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Several Aeolidiella stephanieae nudibranchs feeding on a single Aiptasia pallida anemone (center). Note the brown color of the nudibranchs that is acquired by consuming the tissue of the anemones. Photo by L. Holly Sweat, Smithsonian Marine Station at Fort Pierce.

Species Name: Aiptasia pallida Agassiz in Verrill 1864
Common Name: Brown Anemone
Pale Anemone
Glass Anemone
Synonymy: None

    Kingdom Phylum/Division Class: Order: Family: Genus:
    Animalia Cnidaria Anthozoa Actiniaria Aiptasiidae Aiptasia

    Please refer to the accompanying glossary for definitions of the descriptive terms used in this report.

    Species Description

    The mouth of the brown anemone, Aiptasia pallida, is surrounded by up to 96 long tentacles (Ruppert & Fox 1988). A few of these tentacles are longer, and they are interspersed with several smaller ones (Kaplan 1988). The middle of the column is encircled by two rows of cinclides, through which acontia can protrude. The column is slender and translucent brownish to whitish (Kaplan 1988).

    Potentially Misidentified Species

    A. pallida resembles the ghost anemone, Diadumene leucolena. However, D. leucolena has only 40-60 tapering tentacles of equal size and vertical ridges in the column (Kaplan 1988).


    Habitat & Regional Occurence

    The brown anemone occurs along the entire coast of the United States, from Maine to Florida (Kaplan 1988), across the Gulf of Mexico and throughout the Caribbean (Voss 1976). Individuals are found in variety of habitats, from mangroves to shallow rocky areas (Voss 1976, Kaplan 1988). This anemone is considered a common nuisance species in marine aquaria (e.g. Calado & Narciso 2005). Therefore, it is possible that its distribution has expanded due to transport through the global aquarium trade and subsequent releases.


    Size & Growth

    The average height of A. pallida is 2.5 cm, with a disk diameter of about 1 cm (Kaplan 1988). Under the ideal conditions of partial shade in shallow water, the tentacles of one anemone can spread over 8 cm from the oral disk (Ruppert & Fox 1988).


    No information is available at this time



    A. pallida is fed upon by several nudibranchs, including Berghia coerulescens, Spurilla neopolitana and Aolidiella stephanieae (Ruppert & Fox 1988, Leal et al. 2012). The brown anemone can grow and reproduce quickly, covering rocks in marine aquaria within a matter of weeks. A. stephanieae and other nudibranchs are used as natural controls for these anemones, with some small-scale operations culturing and selling the nudibranchs to interested aquarium hobbyists. Nudibranchs that feed on these anemones acquire stinging nematocysts from their prey that are thought to deter predators (Obermann et al. 2012). As a result, the nudibranchs often develop a brown coloration in their cerata from feeding on A. pallida.

    Associated Species

    The brown color of A. pallida is caused by a symbiotic alga, Symbiodinium microadriaticum, living within the tissues of the anemone (Ruppert & Fox 1988). These microscopic algal cells are known collectively with similar species as zooxanthellae. The zooxanthellae obtain their color through a brown pigment called fucoxanthin, which masks the green coloration of chlorophyll. As with corals and other cnidarians that contain symbiotic algae, the zooxanthellae photosynthesize to support maintenance and growth in the anemone host.


    No information is available at this time


    Kaplan EH. 1988. A field guide to southeastern and Caribbean seashores: Cape Hatteras to the Gulf coast, Florida, and the Caribbean. Houghton Mifflin Co. Boston, MA. USA. 425 pp.

    Leal MC, Nunes C, Alexandre D, da Silva TL, Reis A, Dinis MT & R Calado. 2012. Parental diets determine the embryonic fatty acid profile of the tropical nudibranch Aeolidiella stephanieae: the effect of eating bleached anemones. Mar. Biol. 159: 1745-1751.

    Obermann D, Bickmeyer U & H Wägele. 2012. Incorporated nematocysts in Aeolidiella stephanieae (Gastropoda, Opisthobranchia, Aeolidoidea) mature by acidification shown by the pH sensitive fluorescing alkaloid Ageladine A. Toxicon 60: 1108-1116.

    Calado R & L Narciso. Ability of Monaco shrimp Lysmata seticaudata (Decapoda: Hippolytidae) to control the pest glass anemone Aiptasia pallida (Actiniaria: Aiptasidae). Helgoland Mar. Res. 59: 163-165.

    Ruppert E & R Fox. 1988. Seashore animals of the Southeast: a guide to common shallow-water invertebrates of the southeastern Atlantic Coast. University of SC Press. Columbia, SC. 429 pp.                

    Voss GL. 1976. Seashore Life of Florida and the Caribbean: A Guide to the Common Marine Invertebrates of the Atlantic from Bermuda to the West Indies and the Gulf of Mexico. EA Seeman Publishing, Inc. Miami, FL. 168 pp.

Page by LH Sweat
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Page last updated: 28 December 2012

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