Records of the Western Australian Museum Supplement No. 77: 177–208 (2009). The macromolluscs of Mermaid (Rowley Shoals), Scott and Seringapatam Reefs, Western Australia.
Clay Bryce and Corey Whisson Department of Aquatic Zoology
Mollusc Section, Department of Aquatic Zoology, Western Australian Museum, Locked Bag 49, Welshpool DC, WA 6986, Australia. Email: [email protected], [email protected]
Abstract – This paper records 339 macromolluscan species comprising 261 gastropods, 70 bivalves, six cephalopods and two chiton species from the north-western Australian atolls of Mermaid Reef (Rowley Shoals), Scott and Seringapatam Reefs.
These records result from a survey undertaken by the WA Museum in September 2006, during which both qualitative and quantitative data sets were recorded. The data included a comprehensive inventory of molluscs, based on a presence/absence statistical assessment, and quantitative density records along replicated transects at outer slope and lagoonal stations. The qualitative survey results are compared with those from WA Museum surveys to the Rowley Shoals in 1982 and Scott and Seringapatam reefs in 1984, as well as from other locations of regional significance. While Mermaid Reef appeared little affected, habitat changes were apparent on Scott and Seringapatam Reefs. The shifts in some molluscan populations since the surveys in the 1980s may be related to warm water incursions, cyclonic activity and/or unregulated fishing. The populations of three gastropod species, Cerithium echinatum, Conus miliaris and Conus musicus, appeared to have increased, probably due to habitat change, when compared to data from the 1980s. However, the populations of giant clams (Tridacna spp. and Hippopus hippopus) and trochus (Tectus niloticus) on Scott and Seringapatam reefs had significantly declined, probably with the added pressure of unregulated fishing. These latter declines are supported by the findings of the senior author during a separate survey concerning a survey of the invertebrate marine resources of Scott Reef, Seringapatam Reef and Browse Island in February, 2006 (Bryce, 2006). A new Australian record for Marchia martinetana (Röding,1798) (Muricidae), is documented from North Scott Reef, and three new Western Australian records, for Euplica deshayesii (Crosse,1859) (Columbellidae), Notodoris serenae Gosliner and Behrens, 1997 (Aegiridae) and Monitilora simplex (Reeve,1850) (Lucinidae) are also documented. The records of Pitar spoori Lamprell and Whitehead, 1990 (Veneridae) is also significant as that species has only previously been recorded from Hibernia Reef, off north-western Australia.
INTRODUCTION biodiversity survey undertaken in September 2006 at Mermaid Reef (Rowley Shoals), North and South The Western Australian Museum (WA Museum) Scott Reefs and Seringapatam Reef. Comparisons has now undertaken three marine macromolluscan are made with the results from the WA Museum’s surveys of oceanic, shelf-edge atolls off the North 1986 report. West Shelf of northwestern Australia. The first was Since 1986 several surveys of the offshore reefs to the Rowley Shoals, visiting Clerke and Mermaid and atolls of that region have also been carried Reefs in 1982, the second to North and South Scott out by the Australian Commonwealth Scientific Reefs and Seringapatam Reef in 1984 - the results and Industrial Research Organisation (CSIRO) for these two surveys being published in 1986 (Skewes, 1999a, 1999b) and the Australian Institute (Wells and Slack-Smith in Berry, 1986). A third of Marine Sciences (AIMS) (Rees, 2003; Smith, survey to Ashmore Reef and Cartier Island was 2005). The aim of those surveys was to examine completed in 1986 (Wells in Berry, 1993). the marine resources of the reefs, including This paper inventories the macromolluscs species of giant clams belonging to the genera (Table 1) recorded during a WA Museum marine Tridacna and Hippopus, and the trochid gastropod, 178 C. Bryce, C. Whisson
followed a preset compass bearing. While this provided the greatest degree of habitat change it also resulted in transects of differing lengths. To compensate, molluscan density data were standardised to 50 m2. Because of the hidden nature of most molluscs, rocks and coral slabs, when abundant, were turned at five metre depth intervals along the transects. Where the rocks and slabs on the transects were few, all were turned and investigated. Small, scattered sand patches were raked for infaunal molluscan species and larger sand plains were sub- sampled by raking an area of 1 m2 at every alternate Above: Tectus niloticus Linnaeus, 1767. Species numbers metre along the transect lines. Short handled rakes, were very poor due to unsustainable fishing practices. 500 cm wide, which penetrated the substrate to (Photo: Clay Bryce) a maximum depth of 5 cm, were used for this purpose. Tectus niloticus. In February 2006 the senior author During the transect-swims, extra qualitative, surveyed the marine invertebrate resource species off-transect searches were undertaken to increase of holothurians, giant clams and trochus of Scott the coverage of mollusc species recorded for the Reef, Seringapatam Reef and Browse Island (Bryce, station. This was accomplished in two ways. Firstly, 2006). by the diver periodically halting his progress along the transect, marking his position and then METHODOLOGY exploring mollusc-rich habitats adjacent to that point on the transect. Secondly, by investigation of Only macromolluscan species are included in areas adjacent to the transects once the transect- this report. Macromolluscs are defined as species swim had been completed. This ensured that the with adult size greater than or equal to one molluscan fauna from all depths and habitats along centimetre. Only those species taken/recorded and adjacent to the transects was surveyed within during this survey are included. Data from the allotted one hour dive time. molluscan collections, recorded over time during Progressing along each transect, each diver collecting trips by this and other museums, have manually recorded the species and numbers of not been included. all macromolluscs encountered. Unidentified or The previous molluscan surveys undertaken noteworthy specimens were collected and later in 1982 and 1984 were qualitative in nature identified and retained as registered vouchers in and recorded observed species at each station. the collections of the WA Museum. The methodology adopted for this 2006 survey This method proved efficient. By swimming incorporated both qualitative and quantitative the compass bearing, the time taken to lay and aspects. The former recorded species presence at retrieve a transect-tape was saved. This time saving all stations while the latter recorded the density of impacted favourably on maximising in-water molluscs along replicated transects for lagoon and outer reef slope stations. Intertidal reef platform (intertidal platform) and channel stations were not sampled quantitatively. All stations were sampled over one hour and during daylight hours for logistical and safety reasons.
Transect stations: Outer Reef slope and lagoonal stations. Replicate transects (each one metre wide and five metres apart) were established at outer slope and lagoonal stations. Transects were searched by two divers who recorded the presence and abundance of molluscan species. However, species from the families Vermetidae and Hipponicidae were not counted because of time constraints. Above: Lambis chiragra (Linnaeus, 1758). A common reef Transects ran from the deepest (maximum of species collected by fishers for the international shell 20 m) to the shallowest points of each station and trade. (Photo: Clay Bryce) Marine Fauna - Molluscs 179 data collecting time and limiting the overall diver nitrogen loads. non-quantitative stations: intertidal reef platform and channel drift stations. Intertidal platform stations presented a particular problem for recording molluscan densities. Effective sampling of the very wide intertidal reef platforms, often over one kilometre wide, was difficult within the workable period of a low tide cycle. Intertidal platform stations were treated as biodiversity sites and no attempt was made to quantify the species. Above: Hyotissa hyotis (Linnaeus, 1758) (Photo: Clay Faunal surveys of the stations in the channels, Bryce) where excessive water flow precluded detailed searching, could be accomplished only by drift sediment and algal turf. diving and so were also limited to qualitative assessments. Subtidal Hard Substrate (SH): As above, but situated below low-tide level at HABiTAT DiViSiOnS outer slope and lagoon stations. References to habitats in this paper are double tiered. The first habitat tier describes the broad- Sediment (S): scale topographical features found on many Intertidal and subtidal sand habitats. In such atolls, such as the lagoon, intertidal reef platform habitats, molluscan species may be infaunal or and the outer reef slope. The second tier refers to epifaunal. those habitat divisions within each station that are relevant to molluscan biology and life history. Pelagic (P): Survey stations, particularly those around the This habitat is represented by the water column outer reef slope and in the atoll lagoons, generally from the sea surface to the substrate. encompassed several intergrading habitats e.g. a subtidal coral reef merging through broken coral Associated with another organism: rubble with sandy pockets to an open sandy plain. This habitat type applies to those molluscs Second tier habitat divisions adopted here are: whose survival strategy involves an intimate and obligatory association with another life form. Intertidal Hard Substrate (IH): Epiphytic (EP): This is an intertidal zone consisting mainly of Plant-related associations, in which a species coral rubble and reef pavement. These hard of seagrass or alga is the obligatory substrate substrates may be covered with a thin coating of Epizooic (EZ) Faunal related associations where an animal forms the obligatory substrate, such as coral, gorgonians and another species of m ollusc.
