlife Research. 49 (1): 11–23. doi:10.1071/WR20170. ISSN 1448-5494.
  20. ^ Staniewicz, Agata M. Acoustic Communication of Rare and Threatened Crocodilians and Its Use for Population Monitoring (Ph.D. thesis). England: University of Bristol (United Kingdom). ProQuest 2430834293.