Pandalus eous Makarov, 1935 Common name(s): Alaska pink shrimp, Pink shrimp, Northern shrimp, Deep sea prawn
Synonyms:  Pandalus borealis, Pandalus borealis eous
Phylum Arthropoda   Subphylum Crustacea    Class Malacostraca     Subclass Eumalacostraca      Superorder Eucarida       Order Decapoda        Suborder Pleocyemata         Infraorder Caridea         Family Pandalidae
	Pandalus eous, about 14 cm total length, from a 100 m depth benthic trawl in San Juan Channel, WA
	(Photo by: Dave Cowles, August 2006)

Note:  This shrimp is extremely similar to Pandalus borealis, which is found in the North Atlantic ocean and round Greenland.  Discussion is continuing on whether it is in fact P. borealis, a subspecies (P. borealis eous), or the separate species P. eous.

How to Distinguish from Similar Species:  Pandalus jordani has similar coloration and morphology but has at most a rounded posterodorsal margin on abdominal segment 3 (but no posterodorsal spine) and no posterodorsal spine on segment 4.  Most other pandalids such as P. danae do not have dorsal spines that continue out onto the distal half of the rostrum, plus have more striped coloration.  P. platyceros has dorsal spines on the distal half of the rostrum but has white stripes on the carapace and white spots on the abdomen.

Geographical Range:  In the Pacific, from the Sea of Japan and Korea to the Columbia River.  The very similar species, P. borealis, is found In the Atlantic from Maine to Scandinavia and around Greenland

Depth Range:  Subtidal.  16-1380 m depth.  Common in this area from 50-90 m depths

Habitat:  Soft bottoms (may migrate upward at night)

Biology/Natural History:  Diet is largely small crustaceans.  Pandalids capture their prey by trapping it among their legs.  Predators include dogfish, Pacific cod, hake, and turbot.  Parasites include the isopod Bopyroides hippolytes and the rhizocephalan barnacle Sylon hippolytes.  This species is a protandric hermaphrodite.  Larvae hatch in March and April and remain pelagic for 6 instars before settling to the bottom.  Become sexually mature at about 18 months at a carapace length of 1.6 cm.  At that time there is about a 50/50 ratio of males to females (if few females are present in the population, more males turn to females sooner).  Breed in mid-November.  Females carry eggs through the winter (average about 1600-2100 eggs).  In their second spring most males turn into females.  By 30 months all individuals are females and average just over 2 cm carapace length.  Live about 3-4 years.  Has been an important commercially harvested shrimp in British Columbia and Alaska.

References:

General References:
  Butler, 1980
  Jensen, 1995
  O'Clair and O'Clair, 1998

Scientific Articles:
Komai, T., 1999.  A revision of the genus Pandalus (Crustacea: Decapoda: Caridea: Pandalidae).  Journal of Natural History 33: pp 1265-1372

A related reference:  Viker, Susanne, Asa Noren Klingberg, and Per Sundberg, 2006.  The complete mitochondrial DNA sequence of the northern shrimp, Pandalus borealis.  J. Crustacean Biology 26:3 433-435

Web sites:
 

A profile of abdominal segment 3 shows the spines present near the middle and the posterior end of the middorsal line

The fourth abdominal segment also has a spine present at the posterior end of the middorsal line.

This view of the left antennal scale, which is longer than the telson shows that the antennal lamella is slightly longer than the spine.
Just above the scale the endopodite of the second antenna, which consists of several segments then a flexible whiplike "flagellum" composed of many small segments and being about as long as the animal's body.
The antennal scale is the exopodite of the second antenna.

As with all Pandalids, the carpus of the second leg is "multiarticulated"--it has many ringlike striations in it that allow it to bend.
Most Pandalids that I have observed hold this second leg up next to the body and it is hard to get a clear view of it in a living individual.

The telson has a double row of 6-10 spines along the dorsal surface.  This is an oblique view of the telson from the right side, with the right uropods missing.
The left uropods, which are slightly shorter than the telson, are visible behind the telson.
 

This gravid female was collected at 375 m depth in the Okhotsk sea, near the southwestern shore of Kamchatka on April 12, 2008.

Photo by Andrey Gontchar of VNIRO

Dorsal view of the same shrimp.  Photo by Andrey Gontchar.