RESuLTS AnD DiSCuSSiOn: The molluscan species recorded during the 2006 survey are listed in Table 1 with WA Museum registration numbers being given for significant species. The taxonomic order adopted follows Beesley et al., 1998, with some subsequent taxonomic amendments. Station numbers, relevant habitat divisions and comparative records from the Above: Lopha cristigalli (Linnaeus, 1758). This species, with 1986 survey report (Wells and Slack-Smith 1986) Hyotissa hyotis (Linnaeus, 1758) and Hyotissa numisma are also included whether or not the species were (Lamarck, 1819), had suffered severe population loss due to the destruction of coral habitat from a combination of recorded during this survey. coral bleaching and cyclonic activity. (Photo: Clay Bryce) During the 1982 survey, 389 species were 180 C. Bryce, C. Whisson IH IH IH IH IH IH IH IH IH SH SH SH SH SH SH IH SH IH SH IH,SH IH,SH 45 41,4441,44 IH,SH Seringapatam Habitat orth N 36 36 36 36 33 31,33 32,39 36,38 31,33, 35 31,33, Scott 21 27 30 17,18 18,20 18,20 25,26,29 ATOLL RECORDSATOLL - 2006
Scott South 4 3 5 8 1 14 13 7,14 7,8,15 4,12,13 Mermaid C C C C C SS SS SS SN C,M C,M C,M C,SN SS,SN SS,SN,SE C,M,SS,SE 1986 Records C,M,SS,SN,SE 2,3,4,5,9,10,15,16 17.19,20,21,22,23,24,26,28,30 31,34,35,36,37,39,40 per station for the macromolluscs of Mermaid (Rowley Shoals), Scott (North and South) and Seringapatam reefs, Western Australia. per station of for Mermaid the (Rowley macromolluscs Shoals), Scott (North and South) Western and Seringapatam reefs, hard substrate; substrate; SH= S= subtidal sand; hard hard EZ = associated = with animal, associated EP with plant Clerke, M= Mermaid, SS= Scott South, SN= Scott North, SE= Seringapatam Molluscan species occurrence Molluscan species occurrence Habitat key : IH=intertidal 1986 Records: C= varia Linnaeus, 1758 pustulata (s31189) 1846 Reeve, radiatus (juvenile) Gmelin, 1791 haynesi (s31181) Preston, 1914
Clanculus margaritarius (Philippi, (s31083) RA, 1846) Clanculus atropurpureus 1849) (Gould, Clanculus (juvenile) sp. Euchelus instrictus (Gmelin, 1791) TROCHIDAE Angaria delphinus (Linnaeus, 1758) Turbo petholatus Linnaeus,Turbo 1758 cf. Turbo Turbo argyrostomus Linnaeus,Turbo (s31029) 1758 chrysostomusTurbo Linnaeus, (s31218) 1758 Sowerby, 1914 (s31059) Haliotis 1914 crebisculpta Sowerby, Haliotis(s31048) ovina (Gmelin, 1791) Sowerby, 1833 Haliotis planata Sowerby, Haliotis cf. Haliotis cf. TURBINIDAE Astralium rhodostoma (Lamarck, 1822) argyrostomus/chrysostomusTurbo cf. Turbo Cryptoplax sp. Gastropoda PATELLIDAE Scutellastra flexuosa and (Quoy Gaimard, 1834) HALIOTIDAE Haliotis asinina Linnaeus, 1758 Taxa Polyplacophora CHITONIDAE Lucilina lamellosa and (Quoy Gaimard, (s31174) 1835) Chiton sp. CRYPTOPLACIDAE Cryptoplax(s31196) occulatus 1815) (Burrow, Table 1 Table Marine Fauna - Molluscs 181 S S S S S S S S S S S S S S S S S S IH IH IH IH SH SH SH SH SH SH SH IH.SH IH,SH IH,SH 41 41 41 45 45 41,45 IH,SH 41,42 41,44 41,44,45 SH,S 31 31 31 36 38 40 33 31,37 38,39 31,34,36 33,34,37 37,38,39,40 31,34,35,36 26 20 30 20,22 18,29,30 21,24,27 18,21,24,25 17,18,19,21,22,30 19,20,21,24,27,28 17,18,20,21,22,24,27, 13 12 4,16 4,15 6,12 15,16 1,4,7,8,14,15 7,11,12,13,14 1,2,3,4,7,9,16 2,3,4,5,13,15,16 17,19,20,21,22,23,24,27,28,30 1, 7,9,12,14,15,16 1, C C C C C C M SS SN SN C,M C,SS M,SS C,M,SS C,SS,SN C,SS,SN C,SN,SE C,M,SS,SE C,M,SS,SN C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SEC,M,SS,SN,SE 1,2,3,4,6,9,13,14,15,16 17,18,19,20,22,23,28,29,30 a (Linnaeus, 1758) histrio (s31000) 1842 Reeve, Sowerby, 1855 (s31076) Cerithium1855 salebrosum Sowerby, Sowerby, 1855 (s31147) 1855 Cerithium Sowerby, munitum Rhinoclavis articulata (Adams and 1850) Reeve, Cerithium zonatum 1828) (Wood, (Sowerby, 1855) Cerithium trailli (Sowerby, Cerithium nodulosum Bruguiere, 1792 Cerithiium torresi Smith, (s31077) 1884 Cerithium egenum Gould, 1849 Cerithium lifuense Melvill and Standen, (s31192) 1895 Cerithium nesioticum Pilsbry and (s31121) Vanatta, 1905 Sowerby, 1831 Cerithium columna Sowerby, Cerithium echinatum Lamarck, (s31013) 1822 Cerithium atromarginatum Dautzenberg and 1933 Bouge, (s31168) 1855 Cerithium citrinum Sowerby, Nerita polita Linnaeus, 1758 CERITHIIDAE Cerithium alveolus Hombron and Jacquinot, 1854 Rhinoclavis asper Trochus triserialisTrochus (Lamarck, 1822)(s31009) Nerita plicata Linnaeus, 1758 Rhinoclavis brettinghami 1974 Cernohorsky, Rhinoclavis fasciatus (Bruguiere, 1792) Rhinoclavis sinensis (Gmelin, 1791) Rhinoclavis vertagus (Linnaeus, 1767) Stomatella impertusa (s31090) Burrows, 1815 Stomatia phymotis (Helbling, 1779) niloticusTectus (Linnaeus, 1767) pyramisTectus (Born, 1778) cf. triserialisTectus (Lamarck, 1822) maculatusTrochus Linnaeus, 1758 histrio Trochus 1842 Reeve, cf. Trochus Stomatella varia A..Adams, 1850 NERITIDAE Nerita albicilla Linnaeus, 1758 Tectus virgatus Gmelin,Tectus 1791(s31096) 182 C. Bryce, C. Whisson S S S S S S S S S S IH IH IH IH EZ SH SH SH SH SH SH SH SH SH IH,SH IH, SH 41 41 41 41 45 44 44 44 41 to 4541 IH,SH Seringapatam Habitat orth N 31 31 37 32 39 36 35 35 33 35 35,40 31 to 40 31 31,33,37 31,33,35 33,35,37 36,38,39,40 Scott 31,33,35,39,40 17 21 24 27 28 25 21,29 20,21 24,27 25,28 17 to 30 17 19,24,27 23,24,25 ATOLL RECORDSATOLL - 2006 21,24,27,29 21,24,25,27 Scott South 17,18,21,24,27,30 17,18,20,21,24,27 19,20,21,22,23,24,26,30 7 3 3 4 10 7,15 1,14 3,7,10 7,8,15 1 to 16 6,7,8,9,14 Mermaid 7,8, 9,12,16 7,8, C M SS SS SS SE SE SE SN C,SN C,M,SS C,SN,SS C,SS,SN C,SS,SN SS,SN,SE SS,SN,SE C,M,SS,SE C,SS,SN,SE 1986 Records C,M,SS,SN,SE C,M,SS,SN,SE Cypraea caurica Linnaeus, 1758 Cypraea chinensis Gmelin, 1791 Cypraea cicercula Linnaeus, (s31093) 1758 Cypraea cylindrica Born, 1778 Cypraea caputserpentis Linnaeus, 1758 Cypraea carneola Linnaeus, 1758 Cypraea asellus Linnaeus, 1758 Strombus lentiginosus Linnaeus, 1758 Strombus latissimus Linnaeus, 1758 VERMETIDAE Vermetid spp. CYPRAEIDAE Cypraea Linnaeus,annulus 1758 Cypraea arabica Linnaeus, 1758 Strombus luhuanus Linnaeus, 1758 Strombus microurceus Kira,(s31127) 1959 Strombus mutabilis Swainson, 1821 Lambis lambis (Linnaeus, 1758) Lambis scorpius (Linnaeus, 1758) Lambis truncata 1786) (Humphrey, Strombus dentatus Linnaeus, 1758 Strombus fragilis (Röding , 1798)(s31175) Strombus gibberulus Linnaeus, 1758 Taxa HIPPONICIDAE Hipponix conicus (Schumacher, 1817) VANIKORIDAE cancellataVanikoro (Lamarck, (s31061) 1822) LITTORINIDAE 1839 Littoraria undulata Gray, STROMBIDAE Lambis chiragra (Linnaeus, 1758) MODULIDAE Modulus tectum (Gmelin, 1791) PLESIOTROCHIDAE Plesiotrochus sp. Marine Fauna - Molluscs 183 S S S IH IH IH EZ EZ EZ EZ SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH 41 41 41 45 42 44 44 43,44 37 38 40 40 33 33 31,36 31,33 33,35 31,33,37 33,35,37 31,33,37,38 32,33,35,37,38,39 18 19 19 19 27 29 28 30 22 19,20 21,28 23,27 17,18,19,24 19,21,24,27 20,21,22,24,27 20,22,23,25,28,29 19,20,21,24,25,26,30 17,19,20,22,23,24,27,30 7 6 7 16 15 13 13 15,16 4,7,12 7,13,15 3,7,8,12 1,3,8,12,16 7,9,10,11,14 C C C C M M SS SS SS SE SN C,M C,SS C,SE C,SS,SN M,SS,SE SS,SN,SE SS,SN,SE C,M,SS,SE C,M,SS,SN C,M,SN,SE C,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE scurra Gmelin, 1791 