Anthopleura Artemisia Class: Anthozoa, Hexacorallia Order: Actiniaria, Nynantheae, Thenaria Buried Anemone, Moonglow Anemone Family: Endomyaria, Actiniidae

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Phylum: Cnidaria Anthopleura artemisia Class: Anthozoa, Hexacorallia Order: Actiniaria, Nynantheae, Thenaria Buried anemone, moonglow anemone Family: Endomyaria, Actiniidae

Taxonomy: Anthopleura artemisia was tubercules (verrucae) near the top. Its originally described by Pickering in Dana tentacles are slender and tapering. They are (1846) as Actinia artemisia. The subclass extensions of the gut cavity, and so are Zoantharia has been synonymized with hollow. The anemone has a broad flat oral Hexacorallia (Hoeksema 2015). disc, a prominent collar, and acrorhagi (spherules). Anthopleura artemisia can also Description contract into a crevice with only its crown Medusa: No medusa stage in Anthozoans. showing. When contracted, it forms a low Polyp: round-topped pillar (fig. 1) (Hand 1955). The Size: Most solitary polyps are around column has a groove below the tentacles 2.5 cm in diameter, and can extend 6-7 cm (fosse) covered by a distinct fold (parapet or long. The specimen used for this description collar). Adherent shell and debris are typical was 2 cm long, with a 2.5 cm crown diameter of this solitary species. and 1.5 cm column diameter. The column Column: The column can may have to extend 15-20 cm from its extend to 5 times the diameter. It has a well- attachment to the sediment surface, and a developed collar and longitudinal rows of fully expanded crown and tentacles can be 5 verrucae on uppermost (distal) third of column cm in diameter (Kozloff 1983). (fig. 1). There are rarely any verrucae on Color: The oral disc can be red, proximal 3rd of column (Fautin and Hand brown, gray, or black, and can have solid or 2007). concentric patterns. The specimen used for Collar: The parapet is well- this description had a brown disc with tan developed and separated from tentacles by a spots and a light tan mouth. Tentacles can be deep fosse (groove) in which there are brightly colored and/or patterned with nearly acrorhagi (spherules). The collar is covered every color (red, white, black, blue, or orange, with compound verrucae (fig. 3). Hand 1975; pink and green, Ricketts et al. Oral Disc: The oral disc is a 1985; white bands on gray, brown, black, or large central area without tentacles on the top green background, Kozloff 1974). The of the column, and sometimes has a radial specimen used for this description had "day pattern. It is broad, usually flat, and about 1.5 glow" and pink tentacles and pink spots on times the column diameter when expanded. It oval disc. The discs can also be has radial lines (mesenterial insertions) (fig. semitransparent (Ricketts et al. 1985). The 2). Its lips are not ribbed and do not protrude top third of the column is black, brown, or gray above the disc surface. They usually have shading to white or pink at the bottom third siphonglyphs (ciliate grooves). The mouth is (the specimen used for this description was commonly an elongate slit (Fig. 2). gray). Verrucae on the collar tend to be white- Tentacles: There are tipped (Hand 1955). Mesentery insertions can numerous slender, tapering tentacles. They be visible on the bottom 3rd of column, are about half as long as the oral disc showing as vertical white lines (not on the diameter. There are rarely more than 5 orders specimen used in this description). Acrorhagi (rows) (Hand 1955). Arrangement is are white (fig. 2) (Fautin and Hand 2007). sometimes irregular due to longitudinal Body: The polyp can have a very fission. There are no acontia (thread-like extended column (not figured), with defensive structures expelled through column wall).

