First Records of Striped Boarfish Evistias acutirostris and Ornate ornatissimus from Easter Island Author(s): Sebastián Hernández, Michel García, Carlos F. Gaymer, and Alan M. Friedlander; Source: Pacific Science, 69(4):525-529. Published By: University of Hawai'i Press DOI: http://dx.doi.org/10.2984/69.4.7 URL: http://www.bioone.org/doi/full/10.2984/69.4.7

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BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. First Records of Striped Boarfi sh Evistias acutirostris and Ornate Butterfl yfi sh Chaetodon ornatissimus from Easter Island1

Sebasti á n Hern á ndez ,2 – 4,10 Michel Garc í a ,5 Carlos F. Gaymer , 2,6,7 and Alan M. Friedlander ,2,8,9

Abstract: Here we re port on two new reef fi sh from the remote and iso- lated Easter Island —the striped boarfi sh Evistias acutirostris and the ornate but- terfl yfi sh Chaetodon ornatissimus were ob served during scuba dives and under wa ter video around Easter Island, as well as at nearby Apolo Seamount. These obser- vations are the fi rst re cords of these species for the southeast ern Pacifi c, which rep re sents a ma jor exten sion to their distri butions and raises questions about the or igins and persis tence of reef fi shes in remote subtrop i cal loca tions.

E as ter Island and Salas y G ó mez Island are These sea mounts are consid ered of high bio- among the most iso lated is lands in the Pacifi c di ver sity and are impor tant due to their high Ocean, lying approx i mately 3,700 km from spe cies richness and ende mism (Morato et al. mainland Chile and > 2,000 km from the clos- 2010). The fi sh fauna of Easter Island is ex- est island, which is Pitcairn (Fisher and Nor- tremely impoverished with only 164 shore ris 1960, Randall and Cea 2011, Friedlander and epipe lagic species presently known (Ran- et al. 2013). These is lands are part of the Eas- dall and Cea 2011). However, > 20 % of fi sh ter Island ecoregion and are situated along the spe cies are endemic to Easter and Salas y G ó- Salas y Gó mez Ridge, with a se ries of sea- mez Islands, and regional en dem ics, which mounts connecting these two emer gent land include Pitcairn, Rapa, and the Gambier Is- masses (Newman and Foster 1983, Ray et al. lands, compose > 70 % of lo cal reef fi sh abun- 2012, Friedlander et al. 2013) (Figure 1A ). dance, making these assem blages unique and irre place able (Randall and Cea 2011, Fried- lander et al. 2013). Here we report the pres- 1 This study was supported by the Chilean Millen- ence of two reef fi sh species Evistias acutirostris nium Initiative Grant No. NC120030. Manuscript ac- cepted 24 April 2015. (Temminck & Schlegel, 1844) and Chaetodon 2 Millennium Nucleus for Ecology and Sustainable ornatissimus Cuvier, 1831, newly reported for Management of Oceanic Islands, Coquimbo, Chile. the remote and iso lated Easter Island. 3 Sala de Colecciones Bioló gicas, Facultad de Cien- cias del Mar, Universidad Cató lica del Norte, Coquim bo, Chile. 4 Center for International Programs, Veritas Univer- mate ri als and methods sity, Costa Rica. 5 Sociedad de Explotacion y Exploracion Maritima Underwater photo graphs of E. acutirostris were Orca, Ltd. , Caleta de Hanga Roa, Isla de Pascua, Chile. taken by scuba div ers at Motu Tautara in Oc- 6 Facultad de Ciencias del Mar, Universidad Cató lica ′ del Norte , Coquimbo, Chile. to ber 2013 and Make Make (27 ° 06 S, 109° 7 Centro de Estudios Avanzados en Zonas Á ridas, 25′ W) in Decem ber 2014; at Motu Nui in Coquimbo, Chile. April 2013, and Motu Iti in April 2014 (27° 12 ′ 8 Fisheries Ecology Research Lab, University of S, 109° 27′ W). Additionally, videos of E. acu- Hawai‘i, Honolulu, Hawai ‘ i. were taken on Septem ber 2014 from a 9 Pristine Seas, National Geographic Society, tirostris Washington, D.C. re motely op erated vehi cle (Mariscope Com- 10 Corresponding author (e- mail: pintarroja@ gmail mander MK II) at Apolo Seamount, lo cated .com). ∼ 7 nauti cal miles from Easter Island. Chae- todon ornatissimus was photographed under- wa ter at Omohi on the northwest ern side of Pacifi c Science (2015), vol. 69, no. 4:525–529 Easter Island in 2002 and 2010 (27° 03 ′ S, doi:10.2984/69.4.7 (Includes online sup ple ment) ′ © 2015 by University of Hawai‘i Press 109 ° 23 W) (Figure 1 B ). Species identi fi ca- All rights reserved tion was based on Randall (2005).

