ARTICLE IN PRESS Deep-Sea Research I 52 (2005) 1745–1765 www.elsevier.com/locate/dsr A qualitative zoogeographic analysis of decapod crustaceans of the continental slopes and abyssal plain of the Gulf of Mexico$ Mary K. Wickstena,Ã, Jane M. Packardb aDepartment of Biology, Texas A&M University, College Station, TX 77843-3258, USA bDepartment of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843-2258, USA Received 8 November 2004; received in revised form 25 April 2005; accepted 25 April 2005 Available online 19 July 2005 Abstract Occurrence of 130 species of decapod crustaceans was compared between the continental slope (200–2500 m) and the abyssal plain (2500–3840 m) of the Gulf of Mexico. We compiled records of these species from published literature and from the crustacean catalogue of the Marine Invertebrate Collection of Texas A&M University. Each species was scored as present or absent in each of 10 polygons that were defined by physiographic features of the sea floor. Using cluster analysis, we identified inherent patterns of species richness. A distinct faunal assemblage occurred in the Sigsbee Abyssal Plain. This deep plain was a potential ‘‘coldspot’’ in terms of the number of species in the basin, compared to a ‘‘hotspot’’ in the vicinity of De Soto Canyon. Polygons of the eastern upper slopes (i.e. calcareous substrate of western Florida) contained the most species that were not found elsewhere in the Gulf of Mexico. Usingan inductive approach, we identified the followinghypotheses: (1) most crustacean species of the deep SigsbeeAbyssal Plain occur in oceans world-wide, (2) overall, almost a quarter of the deep sea species in the Gulf of Mexico range from the western Atlantic (south of Cape Hatteras) to the Caribbean, and (3) the Gulf of Mexico is particularly rich in species of Munidopsis (25 species). r 2005 Elsevier Ltd. All rights reserved. Keywords: Benthic macrofauna; Biodiversity; Crustaceans; Biogeography; Gulf of Mexico $Abbreviations: CAR ¼ Caribbean, EATL ¼ eastern Atlantic, EPAC ¼ eastern Pacific, GoM ¼ Gulf of Mexico, 1. Introduction IN ¼ Indian Ocean, IWP ¼ Indo-Pacific, NATL ¼ northern Atlantic, NPAC ¼ northern Pacific, NWPAC ¼ northwestern Although biodiversity hotspots (areas with Pacific, SoF ¼ Straits of Florida, SWPAC ¼ southwestern greater species richness than average) have been Pacific, WATL ¼ western Atlantic. ÃCorrespondingauthor. Fax: +1 979 862 1977. identified for shallow marine systems (Roberts E-mail address: [email protected] et al., 2002), relatively little is known about deep sea (M.K. Wicksten). patterns of beta diversity in tropical macrobenthic 0967-0637/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.dsr.2005.04.006 ARTICLE IN PRESS 1746 M.K. Wicksten, J.M. Packard / Deep-Sea Research I 52 (2005) 1745–1765 fauna, i.e. comparison of species assemblages Soto et al. (1999) described decapod faunal across habitats (Moritz, 2002). Biodiversity in assemblages by depth and related them to food warm deep seas may be sensitive to anomalous sources on the upper continental slope in the climatic (or oceanic current) events as well as southwestern Gulf of Mexico. Since 1970, new global climate change (Danovaro et al., 2004). species have been described by Pequegnat and However, before patterns of global change in Pequegnat (1971), Dardeau and Heard (1983), biodiversity can be evaluated quantitatively, sev- Manningand Holthuis (1984) , Lemaitre (1986), eral factors need to be addressed: (a) the com- Williams (1988), Pequegnat and Williams (1995), pleteness of taxonomic studies (Adrianov, 2003; and Felder and Kensley (2004). Seifried, 2004), (b) the use of specific taxonomic The present inductive study synthesizes infor- groups (Cartes and Carrasson, 2004), (c) commu- mation on occurrence of decapod crustacean nity structure of feedingguilds( Maynou and species in deep waters throughout the Gulf of Cartes, 2000; Cartes et al., 2002), and (d) Mexico (Appendix), usingall records available in consistency across taxonomic levels (Doerries the published literature, ecological surveys and and Van Dover, 2003). museum collections. Patterns of distribution are Decapod crustaceans (crabs, shrimp and lob- related to depth, bottom topography, patterns of sters) are large and conspicuous invertebrates, currents, and sediments, to identify hypotheses readily visible in bottom (in situ) photographs and that could be tested in future deductive analyses. often collected duringecological surveys. At least The purpose is to identify which clusters of areas 130 species inhabit the bathyal regions at depths of are most similar and which are most distinctive in 200–3840 m in the Gulf of Mexico. Beinga well- terms of occurrences of species. For future studies, defined, confined ocean basin, the Gulf of Mexico this exploratory analysis provides insights into the provides a good area in which to study geographic diversification of the deep Gulf decapod fauna in distribution of species. addition to providingan initial basis for other A synthesis of information collected duringthe researchers to