globulus Linnaeus, 1758 OVULIDAE Calpurneus lacteus (Lamarck, 1810) Cypraea vitellus Linnaeus, 1758 Cypraea ziczac Linnaeus, 1758 Cypraea ursellus Gmelin, 1791 Phenacovolva sp. Cypraea stolida Linnaeus, (s31114) 1758 Cypraea talpa Linnaeus, 1758 Cypraea teres Gmelin, 1791 Cypraea testudinaria Linnaeus, 1758 Cypraea tigris Linnaeus, 1758 Cypraea poraria Linnaeus, 1758 Cypraea cf. Prosimnia semperi (s31204) (Weinkauff, 1881) Cypraea cf. Cypraea kieneri Hidalgo, 1906 Cypraea limacina Lamarck, 1810 Cypraea lynx Linnaeus, 1758 Cypraea mappa Linnaeus, 1758 Cypraea moneta Linnaeus, 1758 Cypraea staphylaea Linnaeus, 1758 Cypraea nucleus Linnaeus, (s31113) 1758 TRIVIIDAE oryzaTrivia (s31055) (Lamarck, 1810) Cypraea flaveola Linnaeus, 1758 Cypraea helvola Linnaeus, 1758 Cypraea hirundo Linnaeus, 1758 Cypraea histrio Linnaeus, 1758 Cypraea isabella Linnaeus, 1758 VELUTINIDAE Chelynotus and (Quoy tonganus Gaimard, 1832) NATICIDAE 1908 Natica bougei Sowerby, Notocochlis gualteriana (Recluz, 1844) 1843 Natica robillardi Sowerby, Cypraea erosa Linnaeus, 1758 Cypraea 1824 depressa Gray, 184 C. Bryce, C. Whisson S S S S S S S S S S SH SH SH SH SH SH SH SH SH SH SH SH IH,SH IH,SH IH,SH IH,SH 41 44 42 44 41,44 IH,SH 44,45 IH,SH 41,43,44 SH Seringapatam Habitat orth N 31 31 35 33 31,39 31,38 33,37 33,37 33,37 33,39 33,34 33,37,39 33,35,38 33,37,38,39 Scott 17 24 17 24 24 24 27 27 23 21,24 21,27 26,29 20,21,22 20,22,24 ATOLL RECORDSATOLL - 2006 21,23,24,27 Scott South 6 4 11 13 13 13 13 2,4 10,12 13,15 6,9,11 10,11,15 Mermaid C SS SS SS SE SN C,SS C,SS C,SS C,SE M,SS C,SN SS,SE SS,SN C,M,SS C,SS,SN C,SS,SN SS,SN,SE C,M,SS,SE C,M,SS,SN C,SS,SN,SE 1986 Records C,M,SS,SN,SE s (Röding, 1798) Tonna cepaTonna (Röding, 1798) perdix (Linnaeus,Tonna 1758) Gyrineum lacunatum (Mighels, (s31227) 1845) TONNIDAE Malea pomum (Linnaeus, 1758) Cymatium rubecula (Linnaeus, 1758) Cymatium hepaticum (Röding, 1798) (s31178) Cymatium 1849) mundum (Gould, Cymatium muricinum (Röding, (s31126) 1798) Cymatium gemmatum 1844) (Reeve, Cymatium clandestinum (Lamarck, 1816) RANELLIDAE Charonia tritonis (Linnaeus, 1758) Cymatium aquatile 1844) (Reeve, Tutufa bubo (Linnaeus,Tutufa 1758) CASSIDAE Casmaria erinaceus (Linnaeus, (s31081) 1758) Cassis cornuta (Linnaeus, 1758) Cypraecassis rufa (Linnaeus, 1758) PERSONIDAE Distorsio anus (Linnaeus, 1758) Tutufa rubeta (Linnaeus,Tutufa 1758) Taxa Bursa granulari Bursa granularis (Röding, 1798) Bursa lamarckii (s31070) (Deshayes, 1853) Bursa rhodostoma (Beck in Sowerby II, G. B. 1835) (s31033) (s31169) Bursa sp. Polinices powisiana (Recluz, 1844) Polinices mammilla (Linnaeus, 1758) Polinices melanostomus (Gmelin, 1791) Polinices simiae (Deshayes, 1838) BURSIDAE Bursa bufonia Gmelin, 1791 (s31104) 1841) Bursa cruentata (Sowerby, Marine Fauna - Molluscs 185 IH IH IH EZ EZ EZ EZ EZ EZ SH SH SH SH SH SH SH SH SH SH SH SH IH,SH IH,SH IH,SH IH,SH IH,SH IH,SH IH, SH 43 45 44 44 44 42 44 44 41,45 IH,SH 41,44 IH,SH 41,42,45 EZ 41,44,45 IH 32 38 38 33 36 34 33,37 33,37 38,39 36,37,40 31,33,34,37 31,34,37,38,39,40 31,32,34,36,39,40 31,34,36,38,39,40 26 20 26 30 17,22 26,28 23,30 19,20,26 18,19,20,27 18,20,28,30 19,20,21,23,29 18,19,20,22,30 17,18,19,20,22,27,28,30 4 2 4 15,16 4,7,13 10,15,16 2,3,5,15,16 1,3,4,5,15,16 1,3,4,5,15,16 7,9,10,12,14,15 C C C C C M SS SS C,M C,SS SS,SN SS,SN C,SS,SE M,SS,SN SS,SN,SE SS,SN,SE C,M,SS,SE C,M,SS,SN C,M,SS,SN C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE C,M,SS,SN,SE 1,2,3,4,5,6,7,8,9,10,12,14,15,16 17,18,19,20,22,23,25,26,28,29,30 31,32,33,34,36,38,39,40 41,42,44,45 EZ C,M,SS,SN,SE 4,8,9,10,11,12,14,15,16 17,18,19,20,22,25,26,27,28,29,30 31,32,34,35,36,38 craticulatus (Linnaeus, 1758) Morula (s31221) sp. Morula sp. Muricodrupa fiscella (Gmelin, 1791) Muricodrupa jacobsoni Emerson 1981 and D’Attilio, (s31038) Muricodrupa stellaris (Hombron and Jaquinot, 1853) Nassa serta (s31030) (Bruguiere, 1789) Morula nodicostata (Pease, 1868) Morula spinosa (H. and A. Adams, 1835) Morula uva (Röding, (s31004) 1798) Pascula ochrostoma (Blainville, (s31177) 1832) Quoyula (s31010) monodonta 1833) (Broderip, Muricid sp. Morula margariticola 1832)(s31047) (Broderip, Rapa rapa (Linnaeus, 1758) Thais aculeata (Deshayes, 1844) Thais armigera (Link, 1807) Thais tuberosa (Röding,1798) Morula (s31108) dumosa 1837) (Conrad, Morula granulata (Duclos,1832) Marchia martinetana (Röding, (s31184) 1798) cf. Morula biconica Blainville, (s31031) 1832 Maculotriton serriale (s31213) (Deshayes, 1834) Drupa morum (Röding, 1798) Drupa rubusidaeus Röding, 1798 Drupella cornus (Röding, 1798) Drupella rugosa (Born, 1778) MURICIDAE Chicoreus brunneus (Link, (s31137) 1807) Chicoreus microphyllus (Lamarck, 1822) Coralliophila costularis (Lamarck, 1816) Coralliophila cf. Coralliophila erosa Röding, 1798) Coralliophila neritoidea (s31032) (Lamarck, 1816) Drupa ricinus (Linnaeus, 1758) Drupa grossularia (Röding, 1798) Coralliophila stearnsii Pilsbry, 1895 186 C. Bryce, C. Whisson S S S S S S S IH EP EP EP SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH IH,SH IH,SH 41 41 41 43 42 42 44 41,45 Seringapatam Habitat orth N 31 39 36 38 33,37 32,39 33,39 31,36,39 31,33,34 Scott 19 24 21 24 20 29 20 30 19,20 ATOLL RECORDSATOLL - 2006 Scott South 17,18,19,20,23,30 17,18,19,20,22,25,30 14 16 13 13 13 13 2,4 11,14 15,16 9,10,16 3,10,15 Mermaid C C C C M SS SS SS C,M M,SS SS,SE SS,SN SS,SN C,M,SS C,M,SS,SN 1986 Records C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE 1,2,3,4,5,10,11,15,16 17,19,20,21,22,26,28,30 31,32,33,34,36,37,38,39,40 41,44,45 IH,SH FASCIOLARIIDAE Fusinus undatus Gmelin, 1791 Latirolagena smaragdula (Linnaeus,1758) Nassarius granifer (Kiener, 1834) Nassarius papillosus (Linnaeus, 1758) Latirus amplustris (Dillwyn, (s31035) 1817) Pisania (s31225) iostomus 1833) (Broderip, COLUMBELLIDAE Euplica turturina (Lamarck, (s31091) 1822) 1832 Euplica varians Sowerby, Nassarius gaudiosus (Hinds, 1844) Nassaria sp. Pisania ignea (Gmelin, 1791) Euplica deshayesii # (Crosse, 1859) (s31117) Mitrella albina (Kiener, 1841) Pyrene punctata (s31124) (Bruguiere, 1789) Pardalina testudinaria (Link, 1807) NASSARIIDAE Hebra horrida (Dunker, 1847) Nassarius albescens (Dunker, 1846) Engina lineata 1846) (Reeve, Engina mendicaria (Linnaeus, 1758) Engina zatricum Melvill, 1893 Taxa Cantharus undosus (Linnaeus, (s31161) 1758) Cantharus (s31156) wagneri 1839) (Anton, Colubraria muricata (Lightfoot,(s31063) 1786) Colubraria sp. Engina alveolata(s31202) (Kiener, 1836) Engina bonasia Martens, (von (s31226) 1880) Engina curtisiana (s31207) (Smith, 1884) BUCCINIDAE Cantharus pulcher (s31119) 1846) (Reeve, TURBINELLIDAE ceramicum (Linnaeus,Vasum 1758) Vasum turbinellum (Linnaeus,Vasum 1758) Marine Fauna - Molluscs 187 S S S S S S S S S S S S S S S S S S S S S SH SH SH SH SH SH SH SH SH SH SH SH SH 41 41 41 42 44,45 44,45 36 36 38 36 33,37 34,36,38 32,34,36,38 33,36,37,40, 17 20 20 26 26 20 29 22 25,27 25, 27 25, 19,20,21,22 17,19,20,22,30 19,21,26,27,28 19,20,22,24,27 17,18,19,20,21,22 16 13 13 13 13 13 13 20 3,5 11,14 2,5,9,15,16 2,4,5,10,12,15,16 1,2,4,8,9,11,15,16 C C C M M SS SS SS SS SS SS SS SE SE SN C,SS C,SS C,SS C,SS SS,SN C,M,SS C,SS,SN C,SN,SE M,SS,SN C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE C,M,SS,SN,SE 2,3,4,5,8,10,15,16 C,M,SS,SN,SE (Adams, 1853) (s31220) luctuosa 1853) (Adams, panniculata Duclos, 1835 (Gmelin, 1791) (s31021) Latirus polygonus (Gmelin, 1791) Latirus turritus (Gmelin, 1790) Latirus craticulatus (Linnaeus, 1758) Latirus (s31005) nodatus (Gmelin, 1791) Latirus sp. Peristernia fastigium (s31012) 1847) (Reeve, Peristernia incarnata Kiener, 1840 Peristernia nassatula (Lamarck, (s31011) 1822) Peristernia ustulata 1847) (Reeve, Pleuroploca filamentosa (Röding , 1798) OLIVIDAE Oliva annulata (Gmelin, 1791) Mitra litterata Lamarck, 1811 Mitra mitra (Linnaeus, 1758) Mitra paupercula (Linnaeus, 1758) Mitra ambigua Swainson, 1829 (s31153) 1874 Mitra aurora floridula Sowerby, Mitra coffea Schubert (s31154) 1829 and Wagner, Oliva caerulea (Röding , 1798) Oliva cf. Oliva tessellata Lamarck, 1811 Oliva textilina Lamarck, 1811 HARPIDAE Harpa amouretta Roiling, (s31134) 1798 MITRIDAE Cancilla filaris (Linnaeus, (s31105) 1758) Imbricaria olivaeformis (Swainson, 1821) Imbricaria punctata (Swainson, 1821) Mitra acuminata Swainson, (s31084) 1824 Mitra eremitarum Roiling, 1798 Mitra ferruginea (s31082) Lamarck, 1811 Mitra imperialis Roiling, 1798 Mitra cf. Mitra decurtata 1844 Reeve, Mitra chrysalis 1844 Reeve, Mitra chrysostoma (s31123) 1836 Broderip, Mitra cucumerina Lamarck, 1811 188 C. Bryce, C. Whisson S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S 41 45 42 42 42 Seringapatam Habitat orth N 31 31 31 31 37 35 38 36 36 34 Scott 19 24 25 25 30 30 21,24,27 ATOLL RECORDSATOLL - 2006 23, 29, 30 29, 23, Scott South 4 2 11 13 Mermaid M SS SS SS SS SS SS SS SE SN SN SN SN SN SN SN SN C,SS C,SN C,SN C,SN C,SS,SN C,SS,SN 1986 Records , Reeve, 1844 , Reeve, turrigerum 1845) (Reeve, semifasciatum (juvenile) Lamarck, 1811 roseum 1836 Broderip, rubritincta 1844 Reeve, Eucyclotoma 1979 albomacula Kay, Eucithara funiculata 1846) (Reeve, sp. 1 sp. Turris Taxa Neocancilla papilio (Link, (s31185) 1807) Pterygia dactylus (Linnaeus, 1767) Pterygia nucea (Gmelin, 1791) COSTELLARIIDAE cadaverosumVexillum Mitra vexillum Reeve 1844 (s31138) Mitra cf. Mitra stictica (Link, 1807) Mitra retusa Lamarck, 1811 (Lamarck, 1811) (s31170) crocatum (Lamarck,Vexillum 1811) Vexillum consanguineum (s31160) Vexillum 1845) (Reeve, (s31146) 1845) corallinum (Reeve, Vexillum cf. cf. TURRIDAE cf. (Lamarck, 1811) (s31145) unifascialis (Lamarck,Vexillum 1811) zelotypum 1845) Vexillum (Reeve, cf. Vexillum Vexillum speciosum (s31116) 1844) (Reeve, Vexillum (s31209) stainforthi 1841 Reeve, Vexillum cf. Vexillum Vexillum semicostatum Vexillum Anton, 1839 Vexillum sanguisugum Linnaeus,Vexillum 1758 cf. Vexillum (Reeve, 1845) (S31206) infaustum 1845) (Reeve, Vexillum (s31171) lucidum1845) (Reeve, Vexillum Vexillum granosum Gmelin,Vexillum 1790 Vexillum deshayesiVexillum 1844 Reeve, cf. cf. TEREBRIDAE Hastula albula Menke, 1843 Hastula lanceata (Linnaeus, 1767) 1834 affinisTerebra Gray, Pseudodaphnella pulchella (Pease, 1860) Lienardia rubida (Hinds, 1844) Marine Fauna - Molluscs 189 S S S S S S S S S S S S S S S S S S S SH SH SH S,IH S,IH S,IH S,IH S,IH S,IH S,IH S,IH S,IH S,IH S,SH S,IH,SH 41 41 42 45 45 44 44 44 44 S,IH,SH 41,44 43,44 S,IH 41,44,45 37 37 36 33 35 33 33 34 38,40 33,37 33,37,40 31,33,35 35,36,38 33,34,35 33,34,36,37,38,39 24 24 27 27 20 27 25 25 22 20,27 20,22 19,21,24 19,21,24 21,27,30 19,24,27 19,22,24 21,24,27 18,21,23,24,27 17,18,19,20,21,24,25,27 17,19,20,?21,22,24,27,30 17,19,20,22,23,25,26,28,29,30 31,36,37,38,39,40 9 9 5 10 13 6,9 5,15 6,11 3,9,10 3,5,15 6,11,14 4,5,7,10,15 1,2,3,4,10,16 C C SS SS SS SS SN SN SN SN C,M C,M C,SS C,SN SS,SN SS,SN C,M,SE C,SS,SE C,SS,SN C,SS,SN C,SS,SN SS,SN,SE SS,SN,SE C,M,SS,SN 2,3,4,5,6,10,15,16 17,20,22,23,25,26,28,29,30 31,33,34,36,37,39,40 41,44,45 C,SS,SN,SE C,SS,SN,SE C,SS,SN,SE M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE Conus miliaris Hwass in Bruguiere, (s31023) 1792 cf. cf. Conus pulicarius Hwass in Bruguiere, 1792 Conus quercinus Solander, 1786 Conus miliaris Hwass in Bruguiere, (s31007) 1792 Conus musicus Hwass in Bruguiere, (s31034) 1792 Conus omaria Hwass in Bruguiere, 1792 Conus planorbis Born, (s31212) 1778 Conus marmoreus Linnaeus, 1758 Conus miles Linnaeus, 1758 Conus magnificus (s31085) 1843 Reeve, Conus Hwasslitoglyphus in Bruguiere,1792 Conus lividus Hwass in Bruguiere, 1792 Conus litteratus Linnaeus, 1758 Conus coronatus Gmelin, 1791 Conus distans Hwass in Brugiuere, (s31094) 1792 Conus glans Hwass in Bruguiere, 1792 Conus imperialis Linnaeus, (s31115) 1758 Conus leopardus (Röding , 1798) Conus chaldeus (Röding , 1798) Conus ebraeus Linnaeus, 1758 Conus eburneus Hwass in Bruguiere, 1792 Conus flavidus (s31094) Lamarck, 1810 Conus legatus Lamarck,(s31131) 1810 Terebra felina (Dillwyn,Terebra 1817) Terebra dimidiata (Linnaeus,Terebra 1758) Terebra crenulata (Linnaeus,Terebra 1758) Terebra areolata (Link,Terebra 1807) Conus ceylanensis Hwass in Bruguiere,1792 Conus capitaneus Linnaeus, 1758 Conus catus Hwass in Bruguiere, 1792 Terebra maculataTerebra (Linnaeus, 1758) 1825) nebulosaTerebra (Sowerby, 1934 undulata Gray, Terebra Terebra guttata (RödingTerebra , 1798) Terebra subulata (Linnaeus,Terebra 1767) CONIDAE Conus arenatus Hwass in Bruguiere, 1792 190 C. Bryce, C. Whisson S S S S S S S S S EP EP EP EP EZ SH S,IH S,IH S,IH S,IH S,IH S,IH IH,SH IH, SH 41 41 45 41,44 S,IH 44,45 S,IH 42,44 Seringapatam Habitat orth N 39 35 32,38 32, 33 32, 31,33,37,40 Scott 21 24 26 27 27 21,27 20,29 24,28 21,27,29 17,20,26 20,22,30 ATOLL RECORDSATOLL - 2006 20,22,25,30 Scott South 1 1 11 13 1,3 7,12 10,14 7,12,14,16 Mermaid C C C C C SS SS SN SN C,SN SS,SE SS,SN SS,SN,SE C,M,SS,SE C,M,SS,SN C,SS,SN,SE 1986 Records Quoy and Gaimard, 1834 (Marcus, 1965) westralis Jensen, (s31208) 1993 Otopleura mitralis A. Adams, 1855 Otopleura 1 sp. ARCHITECTONICIDAE Philippia radiata (Röding(s31069) , 1798) PYRAMIDELLIDAE cf. cf AGLAJIDAE Chelidonura amoena Bergh, 1905 PLAKOBRANCHIDAE Plakobranchus ocellatus van Hasselt, 1824 PLAKOBRANCHIDAE Elysia sp. PLEUROBRANCHIDAE Berthellina citrina (Ruppell and Leuckart, 1828) Aglajid sp. 2 Aglajid sp. 3 Aglajid sp. HAMINOEIDAE Atys cylindricus (Helbling, 1779) BULLIDAE Bulla ampulla Linnaeus, 1758 Philinopsis pilsbryi (s31058) (Eliot, 1900) Philinopsis reticulata (s31142) (Eliot, 1903) 1 Aglajid sp. Conus vexillum Gmelin, 1791 Conus vitulinus Hwass in Bruguiere, (s31199) 1792 Conus sugillatus 1844 Reeve, Conus tessulatus Born, 1780 Thuridilla bayeri POLBRANCHIIDAE Polybranchia cf. APLYSIIDAE Dolabella auricularia (Lightfoot, 1786) Conus sanguinolentus Conus sponsalis Hwass in Bruguiere, (s31214) 1792 Conus striatus Linnaeus, 1758 Taxa Conus rattus Hwass in Bruguiere, 1792 Marine Fauna - Molluscs 191 S EZ EZ EZ EZ EZ EZ EZ SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH IH,SH IH, SH 45 45 42 42 42 41,43,45 SH 31 31 38 34 34,36 31,32,33,36,39 26 26 20 29 27 27 27 27 27 23 22 25 19,22 21,27 21,25 19,20,27,28 17,25,27,28,30 17,19,20,22,28,30 9 8 3 10 11 2,4 2,4 5,14,15,16 2,3,5,10,11,14,15,16 C M SS SS SS SE SS,SE SS,SN C,SS,SN,SE (Ruppell and Leuckart, 1831) Brunckhorst, (s31067) 1993 (Risbec, 1956) quadricolor Phyllidiopsis krempfi 1957 Pruvot-Fol, POLYCERIDAE Nembrotha kubaryana Bergh, 1877 (van Hasselt, 1824) (s31074) Phyllidiella Hasselt,nigra (van 1824) 1804) Phyllidiella pustulosa (Cuvier, Phyllidiella rudmani Phyllidia varicosa Lamarck, 1801 Phyllidiella lizae Brunckhorst, 1993 Phyllidia coelestis Bergh, 1905 PHYLLIDIIDAE Phyllidia elegans Bergh, 1869 Dendrodoris nigra (Stimpson, 1855) Nembrotha cristata Bergh, 1877 Glossodoris sp. DENDRODORIDIDAE Dendrodoris tuberculosa and (Quoy Gaimard, 1832) Pleurobranchus forskalii (Ruppell and Leuckart, 1828) Chromodoris sp. Glossodoris atromarginata1804) (Cuvier, Thecacera pacifica Bergh, 1883 GYMNODORIDIDAE Gymnodoris citrina (Bergh, 1875) Chromodoris elisabethina Bergh, 1877 Chromodoris lineolata (Hasselt, 1824) Chromodoris cf. AEGIRIDAE Notodoris serenae Gosliner and Behrens, (s31151) 1997 DISCODORIDIDAE Atagema spongiosa (Kelaart, 1858) Atagema intecta (Kelaart, 1858b) Discodoris boholensis Bergh, (s31022) 1877 Halgerda tessellata (Bergh, 1880) Jorunna pantherina (s31152) (Angas, 1864) Jorunna rubescens Bergh, 1876 CHROMODORIDIDAE Ardeadoris egretta Rudman, (s31075) 1984 Chromodoris coi 192 C. Bryce, C. Whisson S S S EZ EZ SH SH SH SH SH SH SH SH SH SH SH SH SH SH AA,SH 41 42 42 42,45 Seringapatam Habitat orth N 36 35 38 38 34 34 33,37 31,34,36 31,34,36,40 Scott 31,32,33,34,36,38,39,40 31,32,33,34,36,38,39,40 43,45 28 18,20 24,27 20,22,25 ATOLL RECORDSATOLL - 2006 21,24,25,27 Scott South 18,19,22,28,29 23,25,28,29,30 22,23,24,25,26,27,28 3 6 9 13 7,12 13,15 10,12,16 2,12,15,16 Mermaid 5,9,11,12,14 1,2,3,5,6,7,8,9,11,12,14,15,16 18,19,20,23,24,26,28,29,30 31,32,33,34,36,38,39 C C SS SN M,C M,C C,M C,M SS,SN SS,SN SS,SN C,M,SS C,M,SN C,SS,SN,SE 1986 Records C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE nasuta (Philippi, 1846) (Reeve, 1844) (s31194) oma 1844) (Reeve, (Lamarck, 1819) (s31198) ilicula (Lamarck, 1819) fusca (Gmelin, 1791) Electroma ovata and (Quoy (S31182) Gaimard,1834) Taxa Barbatia plicata (Dillwyn, (s31014) 1817) Barbatia tenella 1843) (Reeve, Barbatia sp. GLYCYMERIDIDAE pectunculusTucetona (Linnaeus, (s31079) 1758) PTERIIDAE Electroma alacorvi (Dillwyn, 1817) AEOLIDINA Aeolidia 1 sp. Phyllidiopsis striata Bergh, (s31066) 1888 Reticulidia fungia Brunckhorst and Gosliner in Brunckhorst, 1993 TETHYDIDAE Melibe bucephala Bergh, (s31224) 1902 Barbatia foliata Forsskal, (s31109) 1775 Arca ventricosa Lamarck, 1819 Barbatia amygdalumtostum (Röding, (s31143) 1798) Barbatia aff. c Modiolus auriculatus Krauss, 1848 Septifer bilocularis (Linnaeus, 1758) Bivalvia MYTILIDAE Botula cf. Botula cf. s Lithophaga cf. ONCHIDIIDAE Onchidium sp. FACELINIDAE Phidiana indica (Bergh, 1896) Pteraeolidia ianthina (Angas,1864) Arca avellana Lamarck, 1819 Arca avellana/ventricosa Lamarck, complex (s31042) 1819 ARCIDAE Anadara antiquata (Linnaeus, 1758) Marine Fauna - Molluscs 193 S S S S S SH SH SH SH SH SH SH SH SH SH SH SH SH SH S,SH AA,SH AA,SH AA,SH AA?, SH AA?, 45 43 43 43 42 41,43,45 SH 32 34 31,36 32,39 34,35,38 32,34,38 31,34,36,39 31,32,34,36,39 17 26 18,23 23,29 22,26 26,27,29 23,26,29 23, 26,30 23, 18,19,20,22,23,25,26,27,28,29 6 2 5 7 10 12 3, 7 3, 6,15 8,12 15,16 14,15 9,11,15 7,9,11,12 6,8,9,11,12 C C C C M M SS SS SS SN SN C,M C,M C,M C,SS SS,SN C,M,SS C,SS,SE C,SS,SN SS,SN,SE C,M,SS,SN BEACHDR C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE cookei Dall, Bartsch and 1938 Rehder, pacifica 1835 Broderip, Atrina vexillum(s31089) (Born, 1778) Pinctada albina (Lamarck, 1819) Pinctada maculata 1850) (Gould, Pinctada margaritifera (Linnaeus, 1758) Pteria chinensis (Leach, 1814) Pteria producta 1857) (Reeve, Pteria penguin (Röding, 1798) Pteria sp. ISOGNOMONIDAE Isognomon isognomum (Linnaeus, (s31149) 1758) Isognomon legumen (Gmelin, 1791) Isognomon perna (Linnaeus, 1758) PINNIDAE Atrina pectinata (Linnaeus, 1767) Ctenoides annulatus LIMIDAE Ctenoides (S31148) annulatus (Lamarck, 1819) Pinna muricata Linnaeus, (s31088) 1758 Pinna bicolor Gmelin, (s31173) 1791 Limaria fragilis (Gmelin, 1791) Streptopinna saccata (Linnaeus, (s31092) 1758) Lima sp. GRYPHAEIDAE Hyotissa hyotis (Linnaeus, 1758) Decatopecten (s31049) radula1957) griggi (Webb, Excellichlamys histrionica (Gmelin, 1791) Hyotissa numisma (Lamarck, 1819) OSTREIDAE Lopha cristigalli (Linnaeus, 1758) PECTINIDAE Chlamys cf. Chlamys funebris 1853) (Reeve, Chlamys cf. Gloripallium (Linnaeus, pallium 1758) Dendostrea sp. PLICATULIDAE Plicatula (s31026) australis (Lamarck, 1819) 194 C. Bryce, C. Whisson S S S S SH SH SH SH SH SH SH SH SH SH SH SH 41 45 43,45 43,44 42,43,45 AA,SH Seringapatam Habitat orth N 35 36,39,40 Scott 31,32,34,36,39 31,33,34,36,39,40 41,43,44,45 SH 31,32,34,36,38,39 31,32,34,35,36,38 18 21 21 29,30 24,27 ATOLL RECORDSATOLL - 2006 24,25,26,29 Scott South 18,19,25,26,29,30 18,19,23,25,26,28,29 17,18,19,20,23,25,26,30 17,18,19,20,23,25,26,30 1 11 12 5,10,15 4,10,13,16 Mermaid 1,5,13,15,16 6,7,9,12,14,15 1,2,5,7,9,10,11,14,15,16 1,2,3,5,6,7,9,10,11,12,14,15 18,19,23,26,27,28,29,30 C C C C C C C C C M M M C,M C,M SS,SN 1,2,3,6,7,8,9,11,12,14,15,16 18,19,21,23,24,25,26,27,28,29 31,33,34,36,38,39 SS,SN C,M,SS C,M,SN C,SS,SN C,SS,SN C,M,SS,SN 1986 Records (Gmelin, 1791) paytenorum (Iredale, (s31128) 1937) iostoma Conrad, 1837 CARDIIDAE (s31046) Acrosterigma 1841) alternatum (Sowerby, ANOMIIDAE Anomia (juvenile) sp. CHAMIDAE Chama cf. Spondylus (s31016) spp. Wallucina gordoni (Smith, 1886) Wallucina sp. CARDITIDAE Beguina semiorbiculata (Linnaeus, (s31110) 1758) Cardita variegata (Bruiguiere, 1792) (Reeve, 1850) (s31129) # Monitilora(s31129) simplex 1850) (Reeve, Ctena bella 1837) (Conrad, sp. Linga Fimbria fimbriata (Linnaeus, 1758) Chama lazarus (Linnaeus, (s31101) 1758) Chama (s31001) 1927 plinthota Cox, Chama spp. Codakia punctata (Linnaeus, (s31186) 1758) LUCINIDAE Codakia cf. Spondylus pacificus 1856 Reeve, 1827 Spondylus varius Sowerby, Taxa Chama pacifica 1835 Broderip, Pedum spondyloideumPedum (Gmelin, 1791) Semipallium dianae (s31222) (Crandall, 1979) Semipallium tigris (Lamarck, 1819) Semipallium 1 sp. Semipallium 2 sp. SPONDYLIDAE Spondylus ducalis (Röding , 1798) Gloripallium speciosum (s31037) 1833 Reeve, Laevichlamys squamosa Laevichlamys cuneata (s31203) 1833 Reeve, Marine Fauna - Molluscs 195 S S S S S S S S S S S S S S S IH SH SH SH SH IH,SH 43 42 42 42,44,45 31 31 38 35 35 34 35,36 31,32,36 32,35,36 32,33,38,39,40 31,32,34,35,36,37,38,39 41,42,43,44,45 IH,SH 31,32,33,34,35,36,37,38,39,40 41,42,43,44,45 IH,SH 21 24 26 20 27 8,29,30 8,29,30 21,24,27 18,21,24,27 18,20,28,29 22,25,26,28 18,19,21,22,23,24,25,26,27,2 18,19,20,21,22,23,25,26,27,2 6 3 10 8,14 6,14 15,16 15,16 6,7,9,14 11,13,16 7,9,11,14 1,6,7,8,9,12 1,6,7,8,12,14 1,10,11,12,16 1,2,3,4,5,6,7,8,9,10,11,12,14, 1,2,3,4,5,6,7,8,9,10,11,12,14, C C C C C C C C M SS SS SS C,M C,M C,M C,SN C,SS,SN C,M,SS,SE C,M,SS,SN C,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE C,M,SS,SN,SE (Sowerby, 1896) (s31068) 1896) (Sowerby, (Linnaeus, (s31188) 1758) exculta (s31193) Gould, 1850 crucigera Lamarck,(s31044) 1818 cf. Tellina linguafelis (Linnaeus,Tellina (s31150) 1758) Tellina remies Linnaeus,Tellina (s31155) 1758 MESODESMATIDAE Atactodea stricta (Gmelin, 1791) TELLINIDAE Exotica obliquaria (Deshayes, 1854) Exotica rhomboides and (Quoy Gaimard, 1833) Quadrans gargadia pernaTellina Spengler, 1798 Sowerby, 1758 crassiplicata Sowerby, Tellina cf. Tellina sp. (s31144) sp. Tellina SEMELIDAE Semele (s31028) sp. Semele sp. TRAPEZIDAE oblongum (Linnaeus,Trapezium (s31072) 1758) Tellina virgata Linnaeus,Tellina 1758 Sowerby, 1867 robusta Sowerby, Tellina scobinata Linnaeus,Tellina (s31056) 1758 1867 semitorta Sowerby, Tellina (s31172) staurella (Lamarck,Tellina 1818) Tridacna squamosa Lamarck, 1819 Tridacna maxima (Röding, 1798) Tridacna gigas (Linnaeus, 1758) Tridacna derasa (Röding, 1798) Acrosterigma mendanaense Acrosterigma orbitum 1833) (Broderip and Sowerby, (s31125) Tridacna crocea Lamarck, 1819 Acrosterigma sp. Corculum cardissum (Linnaeus, 1758) fragumFragum (Linnaeus, 1758) TRIDACNIDAE Hippopus hippopus (Linnaeus, 1758) 196 C. Bryce, C. Whisson S S S S S S S S S S S S S SH SH SH SH SH SH Beach IH,SH IH,SH 41 41 45 43 44 44 Seringapatam Habitat orth N 31 32 38 35 31,39 35,39 36,40 33,39 31,34,36 open water Scott 18 18 24 24 29 30 19,21 19,21,22 ATOLL RECORDSATOLL - 2006 21,24,25,29 Scott South 17,19,20,23,28 8 3 16 12 7,14 3,10 4,16 8,12 11,12 6,9,11,12 Mermaid 7,9,11,12,14,15 C C C C SS SS SN SN SN C,M C,SS C,SS SS,SN SS,SN C,SS,SE C,SS,SN 1986 Records cuneiformis 1783) (Spengler, lessoniana Férussac, 1831 tigrina (s31187) (Lamarck, 1816) Gray 1929 (not collected)cyaneas (not 1929 Gray (Conrad, prora1837) (Conrad, sp. (Sowerby, 1853) (s31053) 1853) Antigona resticulata (Sowerby, Sepia pharaonis Ehrenberg, 1831 Tapes literatus (Linnaeus,Tapes (s31201) 1758) Pitar spoori Lamprell # and Whitehead, (s31073) 1990 Pitar sp. Globivenus (s31098) toreuma 1846) (Gould, Lioconcha ornata (Dillwyn, (s31111) 1817) Lioconcha castrensis (Linnaeus, (s31071) 1758) Dosinia Antigona reticulata (Linnaeus, (s31027) 1758) Taxa Octopus (s31211) sp. Octopus cyaneas 1929 Gray Octopus sp. Octopus (juvenile) (s31097) sp. Octopus (s31210) sp. SEPIIDAE Sepia latimanus Quoy and Gaimard,1832 Tapes platyptychaTapes (Linnaeus, (s31057) 1758) Timoclea1 sp. Timoclea3 sp. GASTROCHAENIDAE Gastrochaena cf. Cephalopoda NAUTILIDAE Nautilus pompilius Linnaeus, 1758 SPIRULIDAE Spirula spirula (Linnaeus, 1758) LOLIGINIDAE Sepioteuthis cf. Pitar cf. Lioconcha cf. (Reeve, 1843) (s31167) obesa 1843) (Reeve, Trapezium VENERIDAE Antigona (s31080) clathrata (Deshayes, 1854) sp. (s31223) sp. Photololigo OCTOPODIDAE Octopus cf. Marine Fauna - Molluscs 197 S S S S S S S S S S S S S SH SH SH SH SH SH Beach IH,SH IH,SH Habitat 41 41 45 43 44 44 Seringapatam orth 31 32 38 35 31,39 35,39 36,40 33,39 31,34,36 open water open Scott n 18 18 24 24 29 30 19,21 19,21,22 ATOLL RECORDSATOLL - 2006 21,24,25,29 ScottSouth 17,19,20,23,28
Above: Tridacna derasa (Röding, 1798) (Photo: Clay Bryce)
recorded comprising 280 gastropods, 101 bivalves, are subjected to a water flow gradient across their six cephalopds and two chitons. Molluscs width, diminishing from the wave-pounded outer identified during the 2006 survey totalled 339 slope to the relatively calm waters of the lagoon. 8 3 16 12 species, comprising 261 gastropod, 70 bivalve, Intertidal platforms are also topographically flat 7,14 3,10 4,16 8,12 11,12
6,9,11,12 six cephalopod and two chiton species. Table 2 providing little protection for biota in the form Mermaid 7,9,11,12,14,15 provides a summary of the total number of species of tide pools and coral slab debris. There is little recorded from each reef surveyed, arranged from sediment to be found on the platforms except south to north, together with the percentage of total in isolated back-reef areas. However, a limited species for each reef as represented by the various molluscan fauna exists where there is a sufficient habitat divisions. Many species occurred in more depth of sediment. Desiccation from low tide C C C C
SS SS than one habitat division and so were counted for exposure, wide temperature fluctuations and SN SN SN C,M C,SS C,SS SS,SN SS,SN C,SS,SE C,SS,SN each. increased predation of collectable species by 1986 Records As indicated in Table 2, Subtidal-Hard (SH) and Indonesian fishers also has an impact on diversity Sediment (S) are the two habitat types for which and abundance (pers. obs. C. Bryce). higher species percentages were consistently Table 3 displays the average species count per recorded. The percentages of species from station and the average species count at each major those sites, when considered as totals from all topographical reef feature (outer slope, intertidal reefs surveyed, far exceed those from the third platform and lagoon), with the number of stations dominant division, the Intertidal Hard (IH), and in brackets. The molluscan faunas of South Scott the remaining habitat divisions. These differences and North Scott Reefs appear to be the most diverse may be attributed to the greater number of habitat with greater average species counts per station and (Spengler, 1783) (Spengler, niches available to molluscs within the subtidal across the three topographical reef features. In Férussac, 1831 breakaway zones of the outer and inner reef slopes, general, average species counts were higher at all (Lamarck, 1816) (s31187) (Lamarck, 1816) (Linnaeus, 1758) (s31071) (Linnaeus, 1758) (Sowerby, 1853) (s31053) 1853) (Sowerby, (Gould, 1846) (s31098) 1846) (Gould, Gray 1929 (not collected) (not 1929 Gray which include the majority of SH and S sites. The reefs on the outer slope than at lagoon or intertidal (Linnaeus, 1758) (s31027) (s31027) (Linnaeus, 1758) Linnaeus, 1758 (Deshayes, 1854) (s31080) 1854) (Deshayes, (Linnaeus, (s31057) 1758) cuneiformis (Dillwyn, 1817) (s31111) (Dillwyn, 1817) Gray 1929 Gray (Reeve, 1843) (s31167) 1843) (Reeve, Quoy and Quoy Gaimard,1832 lessoniana
Ehrenberg, 1831 difference in environmental conditions between platform habitats. A comparison of the combined (Linnaeus, (s31201) 1758) (Conrad, 1837) (Conrad, tigrina cf. cf. cyaneas the outer slope, with its vigorous wave action, and outer slope and lagoon figures (equating to SH and Lamprell and Whitehead, 1990 (s31073) # Lamprell (s31073) and Whitehead, 1990 sp. (s31223) sp. cf. sp. 1 sp. 3 sp. prora sp. sp. (juvenile) (s31097) sp. (s31210) sp. (s31211) sp. cf. the inner reef edge, with a relatively quieter, cross- S in Table 2) compared with the intertidal count sp. cf. platform water flow, provides greater opportunities (IH); indicate a similar outcome, as expressed with for habitat niche variability and nutrient retention. Table 2. Antigona resticulata Dosinia toreuma Globivenus ornata Lioconcha castrensis Lioconcha spoori Pitar Pitar literatusTapes Sepia pharaonis Antigona reticulata Antigona Taxa SEPIIDAE Sepialatimanus Lioconcha Pitar platyptychaTapes Timoclea Timoclea GASTROCHAENIDAE Gastrochaena Cephalopoda NAUTILIDAE pompilius Nautilus SPIRULIDAE Spirula spirula (Linnaeus, 1758) LOLIGINIDAE Sepioteuthis Octopus cyaneas Octopus Octopus Octopus Octopus Trapezium obesa Trapezium VENERIDAE Antigona clathrata Photololigo OCTOPODIDAE Octopus In comparison, IH sites on the intertidal platforms Analysis using Multi-Dimensional Scaling (MDS) 198 C. Bryce, C. Whisson
Table 2 Percentage of total molluscan species for each habitat division for the 2006 survey.
Habitat Divisions Reef Total Species IH SH S EPEZP % Species Mermaid 185 22.99 60.96 34.23 1.07 4.81 0.00 South Scott 221 21.72 52.94 38.91 1.36 5.88 0.45 North Scott 183 29.35 54.35 41.30 0.00 3.17 0.54 Seringapatam 120 28.10 56.20 35.54 3.31 4.13 0.00
Table 3 Reefs surveyed in 2006, with average species and number of stations (x).
Average species Average species for Average species for Average species for Reef per station outer reef slope intertidal platform lagoon Mermaid 34 (16) 37 (5) 37 (1) 33 (8) South Scott 47 (14) 49 (6) 59 (3) 38 (5) North Scott 43 (10) 51 (3) 44 (3) 39 (3) Seringapatam 36 (5) 45 (2) 46 (1) 23 (2)
of the molluscan biodiversity presence /absence lagoonal reef-edge stations (Stations 6, 7, 8 and 11) data is presented in Figures 1 and 2 using the Bray indicated that the difference in intertidal platform Curtis Similarity Matrix. The data for the intertidal width has an influence. At Station 1 the intertidal platform and channel stations were omitted to platform was narrow with a more uniform habitat maintain a consistent sampling strategy for all across its entire width, which is favoured by these stations. commonly-occurring species. This is not the case The breakdowns of data in the MDS plot (Figure for the stations on the considerably wider western 1) supported by the dendrogram (Figure 2), clearly lagoon edge (Stations 6, 7 and 8), where deposited differentiate Mermaid Reef, 400 km to the south, coralline sands dominate the inner half of the from South and North Scott and Seringapatam intertidal platform providing poor habitat for these Reefs. same species. Station 11, although on the same narrow platform as Station 1, is subjected to a At a finer scale the data for the lagoons and constant dusting of silt due to its proximity to the outer slopes, for all reefs, show a meaningful channel (pers. obs. C. Bryce). separation. There is also an organised spread of sampling points related to the prevailing Station 18 at South Scott Reef (Figures 1 and 2), environment from very exposed to very protected appears to be intermediate between those of the stations, progressing outward from the centre of lagoon and outer reef stations of Mermaid Reef. the plot (Figure 1). To the left, the sampling points Work being undertaken by AIMS has revealed align with increasingly-exposed, high-energy that the water influencing Station 18, between the environments (Stations 17 and 41) and to the right western horn of South Scott Reef and Sandy Islet, they align with increasingly protected, low energy, is constantly mixed with oceanic water (Gilmore – lagoonal sites (Stations 6, 7 and 43). AIMS pers. comm.) This water mixing, combined with that location’s habitat complexity, may have From the dendrogram (Figure 2), outlier stations buffered the molluscan communities from the are evident at Stations 1, 18 and 43. Station 1 at the effects of elevated water temperatures, which eastern side of Mermaid Reef lagoon revealed a had affected so much of South Scott Reef in 1998 similarity with Stations 32 and 38 from North Scott and 2003. Mermaid Reef had also been affected at lagoon, even though the distance between the two those times but to a lesser extent (Rees et al., 2003; reefs is more than 400 kms. Examination of Table Gilmore et al., 2007). 1 revealed the inclusion of several common outer reef platform species, such as Drupa rubusidaeus, Figures 3 and 4 indicate the more common Vasum turbinellum, Conus miliaris, and Conus species of bivalves and gastropods respectively, sponsalis at Station 1 to be a contributing factor. expressed as the average number of individuals/50 2 All four species are common on the outer reef m . platform. A comparison of the remaining Mermaid Considerable variation is evident between the Marine Fauna - Molluscs 199
Figure 1 Multi-dimensional scaling ordination of molluscan presence /absence data for surveyed lagoon and outer slope stations.
Figure 2 Dendrogram showing station similarity of molluscan presence/absence for lagoon and outer slope stations. 200 C. Bryce, C. Whisson
Figure 3 Average bivalve individuals / 50 m2
Figure 4 Average gastropod individuals / 50 sq. metres
density and makeup of the molluscan assemblages in the first half of 2006 (Bryce, 2006). for North and South Scott Reefs and Seringapatam The density of the coral nestling pectinid, Reefs, when compared with those of Mermaid Reef. Pedum spondyloideum, is also lower at Scott and Of particular note is the lower numbers of the giant Seringapatam Reefs compared with that at clam species, Tridacna maxima and Tridacna crocea , Mermaid Reef. The low numbers in this species at at North and South Scott Reefs and Seringapatam the more northerly reefs may be attributed to the Reef. The densities of the other giant clam species, decline in coral abundance due to bleaching and Tridacna gigas, Tridacna squamosa and Tridacna derasa, cyclonic activity (Rees et al., 2003; Gilmore et al., were too low for a meaningful comparison between reefs. These findings are consistent with the results 2007). reported by the senior author from a survey of the The high densities of the bivalves, Beguina invertebrate marine resources of the shallow water semiorbiculata, Septifer bilocularis and the Arca habitats of North and South Scott Reefs undertaken avellana / ventricosa species complex at North Marine Fauna - Molluscs 201
Above: Lambis lambis (Linnaeus, 1758) (Photo: Clay Bryce)
Scott Reef, and to a lesser extent at South Scott for survival. Neither species could be considered and Seringapatam Reefs, is intriguing. At some to be in plague proportions on this reef at this survey stations, high numbers of these species are time. However, at North and South Scott Reefs and associated with isolated massive coral colonies to a lesser extent at Seringapatam Reef, the low and it would appear that North Scott Reef has a numbers may reflect the damage to coral stock from greater number of such stations. Just as intriguing coral bleaching and subsequent cyclonic activity is the situation with Septifer bilocularis on Mermaid as described by Rees et al. (2003) and Gilmore et al. Reef. While this mussel species is common on (2007). the mainland coast and the more northern atolls, Cerithium echinatum was moderately abundant it was recorded from only a single station on at Scott (North and South) and Seringapatam Mermaid Reef and not from any of the replicated, Reefs during the 2006 survey, being recorded quantitative transects. This situation could perhaps from 50% of transects. There were no records be due to the isolation of Mermaid Reef from the of the species from the quantitative transects at more “clumped” northern reefs closer to Indonesia, Mermaid Reef although the species was recorded, and hence from the northern larval-carrying in low numbers, from 44% of the survey stations currents. However, further work needs to be (Table1). The species does not appear to have been undertaken to fully comprehend the geographical common during the 1980s. The WA Museum’s distribution of this and other molluscan species. 1986 survey report records the species from only Some caution has had to be exercised with regard a single station at Mermaid Reef and not at all on to both the qualitative and the quantitative data North or South Scott Reefs or Seringapatam Reef. from Seringapatam as the reef was under-sampled, However, Wilson (1985) recorded two specimens during this and all other surveys undertaken so far. from Seringapatam Reef in 1978. Representatives The most common gastropods encountered of the family Cerithiidae, to which this species at Mermaid Reef were Coralliophila neritoidea belongs, are generally gregarious detrital feeders and Drupella cornus (Figure 4). Both of these consuming microalgae, bacteria and detrital matter corallivorous species are dependant on live coral (Wilson, 1993). With the decline of holothurians on 202 C. Bryce, C. Whisson
Table 4 Number of stations sampled for Molluscs - 1986 publication and 2006 survey.