525 526 PACIFIC SCIENCE · Oc to ber 2015

Figure 1. Locations of the Easter Island ecoregion off Chile. (A ) Exclusive Economic Zone of Chile represented by lines, includ ing Easter Island and Sala y Gó mez Island. (B ) Locations where Evistias acutirostris and Chaetodon ornatissimus were sighted around Eas ter Island. MN = Motu Nui, MI = Motu Iti, MM = Make Make, LA = Lost Arch at Motu Tautara, OM = Omohi, AS = Apolo Seamount.

results Video S1 [avail able online from www.BioOne .org]). The striped boarfi sh, E. acutirostris was The ornate butterfl yfi sh C. ornatissimus has sighted at four dif fer ent loca tions around only been ob served at Omohi, on the north- Easter Island. A single in di vidual was seen at ern point of Easter Island. Two indi vid u als Motu Nui in April 2013 at 60 m, with another were ob served swimming along a rocky bot- two indi vidu als observed at Motu Iti in April tom covered with Porites lobata and Pocillopora 2014 at 50 m. These in di vid uals were observed spp. corals at 15– 30 m (Figures 2C, D ). on ver ti cal bedrock walls covered with cauli- fl ower coral (Pocillopora spp). Additionally, two indi vid u als were observed at Motu Tautara discus sion and three at Make Make ( Figures 2 A, B ). These fi sh were observed swimming under The striped boarfi sh E. acutirostris and the or- lava arches with small caves and scattered nate butterfl yfi sh C. ornatissimus have not coral at depths of 30– 40 m. During an explor- been pre viously recorded from Easter Island, atory inves ti ga tion at Apolo Seamount, a re- de spite the ichthyo fauna having been ex- motely oper ated vehi cle took video of fi ve ten sively de scribed and studied since the indi vid u als of E. acutirostris swimming on a 1980s (DiSalvo et al. 1988, Randall and Cea lava platform at 150 m cov ered by sea urchins 2011, Friedlander et al. 2013). These obser- and corals of several species (Supplemental vations repre sent very isolated re cords in the Striped Boarfi sh and Ornate Butterfl yfi sh from Easter Island · Hern á ndez et al. 527

