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Context Knowledge on movement patterns within marine fish populations are essential for understanding key aspects of their biology, distribution and stock structure. Many deep-sea fish species possess complex life-history patterns with distributions occurring across vast areas. The nature of connectivity at different life-history stages in a dynamic Patagonian toothfish population on the Patagonian Shelf, Slope and deep-sea plateau around the Falkland Islands remains speculative. Aims We aimed to elucidate the movement patterns as well as the extent that these are driving connectivity during the adult life-history stages of Patagonian toothfish in the region. Methods A 5+-year tag–recapture program was executed and data were analysed using generalised additive models. Key results The majority of individuals (77.59%) displayed high site fidelity (120 cm) fish inhabiting the slope and deep-sea plains (north of 52°S) undertaking southward (direction = 150–240°) home-range relocations to spawning areas. Conclusions and implications The results provide compelling evidence to a single Patagonian toothfish metapopulation, with important considerations in terms of the spawning stock dynamics, and the development of regional management agreements across their Patagonian distribution.

In light of their life-history characteristics, deep-sea fishes display a higher vulnerability to overfishing than most other groups of fish, and their exploitation may not be sustainable even at low levels. In the Falkland Islands, increasing efforts have been made to target deep-sea species, such as the ridge-scaled grenadier Macrourus carinatus, in the waters off the continental slope. Research findings relating to the age and growth of this species remain conflicting, largely as a result of non-representative sampling of the population, inappropriate ageing methods, and the absence of age validation. We show how M. carinatus display life-history characteristics typical of the deep-water fish community, such as a long life (53 years), late age at maturity (females = 14.00 years; males = 12.28 years), slow growth and low levels of natural mortality (females = 0.104 year−1; males = 0.117 year−1) that highlight the susceptibility of M. carinatus to overfishing. In particular, validated age estimates obtained using improved ageing criteria indicate that longevity is up to 28 years greater than previously reported estimates. M. carinatus were shown to be sexually dimorphic in size, with females growing larger (females = 31.49 cm pre-anal length [PAL]; males = 24.97 cm PAL) compared to males. Updated biological parameter estimates indicate M. carinatus are far more vulnerable to fisheries exploitation than previously thought. A precautionary approach must be followed and conservation measures put in place to ensure sustainable management of a directed fishery or bycatch of M. carinatus and other similar deep-sea species.

Although many factors have been identified and used to enhance the iPSC reprogramming process, its efficiency remains quite low. In addition, reprogramming efficacy has been evidenced to be affected by disease mutations that are present in patient samples. In this study, using RNA-seq platform we have identified and validated the differential gene expression of five transcription factors (TFs) (GBX2, NANOGP8, SP8, PEG3, and ZIC1) that were associated with a remarkable increase in the number of iPSC colonies generated from a patient with Parkinson's disease. We have applied different bioinformatics tools (Gene ontology, protein–protein interaction, and signaling pathways analyses) to investigate the possible roles of these TFs in pluripotency and developmental process. Interestingly, GBX2, NANOGP8, SP8, PEG3, and ZIC1 were found to play a role in maintaining pluripotency, regulating self-renewal stages, and interacting with other factors that are involved in pluripotency regulation including OCT4, SOX2, NANOG, and KLF4. Therefore, the TFs identified in this study could be used as additional transcription factors that enhance reprogramming efficiency to boost iPSC generation technology.

Diet analysis can provide an insight into the structure and function of an ecosystem, and can be used in ecosystem-based frameworks to inform management and conservation decisions. Diet composition...

An understanding of the mechanisms that determine host and parasite relationships is a central aim in parasitology. Association of a parasite species with a host species may be influenced primarily by phylogenetic constraints that cause parasite species to co-speciate with their host species, or predominantly by ecological parameters that influence all other co-evolutionary scenarios. This study aimed to investigate the role of co-speciation as well as other co-evolutionary scenarios in influencing the assemblages of tapeworm parasites (marine cestodes) in skate hosts (Rajiformes) using a modification of the PACo (Procrustean Approach to Cophylogeny) method. The study found that phylogeny and host ecology are both significant predictors of skate–tapeworm relationships, implying that co-speciation as well as other co-evolutionary scenarios are shaping these associations. The study also investigated the key ecological parameters influencing host-switching and found that host diet, distribution depth, average body size and geographical location have a combined effect. Given the importance of parasites in ensuring healthy and stable marine ecosystems, the findings of this study have implications for conservation management worldwide.

