Eastern Australian Waters Research Articles

Paradiopatra (Annelida: Onuphidae) from eastern Australian waters, with the description of six new species.

This study recognises eight species of Paradiopatra from eastern Australian waters, of which only one, Paradiopatra ehlersi, had been previously recorded. Six species are newly described: P. acirrata n. sp., P. imajimai n. sp., P. longicappa n. sp., P. piccola n. sp., P. spinosa n. sp., P. variabilis n. sp., and one species is reported as P. cf. papillata. Descriptions of all species (with the exception of P. ehlersi) are given, accompanied by detailed illustrations, including scanning electron micrographs and drawings. A key to all 32 species of the genus is included plus a table summarising specific diagnostic characters of the Australian representatives.

New SNPs for population genetic analysis reveal possible cryptic speciation of eastern Australian sea mullet (Mugil cephalus)

Sustainable management of sea mullet (Mugil cephalus) fisheries needs to account for recent observations of regional-scale differentiation. Population genetic analysis is sought to assess the situation of this ecologically and economically important fish species in eastern Australian waters. Here, we report (i) new population genetic markers [single nucleotide polymorphisms (SNPs) and potential microsatellites], (ii) first estimates of spatial genetic differentiation and (iii) prospective power tests for designing more comprehensive studies. Six DNA samples from three sampling regions (North Queensland, South Queensland and central New South Wales) on the eastern coast of Australia were used to prepare restriction site associated DNA (RAD) tag libraries from genomic DNA digested with EcoRI and MseI. A pooled sample of regional RAD tag libraries was sequenced using the Roche GS-FLX Titanium platform. A total of 172,837 raw reads (17.4 Mbp) were retrieved, 95,500 of which were used to discover 1267 SNPs and 1417 microsatellites. A subset of 161 SNPs was validated based on 63 additional DNA samples genotyped using the Sequenom MassArray (iPLEX Gold chemistry). Altogether 92 SNPs (57%) were confirmed, with 40% of these marking fixed variants between northern and southern sampling regions. Our preliminary findings indicate a multispecies fishery stock of M. cephalus in eastern Australian waters, but suggest that strong genetic differentiation occurs north of major fishing grounds. Low potential differentiation within major fishing grounds (e.g. FST = 0.0025) can be resolved with a likely power ≥67% by using standard sample sizes of 50 and validated subsets of available markers.

Nothria and Anchinothria (Annelida: Onuphidae) from eastern Australian waters, with a discussion of ontogenetic variation of diagnostic characters

Nothria and Anchinothria, two sister genera of onuphid worms were studied from eastern Australian waters. Nothria abyssia, with a wide distribution in Pacific and Antarctic waters is reported from slope depths south-east of Australia, while N. otsuchiensis, described from Japanese waters, was found along the eastern coast of Australia from shallow subtidal to deep slope areas. Anchinothria parvula sp. nov. is described, based on the presence of uni- and bidentate pseudocompound falcigers in the first three pairs of parapodia, absence of branchiae and appearance of limbate chaetae from chaetiger 2, subacicular hooks from chaetigers 6–8 and pectinate chaetae from chaetiger 14. The new species represents the first record of the genus in Australian waters. Ontogenetic variation of chaetal composition and morphology of parapodia was estimated in two Nothria species examined. Three size-related morphotypes with different chaetal composition and morphology of anterior falcigers were revealed in N. abyssia and N. otsuchiensis. The number of chaetigers with pseudocompound falcigers is the only character independent of size of the specimens in both examined species. Distribution of subacicular hooks and postchaetal lobes is shown to be size-dependent. The following characters are considered of diagnostic value only when scored in adults: presence/absence of simple falcigers in anterior parapodia; chaetiger of origin of limbate chaetae, pectinate chaetae, and subacicular hooks; and number of chaetigers with auricular prechaetal lobes and digitiform postchaetal lobes. The use of adult specimens with the final set of definitive morphological structures for diagnoses of Nothria species is suggested.

