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Tarakihi (Nemadactylus macropterus) is a demersal fish that supports valuable commercial, recreational, and customary fisheries in New Zealand. However, little is known about its stock structure. T...

The ecology of all life-history stages of two species of demersal fish, sand flathead (Platycephalus bassensis) and jackass morwong (Nemadactylus macropterus) found in coastal and continental shelf waters of southern and eastern Tasmania was investigated to determine the spatial and temporal patterns of spawning distribution and larval transport, recruitment, abundance and distribution, and size and age composition. The seasonal and interannual variations of the hydrography of shelf waters are described and the influence of such variability on the life-history stages assessed. Spawning in P. bassensis occurred for an extended period of up to six months between October and March in estuaries, coastal embayments and shelf waters of southern and eastern Tasmania. The distribution of spawning fish, larvae and patterns of hydrography indicate that spawning on the shelf is primarily inshore. Larval development of P. bassensis is described. Larvae are concentrated in midwater which retain larvae inshore as cross-shelf subsurface currents are predominantly onshore. Spawning in N macropterus occurred between early January and late April in midand outer-shelf waters. Ichthyoplankton data indicate N macropterus larvae are concentrated in surface waters, with few larvae caught during subsurface sampling of shelf waters over three years, despite large interannual differences in the extent of vertical mixing and stratification. The surface distribution of larvae appears to be a strategy to maximise offshore transport as movement of surface waters of the shelf are generally offshore. However, large interannual variations in the influence of subtropical and subantarctic waters on the shelf are described and the influence of such variations on larval transport assessed. Significant seasonal and spatial variations in abundance of mature P. bass ens is were evident, the variations attributed primarily to the seasonal movement of fish between shelf and nearshore waters. Overlying the seasonal trends in abundance were interannual variations that were at least au order of magnitude in difference. Mature P. bassensis were generally more abundant on the inner-shelf, with little evidence of size-structuring with increasing depth. Settlement occurred over au extended period in summer with juveniles showing a strong preference for unvegetated habitats in nearshore waters, compared to beds of the seagrass, Heterozostera tasmanica. However, mature P. bassensis in nearshore waters showed no preference between vegetated and unvegetated habitats. There is evidence of a seasonal movement of these nearshore fish out onto the shelf close to the size at maturity. In contrast, N macropterus on the shelf showed size-structuring between depths and regions, with juveniles dominating the inner-shelf in both regions surveyed, while the mid- and outer-shelf of the east coast was dominated by mature fish. Settlement from the pelagic post-larval phase occurred in spring and early summer at between 7 to 9 em and 9 to 12 months old. Storm Bay appears to be principally a nursery are;t for the species with migration from the region occurring upon maturity. In addition, the size-structuring by depth was one of the main factors attributed to the significant variations in abundance across the shelf. Significant seasonal variations in abundance were also apparent, which is attributed to the seasonal movement of fish from south-eastern Tasmanian shelf waters. The age, growth and spatial and interannual trends in age composition of P. bassensis and N macropterus were examined using transverse sections of sagittal otoliths. The first annual increment was defined in both species by examination of the progression of otolith radius and length of the 0+ cohort. Sex specific growth curves are presented for both species. Maximum ages of P. bassensis was 17 years for males and 13 for females, while N macropterus reached 41 years for males and 30 for females. The age composition of both species was dominated by 4 to 7 years olds with considerable recruitment variability evident with a strong year-class in 1986 for P. bass ens is and in 1988 for N macropterus. The relationship between the life-history strategies of P. bassensis and N macropterus and recruitment variability is discussed.

