The role of deep reefs in shallow reef recovery: an assessment of vertical connectivity in a brooding coral from west and east Australia

Approximately one quarter of zooxanthellate coral species have a depth distribution from shallow waters (<30 m) down to mesophotic depths of 30-60 m. The deeper populations of such species are less likely to be affected by certain environmental perturbations, including high temperature/high irradiance causing coral bleaching. This has led to the hypothesis that deep populations may serve as refuges and a source of recruits for shallow reef habitats. The extent of vertical connectivity of reef coral species, however, is largely unquantified. Using 10 coral host microsatellite loci and sequences of the host mtDNA putative control region, as well as ribosomal DNA (rDNA) ITS2 sequences of the coral's algal endosymbionts (Symbiodinium), we examine population structure, connectivity and symbiont specificity in the brooding coral Seriatopora hystrix across a depth profile in both northwest (Scott Reef) and northeast Australia (Yonge Reef). Strong genetic structuring over depth was observed in both regions based on the microsatellite loci; however, Yonge Reef exhibited an additional partitioning of mtDNA lineages (associated with specific symbiont ITS2 types), whereas Scott Reef was dominated by a single mtDNA lineage (with no apparent host-symbiont specificity). Evidence for recruitment of larvae of deep water origin into shallow habitats was found at Scott Reef, suggesting that recovery of shallow water habitats may be aided by migration from deep water refuges. Conversely, no migration from the genetically divergent deep slope populations into the shallow habitats was evident at Yonge Reef, making recovery of shallow habitats from deeper waters at this location highly unlikely.     

High connectivity in the deepwater snapper Pristipomoides filamentosus (Lutjanidae) across the Indo-Pacific with isolation of the Hawaiian archipelago

In the tropical Indo-Pacific, most phylogeographic studies have focused on the shallow-water taxa that inhabit reefs to approximately 30 m depth. Little is known about the large predatory fishes, primarily snappers (subfamily Etelinae) and groupers (subfamily Epinephelinae) that occur at 100-400 m. These long-lived, slow-growing species support fisheries across the Indo-Pacific, yet no comprehensive genetic surveys within this group have been conducted. Here we contribute the first range-wide survey of a deepwater Indo-Pacific snapper, Pristipomoides filamentosus, with special focus on Hawai'i. We applied mtDNA cytochrome b and 11 microsatellite loci to 26 samples (N=1,222) collected across 17,000 km from Hawai'i to the western Indian Ocean. Results indicate that P. filamentosus is a highly dispersive species with low but significant population structure (mtDNA Φ(ST)=0.029, microsatellite F(ST)=0.029) due entirely to the isolation of Hawai'i. No population structure was detected across 14,000 km of the Indo-Pacific from Tonga in the Central Pacific to the Seychelles in the western Indian Ocean, a pattern rarely observed in reef species. Despite a long pelagic phase (60-180 days), interisland dispersal as adults, and extensive gene flow across the Indo-Pacific, P. filamentosus is unable to maintain population connectivity with Hawai'i. Coalescent analyses indicate that P. filamentosus may have colonized Hawai'i 26 K-52 K y ago against prevailing currents, with dispersal away from Hawai'i dominating migration estimates. P. filamentosus harbors low genetic diversity in Hawai'i, a common pattern in marine fishes, and our data indicate a single archipelago-wide stock. However, like the Hawaiian Grouper, Hyporthodus quernus, this snapper had several significant pairwise comparisons (F(ST)) clustered around the middle of the archipelago (St. Rogatien, Brooks Banks, Gardner) indicating that this region may be isolated or (more likely) receives input from Johnston Atoll to the south.     

The food and feeding habits of the catfishes, Chrysichthys walkeri (Gunther), Chrysichthys filamentosus (Boulenger) and Chrysichthys nigrodigitatus (Lacépède) in theLekki Lagoon, Nigeria

A total of 1436 specimens were examined in the study of the food habits of the three Chrysichthys species in Lekki Lagoon. Certain differences were found in their food habits. Chrysichthys walkeri fed mostly on insects, Chrysichthys filamentosus on crustaceans and Chrysichthys nigrodigitatus on molluscs. It is suggested the observed diversity in feeding habits might be due to an active response to interspecific competition.     

