White Shrimp
Litopenaeus setiferus
Description 3
The white shrimp, Penaeus setiferus, was the first species of commercially important shrimp in the U.S., with the fishery for this species dating back to 1709 (Muncy 1984). P. setiferus is common in Florida waters and is generally found where water is less than 27 m deep (Muncy 1984). Antennae are significantly longer than body length, and may reach 2.5 - 3 times body length (Muncy 1984). Chromatophores in white shrimp are widely spaced, thus lending a lighter body color to this species than in either pink or brown shrimp. Overall body color is a bluish white, speckled with black, with pink-tinged sides. Pleopods are often marked with dark red, while the margins of the uropods of the tail are green along their margins (Williams 1984). Its carapace has a medial carina (keel-like ridge) that is continuous with the rostrum at the anterior end of the animal, and extends posteriorly approximately 2/3 the length of the carapace. The rostrum is elongate and slender, somewhat distally upcurved, with 5 - 11 (usually 9) sharp teeth on the dorsal surface, and 2 teeth on the ventral edge. Unlike its congeners P. aztecus and P. duorarum, P. setiferus has no bordering groove along the carina. The integument is thin, and appears polished and translucent.The abdomen is carinate on segments 4 - 6, with the carina of segment 6 having a narrow groove on either side. The telson has a deep medial groove along its length, and a sharp tip. The ventral margin of the pleura of the first segment is almost straight.P. setiferus is sexually dimorphic, with females growing larger than males. Additionally, the female thelycum, which lies between pereopods 3- 5, is open and has raised ridges along the anterolateral surface. The male pentasma has a diagonal ridge across the dorsolateral lobe.
Distribution 4
The distribution of the White shrimp (Litopenaeus setiferus) appears to be discontinuous. It occurs along the Atlantic Coast of the United States from Fire Island (New York) south to central Florida and along the north coast of the Gulf of Mexico and the northeastern coast of Mexico (with a center of abundance in Louisiana), continuing southward to Campeche, Mexico (with another center of abundance in northeast Tabasco and the adjacent waters of Campeche). In addition to the large distributional discontinuity around southern Florida and the west side of the Florida Peninsula, this species is patchily distributed within its range on a smaller scale, possibly as a result of local variation in salinity, temperature, substrate, food, or cover. (Perez-Farfante 1969)
Size 5
Large males measure approximately 182 mm in length. Large females grow slightly larger and eventually reach 200 mm. Williams (1984) reported that females beyond the juvenile stage are consistently larger than males.In estuaries, juvenile white shrimp grow approximately 1.2 mm per day during late spring and summer months (Williams 1965). Growth is slow in spring, but quickens with the onset of summer. Growth rates decrease during the fall months, but shrimp that remain in estuaries to overwinter resume growing the following spring (Muncy 1984). Few white shrimp live as long as a year (Anderson 1966), however, mark-recapture studies have revealed that some white shrimp live from 27 months to as much as 4 years (Etzold and Christmas 1977; Klima et al. 1982).
Life cycle 6
White Shrimp eggs hatch within a few hours after spawning and the young emerge as nauplii, the first of 11 larval stages (Perez-Farfante 1969 and references therein).
Reproduction 7
Mature males produce ripe sperm when they reach lengths of approximately 118 mm. Females mature at lengths of approximately 135 - 140 mm. Gonadal development in females can be judged by ovary color. Undeveloped ovaries are opaque and white in color. Developing ovaries appear yellow, a stage which may last 1 - 2 months. Ripe ovaries are an olive color, and may remain so until fully spent (generally in less than 1 month). Spent ovaries quickly develop to the yellow stage within a few days, and will ripen again within 2 - 3 months (King 1948; Brown and Patlan 1974).Spawning behavior in P. setiferus is initiated by an increase in offshore bottom water temperatures during spring (Whitaker 1981). In the Carolinas, spawning occurs from May through September (Williams 1955), while further south in the Gulf of Mexico, spawning occurs from March through September. Williams (1965) and Joyce (1965) each reported only one spawning period for P. setiferus. However, Gunter (1950) suggested spring and fall spawning periods in Texas waters.Spawning occurs as far as 9 km from the shore, in water depths of at least 9 m (Whitaker 1983b), with females discharging eggs directly to the water column without brooding them as is common in other crustaceans. During copulation, which occurs between hard-shelled individuals, the male attaches a spermatophore to the thelycum of a female. Spermatozoa are released simultaneously with eggs from the female, with fertilization occurring in the water column. Eggs are opaque with a blue-tinged chorion (Linder and Cook 1970) and measure approximately 0.19 - 0.20 mm in diameter. Eggs sink to the bottom of the water column as they are released, and hatch within 10 - 12 hours into planktonic nauplii larvae that measure approximately 0.3 mm in length. Between 500,000 to 1 million eggs are released per spawn.
Link to Access Genomic Data 8
http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=64468&lvl=0
Sources and Credits
- (c) David Gardner, some rights reserved (CC BY-NC), uploaded by David Gardner
- (c) cbrown22, some rights reserved (CC BY-NC), uploaded by cbrown22
- (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11527490
- (c) Shapiro, Leo, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11290097
- (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11527495
- Adapted by matbio from a work by (c) Shapiro, Leo, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11290099
- Adapted by matbio from a work by (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11527494
- (c) Emily Rose Sharkey, all rights reserved