Comparative analysis of whole-genome sequences can provide valuable insights into the evolutionary patterns of diversification and adaptation of species, including the genome contents and the regions under selection. However, such studies are lacking for fishes in New Zealand. To supplement the recently sequenced genome of tarakihi (Nemadactylus macropterus), the genomes of five additional percomorph species native to New Zealand (king tarakihi (Nemadactylus n.sp.), blue moki (Latridopsis ciliaris), butterfish (Odax pullus), barracouta (Thyrsites atun), and kahawai (Arripis trutta)) were determined and assembled using Illumina sequencing. While the proportion of repeat elements was highly correlated with the genome size (R2 = 0.97, P < 0.01), most of the metrics for the genic features (e.g. number of exons or intron length) were significantly correlated with assembly contiguity (| R2| = 0.79–0.97). A phylogenomic tree including eight additional high-quality fish genomes was reconstructed from sequences of shared gene families. The radiation of Percomorpha was estimated to have occurred c. 112 mya (mid-Cretaceous), while the Latridae have diverged from true Perciformes c. 83 mya (late Cretaceous). Evidence of positive selection was found in 65 genes in tarakihi and 209 genes in Latridae: the largest portion of these are involved in the ATP binding pathway and the integral structure of membranes. These results and the de novo genome sequences can be used to (1) inform future studies on both the strength and shortcomings of scaffold-level assemblies for comparative genomics and (2) provide insights into the evolutionary patterns and processes of genome evolution in bony fishes.

Genus Nemadactylus Richardson (Fig. 9) Nemadactylus Richardson, 1839: 98 [Type-species: Nemadactylus concinnus Richardson, 1839 (=junior synonym of N. macropterus Forster, 1801) by monotypy]. Dactylopagrus Gill, 1862: 114 [Type-species: Cheilodactylus carponemus Cuvier, 1830 (= junior synonym of N. macropterus Forster, 1801) by original designation]. Dactylosparus Gill, 1862: 117 [Type-species: Cheilodactylus carponemus Cuvier, 1830 (objective synonym of Dactylopagrus Gill, 1862)]. Acantholatris Gill, 1862: 119 [Type-species: Chaetodon monodactylus Carmichael, 1819 (= junior synonym of N. monodactylus Carmichael, 1819) by original designation]. Etymology. Gender masculine. Derived from the Greek nema (filament) and daktylos (finger) for the elongated pectoral fin rays. Inclusive species. Nemadactylus macropterus (Forster) (type species), N. bergi (Norman), N. douglasii (Hector), N. gayi (Kner), N. monodactylus (Carmichael), N. rex Roberts, N. valenciennesi (Whitley), N. vemae (Penrith) Diagnosis. Nemadactylus can be diagnosed by the following combination of characters: dorsal-fin elements XVI���XVIII, 2 4���31; anal-fin elements III, 11���19; pectoral-fin rays 14���16 with one greatly elongated ray that extends past the origin of the anal-fin; body ovoid and compressed without any greatly elongated dorsal-fin spines; dorsal head profile shallow; spinous and soft dorsal-fin portions not separated by a large notch. Habitat and distribution. Widely distributed throughout the temperate Southern Hemisphere. Occur in Australia, New Zealand, South America, and oceanic islands within the Southern Ocean. Typically found on rocky reefs, or sandy habitat near rocky reefs to 400m (Kuiter 2003). Comments. Feed on a variety of benthic invertebrates. Some species targeted in both recreational and commercial fisheries. Material examined. N. bergi, ANSP 102720 [n=1, Argentina: Buenos Aires]; N. douglasii, NMV A13196 [n=5, Australia: New South Wales: Merimbula]; N. gayi, USNM 176401 [n=3], USNM 176402 [n=1]; N. macropterus, CAS 58782 [n=2, New Zealand: Wellington Harbor], NMV A21603 [n=5, Australia: Tasmania: Flinders Island], USNM 39674 [n=1]; N. valenciennesi, NMV A12627 [n=2, Australia: Victoria: Cape Duquesne], WAM P21896 [n=1, Australia: Western Australia: Esperance]., Published as part of Ludt, William B., Burridge, Christopher P. & Chakrabarty, Prosanta, 2019, A taxonomic revision of Cheilodactylidae and Latridae (Centrarchiformes: Cirrhitoidei) using morphological and genomic characters, pp. 121-141 in Zootaxa 4585 (1) on pages 134-135, DOI: 10.11646/zootaxa.4585.1.7, http://zenodo.org/record/2636292