Assessment of the eutrophication status of the Great Barrier Reef lagoon (Australia)

Current scientific consensus is that inshore regions of the central and southern Great Barrier Reef, Australia, are at risk of impacts from increased nutrient (as well as sediment and pesticide) loads delivered to Reef waters. Increases in the discharge of water quality contaminants to the Reef are largely a consequence of the expansion of agricultural practices in northern Queensland catchments following European settlement in the 1850s. In particular, the presence of elevated chlorophyll a and nutrient concentrations in many parts of the inshore Great Barrier Reef together with intense and extensive phytoplankton blooms following the discharge of nutrient-rich river flood waters suggest that the central and southern inshore area of the Great Barrier Reef is likely to be significantly impacted by elevated nutrient loads. The biological consequences of this are not fully quantified, but are likely to include changes in reef condition including hard and soft coral biodiversity, macroalgal abundance, hard coral cover and coral recruitment, as well as change in seagrass distribution and tissue nutrient status. Contemporary government policy is centered around promotion and funding of better catchment management practices to minimize the loss of catchment nutrients (both applied and natural) and the maintenance of a Reef wide water quality and ecosystem monitoring program. The monitoring program is designed to assess trends in uptake of management practice improvements and their associated impacts on water quality and ecosystem status over the next 10 years. A draft set of quantitative criteria to assess the eutrophication status of Great Barrier Reef waters is outlined for further discussion and refinement.     

An evaluation of a double‐tailed deformity in a coral‐reef surgeonfish Acanthurus nigrofuscus (Acanthuridae) using micro‐computed tomography

X‐ray micro‐computed tomography scans were used to examine the caudal‐fin structure of an unusual double‐tailed deformity in an adult brown surgeonfish Acanthurus nigrofuscus from the Great Barrier Reef. In both this case and in a similar double‐tailed deformity in a juvenile Tomini surgeonfish Ctenochaetus tominiensis from the Philippines, the caudal fin was duplicated along the dorsoventral axis. Detailed examination of the A. nigrofuscus specimen revealed that the deformity was associated with duplication and reflection of the hypural plates and the posterior vertebrae, yet the fish survived to adulthood, indicating that the effects of duplication on survival may be limited.     

<Emphasis Type="Italic">Rainfordia opercularis</Emphasis>, a liopropomin serranid (Teleostei: Serranidae: Epinephelinae): corroborative evidence from settlement-stage larvae

Rainfordia opercularis was described in 1923 from a single specimen taken in Edgecumbe Bay, Queensland, Australia. The species is rare in museum collections, and the larvae have not been described. In 1999, two settlement-stage larvae (20–21 mm in standard length) were collected in light traps set off Lizard Island, Great Barrier Reef, Queensland. The smaller of the two has one thin, flexible, extremely elongate dorsal-fin spine encased in a pigmented sheath. The larger specimen lacks an elongate dorsal-fin spine and exhibits caudal-fin pigment characteristic of adults. A combination of features in one or both of the settlement-stage larvae support the placement of Rainfordia in the epinepheline-serranid tribe Liopropomini: presence of an elongate, filamentous dorsal-fin spine serially associated with the first dorsal-fin pterygiophore; presence of a spine on the inner preopercular ridge; presence of dense pigment on the frontals; absence of an elongate spine at the angle of the preopercle; and absence of supraorbital spination. Supplementary material to this paper is available in electronic format at     

Reproductive biology of a large, aggregation-spawning serranid, Epinephelus fuscoguttatus (Forsskål): management implications

The reproductive biology of Great Barrier Reef populations of the long-lived grouper Epinephelus fuscoguttatus (brown-marbled grouper or flowery cod) was investigated using histological analyses. Evidence provided by gonad morphology and age-based demographics suggested monandric protogynous hermaphroditism. Younger age groups contained only immature and mature females, and all males were above the size and age of 100% female maturity, consistent with secondary males derived from mature females by adult sex change. Fishing records confirmed that spawning aggregations of this species and the co-occurring Epinephelus polyphekadion (camouflage grouper) are sometimes targeted on the Great Barrier Reef. Sampling data revealed strong spawning seasonality for E. fuscoguttatus , with a relatively narrow annual spawning period (November to January). The temporal pattern of reproductive activity within the spawning period, based on occurrence of near spawning ovaries (containing hydrated oocytes), indicated spawning events may occur throughout much of the lunar cycle and only partly coincide with seasonal fishing closure periods on the Great Barrier Reef. The results indicate that protection would be enhanced by a longer seasonal closure.     

