Rowley Shoals), Scott and Seringapatam Reefs, North Western Australia

Records of the Western Australian Museum Supplement No. 77: 145–176 (2009). Crustaceans of Mermaid (Rowley Shoals), Scott and Seringapatam Reefs, north Western Australia

M.A. Titelius, A. Sampey, and C.G. Hass

Abstract – The atolls on the north-western Australian continental shelf are recognised in having a diverse shallow-water fauna with many widely distributed Indo-West Pacific species. However, the crustaceans of these reefs are poorly known. A survey of the crustaceans of four of the reefs on these continental-shelf atolls (Mermaid, South and North Scott, and Seringapatam reefs) was conducted in 2006 by the Western Australian Museum, Perth. Identifications focused on the stomatopod and decapod crustaceans, although many species within these groups such as the galatheids, caridean shrimps, and stomatopods, are not yet fully identified. A total of 157 species were recorded, more than doubling the numbers of species previously recorded from these atolls. The number of species will increase with identification of the unidentified specimens. The Xanthidae (Brachyura) was the most diverse family at all reefs, which is typical of Australian coastal waters. Differences in the stomatopods and decapod assemblages among reefs and respective habitats are discussed.

INTRODUCTION of Mermaid and Clerke reefs (Rowley Shoals) produced a small collection of decapod crustacean Along the edge of the continental shelf of north– species, 12 species from Mermaid Reef and 38 western Australia are a series of emergent reefs, species from Clerke Reef (unpublished data, WA from north to south these are: Ashmore Reef Museum Crustacean Collection). Until now these (12°10’S 122°58’E), Cartier Island (12°31’S 123°33’E), records have largely remained the basis of our Hibernia Reef (11°55’S 123°28’E), Seringapatam knowledge of the crustaceans from the Rowley Reef (13°38’S 122°05’E), North and South Scott reefs Shoals. (13°59’S 121°46’E) and the Rowley Shoals (Mermaid, Collection during this 2006 survey was systematic 17°07’S 119°36’E; Clerke, 17°10’S 119°20’E; and and extensive, allowing for a comparison between Imperieuse, 17°35’S 118°56’E, reefs). These reefs have the three reef systems (Rowley Shoals, Scott and been recognised for their regional importance in Seringapatam). The results of this survey represent providing habitat for shallow water coral reef fauna a significant increase to the known crustacean along the north-western Australian coast (Berry fauna of these atolls. and Marsh, 1986). The stomatopod and decapod crustacean faunas of these reefs are poorly known as very few collections have been made. METHODS A Western Australian Museum (WA Museum) expedition to Ashmore Reef and Cartier Island in Sample collection and processing 1986 recorded 93 decapod crustaceans (Morgan A total of 44 stations (7 intertidal and 37 subtidal and Berry, 1993). The collections were dominated stations) across Mermaid (15), South Scott (14), by xanthoids (39 species) and paguroids (25 species) North Scott (10) and Seringapatam (5) reefs were (Morgan and Berry, 1993). The crustacean fauna surveyed. of Scott and Seringapatam reefs, further to the Subtidal habitats (lagoon and outer reef) were north (see maps in Station and Transect data, this surveyed using either SCUBA diving or snorkelling. volume), has been somewhat better studied. Small At each SCUBA station a 30 minute survey was collections were made in the 1970s by various conducted at two depths, 5 m and 12 m mean sea workers and a Russian research ship stopped at level. A 25 m by 1 m transect line was laid at each Scott Reef in 1975. They recorded 55 species of of the chosen depth contours over the dominant decapods from 7 families and 31 genera (Tsareva, habitat and visual records and collections of 1980). Berry and Morgan (1986) reported 56 species crustaceans were made from each transect and collected from Scott and Seringapatam reefs during from the surrounding area. Only one depth was the 1984 WA Museum expedition, but the sampling sampled at two stations: South Scott Reef station 29 effort of the study was low. In 1982 a short survey (depth of 13 m) and Seringapatam Reef station 42 146 M. A. Titelius, A. Sampey , C. G. Hass

Above: The cryptic crab, Huenia brevifrons (Ward, 1941) on the algae, Halimeda. (Photo: Clay Bryce)

(depth of 7 m). Both these stations were in lagoons to placement into ethanol so the live colouration with reduced depth profiles (bommies over sand). could be examined. Where species were not easily Qualitative sampling of the crustacean diversity identified in the field they were treated at the order, was conducted at four stations by snorkel (stn 6) infraorder or family level. The identifications of and drift dives (10, 13 & 40). a small number of specimens were validated at No transect lines were laid at intertidal stations the WA Museum but the majority of species have however, a 30 minute survey was conducted by retained their field identifications. Current accepted shore collecting and visual records at each of the names and systematic placement follow Davie inner and outer platform zones. Sampling effort at (2002) and Ng et al., (2008). Specimens collected these stations varied due to some platform stations during the survey are housed at the WA Museum. having to be sampled at times other than low tide. Given the complexity of recording very motile Emphasis was placed on recording species and cryptic crustaceans with time constraints richness, which involved the examination and (dive time at each station), this survey is based collection of various substrates such as live mainly on decapod and stomatopod crustaceans. and dead coral heads, rocks, sand, sponges, Opportunistic collecting of isopods was echinoderms, and algae. Collected coral and rock undertaken but these were not included in this were systematically broken down, while sponges, paper. Specimens were housed at the WA Museum soft corals and ascidians were cut open to extract and await further study. living crustaceans. The remaining debris was then sorted through to find all remaining crustaceans. Data analysis Complex branching substrates, including algae and Crustacean assemblages were compared among soft corals, were washed in a tray of sea water and the sampled reefs (Mermaid, North Scott, South clove oil to narcotise the crustaceans. Live material Scott, and Seringapatam reefs) and habitats was euthanized by freezing and then preserved in (intertidal vs. subtidal, lagoon vs. outer reef slope). 70% ethanol. Visual records were made only where Data is thus arranged as a species matrix defining a confident identification of species was possible. whole reef systems or parts of it. The degree of Specimens were identified to species whenever similarity between these chosen matrices can possible using a dissecting microscope. All give insights into the relationships between reefs identifications were made where possible prior and the factors that may be influencing species Marine Fauna - Crustacea 147 distributions, such as particular microhabitats, Three main habitat types (platform, outer reef and depth and exposure at low tide. lagoon) were examined. As not all habitats were Data was analysed using PRIMER v6.1.11 and sampled at every reef the PERMANOVA considered PERMANOVA v1.0.1 based on the presence or habitats to be nested in reef and both reef and absence of each species. Due to non-standard habitat were fixed factors. As there was uneven search effort at some stations these were omitted replication of the habitats within each reef system from subsequent data analyses. The first four PERMANOVA was run using a type III (partial) stations (trialling sampling methods), drift dive model and the permutation was done on the stations of reef channels (10, 13 & 40), the snorkel residuals under a reduced model. The p value was stations (6), and any opportunistic collections of calculated by both permutation and Monte Carlo species were all omitted. The resulting data matrix methods, if the number of permutations was > 25 consisted of 138 taxa from 36 stations. then the permutation p values were reported, if the number of permutations was < 25, then the Monte The observed species richness (Sobs) of the Carlo p values were used. four shelf atolls was calculated from the dataset. Differences in the assemblages at different depths Projected values of species richness were calculated were examined only for subtidal habitats, lagoon using two non-parametric methods to estimate and outer reef zones. The unidentified mixed the number of species that would be collected as species (stomatopods, galatheids and caridean the number of samples approaches infinity. The shrimps) were removed prior to analysis. As all Bootstrap method examines the proportion of depths and these two habitats were sampled at all samples containing each species, while the Jacknife reefs the PERMANOVA model considered reef, method is a function of the numbers of species habitat and depth to be fixed orthogonal factors and present in one or two samples (Clarke and Gorley, used a type III (partial) model, and the permutation 2006). was done on the residuals under a reduced model. Non-metric multidimensional scaling (nMDS) and cluster analysis were used to explore the RESuLTS relationships among the reefs and habitats. Similarity profiles (SIMPROF) were used to test Species richness the significance of the clusters formed (Clarke and Gorley, 2006). Similarity percentages (SIMPER, Observed species richness. Clarke and Warwick, 2001) were used to determine which species contributed to differences among A total of 157 species were recorded from the habitats and reefs. Differences between reef system 2006 collections, of which 87 species are new groups and habitat types were further analysed for the region (Table 1). Species richness for the using PERMANOVA (Anderson et al., 2008). All individual reefs was 79 species (Mermaid Reef), analyses used the untransformed presence/absence 105 species (South Scott Reef), 63 species (North species data and a Bray-Curtis similarity matrix. Scott Reef) and 40 species (Seringapatam Reef).