Tarakihi (Nemadactylus macropterus) is an important fishery species with widespread distribution around New Zealand and off the southern coasts of Australia. However, little is known about whether the populations are locally adapted or genetically structured. To address this, we conducted whole-genome resequencing of 175 tarakihi from around New Zealand and Tasmania (Australia) to obtain a dataset of 7.5 million genome-wide and high-quality single nucleotide polymorphisms (SNPs). Variant filtering,FST-outlier analysis, and redundancy analysis (RDA) were used to evaluate population structure, adaptive structure, and locus-environment associations. A weak but significant level of neutral genetic differentiation was found between tarakihi from New Zealand and Tasmania (FST= 0.0054–0.0073,P≤ 0.05), supporting the existence of at least two separate reproductive stocks. No clustering was detected among the New Zealand populations (ФST< 0.001,P= 0.77). Outlier-based, presumably adaptive variation suggests fine-scale adaptive structure between locations around central New Zealand off the east (Wairarapa, Cape Campbell, and Hawke’s Bay) and the west coast (Tasman Bay/Golden Bay and Upper West Coast of South Island). Allele frequencies from 55 loci were associated with at least one of six environmental variables, of which 47 correlated strongly with yearly mean water temperature. Although genes associated with these loci are linked to various functions, the most common functions were integral components of membrane and cilium assembly. Projection of the RDA indicates the existence of a latitudinal temperature cline. Our work provides the first genomic insights supporting panmixia of tarakihi in New Zealand and evidence of a genomic cline that appears to be driven by the temperature gradients, together providing crucial information to inform the stock assessment of this species, and to widen the insights of the ecological drivers of adaptive variation in a marine species.

The distribution of morwong larvae in the southwestern Tasman Sea was investigated during autumn/early winter over three consecutive years (1992-1994). Larvae were confined to surface tows and large numbers (6-30 mm in length) were captured up to 250 km east of Tasmania (the limit of sampling). The jackass morwong (Nemadactylus macropterus) dominated samples, although larvae of the banded morwong (Cheilodactylus spectabilis) were also recorded. N. macropterus larvae were found within water masses derived from the East Australian Current (EAC) and Sub-tropical Convergence Zone (STCZ). Back-calculated spawning dates, significant differences in otolith microstructure, and inferred current patterns suggest that larvae from within each water mass originate from different spawning regions: a northern one (probably southern New South Wales and eastern Victoria) and a southern one (probably western and southern Tasmania). There was a significant positive relationship between larval age and distance offshore. Seasonal movements of the major water masses provide mechanisms that may facilitate regionally self-sustaining populations in northern and southern regions with an area of recruitment derived from both regions covering eastern Tasmania and Bass Strait. Larval distribution and advection processes suggest spatially variable levels of mixing between spawning regions. These data provide an explanation for both the lack of previously detected population sub-structuring from genetics studies and the multiple spawning population scenario suggested by otolith microchemistry studies.

Relationships between the anatomy of the endolymphatic sac, sac otoconia, sagitta and astericus of Nemadactylus macropterus (Cheilodactylidae: Teleostei) are described and the variation in opaque and hyaline zones, sulcal checks, and daily microincrement widths along different growth axes of the otolith measured. The quantitative morphology of the otolith is used to compare the different age estimation techniques for N. macropterus that are based on opaque and hyaline zones, sulcal checks, and daily microincrements. Comparison of the different methods shows that at the present state of knowledge daily microincrements present the most credible age estimation method for N. macropterus.

