Northern Brown Shrimp
Farfantepeneaus aztecus
Summary 4
Penaeus aztecus is a species of marine penaeid shrimps found around the east coast of the USA and Mexico. They are an important commercial species in the USA. The FAO refers to them as the northern brown shrimp; other common names, used in the USA, are brown shrimp, golden shrimp, red shrimp or redtail shrimp.
Description 5
The brown shrimp, Penaeus aztecus, is a species of grooved, burrowing shrimp, common in Florida waters. Antennae are significantly longer than body length. Its carapace has a medial carina on the anterior surface that is bordered on either side by a broad, somewhat rounded groove. The prominent rostrum is slightly upturned with 5-10 sharp teeth on the upper edge. The integument is thin and translucent in appearance. Chromatophores give the animal a brown to olive-green appearance, though both red and green specimens of this species have been reported. The first 3 pairs of walking legs are chelate. Uropods are rounded and generally colored reddish-brown in the distal portions. The telson bears a sharp tip and a deep medial groove anteriorally. This species exhibits sexual dimorphism, with females growing larger than males. Generally, males attain only 3/5 of female weight, and 5/6 of female length. Females are further distinguished by the presence of a closed thelycum located on the ventral sternum of the thorax, while males are identified by the presence of the pentasma.
Distribution 6
Brown shrimp occur along the Western Atlantic coast from approximately Martha's Vineyard, MA through Florida and the Gulf of Mexico to the lower Yucatan Peninsula (Williams 1984). P. aztecus occurs throughout the Indian River Lagoon.
Size 7
Large specimens of P. aztecus males attain an adult size of approximatley195 mm in length, while large female specimens may reach 236 mm in length (Williams 1955). Growth rates for juvenile P. aztecus in North Carolina were estimated by Williams (1955) to be 46 mm per month. In Louisiana, Wilson (1969) estimated growth rates ranging from 45 - 50 mm per month, with overall growth decreasing with age.Growth slows markedly when brown shrimp reach approximately 100 mm. Beyond this size class, male growth slows in comparison to female growth.
Reproduction 8
P. aztecus becomes reproductive after reaching a size of 140 mm (Renfro 1964). This species is known to have an extended spawning season that is likely to vary in different geographic areas of its range. Gonads mature in August and become opaque white, yellow or tan in color when fully ripe (Broad 1950; Brown and Patlan 1974). Brown shrimp spawn offshore at depths that generally exceed 18 m (Larson et al. 1989)Data from Burkenroad (1939) showed that sex ratios of P. aztecus change with water depth. In Louisiana waters, the sex ratio nearshore is balanced at approximately 1:1. However, in deeper waters ranging from 90 - 130 m in depth, the sex ratio changes to 1:2 in favor of females. Impregnated females in these waters occurred only beyond 18 m depth. This occurrence pattern is suggestive that spawning sites for P. aztecus are likely to be further offshore in deeper waters than occurs in other Penaeids such as P. dourarum (pink shrimp) and P. setiferus (white shrimp).
Link to Access Genomic Data 9
http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=6690&lvl=0
Sources and Credits
- (c) Sharleen, some rights reserved (CC BY-NC), uploaded by Sharleen
- (c) matbio, all rights reserved
- (c) Johnny Wilson, all rights reserved, uploaded by Johnny Wilson
- Adapted by matbio from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Farfantepenaeus_aztecus
- 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/11527471
- 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/11527472
- 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/11527477
- 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/11527476
- (c) Emily Rose Sharkey, all rights reserved
