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This is the first study of the life history characteristics of the monotypic Oplegnathus woodwardi. A total of 371 samples were collected from waters along the continental shelf (depths 30–120 m) off south-western Australia from 2010 to 2014, with a further 31 individuals collected in 1978/1979. Maximum ages of 51 and 53 years obtained from these contemporary and historical samples, respectively, are markedly higher than previous age estimates of two congeners from South African waters, whose ages were based on counts of growth zones in whole otoliths. Traditional von Bertalanffy growth (vBG) curves provided the best fit to the length at age data for females and males of O. woodwardi, when compared to vBG curves with t0 constrained to − 0.5 or the four parameter Schnute growth curve. In south-western Australia O. woodwardi exhibits a spring-summer spawning period, which is consistent with other temperate demersal teleosts along this coast. The age-based life history characteristics of O. woodwardi determined from this study, provide important information from which to infer the inherent vulnerability of this species. This study also contributes toward the broader sustainable management of this species, particularly where life history information is unknown but higher catches and smaller length compositions likely render that fisheries resource to be at a higher risk.

The head of a large scaled stargazer Pleuroscopus pseudodorsalis Barnard 1927 was found in the stomach of a bass groper Polyprion americanus caught in deep waters off the south-east coast of Western Australia. The finding of this specimen increases our knowledge of the distribution of P. pseudodorsalis and the estimated age of 22 years of this specimen, based on counts of growth (opaque) zones in the section otoliths, is the first such information for this species.

Due to advances in fish-finding equipment and vessel capabilities, commercial and recreational fishers are now regularly accessing deep waters off the edge of the continental shelf and catching fish species that are rarely encountered in shallower waters or that have not previously been caught. This study details the capture of two Japanese rubyfish (Erythrocles schlegelii) in deep, offshore waters on the south coast of Western Australia, and in waters further south than previously encountered. This study also provides the first age estimates from counts of growth (opaque) zones in sectioned sagittal otoliths. The estimated ages of 8 years for both individuals, one female and the other male, are much lower than what would have been expected based on age estimates for this species derived from scales undertaken in an earlier study. Understanding the biological characteristics of these deepwater fish species will assist in future management of these resources.

The Indian halibut (Psettodes erumei) is an important flatfish species in tropical and subtropical waters of the northern Indian Ocean. However, inappropriate aging methods used in previous studies of Indian halibut limited the use of age and growth data from those studies. This study highlights the importance of correct aging methods and identification of sexually dimorphic growth, particularly if growth characteristics are used to estimate mortality rates. Counts of opaque zones in whole otoliths of Indian halibut were almost always fewer than those in their corresponding sections, particularly for older individuals. Multiple validation methods demonstrate opaque zones form annually in otoliths of Indian halibut. Although the frequency of females increased with size, due to sexually dimorphic growth, males attained a greater maximum age (16 versus 11 years). Because of the greater ages and rapid early growth of Indian halibut described in this study, natural mortality estimates calculated by using Pauly’s equation, particularly for males, were higher than estimates derived from the same equation in previous studies, which employed growth parameter estimates based on ages derived from whole otoliths, vertebrae, or monthly length–frequency trends and, typically, did not account for sexually dimorphic growth. In northwestern Australia, spawning in Indian halibut commences when water temperature and day length begin to increase and occurs between early spring and late summer.

Life-history traits and the ecology of the family Pentacerotidae are known for only a fraction of the 13 species distributed worldwide. The Giant Boarfish (Paristiopterus labiosus) is known for its increasing recreational fishery and for undergoing spawning aggregations in Australasian waters but the biological characteristics remain scarce. Here, we report the capture of a large P. labiosus (962 mm total length and 9.2 kg total weight), close to the reported maximum size of 910 mm total length, from New Zealand waters and its age estimation. An estimated age of 36 years, based on counts of opaque zones in thin otolith sections, provides important information on the potential lifespan of the species, an important step forward to better understand its life history.