Figure 1 Frequency distribution of the number of stations at which species were recorded. 148 M. A. Titelius, A. Sampey , C. G. Hass = Berry 1 2 4 4 4 2 , 3 3 3 3 3 3 3 3 , C S S S S S S S 2 A S RC RM A Previous Collections 44 41, 44-45 41, 31 31 33 34 32, 34-3532, 2 = occurs in the Mediterranean. # STATIONS 27 21, 25 21, 17, 21-22, 27 21-22, 17, 8 1 = species occurs in Western Atlantic, 1 = species occurs in Western # 1, 8 1, = Unpublished Data, Crustacean Collection. WAM *Author listed as Herbst, 1897 - this is incorrect. NB. 4 1, 6, 9-10, 16 9-10, 6, 1, Mermaid Reef South Scott Reef North Scott Reef Seringapatam = Tsareva 1980, = Tsareva 3 1 # 2 # recorded from Mermaid, Scott studies. in and this from Seringapatam study previous reefs and also from recorded = Morgan & Berry 1993, 2 ences in characters the from published description; ? = uncertainty in the identification but likely to be the given genus v or = species. vi- c = carapace only, List of crustaceans cf. = differ sual record, BW = beach walk. Previous collections are based on records in reports or the Western Australian Museum crustacean collection. Location: RM = Mermaid BW = sual beach in or record, walk. collections based reports the Previous are on Western records Reef, Rowley Shoals, RC = Clerke Reef, Rowley Shoals, S = Scott Reef, Ser = Seringapatam Reef, A = Ashmore Reef, C = Cartier Island. Reference Source: & Morgan 1986, Likely misidentification as species does not occur in the area. lpheus dentipes Guérin Ménéville, 1832 (Olivier, 1811) Stenopus hispidus (Olivier, Gonodactylus 1781) (Fabricius, chiragra Odontodactylus scyllarus (Linnaeus, 1758) Gonodactylus platysoma 1895 Wood-Mason, Stenopus1 sp. Alpheus bouvieri Milne-Edwards,A. 1878 Alpheus bucephalus 1905 Coutière, Alpheus Stimpson, collumianus 1860 Alpheus deuteropus 1879 Hilgendorf, A Alpheus frontalis Milne H. 1837 Edwards, Alpheus leviusculus Dana, 1852 Alpheus Guérin-Méneville,lottini 1829 Alpheus acutofemoratus Dana, 1852 Gonodactylus sp.

STENOPODIDAE GONODACTYLIDAE ODONTODACTYLIDAE ALPHEIDAE ALPHEIDAE Stenopodidea STOMATOPODA Caridea Taxa UnidentifiedStomatopods DECAPODA Table 1 . Table Marine Fauna - Crustacea 149 4 4 2 2 2 4 , C 2 2 2 4 2 4 3 3 3 3 3 1 , RC , RC , A S 4 4 , A S S S S S S A A A A 3 1 RC , A S S 3 S RM RM 45 44 32 35 33 33, 39 31-36, 38-40 41-42, 45 17 17 29 25, 26 24, 25 23, 26, 28 26, 23, 17-22, 24-26, 28-29 1 16 10, 13 9-10, 14 1-3, 6, 8, 12, 14, 15 14, 12, 8, 6, 1-3, Dana, 1852 Schenkel, 1902 (Paul’son, 1875) (Paul’son, Coutière, 1905 Coutière, (Von Martens, 1872) (Von (Lund, 1793) (Lund, (de Man, 1888) (de (Oliver, 1811) (Oliver, (Fabricius, 1798) (Fabricius, Dana, 1852 de Man, 1902 de sp. sp. sp. 1 sp. s sp. 2 s sp. sp. sp. Periclimene Panulirus femoristriga Panulirus Alope sp. antarcticus Parribacus Bruce & Svoboda, 1984 1984 philippinensis Svoboda, & Vir Bruce new species record WA Periclimenes Hamodactylus Saron neglectus Saron Alpheus pacificus Alpheus strenuus strenuus Alpheus hastilicrassus Synalpheus Synalpheus Synalpheus stimpsoni marmoratus Saron Saron Thor amboinensis de Man, 1888 Neopontonides brevicarpalis Periclimenes ornatus Panulirus versicolor 1804) (Latreille, Panulirus Synalpheus tumidomanus Synalpheus PALINURIDAE GALATHEIDAE GALATHEIDAE PONTONIINAE HIPPOLYTIDAE SCYLLARIDAE Anomura PALAEMONIDAE PALAEMONIDAE Palinura Unidentified Alpheidae sp. Unidentified caridean shrimp UnidentifiedPalaemonidae sp. 150 M. A. Titelius, A. Sampey , C. G. Hass 2 4 2 2 , C 2 , Ser , C , C 4 2 2 1 2 2 , A 2 1 4 2 2 2 2 2 2 , S 4 4 2 3 4 , A , A , C , C 4 1 , A S C 2 2 A A A A A A A A 2 , Ser RC 1 , Ser S A A 1 S , RM , Ser , Ser , S 4 1 1 4 S RC RC Previous Collections 41 42 44-45 S 24 37 33 33 32, 39-40 32, 32, 35, 37 35, 32, 31, 33-34, 40 31, STATIONS 21 24 22 17, 20 17, 18, 21 18, 25, 29 25, 18, 22, 25 22, 18, 3 4 6 9 4, 16 4, 3-4, 10, 13 3-4, 10, 4, 7, 8-10, 12-14 8-10, 7, 4, 25-26 22, 17-18, 38-39 36, 34, 31-32, 45 42, Mermaid Reef South Scott Reef North Scott Reef Seringapatam 4, 6, 12-13, 15-16 12-13, 6, 4, 28-30 25-26, 22-23, 17-20, 39-40 36, 34, 31-32, 45 41-42, 3, 6, 8-9, 11, 13-14 11, 8-9, 6, 3, 26-27 24, 21, 1-4, 6-9, 11, 13, 15 13, 11, 6-9, 1-4, 30 28, 25, 17-19, 34-36, 38-39 31-32, 41 Wooster, 1984 Wooster, Galathea sp. (Adams and (Adams elegans Allogalathea White, 1848) Neopetrolisthes maculatus Milne(H. 1837) Edwards, ? Lissoporcellana 1 sp. sp. Aniculus Hippa pacifica (Dana, 1852) sp. 1 sp. Polyonyx 1 sp. Porcellanid Petrolisthes asiaticusPetrolisthes (Leach, 1820) haswelli Miers,Petrolisthes 1884 lamarckiiPetrolisthes (Leach, 1820) 1 sp. Petrolisthes 3 sp. Petrolisthes 1811) (Olivier, ursus Aniculus MilneCalcinus(H. elegans 1836) Edwards, Milne(H. Calcinus gaimardii 1848) Edwards, Calcinus ? gaumensis Calcinus laevimanus (Randall, 1839) Calcinus latens (Randall, 1840) Calcinus lineapropodus Morgan and 1991 Forest, Buitendijk, Calcinus1937 minutus Calcinus pulcher 1958 Forest, 1951 Calcinus seurati Forest, Calcinus ? vachoni 1958 Forest, sp. 2 sp. Petrolisthes A Calcinus sp. PORCELLANIDAE DIOGENIDAE HIPPIDAE Taxa Unidentified galatheids Marine Fauna - Crustacea 151 2 2 2 , C 2 2 2 2 2 , A 4 2 1 , C 2 , A 2 2 1 , A , A , A , A 1 1 4 , C 1 1 4 2 2 2 2 2 2 * 2 2 3 1 3 , A , RC , S , C , Ser 1 , C S 4 S 4 , S C 2 A A A A A A 1 S 1 , S 4 RC Ser 4 S , A A 1 , Ser , Ser , S 1 1 4 S RM , Ser S S RC , RC RM 1 4 S RM 41 RM 44 31 35 33 33 18 21 24 26 27 27 21, 26 21, 24, 27 24, 20, 22 20, 2 9 2, 3 2, 3, 10 3, 1, 7, 11 7, 1, 9-10, 13-16 9-10, 1, 3, 12, 14-16 12, 3, 1, 27-28 24-25, 21-22, 17-18, 34-36, 38-39 31, eurysternus (Hilgendorf, 1878) (H. Dardanus Milne(H. scutellatus 1848) Edwards, Pagurid sp. 1 Pagurid sp. Coenobita perlatus Milne H. 1837 Edwards, Pagurid sp. 2 Pagurid sp. sp. B Calcinus sp. 1804) Ciliopagurus (Herbst, strigatus Milne(H. Clibanarius corallinus 1848) Edwards, Clibanarius cf. Clibanarius striolatus Dana, 1852 Clibanarius virescens (Krauss, 1843) 1 Clibanarius sp. 2 Clibanarius sp. Clibanarius ? sp. Dardanus crassimanus Milne(H. 1836) Edwards, Dardanus deformis Milne(H. 1836) Edwards, Dardanus gemmatus Milne(H. 1848) Edwards, 1811) Dardanus guttatus (Olivier, Dardanus lagopodes (Forskål, 1775) Dardanus megistos 1804) (Herbst, Dardanus ? 1804) pedunculatus (Herbst, Dardanus sp. brevirostrisPaguristes 1905 Baker, sp. Pagurus Coenobita Milne H. rugosus 1837 Edwards, Pagurid sp. 3 Pagurid sp. 4 Pagurid sp. sp. 1 sp. Paguritta hirtimanusPagurus Miers, 1880 PAGURIDAE COENOBITIDAE Unidentified Diogenidae sp. UnidentifiedPaguridae sp. 152 M. A. Titelius, A. Sampey , C. G. Hass 2 2 , C 2 2 2 1,3 , A 1 4 4 4 , C 2 2 2 2 3 , A 1 1 , S , A 4 S S S , S S1 A A A 1,3 4 RC RC RC 1,3 , A S 3 , S RC 4 S RM RC Previous Collections 44 44 44 Seringapatam 33 33 STATIONS 27 27 21c 22c 24, 27 South Scott Reef North Scott Reef 1 3 14c Mermaid Reef Balss, 1932 Balss, (Haswell, 1882) (Haswell, Nobili, 1906 Nobili, (Gray, 1831) (Gray, (Linnaeus, 1758) (Linnaeus, 1758) (Herbst, 1803) sp. Dromiid (likely spp. to be two different species) Dromiid sp. Calappa calappa Calappa Aethra ? scruposa (Linnaeus, 1764) Aethra scruposa ? (Linnaeus, 1764) speciesNew record WA (Forskål, convexus Carpilius 1775) rathbunae Dacryopilumnus 1790) Daira perlata (Herbst, 1803) Nodder, & Eriphia sebana (Shaw 1 sp. Goneplacid Heteronucia venusta Unidentified Goneplacidae sp. Goneplacidae Unidentified Carcinoplax Dromidiopsis australiensis Stimdromia lateralis Calappa gallus Calappa hepatica Eriphia scabricula Dana, 1852 ? Petalomera sp. GONEPLACINAE DROMIIDAE CALAPPIDAE New family New AETHRIDAE record WA for CARPILIIDAE DACRYOPILUMNIDAE DAIRIDAE ERIPHIIDAE GONEPLACIDAE LEUCOSIIDAE Brachyura Taxa Marine Fauna - Crustacea 153 2 2 2 4 4 4 4 4 , C 2 2 2 2 2 2 4 1 , A S , A S A A A A A A2 3 1 RC RC RC RC Ser , A S S 3 S 44 44 31 33 33 33 31, 33 31-32, 34 18 27 23 22 22 17, 29 24, 27 24, 30 17, 19, 30 19, 17, 3 1 3 16 13 13, 16 2-4, 16 7, 12, 14, 16 14, 12, 7, 1, 3, 4, 6, 12, 14-15 12, 6, 4, 3, 1, 29 25-26, 20, 18, New AustraliaNew record New AustraliaNew record (Latreille, 1825) (Stimpson, 1858) (De Haan, 1837) (De (Latreille, 1825) Ward, 1941 1941 Ward, Henderson, 1893 Latreille, 1829 Latreille, sp. 1 sp. Dana, 1852 Dana, 1852 sp. heraldica sp. 1 sp. sp. 1 sp. cf. sp. Huenia Huenia brevifrons sp. Hymenosomatidae Unidentified Camposcia retusa 1 sp. Majid Unidentified Majidae sp. Majidae Unidentified Cyclax suborbicularis Cyclax Cyclax Leucosiid 1 sp. Unidentified Leucosiidae sp. Menaethius orientalis 1969) (Sakai, monoceros ? Menaethius Menaethius tumida Perinea Hoplophrys oatesii styx (Herbst,Tylocarcinus 1803) Schizophrys aspera Milne(H. 1834) Edwards, Schizophrys sp. Pseudomicippe ? Micippa Micippa cristata (Linnaeus, 1758) Tiarinia Dana, 1852 angusta cornigera ? Tiarinia Tiarinia EPIALTINAE MAJINAE PISINAE PISINAE MITHRACINAE EPIALTIDAE HYMENOSOMATIDAE INACHIDAE MAJIDAE 154 M. A. Titelius, A. Sampey , C. G. Hass 4 2 4 4 2 2 , S 4 4 4 3 3 1 1 1 1 4 , A S S S S S S S S S A A 3 RC RC S RC Previous Collections 43 44 34 STATIONS 17 24 29 30 22 4 2 11 Mermaid Reef South Scott Reef North Scott Reef Seringapatam Dana, 1852 Caphyra laevis Milne (A. 1869) Edwards, Portunus (Achelous) granulatusPortunus (Achelous) Milne(H. 1834) Edwards, sp. Tiarinia sp. Daldorfia horrida (Linnaeus, 1758) MilneEchinoecus (A. pentagonus 1879) Edwards, Portunid 1 sp. Portunid 2 sp. Portunid 3 sp. Heteropilumnus longipesHeteropilumnus (Stimpson, 1858) Pilumnid 2 sp. Pilumnid 3 sp. Harrovia sp. Tiaramedon spinosum (Miers, 1879) sp. Heteropilumnus (De minutus Haan, cf. 1835) Pilumnus vespertilioPilumnus 1793) (Fabricius, vermiculatusPilumnus MilneA. 1873 Edwards, Viaderiana quadrispinosa (Zehntner, 1894) Pilumnid 1 sp. Lissocarcinus orbicularis sp. Portunus Pilumnid sp. CAPHYRINAE PORTUNINAE PORTUNINAE EUMEDONINAE PILUMNINAE PILUMNINAE PARTHENOPIDAE PILUMNIDAE PORTUNIDAE Taxa Marine Fauna - Crustacea 155 4 2 2 , A 4 4 4 2 3 3 1 1,3 1,3 1,3 1,3 1,3 , C , A S S S C 2 S S S S S , S 3 RC RC 4 S A RC 41 45 41-43 41-42, 45 41-42, 37 32 37 31, 32 31, 31v, 34 31v, 31-32, 38-39 31-32, 31-32v, 34v, 36v, 38-39 36v, 34v, 31-32v, 45 41, 24 24 22 26v 19-20 25-26 25-26 17, 29 17, 17, 23 17, 21, 29 21, 24, 27, 30 27, 24, 28-29v, 30 28-29v, 17, 19-20, 27 19-20, 17, 17, 19, 20v, 23-24, 25-26v, 25-26v, 23-24, 20v, 19, 17, 6 6 6 12 4v 4, 6 4, 14, 16 14, 6-9, 16 6-9, 2, 7, 10 7, 2, 11-13, 1511-13, 29-30 25-27, 23, 17-18, 36 31-32, 1v, 3-4, 12v 1v, 1, 4v, 12v, 16v 12v, 4v, 1, Dana, 1852 bidentata (Forskål, 1775) sp. 2 etralia sp. T Pseudozius caystrus & White, (Adams 1849) Domecia Alcock, glabra 1899 1875 ? cinctipes Paul’son, Tetralia areolata Trapezia Charybdis sp. Thalamita admete1803) (Herbst, Thalamita coeruleipes & Hombron 1846 Jacquinot, Thalamita cooperi Borradaile, 1903 Thalamita picta Stimpson, 1858 Domecia & Souleyet, 1842 hispida Eydoux glaberrima 1790) (Herbst, Tetralia Serène nigrolineata & Pham, 1957 Tetralia cymodoce 1801) Trapezia (Herbst, cf. Trapezia Thalamita ? prymna 1803) (Herbst, Thalamita sima Milne H. 1834 Edwards, Thalamita 1 sp. Thalamita 2 sp. sp. 1 sp. Tetralia sp. 3 sp. Tetralia heterodactylus 1861) Tetraloides (Heller, Thalamita 3 sp. Thalamita 4 sp. Thalamita 5 sp. Thalamita sp. THALAMITINAE PSEUDOZIIDAE DOMECIIDAE TETRALIDAE TRAPEZIIDAE 156 M. A. Titelius, A. Sampey , C. G. Hass 2 4 2 4 , A 4 , C 2 2 2 2 , S 3 3 3 3 3 3 3 1 1 , Ser 1,3 1,3 4 2 S S S S S S S S S C A A S S , A , Ser 1 RC , A 3 S 1,3 S Previous Collections 43 44 41-45 42, 4442, 41-42, 44 41-42, 39 34 34 31, 34 31, 31, 34 31, 33, 37 33, 32-34, 39 32-34, STATIONS 18 21 24 24 24 20 20 25 19, 25 19, 21, 27 21, 20, 21 20, 18, 20, 22 20, 18, 17-18, 25-26, 25-26, 17-18, 38-39 36, 34, 31-32, 45 41-43, S 17, 19, 22, 28-3022, 19, 17, 17-20, 22, 25-26, 28 25-26, 22, 17-20, 1 3 14 3, 6 3, 8-9, 11, 14 11, 8-9, 2, 8, 10, 16 10, 8, 2, 29-30 24-26, 21-22, 18-19, 36 34, 31, 6, 12, 14-15 12, 6, Mermaid Reef South Scott Reef North Scott Reef Seringapatam 2, 4, 12-13, 15-16 12-13, 4, 2, 1-3, 6-9, 11-12, 14, 16 14, 11-12, 6-9, 1-3, 25-26 22, 20, 17-18, (Dana, 1852) hlorodiella ? laevissima (Dana, 1852) Chlorodiella ? cytherea C Latreille, digitalis 1828 Trapezia Actaea sp. Trapezia rufopunctata 1799) (Herbst, Trapezia sp. 1 Pseudoliomera sp. Rüppell, 1830 1830 guttata Rüppell, Trapezia Castro, 1997 lutea Trapezia septata Dana, 1852 Trapezia & Souleyet, 1842 tigrina Eydoux Trapezia Actaea 1861) polyacantha (Heller, Actaeodes 1830) (Rüppell, hirsutissimus Actaeodes tomentosus Milne(H. 1834) Edwards, 1 sp. Gaillardiellus 1 sp. Paractaea Chlorodiella (Borradaile,barbata 1900) 1877) granulatus (Targioni-Tozzetti, Cyclodius ? granulosus (DeCyclodius Man, 1888) (Dana,nitidus Cyclodius 1852) obscurusCyclodius (Hombron & 1846) Jacquinot, ungulatus Milne(H. Cyclodius 1834) Edwards, Pilodius areolatus Milne(H. 1834) Edwards, Actaeodes 1 sp. Actaeodes 2 sp. ? cavipesPsaumis (Dana, 1852) Actaeodes Milneconsobrinus (A. 1873) Edwards, Gaillardiellus orientalis1925) Gaillardiellus (Odhner, CHLORODIELINAE CHLORODIELINAE ACTAEINAE ACTAEINAE XANTHIDAE Taxa Marine Fauna - Crustacea 157 2 2 4 4 2 2 2 2 2 3 3 3 1 1 1 , A 1, 3 S S S , A S S S A A A A A ,3 S 1 RC RC S S1 41 43 43 44 41, 45 35 34 38c 33-34 35, 37 17 24 29 26 20 17, 19 26juv 21c, 24 17, 19, 23 19, 17, 18-19, 21, 29 21, 18-19, 18-23, 25-28, 30 2 4 10c 6, 14 3-4, 6 1, 6, 8 6, 1, 14c, 15c 11, 14, 15c 14, 11, 3, 10, 12, 14 12, 10, 3, in Jacquinot & Lucas, 1853 in Jacquinot1853 & Lucas, (Serène, 1972) New Australia New 1972) (Serène, Dana, 1852 (Herbst, 1790) (Herbst, (White, 1848) (White, (A. Milne (A. 1873) Edwards, (Audouin, 1826) Miers, 1884 Miers, (White, 1847) (White, (De Haan, 1835) (De (Rathbun, 1894) Kossmann, 1877 Kossmann, (Hombron & Jacquinot, 1846) (Hombron & 1846) Jacquinot, A. MilneA. 1873 Edwards, Odhner, 1925 Odhner, Rathbun, 1894 (Herbst, 1785) (Herbst, (A. Milne (A. 1873) Edwards, (A. Milne Edwards, 1865) Milne Edwards, (A. (Herbst, 1801) (Herbst, sp. 1 sp. sp. 1 sp. andreossyi andreossyi demani sp. 2 sp. sp. 1 sp. cf. sp. 1 sp. cf. Etisus New AustraliaNew record Pilodius Jacquinot, utilus ? Etisus exsculptus Euxanthus Liomera cinctimana record Pilodius ? flavus ? Pilodius pilumnoides Pilodius Pilodius melanodactylus Cymo quadrilobatus Cymo Cymo dentatus Etisus electra Etisus huonii Euxanthus abbotti Hypocolpus Paramedaeus Palapedia ? marquesa Liomera edwardsi Liomera monticulosa Liomera rubra Cymo Palapedia ? integra Tweedieia Cymo deplanatus Cymo laevis Liomera ETISINAE ETISINAE EUXANTHINAE EUXANTHINAE LIOMERINAE KRAUSSIINAE CYMOINAE 158 M. A. Titelius, A. Sampey , C. G. Hass 2 2 2 2 , A 4 , C 2 2 2 2 2 2 2 2 2 1,3 2 3 1 1,3 , C S , A S C 2 A A A A A A A A S 1 RC , S 4 , A S A 1 S RC Previous Collections 44 33 35, 37 35, 34, 40 34, STATIONS 19 20 23 21, 24 21, 24, 27 24, 20, 23 20, 27, BW 27, 6 9 4 13 13 8, 9 8, 1, 14 1, 3, 6, 13 6, 3, Mermaid Reef South Scott Reef North Scott Reef Seringapatam (Heller, 1861) (Heller, anaglypta (Latreille, in Milbert, 1812) semigranosa 1861) (Heller, (H. Liomera Milne(H. rugata 1834) Edwards, Atergatis floridusAtergatis (Linnaeus, 1767) Lybia Lybia tessellata Lachnopodus subacutus (Stimpson, 1858) Banareia 1 sp. Platypodia 2 sp. Zozymodes cavipes (Dana, 1852) Liomera tristis (Dana, 1852) Platypodia eydouxiMilne (A. 1873) Edwards, Platypodia 1 sp. (A. MilneLiomera stimpsoni (A. 1865) Edwards, Liomera sp. Leptodius exaratus Milne(H. 1834) Edwards, Leptodius sanguineus Milne(H. 1834) Edwards, Neoxanthias impressus (Latreille, in Milbert, 1812) notatus (Dana,Paraxanthias 1852) Milne pachydactylusParaxanthias (A. 1867) Edwards, 1 Xanthias sp. Xanthias lamarcki Milne(H. 1834) Edwards, 1 Atergatopsis sp. Platypodia granulosa 1830) (Rüppell, Platypodia cf. Zosimus aeneus (Linnaeus, 1758) Lophozozymus cf. Xanthias sp. Lophozozymus 1 sp. ZOSIMINAE POLYDECTINAE XANTHINAE ZALASIINAE Taxa Marine Fauna - Crustacea 159 1 4 2 , S 2 1 4 2 4 4 4 2 2 2 2 , S , A 1 , A , RC 4 4 4 S 4 , A A A A A 1 , RC RC RC RC 4 S RC RC RM RM RM 41 44 37 40 33, 37 33, 31-32, 34, 38-3934, 31-32, 45 43, 41, 24 BWc BWc 25-26 21, 27 21, 21, 24, 27 24, 21, 3 Audouin, 1826 Audouin, Hapalocarcinus marsupialis Stimpson, 1859 1 sp. Grapsid 1 Plagusia sp. Pinnixa sp. Grapsus albolineatus Latreille, in Milbert, 1812 Grapsus tenuicrustatus 1783) (Herbst, Percnon abbreviatum (Dana, 1851) Macrophthalmus (Chaenostoma) boscii Ocypode ceratophthalmus (Pallas, 1772) A. MilneA. minutus Pachygrapsus 1873 Edwards, sp. 1 sp. Pachygrapsus 1838) Planes major (Macleay, Percnon guinotae 1965 Crosnier, 1804) (Herbst, Percnon planissimum Percnon sp. 1790) Uca tetragonon (Herbst, Xanthasia White, 1846 murigera PLAGUSINAE GRAPSINAE PERCNINAE MACROPHTHALMIDAE CRYPTOCHIRIDAE GRAPSIDAE PLAGUSIIDAE PINNOTHERIDAE OCYPODIDAE Unidentified Xanthidae spp. Unidentified Pinnotheridae sp. 160 M. A. Titelius, A. Sampey , C. G. Hass

Above: Calcinus elegans (H. Milne-Edwards, 1836) - Elegant hermit crab. (Photo: Clay Bryce)

Above: A juvenile specimen of the rock lobster, Panulirus versicolor (Latreille, 1804) at Station 28, South Scott Reef. (Photo: Glenn Moore) Marine Fauna - Crustacea 161

Table 2 Number of crustacean species recorded from the 2006 survey compared with the cumulative number of species recorded from previous collections. Recollected Species: number of species recorded at each reef visited during the 2006 survey that were also collected by previous surveys in the region. The numbers of new records of crustaceans for each reef visited in 2006 are provided.

Reef Source Mermaid Scott Seringapatam Previous Collections 12 106 13 2006 Survey 79 128 40 Recollected Species 34 61 22 New Records 45 67 18

These figures represent a more than doubling recorded only from one reef, and are not shared of species previously recorded from Mermaid with the other reefs examined. Mermaid Reef and Seringapatam reefs and an increase in the recorded the highest proportion, 31% (24 species), number of species from Scott Reef (Table 2). of unique crustacean species, with South Scott Reef Furthermore, the number of species will increase recording 29% (29 species) (Figure 2). Proportions with identification of galatheids, caridean shrimp, of unique species at North Scott and Seringapatam stomatopods and other species that require further Reefs were 19% (11 species) and 18% (6 species) identification. respectively. Two species from Mermaid Reef, 40 from Scott Estimated species richness Reef and four from Seringapatam Reef were previously collected from each location (Table The species accumulation curve of observed 1). These values are based on those species only species (Sobs) did not reach an asymptote having full species-level identifications. It is indicating that the sampling had not fully sampled expected that the number of repeat collections the study area and further sampling would likely will increase with further study of the material as reveal more species of crustaceans (Figure 3). several specimens in both the current and previous Projected estimates of diversity for the area, as collections were not fully identified. provided by non-parametric analyses, ranged from The majority of the species collected (112 species, 157 (Bootstrap) to 197 species (Jacknife 1). Neither or 73%) were rare, only being recorded from three estimator reached an asymptote. They therefore or less stations (Figure 1). Twenty-six species (17%) represent minimum estimates of species richness were common, occurring at four to nine stations using these methods. and 16 species (10%) were considered widespread (10+ stations). Species richness within families Unique species are defined as those that were Twenty eight decapod families are represented in

Figure 2 Total number of species and the number of unique species (not shared with other reefs) recorded at Mermaid, South Scott, North Scott and Seringapatam reefs during the September 2006 survey. 162 M. A. Titelius, A. Sampey , C. G. Hass

200 Sobs Jacknife1 Bootstrap

150 un t Co

s 100 ie Spec

0 0 10 20 30 40 Samples Figure 3 Species accumulation curve of the species observed (Sobs) for 36 stations at Mermaid, Scott and Seringapa- tam reefs, and projected estimates of diversity based on Bootstrap and Jacknife non-parametric methods. the 2006 collections. Caridean shrimp families and North Scott Reefs (8 each). Diversity of the Majidae the family Galatheidae have been omitted due to across the reefs is highest at Mermaid and South their identifications being incomplete. Scott reefs (9), and lowest at Seringapatam Reef (2). Species richness within families across the reefs The ordering of families based on species ranged from one species (Palinuridae, Dromiidae, richness should not be treated as conclusive Leucosiidae, Aethridae, Dairidae, Daldorphiidae, because the identifications of galatheids and Carpiliidae, Eriphiidae, Goneplacidae, Crypto- caridean shrimps has yet to be completed. Both chiridae) to a maximum of 45 species (Xanthidae) of these decapod groups were observed to be (Table 3). Seventeen families were represented by significant components of the faunas at all reefs, in three or fewer species. Four families had between particular galatheids. Despite the unavailability of four and ten species Paguridae (6), Porcellanidae (8), this data it is unlikely either family would surpass Trapeziidae (8) and Tetralidae (7). Four families had the observed diversity of the Xanthidae at any of more than 10 species each, Xanthidae (45 species), the reefs. Majidae (14), Diogenidae (14) and Portunidae (14), (Table 3). Site diversity The Xanthidae was the most diverse family at Species richness at sites ranged from a minimum all reefs and had the greatest observed change of six species (Mermaid stn 7) to a maximum of in species richness across reefs: Mermaid (23 species), South Scott (29), North Scott (11) and 25 species (South Scott stn 24). Mean site richness Seringapatam (9). Diversity of the coral inhabiting within reef systems was highest at South Scott crabs (Trapeziidae and Tetralidae) was relatively Reef (16.5 species), followed in decreasing order of consistent across the reefs with a maximum of richness by Mermaid (12.4), Seringapatam (11.8) and 12 species being recorded at South Scott and a North Scott reefs (10.7) (Table 4). The reef platform minimum of seven species at Seringapatam Reef, stations showed the highest species richness and 10 species at both Mermaid and North Scott (average of 17.2 species), and lagoon stations had reefs. A similar pattern was observed in the the lowest (11.8). Outer reef stations had an average anomuran family Diogenidae: South Scott Reef number of 13.7 species. The average across habitats (max. 11), Seringapatam Reef (min. 6), Mermaid and was 13.5 species. Marine Fauna - Crustacea 163

Above: The cleaner shrimp, Stenopus hispidus (Olivier, 1811) was common under ledges. (Photo: Sue Morrison) 164 M. A. Titelius, A. Sampey , C. G. Hass

Table 3 Species richness within decapod families across all reefs and within each reef. Caridean shrimps and galatheids have been omitted due to the incomplete identifications among these groups. The four most species rich families are highlighted, the highest ranked in orange and the others in grey.

Family number of Species All Reefs Mermaid Sth Scott Nth Scott Seringapatam

Stenopodidea STENOPODIDAE 2 2 0 1 0

Palinura PALINURIDAE 1 1 1 1 0

Anomura DIOGENIDAE 14 8 11 8 6 PAGURIDAE 6 5 3 2 0 PORCELLANIDAE 8 3 6 3 1

Brachyura DROMIIDAE 1 1 0 0 1 CALAPPIDAE 2 0 2 0 0 LEUCOSIIDAE 1 0 1 0 0 MAJIDAE 14 9 9 6 2 AETHRIDAE 1 1 0 0 0 DAIRIDAE 1 1 1 1 DALDORPHIIDAE 1 0 1 0 0 PORTUNIDAE 14 5 7 4 1 XANTHIDAE 45 23 29 11 9 TETRALIDAE 7 6 5 3 4 TRAPEZIIDAE 8 4 7 7 3 DOMECIIDAE 2 2 2 0 0 CARPILIIDAE 1 0 1 0 0 PILUMNIDAE 3 1 2 1 1 ERIPHIIDAE 1 0 1 1 0 GONEPLACIDAE 1 0 1 0 0 OCYPODIDAE 2 0 2 0 0 GRAPSIDAE 3 1 3 1 1 PLAGUSIIDAE 3 0 0 2 1 CRYPTOCHIRIDAE 1 1 1 1 Marine Fauna - Crustacea 165

Table 4 Average species richness within each reef, across reefs, and for each habitat type within and across reefs. Cal- culations do not include channel stations.

Mermaid Reef Mean Std Dev Station Richness (all collections) 12.4 4.03 Station Richness (transect only) 10.6 3.58 Lagoon 11.9 4.52 Outer Reef 12 3.46 Platforms 19

South Scott Reef Station Richness (all collections) 16.5 4.99 Station Richness (transect only) 15.8 4.39 Lagoon 16.2 4.27 Outer Reef 14.3 5.12 Platforms 21.3 3.21

North Scott Reef Station Richness (all collections) 10.7 6.07 Station Richness (transect only) 11.6 5.13 Lagoon 10.6 3.51 Outer Reef 16 7.81 Platforms 11.7 6.43

Seringapatam Reef Station Richness (all collections) 11.8 3.7 Station Richness (transect only) 11.6 3.97 Lagoon 8.5 1.41 Outer Reef 12.5 2.12 Platforms 17

Species Richness Across Reefs All Habitats 13.5 5.1 Lagoon 11.8 4.57 Outer Reef 13.7 4.83 Platforms 17.25 5.96 166 M. A. Titelius, A. Sampey , C. G. Hass

Above: The trapeziid crab, Trapezia cymodoce (Herbst, 1801). (Photo: Clay Bryce)

Species distributions and comparisons among Habitats across reef systems reefs The crustacean assemblages at the platform The stations are clearly different due to stations were very different from lagoon or outer differences in habitats, with the intertidal platform reef communities. Separation occurred at 15% habitat being very different from the subtidal similarity and was significant (SIMPROF, p < 0.05, Figure 4a). The lagoon and outer reef communities habitats of the lagoon and outer reef (Figure 4a). also showed some separation. There is a gradient These differences are greater than differences in the communities among reef systems from between reefs, although reef location influenced Mermaid to the more northerly reefs, Scott and the clustering of Mermaid Reef subtidal stations. Seringapatam reefs. The average dissimilarity Strong clustering was observed in the closely between the platform habitat and the two subtidal situated northern reefs of South Scott, North Scott habitats combined (lagoon and outer reefs) was and Seringapatam but there was little separation 86%. of reef systems within this cluster. A gradient Ten species were the main discriminators (SD/ separation of lagoon and outer reef habitats is Diss > 1) of the differences between platform evident. It is apparent that the same habitats need to habitats and the other two habitats combined be compared across reef systems. (Figure 4b). Eriphia scabricula, Pilodius areolatus and Marine Fauna - Crustacea 167

Figure 4 Crustacean taxa from north-west Australian reefs, a) two-dimensional ordination, showing the main habitat types for each reef system, b) discriminating taxa based on average presence or absence across stations within each habitat grouping (SIMPER, Diss/SD >1). M: Mermaid, SS: South Scott, NS: North Scott, and SE: Serin- gapatam. The main groupings are significant at 15% similarity (SIMPROF, p < 0.05), Other includes the two subtidal habitats (lagoon and outer reef). 168 M. A. Titelius, A. Sampey , C. G. Hass

Table 5 PERMANOVA results for the three main habitats (platform, outer reef, lagoon), a) main test, b) pairwise tests, Mermaid and South Scott reefs, p value derived from the permutation method, North Scott and Seringapa- tam reefs, p value from the Monte Carlo method.

a) main test b) pairwise tests

Source df SS MS Pseudo-F P(perm) Groups t P Reef 3 16575 5525.1 2.975 0.001 Mermaid Reef Habitat(Reef) 7 32424 4632 2.494 0.001 Lagoon, Outside 1.465 0.034 Res 25 46438 1857.5 Total 35 98488 South Scott Reef Lagoon, Outside 1.185 0.119 Lagoon, Platform 1.784 0.017 Outside, Platform 1.917 0.015

North Scott Reef Lagoon, Outside 1.368 0.199 Lagoon, Platform 1.879 0.054 Outside, Platform 1.824 0.046

Seringapatam Lagoon, Outside 1.188 0.328 Lagoon, Platform 1.403 0.334 Outside, Platform 2.458 0.167

Pachygrapsus sp. 1 only occurred in the platform sampled at these reefs. The highest p values are habitats and were absent from lagoons and outer recorded for pairwise tests for Seringapatam, reef habitats. This is expected, as the former two which had the lowest number of stations sampled species, and members of the genus Pachygrapsus, (5 stations). are known inhabitants of the intertidal zone, and There is some indication that that there are only P. areolatus is also reported from the shallow differences in the platform crustacean assemblages subtidal. Coral associated species were either across the three reefs where these were sampled, absent (Calcinus minutes and Calcinus lineapropodus, with the South Scott stations grouping together Diogenidae), or of decreased influence (Tetralia and one of the North Scott stations closer to the glaberrima and Tetralia sp. 1), on station similarity Seringapatam station. The North Scott stations of platform stations. Other species, stomatopods were all widely separated from each other, possibly (unidentified), and Calcinus latens, were more due to the low number of species collected at common in this habitat than either lagoon or outer each station. However, there were no significant reef habitats. Stomatopods and galatheids were not groupings of the platform stations below 15% identified to species and it is likely that different similarity. species occur in the different habitats. The PERMANOVA results support the above Depths differences for the outer reef and lagoon results with habitats nested in reefs being habitats significantly different from each other (Table 5, There were no major differences in crustacean p < 0.05). Pairwise comparisons clearly indicate assemblages as a result of the depth sampled at separation of the platform communities from the the subtidal stations, encompassing the lagoon other two habitats at South Scott Reef. Differences and outer reef habitats (Figure 5a). In general, between lagoon and outer reef habitats were only crustaceans from the shallow and deep sampling significant within Mermaid Reef, a separation at the same station were very close on the MDS also evident in the two-dimensional ordination. plot, and species that occurred at 5 m were just as No significant difference (p > 0.05) was observed likely to be collected at the 12 m depth. There was between habitats at North Scott and Seringapatam some evidence of the grouping of stations due to reefs, a result of the low number of stations habitat and reef location (Figure 5b and c). The reef Marine Fauna - Crustacea 169

2D Stress: 0.2 a) 9

15 22 11 20 15 16 23 20 12 18 16 14 14 23 17 17 30 29 28 36 26 2218 12 28 3136 25 30 8 19 19 32 2642 9 454131 25 7 41 34 39 34 38 8 45 3832 11 39 7 43 Depth 43 Shallow Deep

2D Stress: 0.2 b)

Habitat Lagoon Outside

2D Stress: 0.2 c)

Reef Mermaid South Scott North Scott Seringapatam

Figure 5 Two-dimensional ordination of crustacean taxa from subtidal stations on north-west Australian reefs, a) depth and station number, b) habitat and c) reef. 170 M. A. Titelius, A. Sampey , C. G. Hass

Table 6 PERMANOVA results for lagoon and outer reef habitats only. a) main test, b) pairwise tests

