Zootaxa 2985: 26–40 (2011) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2011 · Magnolia Press ISSN 1175-5334 (online edition) List of coastal fishes of Islas Marías archipelago, Mexico, with comments on taxonomic composition, biogeography, and abundance BRAD E. ERISMAN1,5, GRANTLY R. GALLAND1, ISMAEL MASCAREÑAS2, JERRY MOXLEY3, H. J. WALKER1, OCTAVIO ABURTO-OROPEZA1, PHILIP A. HASTINGS1 & EXEQUIEL EZCURRA4 1Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla CA 92093- 0202. E-mail: [email protected]; [email protected]; [email protected]; [email protected]; [email protected] 2Centro para la Biodiversidad Marina y la Conservación, La Paz, Baja California Sur, Mexico. E-mail: [email protected] 3Nicholas School of the Environment, Duke University, North Carolina, USA. E-mail: [email protected] 4Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA. E-mail: [email protected] 5Corresponding author Abstract The first comprehensive list of 318 coastal fish species recorded from the Islas Marías Archipelago, Mexico, was compiled from recent fieldwork, archival museum collections, and literature references. The jacks (Carangidae, 18 species) and the labrisomid blennies (Labrisomidae, 16) were the most speciose families. Most recorded species occur throughout the trop- ical eastern Pacific (160 species), while a significant proportion have wider ranges in the eastern Pacific (39), eastern Pa- cific and Indo-Pacific (39), eastern Pacific and Atlantic (3), or are circumtropical (39) in distribution. Three species occur in the Northeast Pacific, twenty-five are endemic to the Pacific coasts of Mexico, five are endemic to the Gulf of Califor- nia, and three are endemic to Islas Marías. Cephalopholis panamensis (Epinephelidae), Epinephelus labriformis (Epi- nephelidae), Mulloidichthys dentatus (Mullidae), Stegastes flavilatus (Pomacentridae), Acanthurus xanthopterus (Acanthuridae), Pseudobalistes naufragium (Tetraodontidae), and Sufflamen verres (Tetraodontidae) were the dominant conspicuous species observed during underwater surveys in 2010. The absence or low abundance of commercially valu- able shark, ray, and grouper species throughout the archipelago is discussed. Key words: Islas Marías, Mexico, tropical eastern Pacific, coastal fishes, Gulf of California Introduction The Islas Marías (also known as Islas Tres Marías) are an archipelago of four volcanic islands (María Madre, María Magdalena, María Cleofas, San Juanito) located 90–120 km offshore of Nayarit, Mexico. The islands are home to a variety of coastal habitats, including rocky and coral reefs, rhodolith beds, rocky pinnacles, and soft-bottom embayments. The Islas Marías were declared a national biosphere reserve in 2003 and then became part of the Nat- ural World Heritage Serial Site (UNESCO) Islands and Protected Areas of the Gulf of California in 2007 (CONANP-SEMARNAT 2010). Isla María Madre is the only one of the four islands that is currently inhabited, as a federal penal colony was established there in 1905 (CONANP-SEMARNAT 2010). Consequently, much of the archipelago has restricted access and likely serves as a de facto marine reserve. The islands are significant biogeographically as they represent one of only a few offshore archipelagos in the tropical eastern Pacific (TEP) and they lie near the intersection of the Cortez and more southerly TEP biogeo- graphic provinces (Panamic or Mexican depending upon definition; Walker 1960; Hastings 2000; Hastings et al. 2010; Robertson & Cramer 2009). They are considered a part of the Gulf of California (Brusca et al. 2005; Hast- ings et al. 2010), because they lie within a geological/geophysical definition of the Gulf (i.e., north of a line drawn from Cabo San Lucas, Baja California Sur, to Cabo Corrientes, Jalisco). Knowledge of the ichthyofauna of these islands is scarce and is based on a single published account of collec- tions made in 1957 (Ricker 1959) and two recent overviews of the fishes of the region (Pérez-Jiménez et al. 2005; CONANP-SEMARNAT 2010). Here, we present the first comprehensive list of coastal fishes from the Islas Marías 26 Accepted by M.T. Craig: 30 Jun. 2011; published: 4 Aug. 2011 based on underwater visual surveys and collections during an expedition in 2010, supplemented by previous collec- tions or studies at the islands. This list provides a baseline inventory of coastal fishes that can be used in the man- agement and monitoring of the biosphere reserve. In addition, we comment on patterns of taxonomic composition, geographic distributions, and abundance of selected species. Material and methods We conducted underwater visual surveys and collections of coastal fishes at 31 sites at Islas Marías (Fig. 1) from