Scorpaeniformes are an important component of commercial and recreational fisheries world‐wide. The Neosebastes species, found in the western Pacific and south‐east Indian Ocean, have received little attention from a research perspective. Samples of the bighead gurnard perch, Neosebastes pandus, collected from the lower west and south coasts of Western Australia, were used to undertake the first comprehensive investigation of the biological characteristics of a Neosebastes species. Opaque zones in sectioned sagittal otoliths were validated as forming annually. Female N. pandus grow to a significantly larger size, on average, than males and dominate the largest size classes, while males, growing to a smaller size, accumulate in the intermediate size classes. Although males were far less numerous than females in those age classes in which both sexes were found, males and females attain similar maximum ages >25 years. Neosebastes pandus spawns over a brief period between May (austral late autumn) and July (austral mid‐autumn) when water temperature and day length are declining. The mean monthly gonadosomatic indices (GSI, IGS) values of females during the spawning period are 37–50 times higher than those of males, which mature at an earlier age and smaller length compared to females. Histological examination of the ovaries of females indicate that their structure is consistent with “general” teleost ovarian anatomy and thus differs from Scorpaena, Helicolenus and Sebastes species whose ovaries are adapted for specialized reproductive modes. The reproductive strategy of N. pandus of maximizing the reproductive output of females, by this sex attaining a larger size than males and pair spawning (i.e., large disparity in IGS values) demonstrates the close lineage between the Neosebastes and other Scorpaeniformes, such as the Scorpaena, Helicolenus and Sebastes.

Despite the Maori snapper, Lutjanus rivulatus, being a targeted fisheries species throughout its broad geographic distribution across the Indo-Pacific region, this is the first study of its age-based life history characteristics. Information on the age, growth and longevity of a species can improve our understanding of its inherent vulnerability to exploitation. In Western Australia (WA), this species is exploited on a small-scale over a broad area by commercial and recreational fishers. In the current study, L. rivulatus was estimated to attain an exceptional maximum age of 56 years from a total of 102 samples collected from the tropical waters of WA. The growth of this species was sexually dimorphic with males attaining a larger length-at-age than females. Further, the growth of both sexes varied in relation to latitude, and thus water temperature, with L. rivulatus in the cooler, higher latitudes attaining a greater length-at-age than individuals from the warmer, more northern regions at lower latitudes. This relationship between growth and water temperature is consistent with that predicted by the metabolic theory of ecology, and contributes toward knowledge of how the growth of this, and potentially other lutjanids, may respond to climate variability. The improved understanding of age-based demographics of this species also contributes to its broader sustainable management across the Indo-Pacific region.

The small-tooth flounder Pseudorhombus jenynsii (Paralichthyidae) is a common, yet relatively unstudied, flatfish occurring in estuaries and coastal waters around Australia. This study determined the age and growth of P. jenynsii using 1,228 specimens collected between 2004 and 2013 as bycatch by seine netting in estuaries and trawling in coastal waters in south-western Australia. Opaque zones in 1,043 sectioned otoliths were validated as forming annually by otolith edge analysis, with the first opaque zone becoming delineated after the first spring when fish are ~ 12 months old. Female P. jenynsii ranged in total length from 79 to 406 mm and males from 96 to 354 mm. The maximum observed age for females and males was 5 and 4 years, respectively. While the von Bertalanffy growth functions (VBGF) fitted to the lengths at age differed significantly between the sexes, this difference in the length at age was < 5% between the ages of 1 and 3 years (where most of the data lay). The VBGF parameters for both sexes combined are L∞: 381 mm, k: 0.53 year−1, t0: -0.15 years. The large variation in size-at-age of P. jenynsii is indicative of a presumed extended 5–6 months spring and summer spawning period. The presence of small (< 200 mm) and young (< 2 years old) P. jenynsii in estuaries and shallow coastal waters confirms the use of these environments as nursery habitats.

The gobiid Acentrogobius plflaumii, native to estuaries and coastal embayments in East Asia, has recently established a population in the warm-temperate Swan-Canning Estuary (SCE) in southwestern Australia. Data from 432 individuals demonstrated that although A. pflaumii was shown to live for 4 years, the age composition was dominated by 0+ and 1+ individuals. The maximum size of female (94 mm) and male (96 mm) A. pflaumii in the SCE is 33% larger than in its native habitat. Acentrogobius plflaumii grew rapidly, attaining a length of 65 mm, i.e. 84 and 87% of their ’s of 77.3 and 72.9 mm for females and males, respectively, within the first year of life. Gonadosomatic indices, trends in monthly gonadal development and histological examination of gonads indicate that, although peak spawning in the SCE occurs over a similar period and season as in South Korean waters, spawning is more protracted in the SCE. Two discrete modes in oocyte diameter frequencies indicate this species exhibits determinate fecundity. The protracted spawning period enables batches of eggs to be released periodically during favourable conditions. These biological traits are likely to have aided in the successful colonisation of this species in the SCE. Quantifying the phenotypic plasticity of this non-indigenous species may inform risk assessments and subsequent management plans to mitigate the effect of A. pflaumii in the SCE and predict the likelihood of it colonising other southwestern Australian estuaries.

The reproductive biology of Centroberyx gerrardi (Günther) was investigated across ~2,000 km of its southern Australian distribution, encompassing different jurisdictions and varying environmental features. Greater gonad mass and prevalence of spawning fish, along with lower ratios of lengths at maturity:maximum lengths and ages at maturity:maximum ages, were identified at the western-most (Capes) and eastern-most (Great Australian Bight; GAB) regions. Across the study region, spawning peaks in summer/autumn, when water temperatures are warmest. Regional differences in potential “reproductive output,” while not consistent with the eastward decline in mean monthly water temperature, may instead be related to summer upwelling in the Capes and GAB, driving greater oceanic productivity prior to peak spawning, supporting larval survival. In autumn, the prevailing southward and eastward flowing, downwelling Leeuwin Current (LC) strengthens, providing a dispersal mechanism along the west and south Australian coasts, but limiting upwelling effects. Predicted changes in environmental conditions and their potential impacts on C. gerrardi are discussed, in particular how these factors may affect recruitment to stocks and fisheries, requiring a better understanding of source-sink relationships for this species. As environmental changes occur, management strategies to sustain fish resources must adapt to spatially variable and changing reproductive output and be collaborative across jurisdictions.

Non-indigenous species are recognised as a significant threat to estuaries as they can negatively impact native fauna and ecosystem functioning. This study compared the abundance and distribution of the introduced gobiid, Acentrogobius pflaumii, with native gobiids in the shallow, nearshore and deeper, offshore waters of the Swan-Canning Estuary over 31 consecutive months and determined the influence of salinity and water temperature on the gobiid assemblage. Eight gobiid species were recorded (six native and two non-indigenous). Each species was present in offshore waters, with five also occurring in nearshore waters. The contribution of A. pflaumii to the gobiid fauna varied markedly between depths, not being recorded in the 1240 samples from nearshore waters, but representing almost half of all gobiids caught in offshore waters. The percentage contribution of this species to the total gobiid abundance declined with distance from the estuary mouth, from 96% in the most downstream region to only 0.4% in the uppermost. The overwhelming contributions of A. pflaumii in the lower estuary, which historically contained few gobiids, indicate that it has successfully exploited an unoccupied niche. Gobiid composition, in both depths, differed mainly among regions, with species partitioning themselves along the longitudinal axis of the estuary. In offshore waters, Favonigobius lateralis and A. pflaumii dominated the lower regions and Arenigobius bifrenatus, Favonigobius punctatus and Pseudogobius olorum the regions further upstream. The distributions of these species are influenced by salinity and, to a lesser extent, temperature. While there is spatial overlap between A. pflaumii and native gobiid species, its preference for deeper, more saline waters may limit the impact of this non-indigenous species.

