Night Sharks, Carcharhinus signatus
Taxonomy Animalia Chordata Elasmobranchii Carcharhiniformes Carcharhinidae Carcharhinus signatus
Description & Behavior
Night sharks, Carcharhinus signatus (Poey, 1868), measure about 2.8 m in length and weigh a maximum of 76.7 kg. They are slender in shape with long, pointed snouts, small jaws with serrated upper teeth, and large green eyes. Their dorsal fins are low on their body and have long tips. The night shark also has an interdorsal ridge. They are gray-brown on the dorsal side, white on the ventral side.
Similar species include silky sharks and dusky sharks, however both of these sharks lack green eyes when alive. The silky shark also has a more rounded and swept back first dorsal fin. Another species similar in appearance to the night shark are the spinner sharks. Spinner sharks can be distinguished from night sharks by the absence of an interdorsal ridge.
World Range & Habitat
Night sharks, Carcharhinus signatus, are found in subtropical waters 11-16°C and 41°N-41°S in the western Atlantic from Delaware to Florida in the USA, Bahamas, Cuba, southern Brazil, and Argentina. In the eastern Atlantic, night sharks are found from Senegal to Côte d'Ivoire, Ghana to Cameroon, Democratic Republic of the Congo, Angola, and off northern Namibia.
Feeding Behavior (Ecology)
Night sharks, Carcharhinus signatus, named for their nocturnal feeding habits, prey on small bony fishes and squid.
Night sharks are viviparous, meaning their embryos develop and are nourished within the female body.
Conservation Status & Comments
Night sharks, like most sharks, are harmless to humans and they are listed as Vulnerable (VU A2abd+3bd+4abd) on the IUCN Red List of Threatened Species:
A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable (see Section V), and it is therefore considered to be facing a high risk of extinction in the wild.
References & Further Research
Research Carcharhinus signatus » Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library [audio / video] ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SCIRIS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS
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