Clerke Mermaid Sth. Scott nth. Scott Sering. Totals 1986 publication 20 2 12 11 2 47 2006 survey 16 14 10 5 45
Scott Reef (Bryce, 2006) it could be assumed that from around Sandy Islet on South Scott Reef but nutrient levels in the sediment have increased. the latter was recorded only from a single site on With that in mind, it would seem possible that North Scott Reef (Wells and Slack-Smith, 1986). the rise in numbers of Cerithium echinatum may During the 2006 survey, both species were more be related to such a nutrient increase. It should be widely encountered (Table 1) and, as with Cerithium noted that holothurian numbers and diversity on echinatum, this may signify a population increase Mermaid Reef are far greater than on the northern has occurred, perhaps due to habitat changes atolls (Bryce and Marsh, this volume) and would, associated with a possible increase in levels of presumably, have some effect on controlling nutrient in the sediment. sediment nutrient levels and so might account for the lesser numbers of this gastropod species at Comparative results – 1986 report and 2006 survey. Mermaid Reef. Table 4 lists the number of stations surveyed The density spike for Cerithium echinatum on at each reef for the 2006 survey compared with Seringapatam Reef (Figure 4) is unexplained. the previous WA Museum survey results, so Two of the three Seringapatam stations recorded providing an estimate of the differences in effort and collection opportunity across the reefs. The very high numbers giving an average density of numbers of survey stations providing the 1986 5.5 individuals per 50 m 2. If more stations had and 2006 data sets are comparable, being 47 and 45 been sampled, this average figure may have been respectively. reduced to levels more comparable with the other stations. It seems possible that the density of By combining the stations for each reef system Cerithium echinatum may be increasing on all atolls, (i.e., Clerke and Mermaid, South and North Scott, particularly on the northern reefs, until a new and Seringapatam) and comparing them for ecological balance is reached. Obviously, further both the 1986 publication results and the present work would be needed to clarify the matter. survey, a clearer indication of collecting effort was determined (Figure 5). For example, 20 stations There is also an apparent increase in abundance were sampled in the data published in 1986 for of Conus musicus and C. miles. Both species are Clerke Reef with only two stations at Mermaid Reef vermivorous, preferring sandy pockets on intertidal - giving a total of 22 stations for the reef system. and shallow subtidal reefs (Röckel, et al., 1995). The third atoll of the system, Imperieuse Reef, was In the WA Museum’s 1986 published results, the not surveyed in 1986. When this figure (22 stations) former species was found at three stations, all
Left: Pedum spondyloideum (Gmelin, 1791); Right: Lambis truncata (Humphrey, 1786) (Photos: Clay Bryce) Marine Fauna - Molluscs 203
Figure 5 Comparison of the number of stations between reef systems for 1986 and 2006 reports.
Figure 6 Comparative total species counts for Mermaid, South Scott, North Scott and Seringapatam Reefs for 1986 publication results and 2006 surveys.
is compared to the 2006 Rowley Shoals count (16 distribution of all 479 species across three reef stations), the comparison can be seen to be more systems for both the 1986 published results and the meaningful. 2006 survey, combined. A comparison of total molluscan species Scott Reef (North and South), with its greater recorded for all reefs during this survey and for habitat diversity, had the greater species total (372) and also that of reef-confined species (121). The those published in 1986 is provided in Figure 6. lower total of species recorded for Seringapatam Slightly more species were recorded in the 2006 Reef (173) would seem to be due to a lower survey, which may be due to differing collecting collecting effort, yet it still displayed a modest methodologies and advances in taxonomy. species affinity with its near neighbour, Scott Reef The Venn diagram (Figure 7) portrays the (North and South), sharing 27 species. Rowley 204 C. Bryce, C. Whisson
Table 5 Comparison of results of this and similar surveys of northwest Australian areas (listed from north to south)
Indication of Effort Total Surveyed Locality Number of Source Survey days species Collectors 12 Christmas I. 3 313 Wells & Slack-Smith, 1988 (36 person days) 11 Ashmore & Cartier Rf. 2 433 Wells, 1993 (22 person days) 20 Cocos (Keeling) Is. 2 380 Wells, 1994 (40 person days) 16 Mermaid, Scott & Seringapatam Reefs 2 339 This survey (32 person days) 11 Mermaid, Scott & Seringapatam Reefs 2 324 Wells & Slack-Smith, 1986 (22 person days) 13 292 Central Kimberley 1 Bryce, 1997 (13 person days) 13 Southern Kimberley 2 232 Wells & Bryce, 1995 (26 person days) 26 Dampier Arch. 2 695 Slack-Smith & Bryce, 2004 (52 person days) 17 Montebello Is. 3 633 Wells, Slack-Smith & Bryce, 1993 (51 person days)
Shoals and Scott Reef (North and South) share gastropod, Euplica deshayesii (Crosse, 1859) (Figure 100 species but still portray considerable species 8b), the nudibranch, Notodoris serenae Gosliner and exclusivity with 85 and 121 species respectively. Behrens, 1997 (Figure 8c) and the lucinid bivalve The three reefs have 124 species in common, with Monitilora simplex (Reeve, 1850) (Figure 8d). Also a reduction in overall species diversity from Scott of note is the venerid bivalve, Pitar spoori Lamprell Reef to Mermaid Reef. These figures appear to and Whitehead, 1990 (Figure 8e). This species had demonstrate the influence of the Indian Ocean previously been recorded in Western Australia only Through-Flow current regime and the effects of from Hibernia Reef (Willan, 2005). inter and intra-reef system recruitment. Table 5 compares the molluscs recorded from Conclusions: the 2006 survey with those of similar surveys undertaken by the WA Museum at other localities, The molluscan fauna of the surveyed atolls including an indication of effort. Care should be is typical of Indo-West Pacific offshore, oceanic taken in the interpretation of this table regarding coral reefs (Wells & Slack-Smith, 1986; Willan, the figures associated with surveys of the nearby 2005). From Table 1 it can be seen that the fauna Kimberley coast. Despite the greater habitat has a greater affinity with that of the Indonesian diversity of the Kimberley coast, the figures Archipelago than with the Western Australian give a lower species count than for any of the mainland. As such, these reefs are considered to surveyed oceanic locations. This is probably due represent a unique habitat of great conservation to a bias towards the surveying of only intertidal value. platforms, mangals and general shoreline habitats, The inclusion of replicated transects into a and a surveying of only a very small number of molluscan collecting regime has added valuable subtidal stations. Further surveying of Kimberley quantitative information by providing an indication subtidal stations would, undoubtedly, increase the of average molluscan density. The very act of mainland-coast species count appreciably. swimming a transect tends to focus researchers’ attention along a continuous band of substrate. New molluscan records. This band is actually a defined slice through an The discovery of the gastropod mollusc, Marchia otherwise borderless station area, thus providing martinetana (Röding, 1798) (Figure 8a) at North Scott for ongoing monitoring opportunities within Reef is a new record for Australia. New records for a more defined area. Planned deviations from the Western Australian fauna are the columbellid the transect and searching areas adjacent to the Marine Fauna - Molluscs 205
Above: Distorsio anus (Linnaeus, 1758) with eggs. (Photo: Clay Bryce)
From top: Tridacna crocea Lamarck, 1819; Hippopus hippopus (Linnaeus, 1758); Tridacna squamosa Lamarck, 1819; Tridacna gigas (Linnaeus, 1758); Tridacna maxima (Röding, 1798). (Photos: Clay Bryce) Above: Octopus cyanea Gray, 1849 (Photo: Clay Bryce) 206 C. Bryce, C. Whisson
Figure 7 Venn Diagram showing species distributions at the Rowley Shoals, Scott Reef and Seringapatam Reef systems from the 1986 published report and this 2006 survey combined (n = 479 species). transect did allow for the amassing of qualitative Reef, have severely depleted populations of giant species records. This is evidenced by examination clams and of Tectus niloticus in both the shallow of the species collected during this survey when (Bryce, 2006) and the deeper waters of regions compared to other surveys (Table 4). covered in this paper. This was attributed to the The results of the 2006 survey yielded a total effects of environmental pressures and unregulated of 339 species of macromolluscs from Mermaid, fishing practices. Scott and Seringapatam Reefs but is not a complete The apparent increase in abundance of Cerithium inventory of the molluscan fauna as it does not echinatum, Conus miliaris and Conus musicus since include the poorly known and highly speciose the WA Museum’s 1986 report may be attributed micromolluscan fauna or faunal records housed to these species having taken advantage of habitat in the collections of the WA Museum and of other changes due to an increase in nutrient-rich habitats museums in Australia and elsewhere (Table 4). possibly caused by the depletion of holothurian The relative diversity and number of marine stocks (Bryce, 2006) across all reefs, except Mermaid habitats at these atolls influences their overall Reef. molluscan species diversity. South Scott Reef, with its large size, north-facing open lagoon, deep ACKnOWLEDGEMEnTS lagoonal waters (not sampled) and fractured back reef edge, provided a greater variety of habitats The authors would like to thanks the crew of the than the other atolls. However, unregulated fishing, charter vessel Kimberley Quest for their assistance cyclonic activity and recent warm water events during the expedition. Ceri Morgan of Woodside leading to coral bleaching appear to have played an Energy Ltd. provided valuable pre-trip assistance. important part in reducing molluscan abundance Dr. Enrico Schwabe, Glad Hansen, Hugh Morrison and, to some extent, molluscan diversity on this and Shirley Slack-Smith provided invaluable help reef. North Scott and Seringapatam Reefs have with identifications. Constructive manuscript also suffered the same environmental and fishing advice from Dr. Barry Wilson, Dr. Richard Willan pressures as South Scott Reef but appear to have and Shirley Slack-Smith is greatly appreciated. the added constraint of reduced habitat diversity. This is due to their small size, annular shape and a REFEREnCES reduced flushing regime. Mermaid Reef, 400 km to the south, mirrors North Scott and Seringapatam Beesley, P.L., Ross, G.J.B. and Wells, A. (eds) (1998). Reefs in shape and dimensions but apparently was Mollusca: The Southern Synthesis. Fauna of Australia. little affected by high water temperatures (Gilmore Melbourne: CSIRO Publishing Vol. 5, Parts A and B. et al., 2007) or fishing pressure due to its protected Berry, P.F. (ed.) (1986). Faunal Surveys of the Rowley status. Shoals, Scott Reef, and Seringapatam Reef, North- western Australia. Records of the Western Australian All of these atolls, with the exception of Mermaid Museum Supplement. 25: 1–106. Marine Fauna - Molluscs 207
a) b)
c)
d) e)
Figure 8 a: Marchia martinetana (Röding, 1798); b: Euplica deshayesii (Crosse, 1859); c: Notodoris serenae Gosliner and Beh- rens, 1997; d: Monitilora simplex (Reeve, 1850); e: Pitar spoori Lamprell and Whitehead, 1990. 208 C. Bryce, C. Whisson
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