Cheilodactylus rubrolabiatus collected from the south and lower west coasts of Western Australia were used to investigate the influence of habitat and environmental conditions on the biology of this species. A lack of difference in the growth C. rubrolabiatus from cool south coast and warmer lower west coast waters in Western Australia and the greater maximum ages attained by fish on the latter coast, both run contrary to premises of the metabolic theory of ecology (MTE). Although the greater size (L 50 ) and age (A 50 ) at maturity of C. rubrolabiatus on the south coast is consistent with MTE, this may reflect higher densities of fish on discontinuous shoreline rocky reefs on this coast and thus the need for fish, particularly males, to attain a larger size to successfully defend habitat and mates during spawning. Members of the closely related Cheiodactylidae and Latridae vary in maximum fork length (L Fmax 280–950 mm) and age (19–97 years) and display a range of growth patterns. While the L 50 of cheilodactylid and latrid species increased with increasing asymptotic lengths (L ∞ ), their maximum ages did not necessary reflect the A 50 (i.e., mature early, but live long). The M (natural mortality): k (von Bertalanffy growth parameter) ratios indicate that Cheilodactylus and Nemadactylus species exhibit a type II life-history strategy, typified by initial rapid growth, L 50 close to their L ∞ and little or no growth during an extended adult phase. A lack of distinct difference in the biological characteristics of the Cheilodactylidae and latrids may assist in resolving uncertainty regarding the taxonomy of these families.

This study provides a comprehensive assessment of the dietary composition of the ambush predator Neosebastes pandus and compares the diets of 49 species from 39 studies of three benthic predatory families in the Scorpaeniformes: Scorpaenidae (20 species), Triglidae (19 species) and Platycephalidae (10 species). A total of 275 N. pandus were collected from the west (Rottnest Island) and south coasts (Esperance) of south‐western Australia and the percentage frequency and volumetric contribution of the stomach contents identified. Fish from the west coast consumed a greater mean number of broad taxonomic groups and were more diverse in their diet than fish from the south coast. Cephalopods, brachyurans and teleosts were the largest overall contributors to diet, with teleosts being more important to diets of west‐coast fish and polychaetes for south‐coast fish. This reflects differences in habitat between the two locations. Dietary composition also changed with increasing body size, reflecting morphological changes that allow bigger fish to capture and ingest larger, more mobile prey. Meta‐analysis of the diets of 49 species of scorpaenid, triglid and platycephalid revealed that they feed predominantly on teleosts and large crustaceans. Significant differences in diet were detected among families, with platycephalids being the most distinct and feeding more on teleosts than scorpaenids and triglids.

Entrainment of growth patterns of multiple species to single climatic drivers can lower ecosystem resilience and increase the risk of species extinction during stressful climatic events. However, predictions of the effects of climate change on the productivity and dynamics of marine fishes are hampered by a lack of historical data on growth patterns. We use otolith biochronologies to show that the strength of a boundary current, modulated by the El Niño-Southern Oscillation, accounted for almost half of the shared variance in annual growth patterns of five of six species of tropical and temperate marine fishes across 23° of latitude (3000 km) in Western Australia. Stronger flow during La Niña years drove increased growth of five species, whereas weaker flow during El Niño years reduced growth. Our work is the first to link the growth patterns of multiple fishes with a single oceanographic/climate phenomenon at large spatial scales and across multiple climate zones, habitat types, trophic levels and depth ranges. Extreme La Niña and El Niño events are predicted to occur more frequently in the future and these are likely to have implications for these vulnerable ecosystems, such as a limited capacity of the marine taxa to recover from stressful climatic events.

This review provides a composite account of the biological characteristics of the temperate gonochoristic species of the Platycephalidae. Initially, data were obtained for the five abundant platycephalid species in south-western Australia, which each came from either over bare substrata or seagrass and from either estuaries, marine coastal waters or marine embayments. The von Bertalanffy growth curves for females and males of each species differed significantly, with females having a greater TL∞ and lower growth coefficient k. From tests using their upper deciles, the total length (TL) attained by the largest females of each species was significantly greater than that of their males, whereas such a trend did not occur with age. The ratio of females to males in each abundant age class, and overall, exceeded parity for four of the five species (typically P < 0.001) and increased with increasing TL. Mortality estimates, which were similar for each sex of each species, suggest that Platycephalus speculator has been substantially exploited in a seasonally-closed estuary in which it completes its whole life cycle. The above and other biological data for the five species were collated with those published previously for two of those species and five other platycephalid species in south-eastern Australia and one in Japan and another in the Suez Canal, yielding the following conclusions for gonochoristic species of the Platycephalidae. Females attain a larger size than males, the extent varying markedly among species, whereas the longevities of the two sexes of each platycephalid species are similar. The maximum TLs and ages of the various species range widely, with values for females, for example, extending from 221 mm for Ambiserrula jugosa to 985 mm for Platycephalus fuscus and from four years for A. jugosa to 26 years for Platycephalus conatus. The overall ratio of females to males is positively related to the extent to which both the maximum TLs and TL∞s of the females

Curves describing the length–otolith size relationships for juveniles and adults of six fish species with widely differing biological characteristics were fitted simultaneously to fish length and otolith size at age, assuming that deviations from those curves are correlated rather than independent. The trajectories of the somatic and otolith growth curves throughout life, which reflect changing ratios of somatic to otolith growth rates, varied markedly among species and resulted in differing trends in the relationships formed between fish and otolith size. Correlations between deviations from predicted values were always positive. Dependence of length on otolith growth rate (i.e., “growth effect”) and “correlated errors in variables” introduce bias into parameter estimates obtained from regressions describing the allometric relationships between fish lengths and otolith sizes. The approach taken in this study to describe somatic and otolith growth accounted for both of these effects and that of age to produce more reliable determinations of the length–otolith size relationships used for back-calculation and assumed when drawing inferences from sclerochronological studies.

Biological characteristics of Pentaceropsis recurvirostris, Paristiopterus gallipavo and Parazanclistius hutchinsi were determined from commercial gillnet samples from temperate south-western Australian coastal waters. Growth zones in otoliths, with more than a few such zones, were readily detectable only after the otoliths had been sectioned. Visual analyses and modelling of the trends in marginal increments on sectioned otoliths demonstrate that these opaque zones are formed annually. Maximum ages of 55, 36 and 49 years, derived for P. recurvirostris, P. gallipavo and P. hutchinsi, respectively, reflect relatively low mortalities. These longevities greatly exceed those estimated, using otoliths, for Pentaceros wheeleri and Pentaceros richardsoni, which belong to the other pentacerotid subfamily. These differences may be due to the counts of ‘daily’ growth zones in sectioned otoliths of P. wheeleri not representing the complete age range of that species and the zones detected in whole otoliths of P. richardsoni not constituting the complete range of annually-formed zones. Pentaceropsis recurvirostris, P. gallipavo and P. hutchinsi recruited into the fishery in the sampling area as 2–3 year-old fishes. Pentaceropsis recurvirostris and P. hutchinsi exhibited little or no subsequent growth throughout the remainder of their protracted life, whereas, P. gallipavo continued to grow for c. 5 years and then underwent little further growth. Spawning of P. recurvirostris and P. hutchinsi peaked in the austral winter and autumn, respectively, but in the austral spring and summer with P. gallipavo, which is more typical of temperate species. Although the females of P. gallipavo and P. hutchinsi were mature, this did not apply to a few P. recurvirostris, some of which were >20 years old, implying that any given female of this species does not always spawn every year. Ovarian mass greatly exceeded testis mass, indicative of pair spawning, which is consistent with field observati