identify appropriate conservation last half a century is now possible based on units for ecosystem planning. museum collections and published records. Studies on decapods of the Gulf of Mexico date back to the cruises of the U.S. Coast Survey Steamer 2. Methods Blake, under the direction of Alexander Agassiz, in 1877–78 (Milne-Edwards, 1880). More recent We define the Gulf of Mexico (Fig. 1) as that publications include reports of ecological or fish- body of water lyingwithin the northernmost part eries studies sponsored by various governmental agencies. Bullis and Thompson (1965) prepared lists of species taken at stations in 1956–1960 on the continental shelf and upper slope in the Gulf of __30 2 3 Mexico. Thompson (1963) incorporated some of 5 4 200m 9 these records into his work on shrimp of the 2000m 1 southwestern Atlantic, as well as includingkeys, illustrations and comments on nomenclature. _25 10 Pequegnat and Chace (1970) and Pequegnat 8 (1983) prepared detailed reports on locations 6 3000m and depths of collection for many species, and gave historical overviews of collecting. Pequegnat __20 et al. (1990) provided a summary of geographic 7 distribution, zonation by depth, and relative 95 90 85 abundance of invertebrate groups in the Gulf Fig. 1. Map of the Gulf of Mexico showing numbering system of Mexico, with emphasis on the northern Gulf. for polygons. ARTICLE IN PRESS M.K. Wicksten, J.M. Packard / Deep-Sea Research I 52 (2005) 1745–1765 1747 of the Yucatan Peninsula (approximately 211300N, Crosnier (2000) for polychelid lobsters. Other 871 000), the mainland of northeastern Mexico and records and information on world-wide species the southeastern USA and the Florida Peninsula distributions came from the works of Rathbun southward to approximately 251 000N, 831 000W (1918,1925,1937), Chace (1942), Bullis and (north of the Florida Keys and Dry Tortugas). Thompson (1965), Pequegnat and Chace (1970), The Straits of Florida, Yucatan Channel and areas Firth and Pequegnat (1971), Holthuis(1971), Man- north and west of Cuba are excluded, although ningand Chace (1971) , Crosnier and Forest these areas were included in the work by Pequeg- (1973), Perez-Farfante and Bullis (1973), Mayo nat and Chace (1970) as part of the southeastern (1974), Powers (1977), Chace and Holthuis (1978), Gulf of Mexico. We found that at least 10 species Wenner (1979), Dardeau and Heard (1983), reported from the ‘‘Southeast Gulf’’ were taken Takeda and Okutani (1983), Manningand only in the area between the Florida Keys and Holthuis (1984), Gore (1985), Griffin and Tranter Cuba. Following Soto (1985), we consider this (1986), Williams and Turner (1986), Kensley and area as part of the Straits of Florida and exclude Tobias (1985), Williams (1988), Abele and Martin its fauna from this study. (1989), de Saint Laurent and Macpherson Our primary source of information on records (1990a,b), Chan and Yu (1991), Lemaitre of decapods from the Gulf of Mexico was the (1999,2004) and Soto et al. (1999). The earliest Marine Invertebrate Collection, Texas Coopera- collection was Albatross station 2377, 11 February tive Wildlife Collection (TCWC), housed at 1885; the latest was R/V Ronald H. Brown North- Texas A&M University. The collection (formerly ern Gulf Deep Sea Habitats Dive 36, 23 September held by the Department of Oceanography) 2003. In all, the specimens came from 407 contains over 8000 lots of decapods, most of samplingsites, includingsamplingstations of them taken at approximately 200 stations during research vessels as well as locations of crustaceans cruises of the R/V Alaminos from 1963 to 1973. taken duringcommercial fishing. (See Pequegnat and Pequegnat, 1970a,b, for a We include all species known to the senior map of stations through year 1969). Also present author from the Gulf, includingfive unidentified in the collections are specimens taken by the R/V species. A complete list of these species with Oregon and Oregon II in 1955–1974, the Citation information on their occurrence in the Gulf and and Gyre in 1984–85 as part of the Northern elsewhere in the world’s oceans is given in Gulf of Mexico Benthos Project (NGoMB), the Appendix. We provide synonyms for species fishingvessel Success in 1989–90, and specimens whose names have been changed since the taken by other collectors or donated as vouchers publication of the authoritative work edited by from ecological surveys. We included new records Pequegnat and Chace (1970). The records contain from specimens collected by the R/V Gyre in species either that are strictly benthic or that 2000–2002 duringthe Deep Gulf of Mexico commonly are collected in bottom trawls despite Benthos Project (DGoMB). These specimens are some capability to swim. Species of the midwater housed at the United States National Museum of families Oplophoridae, Pasiphaeidae and other Natural History (Smithsonian Institution shrimp that may be taken in benthic trawls, but (USNM)). Records are included of specimens usually occur in the water column, are not taken by trawl or baited trap during2003 as part included.