Alpheus websteri is a western Atlantic snapping shrimp first described from Florida. Originally thought to occur in both the Pacific and Atlantic, Anker et al. (2008) revised this group and restricted A. websteri to the Western Atlantic. Somewhat uncommon throughout its range, this species is associated with corals and coral rubble, and can often be found in the crevices of coral. For more details, see Knowlton et al. 2008, http://biogeodb.stri.si.edu/bioinformatics/alpheus/Alpheus_Template.php?....

Alpheus websteri belongs to the Sulcatus species group within the genus Alpheus; this species and close relatives were recently revised by Anker et al. (2008). Type locality: Key West, Florida (Kingsley 1880), types stored at the National Museum of Natural History, Smithsonian Institution (USNM). Holotype: USNM 84329.

Not Alpheus websteri (sensu Wicksten 1983, Wicksten and Hendrickx 1985, Kim and Abele 1988, Villalobos Hiriart et al. 1989, Wicksten 1993, Hendrickx 1995, Camacho 1996, Vargas & Cortés 1999, Villalobos 2000, Wicksten and Hendrickx 2003 (part), McClure 2005; = A. arenensis); Alpheus Ridleyi (Pocock 1890); Alpheus ridleyi (Crosnier & Forest 1966, Chace 1972, Coelho and Ramos 1972, Fausto Filho 1974, Fausto Filho 1980, Rodriguez 1980, Cubit & Williams 1983, Rodriguez 1986, Marquez 1988, Hernandez Aguilera et al. 1996); Alpheus nigro-spinatus (Rankin 1898); Crangon nigrospinatus (Schmitt 1924). For detailed list of synonomies, see Anker et al. 2008.

Gulf of Mexico

Western Atlantic: Florida Keys (Kingsley 1880); Bahamas, Honduras, eastern Mexico, Dominican Republic, Panama, Venezuela, Lesser Antilles, Barbados, northeastern Brazil (for detailed list of locations and references, see Anker et al. 2008).

Maximum body size (carapace length, or CL) of males is 9.5 mm; females, 9.5 mm (Anker et al. 2008d). Color: body pale grey to cream-colored, with several brown transverse bands extending dorsolaterally; major chela pale brown with white areas and dark brown spots on distal half, dactylus distally pink. Closely related to Alpheus arenensis and A. fagei; A. websteri can be differentiated from A. arenensis by the relatively stouter tooth on the merus of the major cheliped, and can be distinguished from A. fagei by the longer ventrolateral tooth on the antennal basicerite. Also morphologically similar to A. thomasi, but can be differentiated by the biunguiculate dactylus in A. websteri (simple in A. thomasi) and by the absence of a ventrolateral spine on the ischium (present in A. thomasi). See Anker et al. 2008, http://biogeodb.stri.si.edu/bioinformatics/alpheus/Alpheus_Template.php?... for more details.

Type for Alpheus websteri Kingsley, 1879
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Preparation: Alcohol (Ethanol)
Collector(s): H. Webster
Locality: Florida Keys, Key West, Florida, United States, Gulf of Mexico, North Atlantic Ocean

Depth range based on 3 specimens in 1 taxon.
Water temperature and chemistry ranges based on 1 sample.

Environmental ranges
  Depth range (m): 3 - 103.3
  Temperature range (°C): 15.355 - 15.355
  Nitrate (umol/L): 33.933 - 33.933
  Salinity (PPS): 34.855 - 34.855
  Oxygen (ml/l): 0.581 - 0.581
  Phosphate (umol/l): 2.301 - 2.301
  Silicate (umol/l): 21.103 - 21.103

Graphical representation

Depth range (m): 3 - 103.3
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

A. websteri can be found on hard and mixed bottoms, associated with corals and coral rubble, often in crevices of coral rocks (Knowlton et al. 2008, Anker et al. 2008).

Snapping shrimp in the genus Alpheus have been a model system for studying molecular divergence in "transisthmian" taxa that diverged following the closure of the Isthmus of Panama. Alpheus websteri occurs in Western Atlantic, and is morphologically and genetically similar to Alpheus arenensis from the east Pacific; estimates of divergence based on genetic sequence variation suggest that this transisthmian species pair was isolated ~ 6 mya (Anker et al. 2008).

Sequenced in Williams et al. 2001, Anker et al. 2008; sequences available in GenBank for COI (EU339467-70).