Spirontocaris lamellicornis (Dana, 1852)

Common name(s): Dana's blade shrimp, Dana's bladed shrimp
Synonyms: Hippolyte lamellicornis  Spirontocaris lamellicornis
Phylum Arthropoda 
Subphylum Crustacea 
Class Malacostraca 
Subclass Eumalacostraca 
Superorder Eucarida 
Order Decapoda 
Family Thoridae (formerly assigned to Hippolytidae) 
Spirontocaris lamellicornis, captured from 60-100 m depth in San Juan Channel.
(Photo by:  Dave Cowles, July 2010)
Description:   As with all members of family Hippolytidae, this shrimp has no exopodites on its pereopods, the carpus of pereopod 2 is divided into 3-7 units, and it has a rostrum.  Like other members of genus Spirontocaris, this species has two or more supraorbital spines (photo), seven articles in the carpus of pereopod 2, plus the third maxilliped has an exopod, an epipod, and a small chela.  In Spirontocaris lamellicornis the mid-dorsal carapace teeth do not have small spines on their anterior margins (photo).  The third pereopod has an epipodite.  The ventral margins of the pleura of the first five abdominal segments are acute or with a spine.  The dactyls of pereopods 3-5 have simple but curved tips.  The rostrum is deep and extends beyond the peduncle of the first antenna.  The rostrum has 9-23 dorsal teeth including 4-5 on the mid-dorsal carapace, and 1-3 ventral teeth.  Each segment of the peduncle of the first antennae has a distal spine.  The telson has 4 pairs of dorsolateral spines and an acute tip.  Color pattern variable, often dark brown with pereopods dark red to colorless.  Tail fan is banded (photo), may be milkish with fine red mottling, yellow and brown or black spots.  Sixth abdominal segments often red to purple (photo).  Male to 4.2 cm long, female to 6.3 cm.

Recently members of family Hippolytidae which have seven articles in the carpus of the 2nd pereopod have been reassigned to family Thoridae.

How to Distinguish from Similar Species: Spirontocaris prionota has small spines on the anterior margins of its mid-dorsal carapace teeth.  Spirontocaris ochotensis, S. truncata, S. arcuata, S. spina, and S. snyderi have bifid tips on the dactyls of pereopods 3-5.

Geographical Range:   Bering Sea to Santa Monica Bay, CA.  Mostly north of Point Conception, CA but some have been found in canyons in Santa Monica Bay.

Depth Range:  Subtidal, 3-192 m.

Habitat:  Mostly on sand and mud, some in rocky areas.

Biology/Natural History:  This species is often found symbiotically with sea anemones including Cribrinopsis fernaldi and Urticina columbiana.  In the Salish Sea and coastal British Columbia the species is often infested by the branchial isopod Bopyroides hippolytes.


 
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References:

Dichotomous Keys:
  Kozloff, 1987, 1996
  Wicksten, 2009

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

Scientific Articles:

Web sites:

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

Preserved individual

This is frozen specimen about 6 cm long.  Found by Hilary Lease near Friday Harbor.


Closeup of carapace and rostrum
This closer view of the carapace and rostrum shows how deep the rostrum is and the large mid-dorsal teeth.  A frozen individual.


Supraorbital spines
The two supraorbital spines are visible in this photograph.    A frozen individual.

dactyl

The dactyls of pereopods 3-5 have simple but curved tips.  Photo of live individual by Dave Cowles, July 2010


Uropods and telson
The uropods and telson are often banded with lighter colors.    A frozen individual.

Telson--live

This photo of a live individual also shows the banded telson, plus the red color of the sixth abdominal segment.


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