A modern-type Kimmeridgian reef (Ota Limestone,Portugal): Implications for Jurassic reef models

Upper Jurassic reefs rich in microbial crusts generally appear in deeper (sponge—‘algal’ crust reefs) or in very shallow but protected settings (coral or coral-coralline sponge meadows with ‘algal’ crusts). Upper Jurassic high-energy reefs (coral reefs and coral-stromatoporoid reefs) normally lack major participation of microbial crusts but rather represent huge bioclastic piles with only minor framestone patches preserved. An exception to this rule is represented by the high-energy, coral-‘algal’ Ota Reef from the Kimmeridgian of the Lusitanian Basin (Portugal). The narrow Ota Reef tract rims a small intra-basinal carbonate platform exhibiting perfect facies zonation (from W to E: Reef tract, back reef sands, peritidal belt, low-energy shallow lagoon). The reef is dominated by massive corals (Thamnasteria, Microsolena, Stylina). Complete preservation of coral framework is rare: like other Upper Jurassic high-energy reefs, the Ota Reef is very rich in debris; however, this debris is largely stabilized by algal and microbial crusts, what contrasts the other examples and gives the Ota Reef the appearance of a typical modern high-energy coral-melobesioid algal reef. Further similarities to modern reefs are the likely existence of a spur-and-groove system, the perfect sheltering of inner platform areas and the occurrence of small islands, as indicated by local blackenings and early vadose and karstic features.     

Geographic variation in the Laysan Finch (Telespyza cantans)

Summary Significant differences in bill shape exist between the endemic Laysan population and introduced populations of the Laysan Finch (Drepanidinae:Telespyza cantans) at Pearl and Hermes Reef. Furthermore, there are significant differences in bill shape between two of four finch populations on the islands of Pearl and Hermes Reef. The variation in finch bill shape is paralleled by geographic variation in the large, hard mericarps ofTribulus cistoides, an important food item at Pearl and Hermes Reef. There are three possible explanations for the observed variation. Environmental influence may be a non-evolutionary cause of the variation, or genetic drift and natural selection may have caused the differences in morphology. Preliminary results suggest that both genetic drift and natural selection have been acting on the populations. Continuing studies, including investigation of genetic variation and cross-fostering experiments to determine heritability of morphological traits and effects of environment on morphological traits, are planned to test the various hypotheses.     

Genetic signatures through space,time and multiple disturbances in a ubiquitous brooding coral

The predominance of self‐recruitment in many reef‐building corals has fundamental and complex consequences for their genetic diversity, population persistence and responses to climate change. Knowledge of genetic structure over local scales needs to be placed within a broad spatial context, and also integrated with genetic monitoring through time to disentangle these consequences. Here, we examined patterns of genetic diversity over multiple spatio‐temporal scales across tropical Australia in the ubiquitous brooding coral, Seriatopora hystrix. We also analysed complimentary environmental and demographic data to elucidate the seascape drivers of these patterns. Large genetic differences were detected between the east vs. west coasts of Australia. In northwest Australia, geographic differentiation dominated genetic structure over multiple scales. However, three sympatric lineages were detected at the largest offshore reef system (Scott Reef). Similar to the differences observed among putative species in eastern Australia, these lineages were associated with different levels of wave exposure. Local genetic structure within the Scott Reef system was relatively stable over 10 years, but temporal differences were observed that reflected small but important genetic changes over a few generations during recovery after severe bleaching. These results highlight the importance of self‐recruitment together with occasional longer distance connectivity for the persistence of a metapopulation across spatially and temporally variable environments. Our multidimensional research provides a foundation for further long‐term genetic monitoring to inform conservation strategies and highlights that sampling scales, ecological effects and cryptic diversity are important considerations to develop realistic understanding of the evolutionary resilience of corals.     

Lek-like spawning,parental care and mating periodicity of the triggerfishPseudobalistes flavimarginatus (Balistidae)

Synopsis The triggerfishPseudobalistes flavimarginatus has a lek-like spawning system at Yonge Reef, Great Barrier Reef. Males migrate to a traditional mating ground where they establish territories enclosing nest sites and egg chambers. Females arrive several days later and choose a male for mating. There is biparental care of the fertilized eggs and a strict division of labour. Females appeared to be confined to the nest site by the male. Mating was semi-lunar: eggs were observed in nests several days before the new and full moons on days when high tide occurred near sunset. Differences were observed in the spawning system of another triggerfish (P. fuscus) between the Great Barrier Reef and the Red Sea. Observations of another triggerfish (Balistoides viridescens) are also reported.     

Evaluation of a crown-of-thorns starfish (Acanthaster planci) control program at Grub Reef (central Great Barrier Reef)

A crown-of-thorns starfish control program was conducted at Grub Reef (central Great Barrier Reef) in an area (0.64 km²) which encompassed 53 individual patch reefs. During a two week period, 15 divers injected 3175 starfish with copper sulphate. The program was considered unsuccessful. Although starfish abundance had declined significantly after the control efforts, biological surveys indicated that a relatively large number of starfish remained. The surveys also indicated a general decline in the number of starfish along the reef perimeter, outside the control area. The total cost of the control program was $35 per starfish. These results have important implications for the implementation of future control programs and highlight the need to undertake before and after biological surveys to assess the effectiveness of the control efforts.     

