Pacific Science (198 1), vol. 35, no. 1 © 1981 by The University Press of Hawaii. All rights reserved A cropora in Hawaii. Part 1. History of the Scientific Record, Systematics, and Ecology! RICHARDW. G RIGG,2 JOHN W. WELLS,3 and CARDEN WALLACE4 ABSTRACT: Present occurrence of the coral genus Acropora in Hawaii has long been questioned. This paper reviews the scientific literature concerning this controversy and presents the results of a recent resource survey of the entire Hawaiian Archipelago tha t clearly estab lishes the presence of three species of Acropora in Hawaii. These species are Acropora cytherea, A . valida, and A. humilis. Taxonomic descriptions for each species are presented, along with notes on their worldwide geographic distribut ions. In Hawaii, the three species are found only on six islands in the middle of the chain . Extension of their ranges throughou t the archipelago may be limited by discontinuous and sporadic larval recruit ment. THE HAWAIIAN ARCHIPELAGO consists of ap­ results of the United States Exploring Ex­ proximately 132 high volcanic islands, rocky pedition in 1840 and 1841, the "Albatross islets, atolls , reefs, banks, shoals , seamo unt s, Expedition" in 1902, and the Ta nager Expedi­ and guyots (Armstrong 1973). The island tion in 1923. In 1976, a five-year research chain stretches northwest from the Island of program on wildlife and fisheries manage­ Hawaii diagonally across the Pacific to Kure ment in the Northwestern Hawaiian Islands Atoll, a distance of 2450 km. Beyond Kure was planned by the National Ma rine Fisheries Atoll , a series ofdrowned atoll s (guyots) and Service, the U.S. Fish and Wildlife Service, seamounts extend the chain to the Emperor the Hawaii State Division of Fish and Game, Seamounts. The Emperor Seamounts con­ and the University of Hawaii Sea Grant tinue northward all the way to the juncture Program. between the Kuril and Aleutian trenches. In 1978 and 1979, in connection with the In spite of the vast geography of the five-year research plan , the species compo­ Hawaiian Archipelago, knowledge of the sition of coral reefs off the islands of Nihoa, marine biota of the Hawaiian Islands was, Necker, French Frigate Shoa ls, Gardner until abo ut 1976, based largely on research Pinnacles, Maro Reef, Laysan, Lisianski, done in the major high islands (Hawaii to Pearl and Hermes, Midway, and Kure was Niihau) . Prior to this time, knowledge of surveyed. This inventory confirmed and doc­ marine flora and fauna of the Northwestern umented the presence of the coral genus Hawaiian Islands consisted primarily of the A cropora in Hawaii. Three species were re­ corded. Unti l this discovery, a controversy over the occurrence of Acropora in Hawaii persisted for many years. In part, this con­ I Hawaii Institute of Marine Biology contribution troversy was due to the presence in Hawaii number 608. The Nation al Sea Grant Program and the of Acropora in the geological record from Hawaii State Office of the Marine Affairs Coordinator provided funding for this research. Manuscript accepted the Miocene followed by apparent disap­ 12 January 1981. pearance during the Pleistocene. Thus, the 2 University of Hawaii, Hawaii Institute of Marine purpose of Part I of this paper is to sum­ Biology, P.O. Box 1346, Kaneohe, Hawaii 96744. marize the scientific record of the genus in 3 Cornell University, Department of Geological Sciences, Ithaca, New York 14850. Hawaii, substantiate the taxonomic position 4 James Cook University of North Queensland , of the three species discovered, and describe Queensland, Australia 4811. their present patterns of distribution and 2 PACIFIC SCIENCE, Volume 35,January 1981 abundance. In Part 2 of this paper, zoogeo­ SCIENTIFIC RECORD graphic aspects of Acropora are considered. The protean reef coral genus Acropora, with some 325 nominal species, is one of the most widely distributed of living reef cora ls METHODS in the Indo-Pacific, but its current presence Stations were selected off all major islands in Ha waiian waters has long been doubted. or reefs in the Hawaiian Archip elago. At Its absence from early collections of recent each station, the species composition and Ha waiian corals was notable. J. D. Dana, in community structure ofmacrobenthic species the first (1872) and subsequent editions of ( » 2 em in the greatest dimension) were his Corals and Coral Islands, suggested that quantitatively analyzed by conducting 25-m the "Hawaiian Islands . are outside of the or 50-m line transects at depths between 5 Torrid Zone . .., and the corals are con­ and 15m (Grigg and DoIlar 1980). Qualitative sequently less luxuriant and much fewer in estimates of abundance of the macrobenthos species. There are no Madrepores [A cropora] covering much larger areas (about 5000 m-) and but few of the Austraea and Fungia were also coIlected. The number of stations tribes, while there is a profusion of coral of selected per island ranged between two and the hardier genera, Porites and Pocillopora." eight, depending