The biological characteristics of a marine and macrophyte-associated species (Pelates octolineatus) in a large microtidal, eutrophic estuary in 2008-10 were determined. Comparisons are made with those of individuals remaining in coastal waters and during two earlier periods in the estuary when plant biomass differed markedly. P. octolineatus start entering the Peel-Harvey Estuary in mid-summer, soon after metamorphosis, with many remaining there until autumn when they are ∼15 months old. These individuals, and older fish that re-entered the estuary in summer, then return to the sea where they spawn from late spring to early summer. Most P. octolineatus in the estuary were less than or equal to the length at maturity and all were <4 years old, whereas individuals up to 10 years old were caught in coastal embayments, emphasising that the estuary acts mainly as a nursery for this terapontid. Growth in the estuary was seasonal and peaked earlier and was greater than in marine waters. Abundance of P. octolineatus in the estuary was greater in 2008-10 and 1980-81 than in 1996-97, when macrophytes were less abundant. The results demonstrate how a marine estuarine-opportunist can benefit from using both estuaries and coastal waters as a nursery area and capitalise on variations in environmental conditions.

The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats.

This study has determined the extents and basis for variations in the composition of the prey ingested by the abundant species of a family highly adapted for ambush predation, i.e. Platycephalidae, in a region (south-western Australia) where that family is found in different habitats and environments. Dietary data were thus collected for Leviprora inops and Platycephalus laevigatus from seagrass in marine embayments and for Platycephalus westraliae from over sand in an estuary. These were then collated with those recorded previously for Platycephalus speculator from over sand and in seagrass in an estuary and for Platycephalus longispinis from over sand in coastal marine waters. While crustaceans and teleosts together dominated the diet of all five species, their percentage volumetric dietary contributions varied greatly, with those of crustaceans ranging from 7% for L. inops to 65% for P. speculator and those of teleosts ranging from 29% for P. longispinis to 91% for L. inops. For analyses, the data were separated into two sets. The first comprised the 17 dietary categories of invertebrates and all identified and unidentified teleosts collectively, while the second consisted of the 23 identified teleost families, both of which were subjected to permutational analysis of variance (PERMANOVA), analysis of similarities (ANOSIM) and a new (two-way) version of the RELATE procedure. The diets of three species changed seasonally, when using invertebrate dietary categories and teleosts collectively, but with only one species, when employing identified teleost families, probably reflecting a greater tendency for invertebrate than teleost prey abundance to change during the year. On the basis of dietary data for invertebrate taxa+teleosts collectively, the diets of three of the five species changed serially with body size, with a fourth species feeding, throughout life, predominantly on the carid Palaemonetes australis. Based on identified teleost families, the diets of the

Ecological modeling shows that even small, gradual changes in body size in a fish population can have large effects on natural mortality, biomass, and catch. However, efforts to model the impact of climate change on fish growth have been hampered by a lack of long-term (multidecadal) data needed to understand the effects of temperature on growth rates in natural environments. We used a combination of dendrochronology techniques and additive mixed-effects modeling to examine the sensitivity of growth in a long-lived (up to 70 years), endemic marine fish, the western blue groper (Achoerodus gouldii), to changes in water temperature. A multi-decadal biochronology (1952-2003) of growth was constructed from the otoliths of 56 fish collected off the southwestern coast of Western Australia, and we tested for correlations between the mean index chronology and a range of potential environmental drivers. The chronology was significantly correlated with sea surface temperature in the region, but common variance among individuals was low. This suggests that this species has been relatively insensitive to past variations in climate. Growth increment and age data were also used in an additive mixed model to predict otolith growth and body size later this century. Although growth was relatively insensitive to changes in temperature, the model results suggested that a fish aged 20 in 2099 would have an otolith about 10% larger and a body size about 5% larger than a fish aged 20 in 1977. Our study shows that species or populations regarded as relatively insensitive to climate change could still undergo significant changes in growth rate and body size that are likely to have important effects on the productivity and yield of fisheries.

