Featured Elasmobranch – Lined Round Stingray

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Featured Elasmobranch – Lined Round Stingray

lrs

Photo Copyright:  Ross Robertson

 

Lined Round Stingray

 

Urotrygon rogersi (Jordan & Starks, 1895)

 

Family Urotrygonidae

Identification: Disc is somewhat diamond shaped, with anterior margins nearly straight. Snout tip acutely pointed and slightly projecting. Tail length is greater than one-half total length. A single row of thorns extends along the back and tail. Caudal fin is narrow and pointed. Small denticles present on snout, area behind scapular region at midline, and along the disc margin. Coloration is light brown to brown on above; if light brown, scattered dark spots may be visible and it may have a reddish outline along the wings.

Size: Maximum total length (TL) is at least 46.2cm and with a 28cm disc width.  Onset of maturity ( for both males and females) occurs between 10.5 and 13 cm disc width.  Size at birth ranges between 7.5 and 8.2 cm disc width.

Distribution: Occurs along the Eastern Pacific coast from Southern Baja and the Gulf of California to Ecuador.

 

Habitat: A bottom-dwelling species that lives in soft sediment (mud, sand, gravel, beach, mangrove, and estuary).  It occurs coastally in shallow waters, with recorded depths that range from 2-30m. The maximum depth is unknown for this species.

 

Biology: Reproduction is viviparous without a yolk sac .The gestation period is 4-5 months, with three reproductive cycles per year.  Females have a single functional left ovary, and litters range from 1-3 pups.

The diet of this species consists of invertebrates, primarily shrimps and polychaete worms.  The diet of this species changes ontogenetically, with smaller individuals feeding mostly on worms while larger individuals shift to shrimp as they become larger.

 

General Interest: This species is listed as Data Deficient on the IUCN Red List. It is frequently caught as bycatch in artisanal prawn fisheries in the eastern tropical Pacific Ocean from Mexico to Ecuador.  As there is no commercial value for this species, individuals are discarded. The knowledge of this ray is sparse, making management and conservation decisions difficult.

Marty Schmidt

CSU Monterey Bay