Description: This mysid does not have numerous long spines on its carapace and abdomen. The cornea of the eye is not divided into two portions (photo). The scale of antenna 2 has a rounded tip and both the inner and outer margins have setae (photo). The carapace is not expanded laterally and anterolateral margin of the carapace is rounded (photo). The last abdominal segment is smooth, with no transverse folds. It has a nearly straight posterior dorsal margin, without an acute mid-dorsal projection (photo). The telson is not cleft (photo). It has two large spines on the end and a row of many spines of equal size along each margin (photo).
How to Distinguish from Similar Species: Several other mysid species have acute anterolateral margins on the carapace. Pacificanthomysis nephrophthalma has a telson with alternating sets of shorter spines among the longer spines along the lateral margins.
Geographical Range: At least in the Bering Sea, Sea of Okhotsk, and Arctic Ocean. K. Derjugen (1912) lists this species in an article about Arctic Ocean species in the collection from the Murmansk Marine Laboratory near St Petersburg, Russia. A UN project document for NW India (Gujarat?) lists this species as occurring in that portion of the northern Indian Ocean.
Habitat: I found clusters of this mysid hovering around kelp in a low intertidal tidepool (photo).
is probably pelagic
It swims vigorously with its pereopods
(thoracic appendages). Inner branches of these same pereopods
make up the oostegites
(flaplike covers which fit together into a marsupium
(pouch) to shelter the eggs and larvae on the female's abdomen).
Wing (1975) reports in Fishery Bulletin 73: 169-185 that the
(a protist) parasitizes a close relative of this species.
typically appear as a stringy white mass attached to the ventral side
the anterior abdominal segments. The Great Soviet
that mysids such as this can be found from the surface to a depth of 7
km and also in brackish waters, lakes, and rivers and that they serve
food for herring, sprat, perch, cod, and other fish. The
photo with the article in the Great Soviet Encyclopedia, however, is of
than a mysid. This species is one of the food items for young
seals. They can be found near the sea ice over the
in spring feeding on algae under the ice.
Kozloff, 1987, 1996
Derjugen, K., 1912. Die Murmansche biologische station der K. naturforscher Gesellschaft zu St. Petersburg und ihre arbeiten im Nordischen Eismeer. Proceedings of the Seventh International Zoological Congress, Boston, 19-24 August, 1907
Kathman, R. D., W. C. Austin, J. C. Saltman, and J. D. Fulton. 1986. Identification manual to the Mysidacea and Euphausiacea of the northeast Pacific. Department of Fisheries and Oceans,Ottawa, Canada. 411 p.
General Notes and Observations: Locations, abundances, unusual behaviors:
Here is the swarm of mysids in the tidepool the above individual was sampled from. Photo by Dave Cowles, July 2012
Other interesting views:
Authors and Editors of Page:
Dave Cowles (2012): Created original page
CSS coding for page developed by Jonathan Cowles (2007)
Salish Sea Invertebrates web site provided courtesy of Walla Walla University