The jackass morwong (Nemadactylus macropterus), a commercially valuable marine fish in the Australian–New Zealand region, was surveyed for genetic variation as part of a larger project aimed at clarifying its stock structure. Mitochondrial DNA variation in 166 jackass morwong from seven southern Australian localities was examined using nine restriction enzymes. The 28 haplotypes identified gave an overall nucleon diversity of 0.671. Mean nucleotide diversity per sample was 0.458%, with a (corrected) nucleotide divergence among samples of 0.001%. There was no significant spatial patterning. Five hundred individuals from eight southern Australian localities and one New Zealand locality were examined using three restriction enzymes detecting polymorphic cut sites. The 33 haplotypes identified gave an overall nucleon diversity of 0.635. Mean nucleotide diversity per sample was 1.247%, with a (corrected) nucleotide divergence among samples of 0.002%. No differentiation was detected among the Australian localities. The New Zealand sample showed weak but significant divergence from the Australian samples. These results were similar to those from a concurrent allozyme analysis, and we conclude that there is appreciable nuclear and mitochondrial DNA gene flow among Australian localities, while the Tasman Sea separating Australia from New Zealand acts as a partial barrier.

Specimens of king tarakihi from northern New Zealand were shown to differ from specimens of tarakihi, using two genetic methods: allozymes and random amplified polymorphic DNA (RAPD). Allozyme techniques revealed fixed differences between tarakihi and king tarakihi at one locus and very different electromorph frequencies at a further three loci. There was a genetic distance of 0.35–0.39 between the two morphs. RAPD markers were generated with 10‐base oligonucleotide primers. Three out of 9 primers produced different DNA fragments in tarakihi and king tarakihi collected on the same longline, indicating that the morphs are discrete species. The two morphs could not be distinguished by conventional isoelectric focusing of muscle proteins. We conclude that the king tarakihi is a previously undescribed species found in subtropical waters of northern New Zealand.

The short-scale temporal repeatability in the structure and composition of parasite communities of Nemadactylus bergi were analyzed by comparing population and infracommunity descriptors in five samples caught off Mar del Plata, Argentina (38o 27′ S, 57o 90′ W) at intervals of 20 days. This is the first study aiming to detect relevant local or short-term processes in an area where larval endohelminths dominate the parasite assemblages and are expected to provide predictability to the communities they belong. The parasite fauna of this host species was composed by 18 species, 16 of them being endoparasites, among which larval stages accounted for most of both the number of parasite individuals found and the highest percentages of average similarity among infracommunities. The structure of parasite communities of N. bergi was, as predicted, repeatable across samples at short spatial and temporal scales and, as expected, this predictability was mainly provided by larval stages, namely Corynosoma australe and Grillotia carvajalregorum. These results imply that a single sample of N. bergi from this locality will be enough to catch the structure and intrinsic variability of their component communities in further studies aiming to compare parasite assemblages at larger spatial scales. These studies should, however, take into account the heterogeneity in the size of fish among samples, which proved to be an important confounding factor in comparisons among samples by affecting their similarity.

A morwong (Nemadactylus bergi) specimen was caught in May 2009 by a commercial trawler in Falkland Islands waters, outside its normal sub-tropical distribution. This extends its southwards range, possibly as a result of ongoing global warming.