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12638 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Mesenteries: Mesenteries are found occasionally in the lower reaches of the interior vertical partitions. There are up to 24 most marine estuaries. pairs in some adults. They are often irregular Anthopleura elegantissima, the aggregating due to asexual longitudinal fission. anemone, can be solitary, like A. artemisia, Mesenterial insertions are often visible as and is often found in like habitats, i.e., rock white lines on the proximal third of the column substrate with sand and mud over the rock. in elongated specimens (not shown). Anthopleura elegantissima has verrucae in Pedal Disc: The pedal disc longitudinal rows on the entire column, not attaches the column firmly to the substrate. It just on the upper part; the column is green or is circular to irregular, and is often wider than whitish, not black or gray fading to pinkish. the column. There is no physa (bulb) at the The tentacles in A. elegantissima are pink, base. white, purple, blueish or green, not brightly Cnidae: Cnidae are tiny stinging cells. colored red, orange or patterned, as in A. Anthopleura artemisia has many different artemisia. Anthopleura elegantissima, when kinds, varying in size, distribution from other solitary, is usually larger than A. artemisia, species (not shown). which never has symbiotic algae in its Acrorhagi: Also known as spherules, endoderm. Anthopleura artemisia is the only these fighting tentacles are round, hollow species of the genus whose verrucae do not bodies covered with nematocysts. They are extend down to the base. inconspicuous structures in the fosse, just A third species of Anthopleura, A. sola, is very under the tentacles (fig. 2, 3) (Hyman 1940). similar in appearance to A. elegantissima. Verrucae: These are rounded, wart- The primary difference between the two is like tubercule structures that pebble the that A. elegantissima is clonal while A. sola is column. They are well-developed and solitary. Though A. sola is not found locally, arranged in longitudinal rows on upper third of there are many examples in the literature of column, and sparsely spaced and solitary on A. sola being misclassified as A. the middle third of column; there are usually elegantissima, and some examples of it being none on lowest third of column (Hand 1955). misclassified as A. artemisia (Pearse and They are also on the collar, where they are Francis 2000). compound, with 3-6 vesicles each (fig. 3). Retracted A. artemisia can be confused with Verrucae are adherent, and collect a layer of Metridium, for their bright tentacles are hidden shells and debris for protection (MacGinitie and they are plain white or green-gray and MacGinitie 1968). They also contain (Ricketts et al. 1985). cinclides (pores) (see fig. 4, A. elegantissima). Those near the acrorhagi are sometimes Ecological Information white-tipped. Range: The type localities are Discovery Harbor, Puget Sound, and the northwest Possible Misidentifications coast of North America (Pickering in Dana There are other more common estuarine 1846). The range is Alaska to southern anemones (Metridium, Diadumene, etc.), but California (Ricketts et al. 1985), and possibly none of them have acrorhagi inside the fosse Japan (Hand 1955). at the collar edge, or adherent tubercules on Local Distribution: In Coos Bay, they can be the column. Anthopleura species have both of found in high abundance at Pigeon Point. these, as well as a well-developed pedal disc Habitat: In estuaries, Anthopleura artemisia’s (base), and a flat broad oral disc with a clear column is often buried in mud or sand in a central area. crevice or pholad burrow, with only the crown Anthopleura xanthogrammica is usually an exposed, while the base is attached to solid open coast species, large, green solitary and substrate beneath the softer sediment. It unicolored; its column is completely covered withdraws into its burrow when disturbed or at with verrucae (they are not in rows). It is low tide. It can also be found on pilings, floats, and the open coast. It is solitary on open

Piazzola, C.D. and T.C. Hiebert. 2015. Anthopleura artemisia. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. coasts, lives in groups in estuaries, and is prey to other nudibranchs and small fish individually attached to stones buried in the (Ottaway 1977). muddy sand (Fautin and Hand 2007). Behavior: They will retract completely into Salinity: Collected at 30. their "burrow" when disturbed. They will Temperature: 8° C to 13° C (Anderson display aggressive behavior when brought 2000). into contact with members of the same Tidal Level: Distribution centers around species as well as other anemone species. mean lower low water, but specimens are This behavior is similar to the aggressive also found occasionally quite a bit higher response in A. elegantissima, in which the (Hand 1955). acrohagi inflate and attack neighboring Associates: Though there is some debate on anemones (Francis 1973). the topic (Kozloff 1983), it is unlikely that A. artemisia contains the symbiotic green algae Bibliography (zoochlorellae) and dinoflagellates (zooxanthellae) that are found in other 1. ANDERSON, R. C. 2000. Sea Anthopleura species (Geller and Walton anemones of the north-eastern Pacific: 2007; Weis et al. 2005). Copepods the flowers of the sea. International sometimes live on the anemone’s column Zoo Yearbook. 37:321-330. (Lønning and Vader 1984). 2. FAUTIN, D. G., and C. HAND. 2007. Abundance: This species is less abundant Anthozoa, p. 173-184. In: The Light than A. elegantissima in most places (Smith and Smith Manual: intertidal and Potts 1987). invertebrates from central California to Oregon. J. T. Carlton (ed.). University Life-History Information of California Press, Berkeley. Reproduction: There are both sexual and 3. FRANCIS, L. 1973. Intraspecific asexual reproductive cycles. Individual aggression and its effect on the anemones are sexually dioecious. Gonads distribution of Anthopleura are borne on directive mesenteries attached elegantissima and some related sea to siphonoglyphs. This species has been anemones. Biological Bulletin. 144:73- witnessed in mass spawning events during 92. low tide, in which nearly every individual in 4. GELLER, J. B., and E. D. WALTON. the area releases their gametes in broadcast 2001. Breaking up and getting spawning (Weis et al. 2005). Asexually, together: evolution of symbiosis and specimens can divide by longitudinal fission. cloning by fission in sea anemones Larva: This species produces feeding planula (genus Anthopleura). Evolution. larvae with similar development to A. 55:1781-1794. elegantissima (Weis et al. 2005). They are 5. HAND, C. H. 1955. The sea ovaloid to cylindrical, covered in cilia, and anemones of central California. Part II. have an apical tuft. They actively swim using The endomyarian and mesomyaroan the cilia on their apical tuft (Sadro 2001). anemones. Wasmann Journal of Juvenile: Biology. 13:37-99. Longevity: Unknown. 6. —. 1975. Class anthozoa, p. 85-93. In: Growth Rate: Unknown. Light's manual: intertidal invertebrates Food: Anthopleura artemisia is a carnivorous of the central California coast. S. F. stationary hunter in the tidepools (Niesen Light, R. I. Smith, and J. T. Carlton 2007) that uses tentacles to capture prey (eds.). University of California Press, (Ricketts et al. 1985). It primarily eats small Berkeley. crustaceans. 7. HOEKSEMA, B. 2015. Hexacorallia. Predators: This anemone is not one of the Vol. 2015, World Register of Marine preferred foods of coelenterate predator Species: Aeolidia papillosa (Waters 1975). It is eaten http://www.marinespecies.org/aphia.p by occasionally by A. papillosa, and is likely