A New Genus and Two New Species of the Family Aulopidae (Aulopiformes), Commonly Referred to as Aulopus, Flagfins, Sergeant Bakers or Threadsails, in Australasian Waters

Two new species of the aulopiform family Aulopidae are described from waters off northern New Zealand, eastern Australia and the Tasman Sea. Hime pyrhistion sp. nov., previously confused with Hime japonica (Gunther, 1877), differs from that species in having a higher dorsal fin in both males and females, together with slight differences in colouration. Specific recognition of the two is supported by genetic evidence, with genetic distances of CO1 separating the two of a similar magnitude as distances between H. curtirostris (Thomson, 1967), H. diactithrix (Prokofiev, 2008) and H. japonica. A morphological redescription of H. japonica is provided for comparison. A new genus Leptaulopus is erected for Aulopus damasi Tanaka, 1915 and a second new species L. erythrozonatus sp. nov. is described from four specimens collected in northern New Zealand and eastern Australian waters. Leptaulopus is distinguishable from the other three genera of the family, Aulopus Cloquet, 1816, Hime Starks, 1924 and Latropiscis Whitley, 1931, most noticeably in having a more slender body, a more posteriorly placed dorsal fin, and finer, more cardiform teeth in the jaws, as well as relatively great genetic distances of CO1. The new species is separable from L. damasi by its more numerous dorsal fin rays (15 or 16 vs 13 or 14), lateral line scales (44 vs 33–37) and vertebrae (44 vs 36), smaller eye and longer, more depressed snout. A neotype is designated for L. damasi, and a revised description of the species is provided.

C-AMP Dependent Protein Kinase a Inhibitory Activity of Six Algal Extracts from South Eastern Australia and Their Fatty Acid Composition

c-AMP dependent protein kinase (protein kinase A, PKA) is an important enzyme involved in the regulation of an increasing number of physiological processes including immune function, cardiovascular disease, memory disorders and cancer. The objective of this study was to evaluate the PKA inhibitory activity of a range of algal extracts, along with their fatty acid composition. Six algal species were investigated including two Chlorophyta (Codium dimorphum and Ulva lactuca), two Phaeophyta (Phyllospora comosa and Sargassum sp.) and two Rhodophyta (Prionitis linearis and Corallina vancouveriensis), with the order of PKA inhibitory activity of their extracts identified as follows: brown seaweeds > red seaweeds > green seaweeds with the brown alga Sargassum sp. exhibiting the highest PKA inhibitory activity (84% at 100 microg/mL). GC/MS analysis identified a total of 18 fatty acids in the six algal extracts accounting for 72-87% of each extract, with hexadecanoic acid and 9,12-octadecadienoic acid as the dominant components. The most active extract (Sargassum sp.) also contained the highest percentage of the saturated C14:0 fatty acid (12.8% of the total extract), which is a known to inhibit PKA. These results provide the first description of the PKA inhibitory activity of marine algae along with the first description of the fatty acid composition of these six algal species from South Eastern Australian waters. Importantly, this study reveals that abundant and readily available marine algae are a new and relatively unexplored source of PKA inhibitory compounds.

Seasonal forecasting of tuna habitat for dynamic spatial management

Capture of the target, bycatch, and protected species in fisheries is often regulated through spatial measures that partition fishing effort, including areal closures. In eastern Australian waters, southern bluefin tuna (SBT, Thunnus maccoyii ) are a quota-limited species in a multispecies longline fishery; minimizing capture by nonquota holders is an important management concern. A habitat preference model (conditioned with electronic tag data) coupled with ocean reanalysis data has been used since 2003 to generate real-time predicted maps of SBT distribution (nowcasts). These maps are used by fishery managers to restrict fisher access to areas with high predicted SBT distribution. Here we use the coupled ocean–atmosphere model, POAMA (predictive ocean atmosphere model for Australia), and a habitat model to forecast SBT distribution at lead times of up to 4 months. These forecasts are comparable with nowcasts derived from the operational system, and show skill in predicting SBT habitat boundaries out to lead-times of 3–4 months. For this fishery, seasonal forecasts can provide managers and fishers with valuable insights into future habitat distributions for the upcoming months, to better inform operational decisions.