Faustulid trematodes (Digenea) from marine fishes of Australia

Twelve species of faustulid trematode are described or redescribed from Australian marine fishes. Bacciger lesteri Bray, 1982 and B. sprenti Bray, 1982 are redescribed from Selenotoca multifasciata from Moreton Bay. It is suggested that the original host record for these species, Mugil sp., was incorrect. The genera Discogastroides, Odontocotyle and Pseudodiscogasteroides are synonymised with Paradiscogaster. The new combinations Paradiscogaster arabi (Hafeezullah & Siddiqi, 1970), P. hainanensis (Shen, 1970), P. indicus (Srivastava, 1939), P. macrostomus (Shimazu & Kamegai, 1990), P. ostracii (Yamaguti, 1934) and P. pritchardae (Gupta & Ahmad, 1978) are proposed. Discogasteroides hawaiensis Hanson, 1955 is synonymised with P. ostracii. P. macrostomus and P. ostracii are redescribed from Ostracion meleagris and O. cubicus from the Great Barrier Reef. P. farooqii Hafeezullah & Siddiqi, 1970 is redescribed from Monodactylus argenteus from Moreton Bay. The following new species are described: P. machidai n. sp. from Pomacanthus semicirculatus and P. sexstriatus from the Great Barrier Reef, P. dweorg n. sp. from Meuschenia galii, P. lobomyzon n. sp. from Tilodon sexfasciatus and P. habilis n. sp. from Pelates octolineatus, all from Western Australia. Antorchis pomacanthi (Hafeezullah & Siddiqi, 1970) Machida, 1975 is redescribed from Pomacanthus semicirculatus and P. sexstriatus from the Great Barrier Reef. The new combination Antorchis intermedius (Madhavi, 1975) is proposed for Parantorchis intermedius. Parayamagutia ostracionis is redescribed from O. cubicus from the Great Barrier Reef. Trigonocryptus conus is redescribed from Arothron hispidus from South-east Queensland and from A. nigropunctatus from the Great Barrier Reef. The new combination Trigonocryptus australiensis (Kurochkin, 1970) is proposed for Pseudodiscogasteroides australiensis. The Echinobrevicecinae is reduced to synonymy with the Faustulidae.     

Dynamic Regulation of Fluorescent Proteins from a Single Species of Coral

To gain a better understanding of the natural function of fluorescent proteins, we have undertaken quantitative analyses of these proteins in a single species of coral, Montastraea cavernosa, residing around Turneffe atoll, on the Belizean Barrier Reef. We identified at least 10 members of a fluorescent protein family in this species, which consist of 4 distinct spectral classes. As much as a 10-fold change in the overall expression of fluorescent proteins was observed from specimen to specimen, suggesting that fluorescent proteins are dynamically regulated in response to environmental or physiological conditions. We found that the expression of some proteins was inversely correlated with depth, and that groups of proteins were coordinately expressed. There was no relationship between the expression of fluorescent proteins and the natural coloration of the Montastraea cavernosa specimens in this study. These findings have implications for current hypotheses regarding the properties and natural function of fluorescent proteins.     

A large new species of the genus Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae) from Antarctic seamounts

Ptilocrinus amezianeae n. sp. is a new species of stalked crinoid attributed to the family Hyocrinidae. Forty-five specimens were collected from seamounts north of the Ross Sea, and one specimen from the Kerguelen Plateau at depths ranging from 450 to 1,680 m. The collection from Admiralty and Scott seamounts constitutes the first example of a hyocrinid population known both from in situ photographs and from numerous collected specimens ranging from small juvenile to large adult. Variation in theca and stalk articulation characters throughout ontogeny is congruent with the molecular data and indicates that all the specimens examined belong to a single species. Tegmen and pinnule architecture, brachial arrangement, and stalk articular facets indicate that Ptilocrinus amezianeae n. sp. has close affinities with P. clarki and P. pinnatus from the northeastern Pacific and displays the most derived characters among these three species. Two cases of true arm division into two unequal branches suggest that Ptilocrinus and Calamocrinus are closely related. The picture and video transects on Admiralty seamount show a patchy distribution of living specimens with patches of mean density ca. 2.6 individuals m-2. In situ photographs also document predation by a sea urchin and a sea star on tegmen and proximal arms. The COI gene sequences analyzed in 25 specimens from Admiralty and Scott seamounts display low pairwise distances, low nucleotidic diversity, and intermediate haplotype diversity. These results, together with disarticulated ossicles and attachment disks observed on in situ photographs, indicate that the population investigated here is in decline.     

