Rock flower anemone
Red beaded anemone
Actinia crucifera (original name granted by Le Sueur, 1817)
Epicystis crucifer (this outdated name is the one most commonly used in the hobby)
Phymanthus crucifer is a species of sea anemone native to shallow waters in the Caribbean Sea.
Distribution of locations of P. crucifer described in 21 different scientific reports. Map from Hexacorallians of the World website.
It is found in crevices of reef rocks and on sand flats. It either imbeds its foot deep within fissures in the rock or attaches its foot to rock several inches below the sands. In both instances, the entire column will be hidden and only the oral disk will be visible. It also camouflages itself by attaching bits of broken shells, sand and rock to the suckers on the upper part of the column. When disturbed, the anemone can retract into the crevice or sand.
P. crucifer contain symbiotic zooxanthellae, providing the anemone with oxygen and energy. It is hosted by Asteropotius ungellatus, a small copepod measuring approximated 1 mm in length. It is predated on by several types of sea snails belonging to the family Epitoniidae, commonly known as wentletraps.
Zoologist Addison Emery Verrill wrote an elegant description of the species in his 1907 publication The Bermuda Islands:
“When fully extended the body of the larger specimens may be 6 to 8 inches or more long and 2 to 3 inches in diameters, while the disk and tentacles may expand to the breadth of 6 to 8 inches, but specimens of about half these dimension are much more common. In full expansion the edge of the disk is usually curved into six to twelve wavy undulations, or they may become deep sinuous frills; sometimes they disappear and the broad disk is then usually concave, but changeable. Occasionally these are only four great undulations of the disk. The tentacles, which are very numerous, and form three of four crowded rows, are of moderate length, stout and tapered, but not very different in form or length. They are generally crossed by several raised, flake-white, transverse ridges or bars, usually bilobed or dilated at the ends, and containing large batteries of nematocysts.
“The disk is covered with numerous unequal radial rows of small, simple papillae or tubercles of various sizes, the rows corresponding to the tentacles of all but the out cycles. The smaller are rounded and wart-like; the larger, conical or paplliform. The column is smooth below, but has short rows of suckers, usually bright red in color, to which foreign objects adhere, on the upper part. Each row usually has 6 to 10 suckers in large specimens, decreasing in size below. The margin bears a circle of rounded acrorhagi, each one in line with a row of suckers.
“The ground color of the column is usually pale flesh-color, cream-color, or whitish, irregularly striped, streaked on flammulated with carmine, rose-red, light red, or crimson, not unlike some varieties of striped apples; near the upper margin it usually changes to gray; verrucæ bright red. The disk is elegantly variegated with several colors; the central part is often bright iridescent green, beyond which it may be variegated with lavender, russet-brown, green, yellow, and flake-white, in various patterns. Frequently the ground-color of the disk is whitish, grayish or yellowish green; while the tubercles may be darker yellow, green, olive, or brown. The basal disk is usually light red. The lips may be lavender, with white gonidial grooves; inside of mouth often pink. The tentacles also vary in colors, but usually correspond in color more or less with the disk; most commonly they are greenish or olive-brown, with the cross bars flake-white; the white cross-bars are often most numerous and most distinct on the outer tentacles.”
P. crucifer is a hardy specimen to keep in the aquarium and is appropriate for beginner aquarists. Due to its small adult size, it is suitable for the nano aquarium. It will obtain the energy it needs from its photosynthetic zooxanthellae, but will also appreciate supplemental meaty feedings (eg Mysis shrimp). Moderate-to-bright lighting, similar in appropriateness for soft corals, will support photosynthesis. Supplemental feeding will hasten growth and is particularly recommended if aiming for reproduction.
Compared to other sea anemones, P. crucifer has an extremely weak sting. It is not detectable by humans. P. crucifer tends to also be much more stationary than other sea anemones. Once they settle in a place they like in the aquarium (they might travel from where they are initially placed to find this spot), they tend to remain put. P. crucifer will not host anemonefish, but they will host a variety of invertebrates, such as sexy shrimp (Thor amboinensis), anemone shrimp (Periclimenes spp.), and porcelian crabs (Neopetrolisthes spp.)
NOTE: Take care when treating a tank for flatworms that contains P. crucifer. Flatworms release a toxin as they die. VIP Reef reported massive losses of P. crucifer when they treated their systems for flatworms.