Distribution, site affinity and regional movements of the manta ray, Manta alfredi (Krefft, 1868), along the east coast of Australia

Despite the increasing tourism interest worldwide for the manta ray, Manta alfredi, very little is known about its biology and ecology. Knowledge of its distribution and movement patterns is important for conservation purposes. Here we describe the distribution, site visitation and movements of M. alfredi along the east coast of Australia. Photographic identification techniques were used to identify individual manta rays at three study sites: Lady Elliot Island, North Stradbroke Island and Byron Bay. Of 388 M. alfredi individuals identified at Lady Elliot Island, 187 (48%) were subsequently re-identified at least once at the same site. In total, 31 individuals were identified at both Lady Elliot Island and North Stradbroke Island (~380 km to the south) and 4 at both Lady Elliot Island and Byron Bay (~500 km to the south). Manta alfredi was present all year around at Lady Elliot Island, although in higher numbers in winter, and was mainly observed at North Stradbroke Island and Byron Bay from mid-spring to mid-autumn. This is the first report of seasonal movements and site affinity for M. alfredi in eastern Australian waters and emphasises the value of photographic identification for monitoring the occurrence of individuals.

Evolution of Sousa chinensis: A scenario based on mitochondrial DNA study

Taxonomy within genus Sousa is confused largely due to inconsistencies among external morphology, skull morphology, pigmentation patterns and molecular studies. Here we provide our understanding of the evolution of Sousa chinensis by proposing a phylogeographic history based on mtDNA study. It is proposed that the species originated in eastern Australian waters and the current distribution has taken shape over the last 8.02–1.24 million years. Populations in Southeast Asia and Australian region experienced recent expansion about 0.54–1.5 million years ago. It is also proposed that populations in Southeast Asia experienced separation, re-unification and further dispersal during the last glacial age with multiple north–south migration across the Sahul Shelf area of northern Australia.

Genetic structure of a recent climate change-driven range extension

The life-history strategies of some species make them strong candidates for rapid exploitation of novel habitat under new climate regimes. Some early-responding species may be considered invasive, and negatively impact on 'naïve' ecosystems. The barrens-forming sea urchin Centrostephanus rodgersii is one such species, having a high dispersal capability and a high-latitude range margin limited only by a developmental temperature threshold. Within this species' range in eastern Australian waters, sea temperatures have increased at greater than double the global average rate. The coinciding poleward range extension of C. rodgersii has caused major ecological changes, threatening reef biodiversity and fisheries productivity. We investigated microsatellite diversity and population structure associated with range expansion by this species. Generalized linear model analyses revealed no reduction in genetic diversity in the newly colonized region. A 'seascape genetics' analysis of genetic distances found no spatial genetic structure associated with the range extension. The distinctive genetic characteristic of the extension zone populations was reduced population-specific F(ST), consistent with very rapid population expansion. Demographic and genetic simulations support our inference of high connectivity between pre- and post-extension zones. Thus, the range shift appears to be a poleward extension of the highly-connected rangewide population of C. rodgersii. This is consistent with advection of larvae by the intensified warm water East Australian current, which has also increased Tasmanian Sea temperatures above the species' lower developmental threshold. Thus, ocean circulation changes have improved the climatic suitability of novel habitat for C. rodgersii and provided the supply of recruits necessary for colonization.

Two new species of Okenia (Gastropoda: Nudibranchia: Goniodorididae) from eastern Australia and Tanzania

Two new species of the nudibranch genus Okenia Menke, 1830 (Goniodorididae) are described, one from eastern Australian waters and one from the western Indian Ocean. Okenia atkinsonorum sp. nov. is the third Australian species reported to feed on the bryozoan Pleurotoichus clathratus (Harmer, 1902) and is very similar in external shape and colour to the other two species, O. hallucigenia Rudman, 2004 and O. stellata Rudman, 2004. Okenia rhinorma sp. nov. is reported from Tanzania and the Red Sea. Its body shape and anatomy suggest it is related to the ascidian-feeding group in the genus characterised by O. aspersa (Alder & Hancock, 1845).

