Carcharhinus cerdale
| Carcharhinus cerdale | ||||||||||||
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Carcharhinus cerdale |
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| Scientific name | ||||||||||||
| Carcharhinus cerdale | ||||||||||||
| Gilbert , 1898 |
Carcharhinus cerdale is a relatively small species of shark from the family of requiem or gray sharks that is found on the coast of the eastern Pacific from the Gulf of California to Peru .
Appearance
The species becomes about 140 cm long. Like all Carcharhinus species, it has an anal fin and two dorsal fins, the front of which is larger than the rear. The beginning of the first dorsal fin lies above the middle of the inner edge of the pectoral fins. The leading edge of the first dorsal fin is much longer than the distance between the dorsal fin tip and the free-standing posterior tip. The height of the first dorsal fin is 9 to 10.5% of the standard length. The beginning of the second dorsal fin lies above the middle of the anal fin. The interdorsal ridge is only clearly pronounced in embryos and newborns, in larger animals only weakly or completely regressed. The length of the caudal fin is a quarter of the total length. All fins have dark edges or tips. Behind the eyes are inconspicuous, tiny pores on the hyomandibular .
Systematics
Carcharhinus cerdale was described by the American ichthyologist Charles Henry Gilbert in 1898 . A closely related species, the Atlantic dwarf shark ( Carcharhinus porosus ) occurs on the Atlantic side of the American double continent from the Gulf of Mexico to Brazil. Both species probably originated from allopatric speciation when the Isthmus of Panama was closed.
In 1923, the American ichthyologists Seth Eugene Meek and Samuel Frederick Hildebrand identified sharks that came from the fish market in the Panamanian port city of Colón as Carcharhinus cerdale . Colón is on the Caribbean side of Panama and the two scientists therefore assumed that the species occurs on both sides of the Isthmus of Panama, but they did not synonymize it with Carcharhinus porosus . In a 1948 publication, the American ichthyologists Henry Bryant Bigelow and William Charles Schroeder assumed exactly this, however, all later authors adopted this and for more than 60 years it was forgotten that Carcharhinus cerdale is an independent species. It was not until 2011 that Carcharhinus cerdale was reintroduced as a valid species and Carcharhinus porosus was restricted to the Atlantic population.
literature
- Castro, JI, 2011. Resurrection of the name Carcharhinus cerdale , a species different from Carcharhinus porosus. aqua, International Journal 17 (1): 1-10.
Web links
- Carcharhinus cerdale on Fishbase.org (English)