A new nematode species, Paracapillaroides acanthocotylus sp. n., is described from the marine fish Nemadactylus bergi (Norman) (Latridae, Perciformes) from waters off Mar del Plata, Argentina (38°08'S, 57°32'W) (prevalence 81.8%, mean intensity 12.4 ± 10.3). The new species is readily distinguished from P. agonostomi Moravec, Salgado-Maldonado et Caspeta-Mandujano, 1999, the only known species of the genus, by having in both sexes a longer oesophagus in relation to total body length. Males of the new species have a shorter and more complex spicule and a markedly different morphology of the spicular sheath; the rays supporting the caudal bursa are also shorter and rounded, instead of digitiform. Furthermore, females of the new species have elevated vulval lips and longer eggs. The complex structure of both the spicule and spicular sheath is unique among all capillariids parasitizing cold-blooded vertebrates. This is the first record of a species of Paracapillaroides in the southwestern Atlantic Ocean. Fil: Rossin, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Rubberlip morwong Nemadactylus douglasii are important members of temperate reef communities off south-eastern Australia where they are targeted by offshore commercial and recreational fisheries. Macroscopic gonad staging and gonadosomatic indices demonstrated that N. douglasii have a distinct autumn/winter spawning period. Males and females attained sexual maturity at approximately 24 cm fork length, corresponding to an age of approximately 3 years old. During the spawning period male gonadosomatic index values were of an order of magnitude smaller than those for females, suggesting that N. douglasii may belong to the group of cheilodactylids that are not group spawners. The method of counting opaque zones in sectioned otoliths to estimate age was validated using marginal increment analysis. The results showed that opaque zones in the otoliths of N. douglasii were similar to other cheilodactylids in this region and formed once each year during spring/early summer. Males grew at a similar rate to females until approximately 2 years of age, after which males grew faster and attained larger sizes. The longest and oldest fish observed during the study were 52.4 cm fork length and 22 years, respectively. N. douglasii were fully recruited to the commercial fishery by 4 years of age and the fishery was dominated (>93%) by fish between 3 and 15 years of age. The age composition in landings showed evidence of variable recruitment through time. The total instantaneous mortality rate was estimated using catch curve analysis and ranged between 0.27 and 0.37 yr−1. Natural mortality was estimated as 0.14 yr−1 based on the maximum observed age. Steady declines during the past three decades in the quantities and average sizes of N. douglasii in landings suggest that the stock has been substantially depleted.

The species of Nemadactylus and Acantholatris are perciform fishes with representatives in each ocean of the Southern Hemisphere. Mitochondrial DNA sequences were obtained from all five species of Nemadactylus, two of the three Acantholatris species, and several outgroup taxa. Analysis of cytochrome b sequences placed A. monodactylus and A. gayi within an otherwise entirely Nemadactylus clade, suggesting that these genera are synonymous. The Acantholatris sequences were also very similar to those from three of the Nemadactylus species, despite their geographic separation. Analysis of D-loop sequences paralleled the cytochrome b results, but provided greater resolution of species relationships. Nemadactylus sp. and A. gayi are transoceanic sister taxa. Polytypic clades observed for N. macropterus and A. monodactylus most likely reflect incomplete sorting of mitochondrial DNA lineages. It is proposed that this group dispersed and radiated during the last 0.6–2.6 million years, and the possible mechanisms of this process are discussed.

Adults and plerocercoids of a new species of Heteronybelinia (Trypanorhyncha, Tentaculariidae) were recovered from the skate Sympterygia bonapartii (Rajiformes: Rajidae) and two species of teleosts, Raneya brasiliensis (Ophidiiformes: Ophidiidae) and Nemadactylus bergi (Perciformes: Cheilodactylidae), respectively. Heteronybelinia mattisi n. sp. differs from its congeners in its possession of a tentacular armature consisting of hooks with slight differences in size and shape on opposite surfaces of the tentacle (uncinate with rounded bases on the bothrial surface and uncinate with elongate bases on the antibothrial surface), without a characteristic basal armature, hooks increasing in size toward the tip of the tentacles, and pars bothrialis slightly overlapping with bulbs. The description of Heteronybelinia is emended regarding the distribution of testes to include species without postovarian testes (H. palliata and H. mattisi), and without testes anterior to cirrus sac on the poral side (H. robusta and H. mattisi). Host data are summarized for all 15 valid species of Heteronybelinia. Host specificity of adults and plerocercoids of Heteronybelinia is variable among species, the adults being more host specific than the plerocercoids. With the exception of H. mattisi, the definitive hosts of all species of Heteronybelinia for which adults are known include carcharhiniform sharks. Heteronybelinia mattisi seems to have oioxenous specificity for its definitive batoid host, S. bonapartii, and to be more specific for the intermediate hosts than most of its congeners.