proportionately on island Earlier, in 1846, in his great report on the size and diversity of habitats. Where present, zoophytes of the U. S. Exploring Expedi­ fragments from mature (largest) colonies of tion, Dan a pointed out that "at the Sand­ Acropora were coIlected and preserved in wich Island s, which are near the northern formalin. The reproductive condition of limits of the coral seas, Porites and these colonies was determined by directly Pocillopora prevail. .. " Quelch, in his mon­ examining the mesentaries of decalcified ograph of the Challenger reef corals (1886), specimens (G rigg and Boucher, ms) and by observed that "it is a noteworthy peculiarity standard histological techniques. AIl sam­ of the coral faun a of the Sandwich Island s ples used to determine reproductive condi­ that no representative of the widely dis­ tion were collected in the months of Jun e, tributed genus M adrepora [A cropora] is September, and November. At one station at found on the reefs." But Brook , in his 1893 French Frigate Shoals, a core was obtained monograph of the genus, listed the Sand wich from a water depth of 10m to ascertain the Islands as one of the several localities of presence of Acropora in the recent past . Madrepora echinata Dana, although he listed Material from the core was dated using only three specimens of the species in the radiocarbon dating. British Mu seum collections, none of them The taxonomic position ofthe three species from Hawaii . of Acropora was determined from colonies For nearly a century there have been on coIlected in 1978 and 1979 at French Frigate exhibit in the vitrines of the Galerie de shoals. The Hawaiian specimens were com­ Zoologie, Museum Nationale d'Histoire pared with a large number ofAcropora corals NatureIIe, Paris, two specimens of Acropora collected from the Great Barrier Reef. (The labeIled "Madrepora longicyathus M. E. & latter were collected by John Veron and H. lies Sand wich. M. Ballieu 1874," on the Carden Wallace for a revision of the family shell of a large Pinctada and " M adrepora Acroporidae.) Type material of A . variabilis durvillei M. E. & H. lies Sandwich. M. Klun zinger was received on loan from the Ballieu 1875." These were "discovered" in Museum fiir Naturkunde, Humboldt Uni­ 1978 by Denni s M. Devaney, the curator of versity, Berlin. Radial corallites are illus­ invertebrates at the Bishop Museum in trated by scanning electron micrograph s Honolulu, Hawaii. To an inquiry concerning taken at James Cook University, Australia. their origin, J. P. Chevalier replied that he The terminology used in this paper is defined could find no record of their acquisition and by Wallace (1978). that M. BaIlieu was unknown to the Museum. Acropora in Hawaii. Part I -GRIGG, WELLS, AND WALLACE 3 He also pointed out in correspondence "a is the case with the several [actually oneI species of curious thing: besides this sample, there is Acropora recorded from the Hawaiian Island s by Brook. another example of Acropora longicyathus Their occurrence there certainly needs confirmation, for in the large authentic collections of corals I have studied which is fixed also on a shell of oyster from those islands no Acropora has occurred. (Pinctada) but it comes from Tahiti (coil. Clone, no. I, 1871)." Like Studer's M. Studer's specimen was figured again by echinata, also attached to a pearl oyster Vaughan in his monograph on the Ha waiian shell, it is probable that M. Ballieu's corals corals (1907) with no comment on its prove­ were either purchased in Hawaii or were nance, save that "this species has been re­ obtained in Tahiti but were mistakenly attri­ ported from the Hawaiian Islands by Brook buted to Hawaii. and Studer. I have seen no specimens of it In 1875, when the Challenger stopped in from there." Later (1910) he apparently ac­ Honolulu, Moseley noted (as Verrill did later) cepted it: "A cropora is possibly but not that corals not from Hawaiian waters were probably, except for A. echinata, entirely offered for sale: "There is a large shop of absent from Hawaii ." Notwithstanding the Chinese and Japanese curiosities, and two very dubious specimen of A . echinata, it has photographers' shops, where corals , imported sincebeen accepted that the genus isnot found mostly from the Marquesas, and spurious in the Hawaiian coral 'fauna, the nearest imitations of native implements manufac­ occurrence being at Johnston Island, 720 km tured for sale, are disposed of, at exorbitant to the southwest, where there are at least five prices to passengers from the mail steamer" species. Dana's 1872 statement has also been (Moseley 1879:456). accepted as sound, although as late as 1943 The first published evidence of the pres­ Vaughan and Wells pointed out that a ence of Acropora in Hawaii came in 1901 number of tropical Pacific coral genera were when Studer described some corals in the lacking in Hawaii, and that " Acropora is collections of the Berne Museum, including doubtfully represented by a single species." some collected in 1896 and 1897 by H.