The hammerhead sharks are a group of sharks that form the family Sphyrnidae, named for the unusual and distinctive form of their heads, which are flattened and laterally extended into a cephalofoil. The shark's eyes are placed one on either end of this T-shaped structure, with their small mouths directly centered and underneath. Most hammerhead species are placed in the genus Sphyrna, while the winghead shark is placed in its own genus, Eusphyra. Many different— but not necessarily mutually exclusive—functions have been postulated for the cephalofoil, including sensory reception, manoeuvering, and prey manipulation. The cephalofoil gives the shark superior binocular vision and depth perception.
The cownose ray is a species of Batoidea found throughout a large part of the western Atlantic and Caribbean, from New England to southern Brazil. These rays also belong to the order Myliobatiformes, a group that is shared by bat rays, manta rays, and eagle rays.
Franz Steindachner was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner described hundreds of new species of fish and dozens of new amphibians and reptiles. At least seven species of reptile have been named after him.
The bonnethead, also called a bonnet shark or shovelhead, is a small member of the hammerhead shark genus Sphyrna, and part of the family Sphyrnidae. It is an abundant species in the littoral zone of the North Atlantic and the Gulf of Mexico, is the only shark species known to display sexual dimorphism in the morphology of the head, and is the only shark species known to be omnivorous.
The white-margin fin smooth-hound is a smooth-hound from the Gulf of California, off the coast of Mexico. The white-margin fin smooth-hound shark is slender, dark grey-brown in color, and grows up to 1.2 m (4 ft) long.
The scalloped bonnethead is a rare, little-known species of hammerhead shark in the family Sphyrnidae. Its other common names include the mallethead shark and the crown shark. It is found in tropical and subtropical waters in the eastern Pacific Ocean, from Mexico to Peru, and possibly as far north as the Gulf of California. It frequents inshore habitats over soft bottoms to a depth of 100 m, and also enters mangroves and estuaries.
The scoophead is a little-known species of hammerhead shark, part of the family Sphyrnidae. It inhabits the tropical waters of the western Atlantic Ocean, from Panama to southern Brazil, and in the eastern Pacific Ocean from the Gulf of California to Ecuador, and probably northern Peru, as well. It is found in shallow, inshore habitats.
The Pacific sharpnose shark often migrates along the Pacific coast of Mexico. They are most commonly caught in the artisanal fishery of Mazatlán. When a large sample of Pacific sharpnose sharks were observed scientists concluded that this type of shark was a "viviparous shark of small size which is born at an average length of 31 cm." Their gestation period is between ten and eleven months.
The Mexican hornshark is a bullhead shark of the family Heterodontidae. This shark is grey-brown in color, with black spots scattered on the fins and body. It has a cylindrical trunk, conical head, and small spiracles behind the eyes. The snout of the Mexican hornshark is very round and blunt. Like all members of the order Heterodontiformes, this shark has fin spines in front of both of its dorsal fins. The first dorsal fin originates before the pectoral fins, while the second dorsal fin originates behind the pelvic fins. The Mexican hornshark reaches a maximum length around 70 cm, but usually reaches between 50 and 60 cm on average. Young hornsharks hatch around 14 cm.
The longtail stingray, is a species of stingray in the family Dasyatidae, found in the eastern Pacific Ocean from Baja California to Colombia. It inhabits sandy habitats down to a depth of 90 m (300 ft). Measuring up to 1.56 m (5.1 ft) across, this species has a rhomboid pectoral fin disc, a lower fin fold on the tail, and numerous dermal denticles along the back and behind the stinging spine. The longtail stingray feeds mainly on bottom-dwelling bony fishes and crustaceans. It is aplacental viviparous, with females giving birth to 1–5 young in late summer. It is caught for food, likely throughout its range, but specific fishery data is lacking.
The diamond stingray is a species of stingray in the family Dasyatidae. It is found in the coastal waters of the eastern Pacific Ocean from southern California to northern Chile, and around the Galápagos and Hawaiian Islands. This bottom-dweller generally inhabits sandy or muddy flats near rocky reefs and kelp forests, to a depth of 30 m (98 ft), though off Hawaii it may range considerably deeper. As its common name suggests, this species has an angular, diamond-shaped pectoral fin disc that is plain brown or gray above, with rows of tubercles along the midline and on the "shoulders". The long, whip-like tail has both dorsal and ventral fin folds, which distinguish this ray from the closely similar longtail stingray. It typically grows to 1 m (3.3 ft) across.