a) main test b) pairwise tests

Source df SS MS Pseudo-F P(perm) Groups t P(perm) Reef 3 31569 10523 4.083 0.001 Lagoon Habitat 1 8094.5 8094.5 3.140 0.002 Mermaid, South Scott 2.171 0.001 Depth 1 4170.5 4170.5 1.618 0.074 Mermaid, North Scott 2.226 0.001 Reef x Habitat 3 16011 5337 2.071 0.001 Mermaid, Seringapatam 1.544 0.005 Reef x Depth 3 6357.9 2119.3 0.822 0.776 South Scott, North Scott 1.963 0.002 Habitat x Depth 1 2551.5 2551.5 0.990 0.445 South Scott, Seringapatam 1.507 0.014 Reef x Habitat x Depth 3 5272.8 1757.6 0.682 0.925 North Scott, Seringapatam 1.356 0.08 Residual 40 1.03E+5 2577.5 Total 55 1.85E+5 Outer Reef Mermaid, South Scott 1.727 0.003 Mermaid, North Scott 2.074 0.003 Mermaid, Seringapatam 1.969 0.029 South Scott, North Scott 1.607 0.009 South Scott, Seringapatam 1.393 0.025 North Scott, Seringapatam 1.502 0.045 by habitat by depth, habitat by depth, and reef by greater than 50% of the group’s composition. Two depth interactions were all not significant (Table of the species, Trapezia guttata and Haplocarcinus 6a). marsupialis, were not dominant within the other A clearer picture of the differences among reefs groups. Separation of the two single station groups was obtained by pooling the two depths sampled at at South Scott (stn 23, group a, and stn 29, group each station and examining the reef dissimilarities c) was driven by the strong influence of rare for each habitat. The crustacean assemblages in species (80% and > 80% respectively). The three lagoons were very different at Mermaid Reef discriminating species for both groups are the same compared to those from the other atolls (Figure 6a). and are also common with Group d. Only one of Three of the stations at South Scott grouped with the species is shared with the Mermaid Reef group. lagoon stations from North Scott and Seringapatam The crustacean assemblages at outer reefs reefs, and there is a north/south gradient evident were very similar across atolls and no significant on the plot. Two of the South Scott stations (stn groupings were formed (Figure 7a). However, some 23, group a and stn 29, group c) formed their own difference is evident in the Mermaid Reef stations, groups. which are well separated from the other reef Six of the top ten species contributing to stations, and evidence of a north/south change in the similarities within the groups are obligate communities in the more northern reefs. coral associates (Trapezia guttata, Tetralia sp.1, T. Examination of the top ten species contributing to nigrolineata, T. glaberrima, Haplocarcinus marsupialis similarity within each reef supports the observed and Calcinus minutus) (Figure 6b). Mermaid Reef separation of the Mermaid outer reef stations lagoon stations (Group b) were the least influenced (Figure 7b). The coral associated hermit crab by these coral associates and separated out largely Calcinus minutus was common to all reefs. Only due to the dominance of the xanthid Chlorodiella ? three species, Trapezia tigrina, Dardanus lagopodes cytherea (>25%) and the occurrence of the xanthid and Calcinus minutus, contributed to similarities at Psaumis ? cavipes, the latter species not being present Mermaid Reef and comprised 75% of the species at any of the other reefs. Overall, the percentage composition of the outer stations. Similarity of outer composition of species driving similarity within reef assemblages of South Scott, North Scott and Group b is markedly different from the other three Seringapatam reefs was determined by eight, seven groups. Station similarity in Group d, the northern and six species respectively. Two species, Tetralia reefs collective group, was strongly influenced by sp. 1 and T. glaberrima, were common drivers to all coral associates with five of the nine discriminating three northern reefs. Three species, Trapezia lutea, species being coral associates and comprising Calcinus lineapropodus and Dardanus lagopodes, were Marine Fauna - Crustacea 171

Figure 6. a) Two-dimensional ordination of lagoon stations, depth has been pooled. Clusters were significant (SIM- PROF, p < 0.05). b) Top ten taxa that contributed to the similarity within each group (SIMPER). 172 M. A. Titelius, A. Sampey , C. G. Hass

Figure 7 a) Two-dimensional ordination of outer reef stations, depth has been pooled. There was no significant clustering of stations in this habitat (SIMPROF, p < 0.05). b) Top ten taxa that contributed to the similarity within each reef (SIMPER). Marine Fauna - Crustacea 173

Above: Boxer crab, Lybia tesselata (Latreille, 1812), can be found under coral slabs. (Photo: Clay Bryce) shared drivers of similarity for South Scott and the crustacean fauna. Firstly, these anticipated North Scott reefs stations. The latter species also changes to the fauna could have been expressed in contributed to similarity at Mermaid Reef. South abundance rather than in diversity values, which Scott and Seringapatam reefs shared two species, highlights the need to include abundance studies Chlorodiella ? laevissima and Pilodius sp. 1. One in future surveys. Abundance studies would need species, Trapezia guttata, was shared by the closely to be targeted on specific taxa. For example, a study situated North Scott and Seringapatam reefs. of the abundance of trapeziid crabs per area would be a good measure of the potential effects that coral DiSCuSSiOn damage could have on these crustaceans. Secondly, each species defines an ecological niche, which is Species richness potentially affected by change and the more species recorded the more likely that minor changes can The increased number of species recorded in this survey compared with previous studies is be detected. The high diversity presented in this due to increased sampling effort and the close survey will therefore provide a good baseline and examination of a variety of substrates. The fact starting point for future monitoring programs. that many previously recorded species have been The Xanthidae have long been recognised as collected again at the same location is encouraging a strong element of coastal reef communities. and with completion of all species identifications Previous collections from Scott, Seringapatam the discrepancy between previous collections and and Ashmore reefs, as well as Cartier Island repeat collections is expected to further diminish. indicated this pattern is also true of the north- Comment on temporal changes in the crustacean western Australian shelf atolls, and certainly communities between surveys is not practical as the high diversity recorded in the present study previous collections were limited. Nonetheless, strongly supports this. The Xanthidae is the most between the first faunal surveys (early 1980s and diverse crab family in Australian waters, reaching 1990s) and the 2006 survey significant natural its highest diversity in shallow reef communities events, such as cyclonic activity, have occurred (Davie, 2002). The family encompasses a broad and led to the destruction of corals and physically range of trophic levels and associations with altered the reefs. It would, therefore, be expected substrate types and the recorded high diversity that some change should also be visible in during the survey likely reflects this ability to fill 174 M. A. Titelius, A. Sampey , C. G. Hass

