bishop museum bulletins in cultural and environmental studies

Carlton & Eldredge — Marine Bioinvasions of Hawai‘i
43
Order Actiniaria (sea anemones)
As with many of the Hawaiian corals, several widespread Indo-Pacific sea anemones occur in the
Hawaiian Islands. While some of these are potential candidates as introduced species, genetic work
on possible source regions, an understanding of their potential (or lack thereof) for long-distance
planktonic or drifting dispersal, as well as verification that some of these taxa could interface with
human-mediated dispersal vectors (such as fouling or ballast) would be necessary before assigning
taxa to a cryptogenic category. An example is the phymanthid anemone Heteranthus verruculatus
Klunzinger, 1877, known in Kāne‘ohe Bay “on sills of concrete spillways between fish ponds”
(Cutress, 1977), and otherwise known from the Red Sea and Eastern Australia. It was not recorded
by Verrill (1928) but nor were other apparently native shallow-water actinians reported by Cutress
(1977).
Another example is Gyractis excavata Bovieri, 1893 [=Actinogeton sesere (Haddon &
Shackleton, 1893) fide England, 1987]. Dunn (1974), upon newly finding this anemone on O‘ahu (in
1973, fide England, 1987, p.255) asked “whether this actinian has arrived in the islands only recently,
or whether it was overlooked or not recorded” in previous studies. It occurs in Kāne‘ohe Bay on
“firm substrates, usually on pieces of dead coral, intertidally and in shallow water on sandy shores
and reef flats” (Dunn, 1974) and also on “exposed coasts” at Manana Island, O‘ahu (Cutress, 1977).
It is possible to visually lump this anemone in the field with the zoanthiniarian Palythoa, and this
potential confusion may account for the lack of earlier records (D. Fautin, pers. comm., 18 February
1998). It is known from the Torres Strait (the type locality of A. sesere), and by synonymy with other
species and by additional collections from Sri Lanka, Zanzibar, South Africa, Western Australia,
Aden, Goa, Singapore, and Fiji ( England, 1987). Fautin (pers. comm.,1998) notes that she has further
collected it in Madang, Papua New Guinea. If the species England identified as synonyms do in
fact encompass one biological species, then this is a widespread anemone of the South Atlantic and
Indian Oceans.
If taxa such as Heteranthus and Gyractis are associated with ship-bottom fouling communities,
or could be dispersed as planulae or as newly settled stages on floating debris in ballast water, then
such distributions could have been achieved long ago, and they should be regarded as cryptogenic.
Diadumenidae
Diadumene leucolena (Verrill, 1866)
Introduced
This small translucent anemone was probably collected as early as the 1950s in O‘ahu. Hiatt (1954)
listed “Diadumene (leucolena?)” in his key to Hawaiian invertebrates. Hiatt would have been familiar
with D. leucolena in his graduate student years at the University of California at Berkeley, as this
anemone was used in zoology classes at the time and is common on the eastern shore of San
Francisco Bay. He described his D. leucolena (1 cm x 4 cm) as having white catch tentacles, with a
green-black column distinctly divided into regions and with green or white tentacles. Diadumene
leucolena, as described by Cutress (1977) has the column distinctly divided into two regions, with a
color varying from a dark, dirty green to greenish brown to dirty white. Hiatt’s tentacle description
matches that of Hand (1956). Cutress (1977), definitely identifying this anemone, recorded it from
Pearl Harbor, Honolulu Harbor, and the Ala Wai Canal. It also occurs in Honolulu Harbor (1997,
Coles et al., 1999b) and in Waikīkī (2000, Coles et al., 2002b).
Diadumene leucolena is native to the Northwest Atlantic Ocean as far south as the West Indies
and Caribbean (Cutress, 1977) and has also been introduced to the Pacific coast of America (Carlton,
1975, 1979b). Cutress suggested it could have been introduced with commercial oyster culture,
although introduction by ships is possible as well. As warmer-adapted genotypes would fair better
in Hawai‘i, it may be that this is another Caribbean element in the Hawaiian biota.
Godwin (2003b) notes that D. leucolena was present on a barge towed from San Diego to O‘ahu
in 1999; D. leucolena is a nonnative species in California as well.