Published December 31, 2016 | Version v1
Taxonomic treatment Open

Mediaster aequalis Stimpson 1857

Description

Mediaster aequalis Stimpson 1857

Stimpson 1857: 530; Fisher 1911: 198; Ziesenhenne 1937: 214; Alton 1966a: 1682, 1701; Blake 1973: 49; Kozloff 1987: 449, 450, 453 (key & checklist); Maluf 1988: 34, 118; A.M. Clark 1993: 262; Lambert 2000: 57, 67; Lamb & Hanby 2005:327; Mah 2007b: 927(in key) (as Mediaster aequalis)

Dujardin & Hupé 1862: 365 (as Ophidiaster)

Occurrence. Alaska / Aleutian Islands, British Columbia, Washington, Oregon, California (including Cordell Bank) to Southern California and Gulf of California (Cortez Seamount), intertidal to 1500 m.

Comments. Although three specimen lots are outlined below, they all represent sampling from one locality. This record of this primarily shallow-water species below 1000 m suggests that it is the lower limit of this species’ distribution. The largest of those sampled had an R=2.6 with only three furrow spines. Larger, shallower individuals display up to five furrow spines. Pedicellariae were not observed on these smaller individuals (R<2.0) which also display three furrow spines. These specimens also showed a more weakly stellate body form (R=~1.8) versus the R/r=2.6 as outlined by Fisher (1911).

One specimen of Mediaster aequalis collected from Cortez Bank in the Gulf of California from 91.4 m showed a stellate body from (R/r=2.3) but with sharply triangular arms, four furrow spines (at R=2.8), and a strongly expressed superomarginal plate series which occupies approximately 28% of the distance r (disk center to edge of interradius) whereas more northern individuals display superomarginals which occupy only 14% of the distance r.

Material examined. CASIZ 117511, 2–3 nautical miles SW of Pt. Soberantes, Monterey County, California. 36º25’7N, 120º58’20”W, 1280–1500 m (700–820 fms). Coll. R / V Searcher. 7 wet spec. R=1.6, r=0.8; R=1.1, r=0.6; R=1.2; r=0.6; R=1.7, r=0.8; R=1.4, r=0.7; R=1.8, r=0.9; R=2.6, r=1.4. CASIZ 117603, 2–3 nautical miles SW of Pt. Soberantes, Monterey County, California. 36º25’7N, 120º58’20”W, 1280–1500 m (700–820 fms). Coll. R / V Searcher. 1 wet spec. R=1.0, =0.5. CASIZ 115535, 2–3 nautical miles SW of Pt. Soberantes, Monterey County, California. 36º25’7N, 120º58’20”W, 1280–1500 m (700–820 fms). Coll. R / V Searcher. 1 wet spec. R=1.1, =0.6.

Gulf of California. CASIZ 117620 Cortez Bank 32º34’N, 119º16’W, 91.4 m (50 fms). Coll. Crocker-Stanford Deep-Sea Expedition, R / V Zaca. 1 wet spec. R=2.8, r=1.2.

Notes

Published as part of Mah, Christopher L., 2016, Deep-sea (> 1000 m) Goniasteridae (Valvatida; Asteroidea) from the North Pacific, including an overview of Sibogaster, Bathyceramaster n. gen. and three new species, pp. 101-141 in Zootaxa 4175 (2) on pages 119-120, DOI: 10.11646/zootaxa.4175.2.1, http://zenodo.org/record/257286

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Linked records

Additional details

Biodiversity

Collection code
CASIZ
Family
Goniasteridae
Genus
Mediaster
Kingdom
Animalia
Material sample ID
CASIZ 115535, 2-3 , CASIZ 117511, 2-3 , CASIZ 117603, 2-3 , CASIZ 117620
Order
Valvatida
Phylum
Echinodermata
Scientific name authorship
Stimpson
Species
aequalis
Taxon rank
species
Taxonomic concept label
Mediaster aequalis Stimpson, 1857 sec. Mah, 2016

References

  • Stimpson, W. (1857) On the Crustacea and Echinodermata of the Pacific shores of North America. Boston Journal of Natural History, 6, 444, 532.
  • Fisher, W. K. (1911) Asteroidea of the North Pacific and adjacent waters. 1. Phanerozonia and Spinulosida. Bulletin of the US National Museum, 76: xiii + 420 pp. 122 pls.
  • Ziesenhenne, F. C. (1937) The Templeton Crocker Expedition. X. Echinoderms from the West Coast of Lower California, the Gulf of California and Clarion Island. Zoologica. Scientific Contributions New York Zoological Society, 22 (3), 209 - 289.
  • Alton, M. (1966 a) Bathymetric distribution of sea stars (Asteroidea) off the Northern Oregon coast. Journal of the Fisheries Research Board of Canada, 23 (11), 1673 - 1714.
  • Blake, D. B. (1973) Ossicle morphology of some recent asteroids and description of some west American fossil asteroids. University of California Publications in Geological Science, 104, 1 - 59.
  • Kozloff, E. N. (1987) Marine Invertebrates of the Pacific Northwest. University of Washington Press, Seattle, WA, 511 pp.
  • Maluf, Y. (1988) Composition and distribution of the central eastern Pacific echinoderms. Natural History Museum of Los Angeles County, Technical Reports, 2, 242 pp.
  • Clark, A. M. (1993) An index of names of recent Asteroidea - Part 2: Valvatida. E chinoderm Studies, 4, 187 - 366.
  • Lambert, P. (2000) Sea Stars of British Columbia, southeast Alaska, and Puget Sound. Royal British Columbia Museum Handbook, 186 pp.
  • Lamb, A. & Hanby, B. P. (2005) Marine Life of the Pacific Northwest: A photographic encyclopedia of invertebrates, seaweeds and selected fishes. Harbour Publishing, Medeira Park, British Columbia, 398 pp.
  • Mah, C. L. (2007 b) Asteroidea, In: Carlton, J. T. (Ed.), The Light & Smith Manual: Intertidal Invertebrates from the Central California to the Oregon coasts. Fourth Edition. University of California Press, Berkeley and Los Angeles.
  • Dujardin, M. F. & Hupe, M. H. (1862) Histoire naturelle des Zoophytes. Echinodermes. 627 pp. [Paris: Libraire Encyclopedique de Ronet.]