Above: The shrimp, Allogalathea elegans (Adams & White, 1848) is only found on crinoid seastars. (Photo: Clay Bryce) many ecological niches within a habitat. The large known suitable habitats for both life history phases proportion of rare species (occurring at three or less were sampled adequately during this present stations) suggests the composition of the family is expedition. If recruitment of spiny rock lobster highly variable between stations. A high occurrence larvae to these offshore reefs is low, predation may of rare species in the north-west reef communities be enough to keep numbers of individuals low. would also indicate that to adequately sample These outer-shelf atolls are under the influence of xanthids a greater number of sample sites are the Indonesian Throughflow, the warm water body required. The less sampled reefs of North Scott and that pushes through the Indonesian Archipelago to Seringapatam reefs recorded a considerably lower eventually form the Leeuwin Current (Hutchins, diversity in this family. 2001). Thus the recruitment source for the atolls The painted rock lobster, Panulirus versicolor is likely to be from the Indonesian Archipelago. (Latreille, 1804), is the only species of rock lobster This fact would help to explain the extremely rare known from the reefs. Live specimens were occurrence of the species at Mermaid Reef, which recorded only from North and South Scott reefs experiences a reduced impact from the current and all were juveniles. A single carapace of a due to the reef’s distance from the current source. juvenile was also collected from Mermaid Reef, Further investigations are nevertheless required Rowley Shoals, indicating the species occurs there into current strength and flow patterns from but possibly in low numbers. Berry and Morgan the Indonesian Archipelago to the atolls before (1986) did not record the species from the Rowley any conclusions can be made regarding lobster Shoals during the WA Museum 1984 survey and recruitment. suggested there may be too many predators of spiny lobsters present, such as large serranid Distribution fishes, for the species to exist in the Rowley Shoals. Mermaid Reef is situated 400 km south-west However, high numbers of these fishes also occur of Scott Reef and was the most southerly reef in coastal waters where spiny lobsters are abundant surveyed. It is therefore not surprising that results (B. Hutchins, pers. comm.). It remains unknown as presented by the multidimensional scaling analysis to why only juveniles of P. versicolor were recorded. and PERMANOVA established a clear separation While adults of the species are known to tolerate of the Mermaid Reef communities from the more slightly less turbid conditions than juveniles, the northerly Scott and Seringapatam reefs. This was Marine Fauna - Crustacea 175 particularly true of the lagoon stations, where observed between the reef communities in the Mermaid Reef stations were significantly different multidimensional scaling plots. The PERMANOVA (SIMPROF, p < 0.05) from the stations at the other results indicated the North Scott lagoon fauna reefs. Compared to the other reefs surveyed is more similar to Seringapatam Reef despite its Mermaid Reef has suffered less environmental closer proximity to South Scott Reef. The open disturbance from high sea water temperatures morphology of the South Scott lagoon possibly than the more northerly reefs (Gilmour et al., 2007). contributes to this difference (see maps in station Nor has the reef been subjected to the same levels and transect data, this volume). The open lagoon of fishing pressure as the northern reefs due to its of South Scott Reef is likely to reduce differences status as a marine national nature reserve since between lagoon and outer reef environments. 1991 (DEWHA, 2009). Furthermore, the frequency It could also explain the separation of the two and ferocity of cyclonic events appears to be lower South Scott lagoon stations from the northern reef at Mermaid Reef than experienced at Scott and collective group in the two-dimensional plots. Seringapatam reefs (Bureau of Meteorology, 2009). There was a strong separation of all reef platform Distance from such events may allow for sites communities from outer reef and lagoonal sites. within the Mermaid reef system to develop greater The fauna encountered on the platforms need to site distinctness. withstand the extreme conditions experienced The geographic separation of Mermaid Reef when the reef is exposed. The diversity of living from the northern atolls is likely to result in substrates (such as corals) with which some greater differences in crustacean assemblages crustaceans associate is dramatically reduced in than in the other reefs. The life histories of many such exposed areas. Furthermore, the absence or crustacean species include a long-distance larval presence of tidal pools can have a dramatic effect dispersal phase. A dilution effect of the Indonesian on the species diversity observed in a platform Throughflow could explain the absence, or reduced environment. The high variability of platform influence, of the species at Mermaid Reef with such habitats is evident in the low level clustering of the a life history, and Indo-Malaysian affinities. Castro stations in the multidimensional scaling analysis. (2000) suggested that geographic distribution of most species of the brachyuran family Trapeziidae Sampling methods for crustaceans (Trapezia spp.) and Tetraliidae (Tetralia spp. and Many crustaceans are inherently cryptic, well Tetraloides spp., Castro et al., 2004) is best explained camouflaged and highly mobile. This ”…habit by long distance larval dispersal. Members of these of lurking in crevices…” and when alarmed “… families had a strong presence in the top ten taxa darting with great swiftness through the water…” contributing to similarity within reefs, and showed (Calman, 1911) requires the employment of special considerable variation in composition between the collection and extraction methods. It also means reefs, the greatest difference being at Mermaid Reef. that the process of collecting and extracting Serious consideration must be given to the fact that crustaceans from their substrate, in order to obtain members of these families of crabs are obligate a species record, is more time consuming than the symbionts of reef building, hermatypic corals and recording of species of other groups. other colonial cnidarians. Species of Trapezia are A fully quantitative method of sampling associated with pocilloporid corals and Tetralia and involving quadrat counts and transect visual Tetraloides with acroporid corals (Castro & Titelius, surveys was initially trialled for the collection and 2007). Their distribution is therefore linked to the documentation of crustaceans (stations 1–4), but did distribution and occurrence of their hosts. Along not produce the best possible results for recording the Western Australian coastline the numbers of biodiversity. Collecting particular substrates species of these families of corals declines at lower and thereby capturing the large proportion latitudes, five species of Pocillopora and 48 species of crustaceans that live as epi- and endofauna of Acropora have been recorded from Western was found to be the most successful method for Australian waters in the Timor Sea and only one maximising species richness. Because this type species of Pocillopora and two species of Acropora of study is more time consuming than relying being recorded south of Perth (Veron, 1993). By mainly on visual recognition of species, a study of comparison, 17 species from within the three abundances was not possible within the timeframe genera of these crabs have been recorded from set for each station. Should abundance studies be Western Australian waters previously and of these included in future surveys, it is suggested that only five species occur as far south as Perth (Castro these should be based on selected less cryptic and & Titelius, 2007). easily identifiable species, such as hermit crabs. One The close proximity of Scott and Seringapatam of the main advantages of the substrate sampling reefs to one another (approximately 25 km method is that species are identified with the apart) is evident in the degree of clustering habitat they are associated with. This information 176 M. A. Titelius, A. Sampey , C. G. Hass is often missing from faunal surveys but is Reef North-western Australia. Records of the Western invaluable in directing future sampling efforts Australian Museum, Supplement 25. and collection methods, in understanding and Bureau of Meterology, 2009. Tropical Cyclones in Western interpreting the complexity of ecosystems and in Australia – Climatology. http://www.bom.gov.au/ providing topics for future studies into the biology weather/wa/cyclone/about/climatology.shtml of marine crustaceans. For instance, a study linking Calman, W.T. (1911). The life of Crustacea. p. 90, London. the distribution of trapeziid crabs, which inhabit Castro, P. (2000) Biogeography of trapeziid crabs corals, with the distribution and abundance of the (Brachyura, Trapeziidae) symbiotic with reef corals and other cnidarians. Pp. 65–74. In: J.C. von Kaupel host coral species may highlight the dependencies Klein and F.R. Schram (eds), The Biodiversity between these two taxa. One of the discoveries Crisis and Crustacea: Proceedings of the Fourth made during this survey was a pilumnid crab International Crustacean Congress, Amsterdam, inhabiting tube-shaped sponges. It would be Netherlands, 20–24 July 1998, vol. 2.CRC Press, 848 worthwhile to explore the possible relationship pgs. between the sponge and the crab species to Castro, P. and Titelius, M.M. (2007). Trapeziidae Miers, investigate the biology of the crab, which is found 1886 and Tetraliidae Castro, Ng and Ahyong, 2004 in breeding pairs within the sponge, apparently (Crustacea: Brachyura): coral crabs of Western forming part of the crabs’ reproductive strategy. Australia with notes on their biogeography. Records of the Western Australian Museum Supplement no. 73: The fact that many crustaceans are nocturnal 315–327. has not been addressed by the collection method Castro, P., Ng, P.K.L. and Ahyong, S. (2004). Phylogeny employed in this survey. Nocturnal collections and systematics of the Trapeziidae Miers, 1886 would undoubtedly provide a more accurate (Crustacea: Brachyura), with a description of a new estimate of crustacean biodiversity and most family. Zootaxa 643: 1–70. likely expand the current species list. It would Clarke, K. and Gorley, R. (2006). PRIMER v6: User be worthwhile, therefore, to include some night Manual/Tutorial. PRIMER-E: Plymouth, UK. sampling in future surveys. The current sampling Clarke, K. and Warwick, R. (2001). Change in Marine regime also does not take into account the biphasic Communities: An Approach to Statistical Analysis life style of many crustaceans. Many species are and Interpretation. 2nd edition. Primer-E. known to colonise a particular habitat as juveniles Davie, P.J.F. (2002). Crustacea: Malacostraca: Eucarida (for example shallow depths) and then migrate to (Part 2): Decapoda-Anomura, Brachyura. In A. Wells a different habitat (deeper depths) as reproductive and W.W.K. Houston, editors, Zoological Catalogue of adults. As this survey only sampled depths to Australia, vol. 19.3B, CSIRO Publishing, Melbourne, xiv + 641 pp. 12 m mean sea level the inclusion of sampling DEWHA, 2009. Management of Mermaid Reef to greater depths would increase the chance of Marine National Nature Reserve. Department of discovering adult specimens of species currently Environment, Water, Heritage and the Arts. http:// only represented by juveniles in this study. www.environment.gov.au/coasts/mpa/mermaid/ management.html Acknowledgements Gilmore, J., Cheal, A., Smith, L., Underwood, J., Meekan, M., Fitzgibbon, B. and Rees, M. (2007). The authors are grateful to the staff and crew Data compilation and analysis for Rowley Shoals: of the Kimberley Quest I for providing assistance Mermaid Imperieuse and Clerke Reefs. Prepared for and transportation in the field. Jane Fromont Department of the Environment and Water Resources. and David McKinney provided a number of field Unpublished Report. identifications for sponges and corals and were Hutchins, J.B. (2001). Biodiversity of shallow reef fish also excellent company on the sometimes long assemblages in Western Australia using rapid a dinghy journeys. Special thanks to Yuki Konishi, censusing technique. Records of the Western Australian Lyle McShane and Mark Salotti who were very Museum 20: 247 – 270. helpful in the long task of processing, sorting Morgan, G.J. and Berry, P.F. (1993). Part 5. Decapod and documenting the collected material. Thanks Crustacea of Ashmore Reef and Cartier Island. In Berry, P.F. (ed) Marine Faunal Surveys of Ashmore to Sue Morrison, Jane Fromont, Peter Castro and and Cartier Island North-western Australia. Records of Peter Davie for their invaluable comments on the the Western Australian Museum, Supplement 44, 47–51. manuscript. Ng P., Guinot D., Davie P. (2008). Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran REFERENCES crabs of the world. The Raffles Bulletin of Zoology 17: 1–286. Anderson, M., Gorley, R., and Clarke, K. (2008). 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