Gulf of Mexico Pygmy Skate

Fenestraja sinusmexicanus - Gulf of Mexico Pygmy Skate

Gulf of Mexico Pygmy Skate. Image © George Burgess

Fenestraja sinusmexicanus

This deep-water, bottom-dwelling skate has a heart-shaped pectoral disc that is reddish brown to purple on top and pale yellowish underneath. There are several rows of thorns around the edge of the pectoral fins and down the spine of the skate, onto its slender, long tail. It is smaller than many skates, reaching about 14 inches long, and it releases small leathery egg cases on the sea floor, but not much is known about the life of this skate because of its preference for depths.

Order - Rajiformes
Family - Rajidae
Genus - Fenestraja
Species - sinusmexicanus

Common Names

English language common names are Gulf of Mexico pygmy skate and gulf skate. Other common names include Mexicaanse dwergrog (Dutch) and raya pigmea (Spanish).

Importance to Humans

There are no fisheries directed at this species in particular, however it may be taken as bycatch in the numerous fisheries within its geographical range.

Danger to Humans

This skate is considered harmless to humans. Interactions are rare as this skate is found in the deep water.

Conservation

> Check the status of the Gulf of Mexico pygmy skate at the IUCN website.

The Gulf of Mexico pygmy skate is not listed as endangered or vulnerable with the World Conservation Union (IUCN). The IUCN is a global union of states, governmental agencies, and non-governmental organizations in a partnership that assesses the conservation status of species.

Geographical Distribution

Fenestraja sinusmexicanus - Gulf of Mexico Pygmy Skate, Map

World distribution map for the Gulf of Mexico pygmy skate

The geographical range of this skate is limited to the Gulf of Mexico, Caribbean Sea, and the Bahamas. It has been reported from southeastern Florida, the Bahamas, and throughout the Gulf of Mexico as well off the Caribbean coasts of Nicaragua and Venezuela and in waters surrounding Cuba.

Habitat

The Gulf of Mexico pygmy skate is a benthic (bottom-dwelling) fish that lives along the outer continental shelf and slope from 184-3,595 feet (56-1,096 m) in depth.

Biology

Fenestraja sinusmexicanus - Gulf of Mexico Pygmy Skate

Gulf of Mexico pygmy skate. Illustration courtesy FAO

Distinctive Features
The body is compressed with the head, body, and expanded pectoral fins forming a heart-shaped disc. The cartilage forming the rostrum is short. The pectoral fins are fused from the head through the trunk. The front lobes of the pelvic fins are as long or slightly shorter than the rear lobes. There are two closely spaced dorsal fins present on the tail. The tail is long and thorny and easy to distinguish from the body.

Coloration
The dorsal surface of the Gulf of Mexico pygmy skate is brownish purple, sometimes with irregular dark blotches. In contrast, the ventral surface is yellowish-white with no distinct markings. The dorsal fins are pale in color.

Fenestraja sinusmexicanus - Gulf of Mexico Pygmy Skate

Gulf of Mexico pygmy skate captured in the Gulf of Mexico off the coast of Texas. Image © George Burgess

Dentition
There are numerous small teeth arranged in bands along both jaws.

Denticles
The disc of this skate has three rows of thorns. These rows occur from the midline of the posterior half of the disc and tail to the origin of the first dorsal fin.

Size, Age, and Growth
The maximum size of the Gulf of Mexico pygmy skate is 14.2 inches (36 cm) total length. Male specimens reach maturity at 12.2-13.4 inches (31-34 cm) total length.

Food Habits
Little is known about the diet of this skate as evidenced by the lack of information and data in scientific literature.

Reproduction
The Gulf of Mexico pygmy skate is oviparous. Paired eggs are released into the benthic environment. The egg cases possess horn-like projections, allowing the cases to be held securely. The embryos feed entirely on the yolk within the egg case until they hatch and become free-swimming.

Predators
Potential predators of the Gulf of Mexico pygmy skate include larger fish such as sharks as well as marine mammals.

Parasites
There are no known parasites of this species due to lack of information and data in scientific literature.

Taxonomy

The Gulf of Mexico pygmy skate was originally described by Bigelow & Schroeder in 1950 as Breviraja sinusmexicanus. This name was later changed to the currently valid Fenestraja sinusmexicanus (Bigelow & Schroeder 1950). The genus name, Fenestraja, is derived from the Latin "fenestra", "-ae" meaning small hole or opening in a bone and the Latin "raja", "-ae" meaning a fish, Raja sp. The species name, sinusmexicanus, refers to the geographic location where this skate is found. There are no known synonyms appearing in past scientific literature referring to this species.

Prepared by: Cathleen Bester