Naricolax hoi n. sp. (Cyclopoida: Bomolochidae) from Arius maculatus (Siluriformes: Ariidae) off Taiwan and a redescription of N. chrysophryenus (Roubal, Armitage & Rohde, 1983) from a new host, Seriola lalandi (Perciformes: Carangidae), in Australian waters

We propose that Naricolax stocki (Roubal, 1981) (Cyclopoida: Bomolochidae) of Ho & Lin (2005), reported from the spotted catfish Arius maculatus (Thunburg) off Taiwan, represents a new species, N. hoi n. sp. N. hoi can be distinguished from six known congeners by the shape of the rostral area, the maxillary armature and the structural details of legs 3 and 4. N. chrysophryenus (Roubal, Armitage & Rohde, 1983) is redescribed on the basis of recently collected material from wild and farmed yellowtail kingfish Seriola lalandi Valenciennes in southern and eastern Australian waters, providing the first record of Naricolax Ho, Do & Kasahara, 1983 from a carangid host. A key to the species of Naricolax is provided.

Spectral diversity of phycoerythrins and diazotroph abundance in tropical waters

Phycoerythrin (PE) spectral diversity was investigated in eastern tropical Australian waters and around New Caledonian and Fijian archipelagos. Colony sorting of filamentous cyanobacteria revealed slight differences in the PE excitation spectrum of Trichodesmium thiebautii and T. erythraeum. Spectra of PE from Katagnymene spiralis and Richelia intracellularis were examined for the first time. PE spectra of filamentous cyanobacteria (Trichodesmium, Katagnymene, and Richelia) showed a broader phycoerythrobilin (PEB) band than those of Synechococcus. The influence of PE Trichodesmium on the global spectrum of PE in natural waters was clearly visible at various stations. The PEB band was large at the surface and narrower at increased depth, suggesting a shift of the cyanobacterial community from a dominance of diazotrophic filamentous cyanobacteria to small Synechococcus. Size fractionation of water samples confirmed this. A good linear relationship was observed between PE concentration in the >10‐µm cellular‐size fraction and the abundance of filamentous cyanobacteria expressed by either trichome numbers, total trichome surface area, or total trichome volume. PE in the >10‐µm fraction is a useful tool for rapidly quantifying filamentous cyanobacteria. Neither diel variations nor photoacclimation significantly influenced the PE fluorescence excitation spectra in T. thiebautii and T. erythraeum. Using this method, we identified green colonies of filamentous cyanobacteria in deep waters (50–120 m) of the Coral Sea with a novel high‐phycourobilin PE. While morphologically similar to Trichodesmium, it possesses distinctive photosynthetic responses and could be a new species.

New calliopiid and eusirid amphipods from eastern Australian waters (Crustacea: Amphipoda: Calliopiidae: Eusiridae)

ABSTRACT The genera Membrilopus, previously known from southern Africa, and Regalia, previously known from the western Indian Ocean, eastern Indonesia and northern New Zealand, are reported for the first time in Australian waters. Three new species—Membrilopus kensleyi, Regalia juliana and Rhachotropis elliottana—are described. Membrilopus kensleyi is a scavenger living at the base of the continental slope; Regalia juliana is a sublittoral algaldweller living along the central eastern Australian coast; and Rhachotropis elliottana occurs off the Great Barrier Reef in depths of 500 m.

First report of three Kudoa species from eastern Australia: Kudoa thyrsites from mahi mahi (Coryphaena hippurus), Kudoa amamiensis and Kudoa minithyrsites n. sp. from sweeper (Pempheris ypsilychnus).