Key biological characteristics of the harlequin fish Othos dentex, a representative of a monospecific genus of the Anthiinae (Serranidae), were determined from samples collected around reefs on the south coast of Western Australia. The females of this relatively long-lived species (maximum recorded age in this study=37years) attained only a slightly greater maximum total length and age than males and neither the length nor the age-frequency distributions showed a conspicuous sex-based bimodality. Furthermore, gonads from a wide size and age range of O. dentex were shown by histology, at several locations along their length, to always comprise exclusively either ovarian or testicular tissues. Thus, O. dentex is a gonochorist, a sexual pattern only previously recorded definitively for one other anthiine serranid, i.e. Epinephelides armatus, which also occurs in south-western Australia. Similar to E. armatus, O. dentex possesses 'solid' testes with a central sperm duct, thereby differing in structure from those typically found in serranids, in which there is a central membrane-bound 'ovarian' lumen and peripherally located sperm sinuses. The gonadal characteristics and sexual pattern of these two gonochoristic anthiines are not consistent with a recent proposal for the trends exhibited by the evolution of gonochorism and protogyny within the Serranidae. Othos dentex has indeterminate fecundity and a protracted spawning period (7months) and, on the basis of underwater observations and a low gonado-somatic index (IG) for males, is a pair spawner, which is unusual for a gonochorist of a serranid or member of a related family. While the large spots on the lower half of the body of O. dentex are shown quantitatively to be similarly yellow in juveniles and adult females, they then become blue in males at maturity and this intensifies during the spawning period, when they presumably play an important role in agonistic interactions among males and courtship with females. The a

This study has determined the biological characteristics of Scorpis aequipinnis on the south coast of Western Australia. It thus supplements the limited amount of data for members of the widely distributed and speciose Kyphosidae, which contains species that make an important contribution to certain ecosystems and local commercial and recreational fisheries and have considerable aquaculture potential. S. aequipinnis was aged using the number of annuli in sectioned otoliths and its growth described using the Schnute growth equation. This species attains a greater maximum fork length (FL), i.e. 477 vs. 330 mm, and greater maximum age, i.e. 68 vs. 54 years, than S. lineolatus on the eastern Australian coast, where its stock has apparently experienced excessive exploitation. S. aequipinnis thus exhibits characteristics that would make it particularly susceptible to over-fishing should fishing effort on the south coast increase as anticipated. S. aequipinnis and S. lineolatus exhibit similar and very rapid growth initially, reaching 90% of their asymptotic fork lengths (FL infinity) at 14-16 and 12 years, respectively, and then grow only slightly for much of the remainder of their extensive life spans. The FL(50)s at maturity for female and male S. aequipinnis (363 and 379 mm, respectively) and for both sexes of S. lineolatus combined (172 mm) were each far greater than would be expected given their respective FL(infinity)s. There have thus been strong selection pressures for the attainment by both species of a relatively large size prior to maturation. The main spawning period of S. aequipinnis, which occurs between late autumn and mid-winter when water temperatures are declining rapidly, and those of other recreational and commercial species on the south coast of Western Australia vary markedly, thereby reducing the potential for inter-specific competition for resources by their larvae and juveniles. The estimate of fishing mortality for male S. aequipinnis was greater

The demonstration by this study that the life cycle characteristics of the reef fish Nemadactylus valenciennesi differed markedly from those of other cheilodactylids led us to compare these differences and hypothesise on their evolutionary implications. The distribution, length and age compositions, growth and the length and age at maturity of N. valenciennesi in south-western Australian waters have been determined. The maximum age (21 years) of N. valenciennesi (maximum total length = 984 mm) is far less than those of the much smaller Cheilodactylus fuscus, Nemadactylus macropterus (both ∼40 years) and Cheilodactylus spectabilis (97 years). Yet N. valenciennesi, N. macropterus and C. spectabilis mature at a similar young age (3-7 years). While, on the basis of data for other species, all three species mature at lengths consistent with their asymptotic lengths, the last two species mature at a far earlier age than would be predicted from their long life spans. The early attainment of maturity by N. macropterus and C. spectabilis may reflect a response to high juvenile mortality or constrained adult growth, whereas their long life spans could reflect a response to variable recruitment in the past or compensation for limited annual reproductive output due to very constrained adult growth.

