Roughtail Catshark

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

Order– Carcharhiniformes

Common Name– Ground Sharks

Family– Scyliorhinidae

Common Name– Catsharks

Genus– Galeus

Species– arae

Status: IUCN Red List LEAST CONCERN

Average Size and Length: Mature sharks have been measured between 27-33 cm/10.6 inches-1 foot and the maximum recorded has been 1 foot. The Roughtail catshark is smaller than the Antilles catshark.

Current Rare Mythical Sightings: John T. Nichols of the American Museum of Natural History originally described the Roughtail catshark as Pristiurus arae in a 1927 issue of American Museum Novitates. He named the species after the trawler Ara, which collected the first two specimens, both 16 cm/6.3-inch-long immature females, off Miami Beach on March 31, 1926. Later authors have recognized Pristiurus as a junior synonym of Galeus. The Antilles catshark (G. antillensis) and the Longfin Sawtail catshark (G. cadenati) were regarded as subspecies of G. arae, until taxonomic revisions were published by Hera Konstantinou and colleagues in 1998 and 2000. The three species, along with the Southern and Springer’s Sawtail catsharks (G. mincaronei and G. springeri), are grouped together in the G. arae species complex.

Teeth and Jaw: The mouth is large and forms a broad arch, with long furrows around the corners. The teeth are small and number 59–65 rows in the upper jaw and 58–60 rows in the lower jaw. Each tooth has a thin central cusp flanked by 1–3 pairs of cusplets on either side.

Head: The head is slightly flattened. The snout is long and pointed, with the nostrils divided by triangular skin flaps in front. The horizontally oval eyes are equipped with nictitating membranes. There are tiny spiracles behind the eyes.

Denticles: They have a prominent saw-tooth crest of enlarged dermal denticles along the dorsal edge of the caudal fin. The dermal denticles are small and overlapping. Each has a leaf-shaped crown with a horizontal ridge and three marginal teeth.

Tail: The caudal fin is low, with a small lower lobe and a ventral notch near the tip of the upper lobe.

Demographic, Distribution, Habitat, Environment and Range: The Roughtail catshark can be found in the western Atlantic, including the Gulf of Mexico and continental Caribbean Sea. There are apparently two separate populations, one off the USA from North Carolina to the Mississippi Delta, Mexico and Cuba, and the second off of Belize, Honduras, Nicaragua, Costa Rica and the adjacent islands. They can be found on the upper continental and insular slopes on or near the bottom between 958-2,401 feet. Temperature may play a role in the depths of each population. Both populations of the Roughtail catshark has been captured from water ranging from 42.1 to 52.0 °F. They are considered bathydemersal.

Diet: They feed mainly on deep-water shrimp.

Aesthetic Identification: The Roughtail catshark is similar to the Antilles catshark. The Roughtail catshark has a slender and firm body with a yellowish-brown background, and a marbled color pattern of dark saddles and spots. Some smaller sharks have markings that form horizontal lines, while some larger sharks have round blotches along the sides. These markings can range from faint to well-defined by white outlines. The ventral side is pale. The first dorsal fin has a blunt apex and is positioned over the latter half of the pelvic fin bases. The second dorsal fin is nearly as large as the first and similar in shape, and positioned over the latter half of the anal fin base. The large, broad pectoral fins have rounded corners. The pelvic and anal fins are low and angular. The anal fin base measures roughly 10–14% of the total length, exceeding the distance between the pelvic and anal fins and about the same as the distance between the dorsal fins.

Biology and Reproduction: The Roughtail catshark has fewer precaudal vertebrae. In the past it was thought that their reproduction was possibly ovoviviparous, but research has since confirmed that they are oviparous. Adult females have a single functional ovary, on the right, and two functional oviducts. A single egg matures within each oviduct at a time. The eggs are enclosed within tough, flask-shaped capsules or egg cases that are around 4.9–5.1 cm/1.9–2.0 inches long, 1.2–1.4 cm/0.47–0.55 inches across the top, and 1.6 cm/ 0.63 inches across the bottom. The rounded upper corners of the egg case have coiled tendrils. The spawning grounds of the Roughtail catshark may be located in very rough terrain.

Behavioral Traits, Sensing and Intelligence: They are partially segregated by depth. Only the adults can be found in deeper water, but both adults and juveniles can be found above 1,476 feet. They may school in large numbers. Hey may segregate by sex, but this is not confirmed and there is not enough data to support the theory.

Roughtail Catshark Future and Conservation: They are currently of least concern. They are quite common in their range and are occasionally caught by shrimping trawlers especially in Florida.

Roughtail Catshark Recorded Attacks on Humans: Not a threat to humans.