Figure 2. (A,B ) Two in divid u als of Evistias acutirostris photographed at Make Make. (C,D ) Single indi vid u als ob- served at Omohi. southeast ern Pacifi c, and consid er ing the Sri Lanka to Hawai‘ i, the Marquesas, the Pit- great distances from the known geo graphic cairn Islands, north to south ern Japan, south dis tribu tions, these re cords should be con sid- to Lord Howe, and Rapa in the Austral Is- ered as a major exten sion to their range of lands. The clos est known ob ser vation for this occur rence. spe cies to Easter Island is Ducie Atoll in the These species have very differ ent global Pitcairn Group (∼ 1,550 km). This spe cies is distri bu tion patterns. The striped boarfi sh has charac terized as an obli gate (Beru- an antitropical distri bution and is known only men et al. 2011) and will therefore likely be from Japan, Hawai‘ i, Australia, New Zealand, neg a tively affected by the loss of corals asso- Lord Howe, Norfolk, and the Kermadec Is- ciated with climate change, reduc ing the rich- lands (Froese and Pauly 2011, Francis 2012). ness and den sity of coral reef fi shes and other The closest known re cords for this species are organ isms as well (Hoegh- Guldberg and the Kermadec Islands ( ∼ 6,650 km) in the Bruno 2010). south ern hemi sphere and Hawai ‘i ( ∼ 7,150 km) Young geo log i cal age ( ∼ 2.5 mil lion years), in the north ern hemisphere. The spe cies is isola tion, small island size, and a low di ver sity thought to consume mostly crusta ceans and of marine habi tats may all be fac tors explain- fe cal pellets, although a spec i men in Hawai ‘i ing the low number of shore fi sh species at revealed pieces of brittle stars (Randall 2007). Easter Island (Kulbicki et al. 2013). Despite In con trast, C. ornatissimus is widespread this low species richness, the island has ex- through the Indo- Pacific, ranging from tremely high biodi ver sity value due to the 528 PACIFIC SCIENCE · Oc to ber 2015 large propor tion of endemic species and the and raise a number of questions about the high repre sen ta tion of these endem ics in the ori gins and persis tence of re mote reef fi sh ecology of the nearshore fi sh as semblage as semblages. (21.7 % ) (Randall and Cea 2011, Friedlander et al. 2013, Kulbicki et al. 2013). Only Hawai ‘i acknowl edg ments has a higher propor tion of ende mism (25 %) in the tropi cal Pacifi c region, and the fi sh assem- We are grateful to all scuba divers that pho- blages between these two is lands share a tographed and video recorded indi vid u als of num ber of simi lar i ties. The low rate of col o- both species at Easter Island. ni za tion and lim ited con nec tivity with other reefs in the re gion may help explain the fi sh Literature Cited as semblage structure observed and contrib- utes to the distri bu tion of antitropical species Berumen, M. L., M. S. Pratchett, and B. A. that we see to day. In this context, the island Goodman. 2011. Relative gut lengths of inte gra tion hypoth esis (Rotondo et al. 1981, coral reef butterfl yfi shes (Pices: Chae- Springer 1982) predicts that Ha wai ian en dem- todontidae). Coral Reefs 30:1005– 1010. ics should be closely related to spe cies found DiSalvo, L. H., J. E. Randall, and A. 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Gorny, and eastern Pacifi c, it is likely that lo cal recruit- E. Sala. 2013. Effects of isola tion and fi sh- ment ac counts for most of the pop ula tion ing on the marine ecosys tems of Easter Is- re plen ishment. Striped boarfi sh and or nate land and Sala y Gó mez, Chile. Aquat. butterfl yfi shes, simi larly to most coral reef Conserv. 23:515 – 531. fi sh es, are broadcast spawners, con sequently Froese R., and D. Pauly. 2011. FishBase. Ac- re cruitment may be restricted to lo cal con- cessed 30 March 2015. www.fi shbase.org. nectiv ity within Easter Island and / or between Hensley, D. A., and A. Y. Suzumoto. 1990. Easter Island and Salas y G ó mez Island. Sev- Bothids of Eas ter Island, with de scription of eral seamounts found between both islands a new species of Engyprosopon (Teleostei: are shal low enough to act as step ping -stones Pleuronectiformes). Copeia 1990:130 – 137. to pro mote connec tiv ity and repro duc tion Hoegh- Guldberg, O., and J. F. Bruno. 2010. of reef fi shes in the Easter Island ecoregion. The im pact of climate change on the However, fur ther re search is needed to world ’ s marine ecosys tems. Science 328: study the ich thyo fauna of these seamounts 1523– 1528. from the Easter Island ecoregion and es- Kulbicki, M., V. Parravicini, D. R. Bellwood, tablish the degree of connec tiv ity of the E. Arias- Gonzalez, and P. Chabanet. 2013. spe cies from adja cent ecosys tem to Easter Global bio ge og raphy of reef fi shes: A hi er- Island. Our fi ndings greatly expand the ar chi cal quanti ta tive de lin ea tion of regions. ranges of a common trop i cal and some what PLoS ONE 8:1 –11. common antitropical spe cies to the extreme Morato, T., S. D. Hoyle, V. Allain, and S. J. south eastern region of the tropi cal Pacifi c Nicol. 2010. Seamounts are hotspots of Striped Boarfi sh and Ornate Butterfl yfi sh from Easter Island · Hern á ndez et al. 529

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