The western blue groper (Achoerodus gouldii) is shown to be a temperate protogynous hermaphrodite, which spawns between early winter and mid-spring. Because A. gouldii changes body color at about the time of sex change, its color can be used as a proxy for sex for estimating the size and age at sex change and for estimating growth when it is not possible to use gonads for determining the sex of this fish. The following characteristics make A. gouldii highly susceptible to overfishing: 1) exceptional longevity, with a maxi-mum age (70 years) that is by far the greatest yet estimated for a labrid; 2) slow growth for the first 15 years and little subsequent growth by females; and 3) late maturation at a large total length (TL50=653 mm) and old age (~17 years) and 4) late sex change at an even greater total length (TL50=821 mm) and age (~35 years). The TL50 at maturity and particularly at sex change exceeded the minimum legal total length (500 mm) of A. gouldii and the lengths of many recreationally and commercially caught fish. Many of these characteristics are found in certain deep-water fishes that are likewise considered susceptible to overfishing. Indeed, although fishing effort for A. gouldii in Western Australia is not particularly high, per-recruit analyses indicate that this species is already close to or fully exploited.

This study provides the sound quantitative data that are required by managers for developing plans for conserving the stocks of the Western Blue Groper Achoerodus gouldii, the Blue Morwong (previously Queen Snapper) Nemadactylus valenciennesi and the Yellowtail Flathead (previously Bar-tailed Flathead) Platycephalus endrachtensis in south-western Australian waters. The first two species are commercially and recreationally important in coastal waters and the third is one of the most important angling species in the Swan River Estuary. All three species have been identified by managers as requiring detailed studies of their biology, and Blue Morwong and Yellowtail Flathead are among a small suite of species selected as indicator species for the status of fish populations in marine and estuarine waters, respectively, in south-western Australia. As juveniles, Western Blue Groper typically occupy reef areas in protected inshore waters along the coast and around neighbouring islands. As the individuals of this species increase in size, they move offshore to deeper and more exposed waters over reefs. Spawning occurs in the latter environment, between early winter and mid-spring. The maximum length and age we recorded for Western Blue Groper were 1162 mm and 70 years, respectively, the latter age being the greatest by far yet recorded for any species of wrasse. However, most of the growth of this species occurs in the first 20 years of life. The Western Blue Groper is shown to be a monandric protogynous hermaphrodite, namely all of its individuals begin life as females and, after maturing, many subsequently change sex to males. Females typically first become mature at about 650 mm and 15-20 years and typically change to males at lengths of about 800-850 mm and ages of about 35- 39 years. As sex change takes place over a narrower range in lengths (650 to 900 mm) than in ages (15 to 49 years), that change is apparently related more to size than age. The fact that sex change i

We compare the biology of the tropical species Sillago analis and the temperate species Sillago schomburgkii in Shark Bay, a large subtropical marine embayment on the west coast of Australia. This environment constitutes approximately the southernmost and northernmost limits of the distributions of these two species, respectively. The annuli visible in sectioned otoliths of S. analis and S. schomburgkii form annually. Their numbers were thus used to age the individuals of these two species, which are morphologically very similar and live in the same habitats. Although the growth rates of S. analis and S. schomburgkii are very similar until maturity is attained, they subsequently diverge, with S. schomburgkii investing relatively more energy into somatic growth. The maximum total lengths and ages of both the females (320 mm, 6 years) and males (283 mm, 8 years) of S. analis were not as great as those of the females (383 mm, 9 years) and males (302 mm, 9 years) of S. schomburgkii. In Shark Bay, S. schomburgkii spawns earlier and longer than S. analis, i.e. August-December vs. January-March, which would result in the juveniles of these two species recruiting into nursery areas at different times. In addition, S. schomburgkii spawns earlier and for longer in Shark Bay than in temperate marine waters 800 km further south, presumably reflecting the fact that, in that subtropical embayment, water temperatures over which this species typically spawns are attained earlier and last for longer. However, although environmental conditions in Shark Bay and those temperate marine waters differ markedly, the growth of the corresponding sexes of S. schomburgkii in these two water bodies is similar.