November 13–21, 2010. Dives were made on SCUBA at rocky reefs, rhodolith beds, and sandy bottom habitats of 1–30 m depth. Pairs of divers swam along the substrate and recorded the identity of conspicuous fishes. Cryptoben- thic and other fishes were collected with the ichthyocide rotenone and the anaesthetic quinaldine, and specimens were deposited in the Marine Vertebrate Collection, Scripps Institution of Oceanography (SIO), University of Cal- ifornia, San Diego. We compiled a list of coastal fishes known from the islands (Table 1) from our 2010 collections and visual data, three publications on fishes from the area (Ricker 1959; Pérez-Jiménez et al. 2005; CONANP-SEMARNAT 2010), and archival collection records from the following museums: California Academy of Sciences (CAS), Natu- ral History Museum of Los Angeles County (LACM), Smithsonian Institution National Museum of Natural His- tory (USNM), SIO, and University of British Columbia (UBC). Notably, all species recorded by Ricker (1959) are listed in Table 1 as “UBC”. We included only species recorded at depths shallower than 200 m and within 20 km of the islands’ coastlines. Records from publications and museum collections included only those that were identified to species level and excluded questionable records that we could not confirm (e.g., species not otherwise known to occur in the Pacific Ocean). TABLE 1. Taxonomic list of coastal fish species from Islas Marías, Mexico. Record designations: C = collections 2010; CAS = California Academy of Sciences; CON = CONANP-SEMARNAT 2010; LACM = Natural History Museum of Los Angeles County; P = Pérez-Jiménez et al. 2005; SIO = Scripps Institution of Oceanography; UBC = University of British Columbia, including Ricker (1959); USNM = Smithsonian Institution National Museum of Natural History; V = visual observation 2010. Distribution: CT = Circumtropical; EP = Eastern Pacific; EP + ATL = Eastern Pacific & Atlantic oceans; EP + IP = Eastern Pacific & Indo-Pacific; GOC = Gulf of California; IM = Islas Marías; M = Mexico; NEP = Northeast Pacific; TEP = Tropical Eastern Pacific. Occurrence (conspicuous fishes only): D = dominant; VC = very common; C = common; U = uncommon; R = rare. Family Species Record Designation Distribution Occur- rence Ginglymostom- Ginglymostoma cirratum (Bonnaterre, 1788) CON, LACM, P, UBC, V EP + ATL U atidae Rhincodontidae Rhincodon typus Smith, 1828 CON CT - Triakidae Mustelus lunulatus Jordan & Gilbert, 1882 CON, P TEP - Carcharhinidae Carcharhinus albimarginatus (Rüppell, 1837) SIO EP + IP - Carcharhinus falciformis (Müller & Henle, 1839) SIO CT - Carcharhinus leucas (Müller & Henle, 1839) P, V CT R Carcharhinus limbatus (Müller & Henle, 1839) P CT - Carcharhinus obscurus (Lesueur, 1818) P CT - Galeocerdo cuvier (Péron & Lesueur, 1822) CAS, CON, P CT - Triaenodon obesus (Rüppell, 1837) P, V EP + IP R Sphyrnidae Sphyrna lewini (Griffith & Smith, 1834) CON, P, V CT R Sphyrna zygaena (Linnaeus, 1758) P CT - Torpedinidae Narcine entemedor Jordan & Starks, 1895 CON, V TEP U Rhinobatidae Rhinobatos productus Ayres, 1854 V NEP R Zapteryx exasperata (Jordan & Gilbert, 1880) V NEP R continued next page COASTAL FISHES OF ISLAS MARÍAS Zootaxa 2985 © 2011 Magnolia Press · 27 TABLE 1. (continued) Family Species Record Designation Distribution Occur- rence Dasyatidae Dasyatis dipterura (Jordan & Gilbert, 1880) V EP R Dasyatis longa (Garman, 1880) CON, V TEP R Myliobatidae Aetobatus narinari (Euphrasen, 1790) CON CT - Manta birostris (Walbaum, 1792) CON CT - Mobula japanica (Müller & Henle, 1841) V CT R Mobula munkiana Notarbartolo di Sciara, 1987 CON TEP - Rhinoptera steindachneri Evermann & Jenkins, VTEPR 1892 Elopidae Elops affinis Regan, 1909 SIO, UBC EP - Muraenidae Anarchias galapagensis (Seale, 1940) C, LACM, SIO TEP - Echidna nebulosa (Ahl, 1789) CON, UBC, V EP + IP R Echidna nocturna (Cope, 1872) UBC, SIO TEP - Enchelycore octaviana (Myers & Wade, 1941) SIO TEP - Gymnomuraena zebra (Shaw, 1797) CON, SIO, UBC EP + IP - Gymnothorax castaneus (Jordan & Gilbert, 1883) CON, SIO TEP - Gymnothorax dovii (Günther, 1870) UBC, V TEP R Gymnothorax equatorialis (Hildebrand, 1946) SIO TEP - Gymnothorax panamensis (Steindachner, 1876) C, CAS, SIO, UBC TEP - Muraena lentiginosa Jenyns, 1842 CON, LACM, SIO, UBC,V TEP R Uropterygius macrocephalus (Bleeker, 1865) C, LACM, SIO EP + IP - Uropterygius versutus Bussing, 1991 SIO TEP - Ophichthidae Ichthyapus selachops (Jordan & Gilbert, 1882) SIO TEP - Myrichthys aspetocheiros McCosker & Rosenblatt, SIO TEP - 1993 Myrichthys tigrinus Girard, 1859 SIO, UBC TEP - Ophichthus apachus McCosker & Rosenblatt, 1998 SIO TEP - Ophichthus zophochir Jordan & Gilbert, 1882 SIO EP - Quassiremus nothochir (Gilbert,