Instituto de Investigaciones Oceanologicas,FAREMAR, Universidad de Antofagasta, CasillaPostal 170, Antofagasta, Chile *Departamento deParasitologia Animal, Universidade Federal Rural doRio de Janeiro, Caixa Postal 74508, 23851-970Seropedica, RJ, BrasilKey words: monogenea - marine fishes - ecology -habitat segregation

Depth-stratified random demersal trawl surveys of the shelf of southern and eastern Tasmania from summer 1993 to summer 1995 showed seasonal variations in abundance of N. macropterus in all depth strata, although the trend varied between years, with abundance peaking in summer 1993 and winter 1994. This variation is attributed to the seasonal movement of fish from south-eastern Tasmanian shelf waters, although some seasonal change in size composition is also evident. Catch rates were highest on the outer shelf and lowest on the inner shelf, reflecting the distinct size-structuring, with juveniles concentrated on the inner and mid shelf and mature fish on the outer shelf. Size compositions differed among shelf regions, with few mature fish on the mid shelf of Storm Bay compared with the same stratum on the east coast, indicating that the bay is primarily a nursery area for the species. Settlement from the pelagic post-larval phase occurred in spring and early summer at 7–9 cm, with evidence of movement between inner-and mid-shelf strata by autumn. Abundance of 0+ fish was highest in 1993 and 1994 and a considerable decrease in the abundance in both regions in 1995. The influences of local hydrography and the large size at settlement are discussed.

Transverse sections of sagittae were examined. The first and second annual increments were defined by examination of the progression of otolith radius and length of the 0+ and 1+ cohorts. Growth in both sexes is rapid until ~5 years old (32–35 cm), and then slows appreciably. There was a broad range of lengths within individual age-classes, with a maximum of 12 age-classes present in a 1 cm length-class. Maximum ages of males and females were 41 and 30 years, respectively, which is considerably higher than previously estimated from whole otoliths. There was no significant difference in the growth curves between males and females, although this is influenced by the large number of juveniles and by the examination of relatively few large, older fish. The sex-specific von Bertalanffy growth parameters are: L∞ 38.4 cm FL, t0 –0.07 years, K 0.36 year–1 for females and L∞ 36.2 cm FL, t0 0.15 years, K 0.42 year–1 for males. The age composition was dominated by 4–7 year olds but showed evidence of considerable recruitment variability, particularly in the strong 1988 year-class. The relationship between the life-history strategy of N. macropterus and recruitment variability is discussed.

Adults and plerocercoids of a new species of Heteronybelinia (Trypanorhyncha, Tentaculariidae) were recovered from the skate Sympterygia bonapartii (Rajiformes: Rajidae) and two species of teleosts, Raneya brasiliensis (Ophidiiformes: Ophidiidae) and Nemadactylus bergi (Perciformes: Cheilodactylidae), respectively. Heteronybelinia mattisi n. sp. differs from its congeners in its possession of a tentacular armature consisting of hooks with slight differences in size and shape on opposite surfaces of the tentacle (uncinate with rounded bases on the bothrial surface and uncinate with elongate bases on the antibothrial surface), without a characteristic basal armature, hooks increasing in size toward the tip of the tentacles, and pars bothrialis slightly overlapping with bulbs. The description of Heteronybelinia is emended regarding the distribution of testes to include species without postovarian testes (H. palliata and H. mattisi), and without testes anterior to cirrus sac on the poral side (H. robusta and H. mattisi). Host data are summarized for all 15 valid species of Heteronybelinia. Host specificity of adults and plerocercoids of Heteronybelinia is variable among species, the adults being more host specific than the plerocercoids. With the exception of H. mattisi, the definitive hosts of all species of Heteronybelinia for which adults are known include carcharhiniform sharks. Heteronybelinia mattisi seems to have oioxenous specificity for its definitive batoid host, S. bonapartii, and to be more specific for the intermediate hosts than most of its congeners.