Neocrangon communis (Rathbun, 1899)

Common name(s): Gray shrimp, twospine crangon, common two-spined crangon
Synonyms: Crangon communis, Sclerocrangon communis Sclerocrangon (Neocrangon) communis
Phylum Arthropoda 
Subphylum Crustacea 
Class Malacostraca 
Subclass Eumalacostraca 
Superorder Eucarida 
Order Decapoda 
Adult female Neocrangon communis from 308 m depth near the southwest coast of Kamchatka
(Photo by: Andrey Gontchar )
Description:   As with other members of Family Crangonidae, this species has a subchelate  pereopod 1 and the carpus of pereopod 2 is not subdivided into several units.  Neocrangon communis  has a rostrum less than half as long as the carapace (as is true for most local Crangonids) and has 5 pairs of thoracic legs.  The dactyl of leg 5 is not broad and flattened.  The eyestalks are not parallel and shielded by a spiny hood.  The rostrum has a rounded tip.  It does not extend beyond the eyes and does not have a ventral expansion.  They eyes are not contiguous.  The carapace has two median dorsal spines, which are in the anterior half.  The anterior median dorsal spine does not extend beyond the bases of the orbits of the eyes and  isslightly smaller than the posterior one.  The median dorsal carina extends back to the posterior half of the carapace.  A large branchiostegal spine is present.  The general surface of the carapace is smooth, not sculptured. There is no submedian spine on the carapace. Color is gray over much of the body, with brown over the gill area.  Has pale yellow spots and fine brown to charcoal spots.  Brown spots and blotches on the abdomen, with light yellow spots along the side (except on the 5th abdominal segment).  Telson and uropods have brown spots.  The outer margin if the outer uropod is magenta.  Light pubescence on the anterior part of the carapace and in some of the grooves of the abdomen, easily rubbed off.  Male length up to 6.1 cm, females  to 8 cm.

How to Distinguish from Similar Species:

Geographical Range:   Japan, Chukchi Sea, Russia, Alaska, British Columbia down to central California

Depth Range:  16 m down to at least 1537 m.

Habitat:  Mud or mud and sand bottoms

Biology/Natural History:   This is one of the most common subtidal shrimp in this area.  It sometimes swims up into the water column, to at least 100 m off the bottom.  Ovigerous females can be found in January-February and May-September.  They bear about 2200 eggs.

Parasites include the branchial parasitic isopod Argeia pugettensis (especially in Puget Sound) and the rhizocephalan barnacle Mycetomorpha vancouverensis.

The genus Neocrangon is separated from Crangon by the fact that Crangon has an arthrobranch gill on the third maxilliped and one median spine, while Neocrangon does not have the arthrobranch gill on the third maxilliped but does have the single median spine.  Butler (1980) notes that along our coast this species does not have the arthrobranch gill but it has two median dorsal spines instead of one.  On this basis, Butler (1980) decided the separation of

the two genera is invalid and called this species C. communis.  Lamb and Hanby (2005) also follow this nomenclature.


 
 
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References:

Dichotomous Keys:
  Kozloff, 1987, 1996

General References:
  Butler, 1980 (as Crangon communis)
  Lamb and Hanby, 2005 (as Crangon communis)
  Ricketts et al., 1981

Scientific Articles:

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:
 


Authors and Editors of Page:
Dave Cowles (2009):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)

Rosario Invertebrates web site provided courtesy of Walla Walla University