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Phylum: Cnidaria Anthopleura artemisia (=Evactis artemisia) Class: Anthozoa, Zoantharia Order: Actiniaria A burrowing anemone (Pickering in Dana, 1848) Tribe: Thenaria, Endomyaria Family: Actiniidae

Description Size—most around 25 mm diameter, 60-70 Verrucae (Tubercules)—rounded, wart-like mm long; largest observed (California): 90 structures; adherent, collect shell, debris for mm long, 25 mm column diameter (Hand protection; also contain cinclides (pores) (see 1955b). This specimen is 20 mm long, 25 mm fig. 4, A. elegantissima). Verrucae on collar crown diameter, 15 mm column diameter. (where they are compound, with 3-6 vesicles Color—oral disc can be red, brown, gray, each (fig. 3); well-developed, in longitudinal black (solid or con-centric patterns); this rows on upper third of column, sparsely specimen: brown disc, tan spots, light tan spaced and single in middle third of column; mouth. Tentacles brightly colored and/or usually none on lowest third of column: patterned: red, white, black, blue, or orange; species Artemisia (Hand 1955b). Verrucae species Artemisia (Hand 1975). This near acrorhagi sometimes white-tipped. specimen: "day glo" and pink tentacles, pink Mesenteries—interior vertical partitions; up to spots on oval disc. Column: top (distal) third 24 pairs in some adults; often irregular due to black, brown, or gray shading to white or pink asexual longitudinal fission. Mesenterial at proximal third (this specimen: gray). insertions often visible on proximal third of Verrucae on collar tend to be white-tipped column in elongated specimens, as white (Hand 1955b). Mesentery insertions can be lines (not shown). visible on bottom 3rd of column, showing as Nematocysts (Cnidae)—tiny stinging cells; vertical white lines (not on this specimen). many kinds, differing in size, distribution from Acrorhagi white (fig. 2). other species (not shown). Shape—can be quite elongate (not figured); Acontia—(thread-like defensive structures long column, with tubercules near top; slender, expelled through column wall); none. tapering tentacles; broad flat oral disc. Tentacles—numerous, slender, tapering; Prominent collar and acrorhagi (spherules). A. about 1/2 as long as oral disc diameter; rarely; artemisia can also contract into a crevice with more than 5 orders (Hand 1955b). only its crown showing. When contracted, it Arrangement sometimes irregular due to forms a low round-topped pillar (fig. 1) (Hand longitudinal fission of animal. 1955b). Adherent shell and debris are typical Oral Disc—broad, usually flat, about 11/2 x of this solitary species. column diameter when expanded. Radial Base—circular to irregular; well attached to lines (mesenterial insertions) (fig. 2). Open substrate; often wider than column; no physa central area (tentacle-free) sometimes with (bulb) at base. radial pattern. Column—can extend to 5x diameter; well- Lips—not ribbed; do not protrude above disc developed collar; longitudinal rows of surface; usually with siphonglyphs (ciliate verrucae, especially on uppermost (distal) grooves) but can have 1 or 3. Mouth third of column (fig. 1), rarely any verrucae on commonly an elongate slit (Fig. 2). proximal 3rd of column: species Artemisia (Hand 1975). Possible Misidentifications Collar (Parapet)—well-developed, separated There are other more common estuarine from tentacles by deep fosse (groove) in anemones (Metridium, Haliplanella, etc.), but which there are acrorhagi (spherules). Collar none of them have acrorhagi covered with compound verrucae (fig. 3). inside the fosse at the collar edge, or Acrorhagi (Spherules)—round, hollow white adherent tubercules on the column. in-conspicuous structures in fosse, just under Anthopleura species have both of these, as tentacles (fig. 2, 3): genus Anthopleura; well as a well-developed pedal disc (base), contain nematocysts (Hyman 1940c). Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected] and a flat broad oral disc with a clear central Life History Information area. Reproduction—sexual: separate sexes; Anthopleura xanthogrammica is usually an gonads borne on directive mesenteries open coast species, large, green solitary and attached to siphonoglyphs; asexual unicolored; its column is completely covered reproduction by longitudinal fission. with verrucae (they are not in rows). It is Growth Rate— found occasionally in the lower reaches of the Longevity— most marine estuaries. Food—small crustaceans. Anthopleura elegantissima, the Predators—not one of the preferred foods of aggregating anemone, can be solitary, like A. coelenterate predator Aeolidia (Waters 1975). artemisia, and is often found in like habitats, Behavior—retracts completely into "burrow" i.e. rock substrate with sand and mud over when disturbed. the rock. A. elegantissima has verrucae in longitudinal rows on the entire column, not Bibliography just on the upper part; the column is green or 1. HAND, C. H. 1955b. The sea whitish, not black or gray fading to pinkish. anemones of central California. Part II. The tentacles in elegantissima are pink, white, The endomyarian and mesomyaroan purple, blueish or green, not brightly colored anemones. Wasmann Journal of red, orange or patterned, as in A. artemisia. A. Biology. 13:37-99. elegantissima, when solitary, is usually larger 2. ——. 1975. Class anthozoa, p. 85-93. than A. artemisia, which never has symbiotic In: Light's manual; intertidal algae in its endoderm. A. artemisia is the only invertebrates of the central California species of the genus whose verrucae do not coast. S. F. Light, R. I. Smith, and J. T. extend down to the base. Carlton (eds.). University of California Small artemisia can be confused with Press, Berkeley. Metridium when contracted, for their bright 3. HYMAN, L. H. 1940c. The tentacles are hidden and they are plain gray invertebrates: protozoa through or greenish (Ricketts and Calvin 1971). ctenophora. McGraw-Hill, New York. 4. RICKETTS, E. F., and J. CALVIN. Ecological Information 1971. Between Pacific tides. Stanford Range—Alaska to southern California; University Press, Stanford, California. possibly Japan (Hand 1955b). 5. WATERS, V. L. 1975. Food Local Distribution—Coos Bay Pigeon Point. preference of the nudibranch Aeolidia Habitat—in estuaries, attached to a solid papillosa and the effect of the substrate, often in a crevice or pholad burrow; defences of the prey on predation. The column often buried in mud or sand, with only Veliger. 15:174-192. crown exposed; withdraws into its burrow when disturbed or at low tide. Also on pilings, floats, and on open coast. Salinity—collected at 30‰ salt. Temperature— Tidal Level—distribution centers around mean lower low water, but also found occasionally quite a bit higher (Hand 1955b). Associates—

Quantitative Information Weight— Abundance—

Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected]

Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected]