Common sawfish
| Common sawfish | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Order: | Pristiformes |
| Family: | Pristidae |
| Genus: | Pristis |
| Species: | P. pristis |
| Binomial name | |
| Pristis pristis (Linnaeus, 1758) | |
The common sawfish, Pristis pristis, is a sawfish of the family Pristidae. It is found worldwide in tropical and subtropical coastal regions, but also enters freshwater. It has declined drastically and is considered critically endangered.[1]
Taxonomy
Its taxonomy in relations to P. microdon and P. perotteti has caused considerable confusion, but recent evidence strongly suggests the three are conspecific (in which case P. microdon and P. perotteti are synonyms of P. pristis), as morphological and genetic differences are lacking.[2] Three main clades based on NADH-2 genes were evident (Atlantic, Indo-West Pacific, and East Pacific), but these do not match the distributions claimed for P. pristis (circumtropical), P. microdon (Indo-West Pacific) and P. perotteti (Atlantic and East Pacific) respectively.[2]
Description
Its maximum length is 7.5 metres (25 ft), though 2.5 metres (8.2 ft) is more common.[3] Reproduction is ovoviviparous.
Distribution and status
This species can be found worldwide in tropical and subtropical coastal regions, but it also enters freshwater and has been recorded in rivers as far as 1,340 km (830 mi) from the sea.[1] Juveniles stay in freshwater for the first years of their life, while adults mainly are found in estuaries and coastal waters. Specimens from the population in Lake Nicaragua appear to spend most, if not all, of their life in freshwater.[1]
As suggested by its name, it was once plentiful, but has now declined drastically leading to it being considered a critically endangered species by the IUCN.[1] It has been extirpated from many regions where formerly present. The main threat is overfishing, but it also suffers from habitat loss.[1] Sawfish are proteced in some parts of the world, and it is listed by the Endangered Species Act and CITES Appendix I, but illegal fishing continues and enforcement of fishing laws are often lacking.[1]
See also
References
- 1 2 3 4 5 6 7 Kyne, P.M., Carlson, J. & Smith, K. (2013). "Pristis pristis". IUCN Red List of Threatened Species. Version 2014.3. International Union for Conservation of Nature. Retrieved 2 June 2015.
- 1 2 Faria, V. V.; McDavitt, M. T.; Charvet, P.; Wiley, T. R.; Simpfendorfer, C. A.; Naylor, G. J. P. (2013). Species delineation and global population structure of Critically Endangered sawfishes (Pristidae). Zoological Journal of the Linnean Society 167: 136–164. doi:10.1111/j.1096-3642.2012.00872.x Retrieved 26 August 2013.
- ↑ Froese, Rainer and Pauly, Daniel, eds. (2006). "Pristis pristis" in FishBase. May 2006 version.