The ocellated electric ray or bullseye electric ray is a species of electric ray in the family Narcinidae, native to the shallow inshore waters of the eastern central Pacific from the Gulf of California to Ecuador. Reaching 25 cm (9.8 in) in length, this species has a rounded pectoral fin disc and pelvic fins with convex margins. Its short and thick tail bears two dorsal fins and terminates in a triangular caudal fin. The ocellated electric ray is named for the distinctive large eyespot on the middle of its disc, consisting of a black or yellow center surrounded by concentric rings. Its dorsal coloration is otherwise highly variable, ranging from plain to ornately patterned on a light to dark brown background. The front part of its disc is darker brown.
Rhinoptera is a genus of ray commonly known as the cownose rays. This genus is the only member of the family Rhinopteridae.
Urobatis maculatus, known as the spotted round ray or Cortez round stingray, is a species of round ray, within the genus Urobatis, and of the family Urotrygonidae. It is endemic to Mexico, with its natural habitats being shallow seas, subtidal aquatic beds, coral reefs, estuarine waters, intertidal marshes, and coastal saline lagoons.
The banded guitarfish, mottled guitarfish, prickly skate or striped guitarfish is a species of fish in the Trygonorrhinidae family. Originally Z. exasperata was placed in the Rhinobatidae family, however recent mitochondrial DNA analysis shows their placement into the new family of Trygonorrhinidae. They are found from shallow water to a depth of 200 m (660 ft) in the East Pacific from California, United States, to Mazatlan, Mexico, including the Gulf of California. The species has also been recorded further south, but this likely involves its close relative, the southern banded guitarfish.
Narcine entemedor, the giant electric ray or Cortez electric ray, is a species of numbfish, family Narcinidae, native to the eastern Pacific Ocean from the Gulf of California to Panama. It is found in shallow water on sandy bottoms and sometimes adjacent to reefs. This species is closely related to the lesser electric ray from the western Atlantic, and may represent the same species. The specific epithet entemedor seems to be the Spanish equivalent of "intimidator".
The Pacific smalltail shark is a species of requiem shark, in the family Carcharhinidae. It was described in 1898, but later mistakenly merged with Carcharhinus porosus. The mistake was corrected in 2011.
Urotrygon aspidura, also known as the spiny-tail round ray or Panamic stingray, is a species of stingray native to the eastern-central and south-eastern Pacific, southern Baja, and the Gulf of California. It can grow up to 42 cm. They are severely threatened by shrimp fisheries.
Ginglymostoma unami, also known as the Pacific nurse shark is a nurse shark of the family Ginglymostomatidae. It is found in southeastern coast of Baja California, Mexico to Costa Rica including Gulf of California. It is 2.8 meters long. This species differs from Ginglymostoma cirratum between posterior end of the second dorsal fin and the beginning of the caudal lobe, both being shorter; the new species also differs by the position of the insertion of the first dorsal fin with regard to the pelvic fins and in the form and number of keels on the dermal denticles and teeth morphology. The Ginglymostoma unami was previously recognized as G.cirratum exhibiting a divided distribution of a species in the northern half of the Atlantic Ocean. However, that species is now considered to be restricted to just the Atlantic Ocean.
Aetobatus laticeps, the Pacific white-spotted eagle ray, is a species of cartilaginous fish in the eagle ray family Myliobatidae. It is found in the tropical East Pacific Ocean, ranging from Baja California to northern Peru, including the Galápagos. There has been recent evidence to suggest A.laticeps is in the Mexican tropical Pacific, more specifically in Chacahua Lagoon. However this evidence is insufficient and so the research being done on the spotted eagle rays in Chacahua Lagoon is working under the name A. narinari. Until 2014, it was included in the similar spotted eagle ray, but the two differ in genetics. Studies have been conducted to attempt to identify spot patterns at the individual level. A. laticeps and A. narinari both have white spots on the dorsal side of their dark body, making them difficult to differentiate. Following the split, A. narinari is restricted to the Atlantic, while the Indo-Pacific is inhabited by the closely related A. ocellatus.