Fish species around the world are parasitized by myxozoans of the genus Kudoa, several of which infect and cause damage of commercial importance. In particular, Kudoa thyrsites and Kudoa amamiensis infect certain cultured fish species causing damage to muscle tissue, making the fish unmarketable. Kudoa thyrsites has a broad host and geographic range infecting over 35 different fish species worldwide, while K. amamiensis has only been reported from a few species in Japanese waters. Through morphological and molecular analyses we have confirmed the presence of both of these parasites in eastern Australian waters. In addition, a novel Kudoa species was identified, having stellate spores, with one polar capsule larger than the other three. The SSU rDNA sequence of this parasite was 1.5% different from K. thyrsites and is an outlier from K. thyrsites representatives in a phylogenetic analysis. Furthermore, the spores of this parasite are distinctly smaller than those of K. thyrsites, and thus it is described as Kudoa minithyrsites n. sp. Although the potential effects of K. minithyrsites n. sp. on its fish hosts are unknown, both K. thyrsites and K. amamiensis are associated with flesh quality problems in some cultured species and may be potential threats to an expanding aquaculture industry in Australia.

Age and growth of black marlin, Makaira indica, in east coast Australian waters

Sagittae, anal and dorsal fin spines were collected from black marlin, Makaira indica, in eastern Australian waters to evaluate and interpret age information from these structures. Presumed annual marks in sections of the third anal and third dorsal spines from 69 fish ranging in size from 8.5 to 451 kg were examined. Sectioned otoliths were also examined for presumed daily microincrements using both light and scanning electron microscopy. Spine radius and sagitta weight each varied predictably with the length and weight of the fish. The time period between consecutive growth marks was checked against the growth of these hardparts recovered from a tetracycline-injected and recaptured fish at large for 6 months. The increase in the size of fin spines from the recaptured fish was consistent with calculated growth curves derived from counts of presumed annual zones. Lengths and weights at age, based on these bands, are presented for black marlin. External ridges were observed on the edge and ventral surface of the rostrum of the sagitta, but they were inconsistently clear to be reliably counted. Sagittae displayed an internal record of microincremental growth on a scale that suggested a daily periodicity. Confident and consistent enumeration of these increments was restricted to fish <40 kg (~1600 mm lower jaw–fork length). A daily cycle of increment deposition was not confirmed by a count from the recaptured fish that fell short of the 198 days at large. The discrepancy was most likely associated with the difficulties of enumerating microincrements. The ages assigned to black marlin in this study support ages suggested from analysis of length–frequency data on juvenile fish. They underline the restraints previously recognized in decoding sagittae of blue marlin and confirm the utility of fin spines in providing age information for istiophorids.

Two New Species of Paraulopus (Osteichthyes : Aulopiformes) from New Zealand and Eastern Australia, and comparisons with P. nigripinnis

Two new paraulopid fishes, Paraulopus okamurai sp. nov. and P. novaeseelandiae sp. nov., are described on the basis of specimens collected from 235-553 m depth in eastern Australian and New Zealand waters. Within Paraulopus, the two new species are most similar to P. nigripinnis (Gunther, 1878) in having a supraocular ridge, 4.5-5.5 transverse scale rows above the lateral line, and a large body size. Paraulopus okamurai, P. novaeseelandiae, and P. nigripinnis differ from one another in the following characters : caudal-fin coloration (black with a transverse white band on the upper lobe and a white tip on the lower lobe in P. okamurai ; white with a black posterior margin on the upper lobe and a short, dark, oblique band on the lower lobe in P. novaeseelandiae ; white with a black posterior margin on both lobes in P. nigripinnis), counts of pectoral-fin rays (modally 17 in P. okamurai, 18 in P. novaeseelandiae, and 16 in P. nigripinnis), and predorsal scales (modally 17 in P. okamurai, 18 in P. novaeseelandiae, and 14 in P. nigripinnis).