Blue spectrum lighting, particularly from LEDs, will enhance P. crucifer’s fluorescing properties, making specimens pop. Photos from Coral.
P. crucifer at Coral Morphologic releasing sperm. For the full video go to http://coralmorpholo...1/anemone-spawn
P. crucifer reproduces sexually. No confirmed reports of asexual reproduction of P. crucifer by fragging have been identified, but if anyone has a documented example, please post it. Most temperate sea anemones that reproduce sexually have an annual cycle influenced by various factors such as water temperature, sunlight intensity, lunar cycle or food availability. In Brian Jennison’s study of P. crucifer, he found a low level of gametogenesis throughout the year, with a significant increase in the spring. Dick Perrin comments in his article on captive breeding of P. crucifer that collectors of wild specimens off the Florida coast see an increase in juvenile anemones in the spring and fall, suggesting a biannual pattern.
Captive bred P. crucifer offspring surrounding an adult at Tropicorium.
P. crucifer is dioecious and exhibits a sex ratio of 1:1. Males release sperm into the water column. Coral Morphologic reports they have always witnessed spawning in the evening, between 5-6 PM. Fertilization occurs internally in the female. The female broods the young internally, up to the 6, 12, or 24 tentacle stages of development. When the young are released, they tend to settle around the disk of the female. The young will accept feeding with items such as, brine shrimp naupulii, rotifers, Cyclop-Eeze, and phytoplankton. Newly released young are colorless; color development occurs within a few weeks.
Left: Two newborn P. crucifer anemones attached to Valonia sp. bubble algae at the base of their mother anemone at Coral Morphologic. Right: Colorful juvenile P. crucifer captive bred at Tropicorium.
Nano-Reef.com Tanks Showcasing P. crucifer:
Please post below with a link to your tank thread if you would like to be added to the list.
- 1stimereefer's A Maiden's Voyage & My Rockin' Flower Garden
- DaveFason's Nano Box Flower Garden
- Frank's Nuvo 8
- Gena's You Grow Girl
- Keydiver's Psychedelic Pico 2s
- Mirya's Mini Flower Garden
Non-fluorescing specimens can be purchased for as inexpensively as $10. Ultra-colored, fluorescing specimens can cost in excess of $100. The following vendors have been used by Nano-Reef members in the past to purchase ultra P. crucifer specimens. If you have any other recommendations, please post them.
- Chen C, Soong K, Chen CA. The smallest oocytes among broadcast-spawning actiniarns and a unique lunar reproductive cycle in a unisexual population of the sea anemone, Aiptasia pulchella (Anthozoa: Actiniaria). Zool Stud. 2008;47: 37-45.
- Fautin, DG. Hexacorallians of the World [Internet]. Lawrence (KS): University of Kansas (US); [updated 2013 Jan 2; cited 2014 Mar 8]. Available from: http://geoportal.kgs...mone2/index.cfm
- Foord C. Anemone spawn. 2012 May 31 [cited 2014 Mar 8]. In: Morphologic Blog [Internet]. Miami: Coral Morphologic. C2008- . Available from: http://coralmorpholo...1/anemone-spawn
- Foord C. Summer solstice birthing. 2009 Jul 6 [cited 2014 Mar 8]. In: Morphologic Blog [Internet]. Miami: Coral Morphologic. C2008- . Available from: http://coralmorpholo...lstice-birthing
- Humes AG. A review of copepoda associated with sea anemones and anemone-like forms (Cnidaria, Anthozoa). Philadelphia: American Philosophical Society; 1982.
- Jennison BL. Reproduction in three species of sea anemones from Key West, Florida. Can J Zool. 1981;59:1708-19.
- Perrin D. Captive culture of the rock anemone, Epicystis crucifer. Coral. 2012 Sep/Oct;9(5):60-8.
- Verrill AE. The Bermuda Islands Part V. New Haven: Yale; 1907.
Reef Hobbyist Magazine article "Rock Flower Anemonies: Breeding What Can't Be Fragged" by Miguel Tolosa in the second quarter 2015 issue.
VIP Reef goes on a dive trip for P. crucifer. You can check out the habit these come from in the wild:
These videos don't apply to just P. crucifer, but are useful for any anemone owner (or potential owner).
First off, how to buy a good quality anemone:
Secondly, how to (try to) move an anemone: