Pandalus goniurus Stimpson, 1860

Common name(s): Humpy shrimp, flexed pandalid

Synonyms: Pandalus dapifer Pandalus goniurus
Phylum Arthropoda 
Subphylum Crustacea 
Class Malacostraca 
Subclass Eumalacostraca 
Superorder Eucarida 
Order Decapoda 
Suborder Pleocyemata 
Superfamily Pandaloidea 
Pandalus goniurus, nearly 8 cm long from telson tip to rostrum tip.  Captured by otter trawl at 75 m depth, San Juan Channel.  Note the bend in the abdomen, which is more prominent than in most Pandalid shrimp.
(Photo by: Dave Cowles,m July 2008 )
Description:   As with other shrimp in Family Pandalidae, this shrimp has no exopodites on the pereopods, pereopod 1 is not subchelate, and the carpus of pereopod 2 is multiarticulated (divided up into many subunits--7 or more).  The rostrum is prominent, with movable dorsal spines. Pandalus goniurus has first antennae about as long as the carapace (the long antennae above are the second antennae).  Abdominal segment 3 is laterally compressed and has a median lobe or spine (photo).  Abdominal segment 4 does not have a mid-dorsal sharp spine on the posterior margin (photo) but does have a small ventral spine on the pleuron.  The fifth abdominal segment has a well-developed posterolateral spine.  The telson has a blunt tip and 5-7 dorsolateral spines (photo).  The uropods are longer than the telson.  The distal half of the lamella of the antennal scale is at least as wide as the spine (photo), but the spine is slightly longer than the lamella.  The distal half of the rostrum angles upward, does not have dorsal spines (photo) and is bifid (has two points).  The shrimp's overall color is translucent white with fine red stripes and small red dots.  The fine red stripes on the abdomen angle upward toward the rear.  The outer margin of the antennal scale is red.  The telson and uropods have yellow spots near their bases (photo).  The eyes are fairly large.  The left pereopod 2 is longer and thinner than the right pereopod 2 and has more annulations on the multiarticulated carpus (51-54 vs 18-20).  Males total length to about 6.2 cm, females to 7.8 mm.

How to Distinguish from Similar Species:  The laterally compressed, "humpy" third abdominal segment with the median dorsal lobe, as well as the distinctive abdominal striping help distinguish this species from other Pandalids. Pandalus danae has diagonal abdominal stripes but they are coarser and angle downward toward the back.  Pandalus stenolepus has a humped back and abdominal stripes which angle upwards toward the back like this species does, but it also has large, dark red spots and blue dots.

Geographical Range:  Off Japan, Siberia, Alaska (Bering Sea), British Columbia, down to Puget Sound.

Depth Range:  Subtidal to 450 m

Habitat:  Sandy and muddy bottoms

Biology/Natural History:   This species captures its prey between its legs before feeding on it.  It is a protandrous hermaphrodite (male first, then female later in life).  It probably is a male its first year, becomes female the second year and lays eggs, then dies.  Eggs are seen from late November to April.  Predators include sand sole.



 

References:

Dichotomous Keys:
  Kozloff, 1987, 1996
 

General References:
  Butler, 1980
  Jensen, 1995
  Lamb and Hanby, 2005

Scientific Articles:

Web sites:


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

 
Rostrum Antennal scale
The rostrum has movable dorsal spines on the proximal half but none on the distal half.  The distal half angles upward. The distal half of the lamella of the antennal scale is at least as wide as the spine, but the spine is longer than the lamella and projects beyond it.  There is red on the outer margin of the antennal scale.
These two views of the head show characteristics of the rostrum and of the antennal scale.


 
Pandalus goniurus abdomen side view Pandalus goniurus abdomen dorsal view
Abdomen side view Abdomen dorsal view
These views of the abdomen show the slightly compressed nature of the high lobe on the 3rd abdominal segment.  Note also that there is no mid-dorsal sharp spine on the ventral margin of segment 4, but there is a small spine on the posteroventral margin of that segment (on the back tip of the pleuron).  The fifth segment has a large posteroventral spine.

Telson

The telson has 5-7 lateral spines along the dorsal side and a blunt tip.  Notice that the spots near the base are yellowish.  The uropods are longer than the telson.



Authors and Editors of Page:
Dave Cowles (2008):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)