Description of Arichlidon New Genus and Two New Species from Australia; Bhawania Reyssi Redescribed and Assigned to Arichlidon (Chrysopetalidae: Polychaeta)

Arichlidon hanneloreae gen. nov., sp. nov. is described from coastal and offshore coral reefs in tropical Eastern and western Australian waters, Papua New Guinea, Indonesia and the Marshall Islands. Arichlidon acropetalon sp. nov. is described from deeper waters off north Queensland, eastern Australia. Bhawania reyssi Katzmann, Laubier and Ramos, 1974, is redescribed and assigned to the new genus Arichlidon. Additional material of B. reyssi is recorded from Cape Verde Is lands, Eastern Atlantic; Mediterranean localities, including specimens from abyssal depths of the eastern Mediterranean, and the Red Sea. The new genus is characterised by a distinct convex, broad, short body form and the shapes of the highl y ornamented lateral, main and median paleae groups. Epitokous spinigerous neurosetae, not recorded before in the Chrysopetalidae, are described for Arichlidon lwnneloreae sp. nov .

Distribution and abundance of giant sea anemones (Actiniaria) in subtropical eastern Australian waters

Five of the 10 known Indo-Pacific giant anemone species were recorded on subtidal reefs within the eastern Australian subtropics (26°37′S to 30°56′S) during surveys between 1993 and 1995. Giant anemones had a patchy distribution among the 30 localities sampled, and species richness did not display any latitudinal trends within this province. Spatial distribution patterns and abundance of anemones were assessed from total counts and from line-intercept and belt transects. Anemone abundance was significantly higher on reefs to the leeward of the prevailing swell than on more exposed sites, at Julian Rocks and North Solitary Island, northern NSW. Significant reductions in anemone cover were detected among years within shallow reefal sites at North Solitary Island, coinciding with two major storm events. The abundance of the widespread Entacmaea quadricolor at North Solitary Island was the highest reported worldwide. Significant differences were detected between two morphological types of E. quadricolor in terms of microhabitat type, oral disk size and spatial distribution patterns. Important factors influencing the distribution, abundance and spatial patterns of giant anemones over both large and localized spatial scales appear to be water temperature, wave disturbance and water depth.

LOW FREQUENCY NARROW‐BAND SOUNDS PRODUCED BY BOTTLENOSE DOLPHINS

AbstractWe present a new sound type recorded from bottlenose dolphins, Tursiops truncatus, in eastern Australian waters: low‐frequency, narrow‐band (LFN) harmonic sounds (defined as less than 2 kHz). Most of these sounds were of frequencies less than 1 kHz and were recorded commonly from socializing dolphins. These sounds differ significantly from narrow‐band whistles, which are higher in frequency and longer in duration. The absence of these sounds in most studies of the acoustic behavior of bottlenose dolphins may reflect geographic differences in repertoires or result from insufficient sampling. Alternatively, these sounds may have been ignored where the focus of research was on other sound types.

Iodide and iodate concentrations in eastern Australian subtropical waters, with iodide by ion chromatography

Iodide and iodate concentrations were measured in the subtropical waters along the continental shelf and slope waters of eastern Australia. A thermocline between 50–100 m separated Coral Sea waters from Subtropical Lower Water on all transects. There was a sharp change in the iodide and iodate concentrations at the thermocline. The concentration of iodide in the shelf waters between 0 and 50 m ranged from 0.07 to 0.18 μM and ranged from 0.01 to 0.03 μM below a depth of 100 m. Iodate concentrations showed the inverse trend to iodide, ranging from 0.32 to 0.39 μM in the top 50 m, increasing to 0.46 μM below a 100 m. The ratio of iodate to phosphate in the Coral Sea waters was about eight times greater than deeper Subtropical Lower Water. This suggested that either (1) processes other than biological assimilation dominate in the Coral Sea, or (2) biological assimilation is greater in the Coral Sea, and more iodate is reduced to iodide, but this form of iodine does not enter the uptake cycle again as readily as phosphate, or (3) disparate paths for the biological cycling of iodine operate in different water bodies. Iodate was reduced to iodide in Coral Sea surface waters in the presence of both low concentrations of phosphate and nitrate. However, the reduction was for the most part effected before nitrate departed appreciably from its Redfield relationship with phosphate to become nutrient limiting.