Ginglymostoma unami
| Ginglymostoma unami | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Ginglymostoma unami | ||||||||||||
| Del-Moral-Flores , Ramírez-Antonio , Angulo & Pérez-Ponce de León , 2015 |
Pacific nurse shark is a shark species from the family of nurse sharks (Ginglymostomatidae). The species was in 2015 by a group of Mexican scientists described and after the National Autonomous University of Mexico , UNAM short, one of the oldest and largest universities in the Americas named. It includes the East Pacific nurse shark populations , which were previously included in the Atlantic nurse shark ( Ginglymostoma cirratum ), and thus occurs in the eastern, tropical Pacific from Baja California to Peru .
features
Ginglymostoma unami is a medium-sized shark that can reach a length of about three meters. The eyes and gill openings are dorsolateral . The nasal whiskers extend to the mouth. The tips of the dorsal and anal fin are rounded. The second dorsal fin is much smaller than the first and anal fin. Adult specimens are brown to dark yellowish. The ventral side is light, whitish to pink. Specimens that are not yet fully grown show a pattern of dark spots all over their bodies. The spots are smaller than the diameter of the eyes.
Ginglymostoma unami differs from the Atlantic nurse shark in the following external characteristics, among other things.
The head is on average longer than that of the Atlantic nurse shark (14.5 to 18.0% of the standard length vs. 12.0 to 15.0% of the SL). The distance between the pelvic fin attachment and the beginning of the anal fin is smaller in Ginglymostoma unami and the rear edge of the first dorsal fin extends to the beginning of the second, while in the Atlantic nurse shark it does not extend as far. The distance between the two dorsal fins is smaller in Ginglymostoma unami (3.6 to 5.6% of the SL vs. 5.4 to 9.5% of the SL). In the Atlantic nurse shark, the rear end of the second dorsal fin extends to the beginning of the caudal fin or ends shortly before it, the rear end of the second anal fin does not extend to the base of the caudal fin. In Ginglymostoma unami , the second dorsal fin ends well in front of the caudal fin and the rear edge of the second anal fin extends to the caudal fin base or extends beyond it. The placoid scales in Ginglymostoma unami are wider than long and have 5 to 6 keels, in the Atlantic nurse shark they are longer than wide and they have less than 5 keels.
literature
- Del Moral-Flores, LF, Ramírez-Antonio, E., Angulo, A. & Pérez-Ponce de León, G. (2015): Ginglymostoma unami sp. nov. (Chondrichthyes: Orectolobiformes: Ginglymostomatidae): a new species of nurse shark from the Tropical Eastern Pacific. Revista Mexicana de Biodiversidad, 86: 48-58.