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12638 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] hp?p=taxdetails&id=1340. [Accessed under C. Wilkes, USN commander, in 9/23/2015]. the years 1838-1842. J. D. Dana (ed.). 8. HYMAN, L. H. 1940. The Google eBooks. Invertebrates: Protozoa through 18. RICKETTS, E. F., J. CALVIN, J. W. Ctenophora. McGraw-Hill, New York, HEDGEPETH, and D. W. PHILLIPS. London. 1985. Between Pacific tides. Stanford 9. KOZLOFF, E. N. 1974. Keys to the University Press, Stanford, CA. marine invertebrates of Puget Sound, 19. SADRO, S. 2001. Cnidaria the San Juan Archipelago, and (Coelenterata), p. 13-23. In: An adjacent regions. University of identification guide to the larval marine Washington Press, Seattle. invertebrates of the Pacific Northwest. 10. —. 1983. Seashore life of the northern A. L. Shanks (ed.). Oregon State Pacific coast. University of University, Corvallis. Washington Press, Seattle. 20. SMITH, B. L., and D. C. POTTS. 1987. 11. —. 1987. Marine invertebrates of the Clonal and solitary anemones Pacific Northwest. University of (Anthopleura) of western North Washington Press, Seattle. America: population genetics and 12. LONNING, S. V., W. 1984. Sibling systematics. Marine Biology. 94:537- species of Doridicola (Copepoda: 546. Lichomolgidae) from California sea 21. WATERS, V. L. 1975. Food anemones: biology and host preference of the nudibranch Aeolidia specificity. Journal of Experimental papillosa and the effect of the Marine Biology and Ecology. 77:99- defences of the prey on predation. The 135. Veliger. 15:174-192. 13. MACGINITIE, G. E., and N. 22. WEIS, V. M., E. A. VERDE, A. MACGINITIE. 1968. Natural history of PRIBYL, and J. A. SCHWARZ. 2002. marine animals. McGraw-Hill Book Aspects of the larval biology of the sea Co., New York. anemones Anthopleura elegantissima 14. NIESEN, T. M. 2007. Intertidal and A. artemisia. Invertebrate Biology. habitats and marine biogeography of 121:190-201. the Oregonian Province, p. 3-17. In: The Light and Smith manual: intertidal invertebrates from central California to Oregon. J. T. Carlton (ed.). University of California Press, Berkeley, CA. 15. OTTAWAY, J. R. 1977. Predators of sea anemones. Tuatara. 22:213-221. 16. PEARSE, V., and L. FRANCIS. 2000. Anthopleura sola, a new species, solitary sibling species to the aggregating sea anemone, A. elegantissima (Cnidaria: Anthozoa: Actiniaria: Actiniidae). Proceedings of the Biological Society of Washington. 113:596-608. 17. PICKERING. 1846. Actinaria artemisia, p. 11. In: Synopsis of the report on zoophytes of the US Exploring Expedition around the world,