Sediment Microbes of Deep-Sea Bioherms on the Northwest Shelf of Australia

The northwest shelf of Australia is a region with known petroleum reserves. Recent geological investigations have revealed carbonate knolls postulated to be of biological origin. Sediment microbial populations at three sites on the northwest shelf, Pee Shoal, Mermaid Reef, and Scott Reef, were investigated for the presence of hydrocarbon-degrading bacteria. From two sampling trips, 246 bacterial strains were purified, and 182 of these strains displayed preferential growth on hydrocarbon-selective media. Strains were tested for nutrient specificity using single hydrocarbon fermentations. Metabolic profiles were constructed using biochemical testing, fatty acid analysis, and metabolic rate experiments. 16S rRNA gene sequence analysis of four strains identified these strains as members of the genera Sphingomonas, Bacillus, and Microbacterium, and one strain as a member of the -Proteobacteria. The potential of these strains as bioindicators of hydrocarbon pollutants or for bioremediation in marine environments is discussed.     

Two new species ofCerioxynus (Copepoda: Poecilostomatoida) parasitic in corals (Scleractinia: Faviidae) in the South Pacific

Summary The copepodsCerioxynus oulophylliae n. sp., parasitizing the hard coralOulophyllia crispa (Lamarck) on the Great Barrier Reef, Australia, and at Banda in the Moluccas, andCerioxynus montastreae n. sp., living inMontastrea curta (Dana) on the Great Barrier Reef, are described and illustrated. Both new species are distinguished from their four congeners by having wing-like epimera on the segments bearing leg 2 and leg 3. ac]19850419     

A revision of the genus Halectinosoma (Harpacticoida: Ectinosomatidae): a reappraisal of H. sarsi (Boeck) and related species

Ectinosomatid material was examined from extensive collections around the British Isles and from several additional world localities and museum collections, permitting a revision of the genus Halectinosoma. This paper describes 12 morphologically similar species and erects five new species. H. sarsi (Boeck) is regarded as species incertae sedis, while H. sarsi sensu Sars (1904) is redescribed as H. pseudosarsi sp. nov.; H. sarsi sensu T. & A. Scott (1894) is synonymized with H. canaliculatum (Por). H. propinquum is regarded as a junior subjective synonym of H. chrystalli (T. Scott). H. clavatum (Sars) is resurrected, having previously been regarded as a synonym of H. brunneum (Brady). A key for the identification of females belonging to this group of species is provided.     

Habitat preference in newly settled coral trout (Plectropomus leopardus, Serranidae)

 The densities of newly settled coral trout (Plectropomus leopardus, Pisces, Serranidae) were monitored in a variety of habitats on Green Reef in the Cairns section of the Great Barrier Reef to assess whether spatial patterns of recruitment are influenced by physical features of the substratum, and whether this species uses different habitats during its ontogeny. Surveys showed that small juveniles used sites that were significantly different from random and that these habitat associations changed as the fish grew larger. Specifically, coral trout recruited to level patches of rubble substrata >5 m² and subsequently shifted to high relief features. Densities of recruits were related to the amount of rubble substrata available. Accepted: 4 July 1996     

Hybridization in coral reef fishes: introgression and bi-directional gene exchange in Thalassoma (family Labridae)

Hybrids in coral reef fishes have traditionally been described based on external features using meristic characters and colouration to identify putative parental contributors. This study utilised molecular genetic techniques to verify hybrid status and identify putative parental species for five hybrid specimens (Labridae: Thalassoma) collected from Holmes Reef in the Coral Sea. Phylogenetic analyses support hybrid origins of the specimens. Mitochondrial COI gene, nuclear S7 (intron 1) and nuclear copy of mitochondrial (NUMT) D-loop region corroborate the identity of T. quinquevittatum as the maternal and T. jansenii as the paternal contributor. Backcrossing to parental species by hybrids and bi-directional gene exchange between the Holmes Reef populations of T. jansenii and T. quinquevittatum was detected, suggesting that hybrids are fertile and able to reproduce successfully. F(1) hybrids display a mixture of the colouration attributes of the two parental species, but subsequent backcrossed individuals were unrecognisable as hybrids and displayed colouration of either parental species. A large numerical imbalance exists between the putative parental species at Holmes Reef, with T. quinquevittatum outnumbering T. jansenii by approximately 25:1. In this case study, hybridization appears to be driven by ecological rather than evolutionary factors.