As a part of a comprehensive survey of macroparasites of commercially exploited fish species off the coast of Otago, New Zealand, the parasite fauna of the New Zealand sole Peltorhamphus novaezeelandiae Günther was recently studied. Steringotrema robertpoulini n. sp. is described from this host and compared with known species of Steringotrema Odhner, 1911. The new species is readily distinguished from all of its congeners, except for S. divergens (Rudolphi, 1809) Odhner, 1911, by having the follicular vitellarium divided in four zones rather than two, and can be differentiated from S. divergens mainly by the posterior extent of the intestinal caeca in the hindbody, as well as by host association and geographical distribution. DNA sequences of the 28S ribosomal gene were generated and phylogenetic analyses were undertaken using maximum likelihood and Bayesian inference to assess the phylogenetic position of the new species within the family Fellodistomidae Nicoll, 1909. Analyses included the available sequences for 14 species of the family distributed among eight genera, along with nine species of other members of the order Plagiorchiida La Rue, 1957 as outgroups. The resulting topology shows that the new species of Steringotrema is nested as the sister species of Steringophorus dorsolineatus (Reimer, 1985) Bray, 1995. However, low nodal support indicates that relationships among these species are not fully resolved and require further revision and denser taxon sampling for more detailed molecular work. More information is required to draw further conclusions about the taxonomic status of the genera Steringotrema and Steringophorus Odhner, 1905.

The notothenid Patagonotothen ramsayi is one of the most abundant fin fish species on the Patagonian Shelf and it is an important prey species and central to the trophic ecology of the shelf ecosystem of the region. 353 otoliths and the parasites analysed from 80 fishes collected in January 2010, and 2004 and 2006, respectively, from the Falkland Islands Shelf and in an area north of the Falkland Islands on the high seas, were used to gain insights into the stock discrimination using elemental signatures and parasitology. Multivariate analyses (Quadratic Discriminant Function Analysis (QDFA)) of trace elements in the edges of the otolith was extremely well resolved indicating samples taken from the southern (SS), northern Falkland Islands shelf (NS) and the high seas (HS) to the north are clearly separated. Analyses of the otoliths cores were less well resolved, but showed good separation. However, there was overlap with the samples taken on the SS / NS, NS / HS, but no overlap between the samples taken on the SS / HS, indicating some intermixing during larval dispersal. Univariate and multivariate analyses of parasite communities showed a clear separation of samples taken from the SS and HS. In addition, this study has added to the biogeography and knowledge of host specificity of the parasites inhabiting the Patagonian Shelf. Our results demonstrate that the multi-pronged approach of using both otolith trace elemental analyses and parasites can be a powerful tool to resolve stock discrimination in P. ramsayi.

Understanding the spatial and temporal dynamics in marine fish populations is essential for the development of effective adaptive management strategies. Many marine fish species undergo ontogenetic shifts in abundance, with the utilization of productive shelf-based habitats during early life-history stages. For instance, in the shelf ecosystem around the Falkland Islands, a dynamic Patagonian toothfish population undertakes an early life-history ontogenetic migration after recruitment from spawning areas off southern Chile and the Burdwood Bank. To better understand the spatial-temporal dynamics for this species, Bayesian species distribution models were used to (1) identify oceanographic drivers of recruitment success; (2) assess the spatial-temporal distribution patterns; and (3) describe the habitat preferences and ecological interactions during a six-year study period (2015–2020) on the Patagonian Shelf. The presence of seasonal mesoscale eddies linking the Sub-Antarctic Front with the Falkland Current appear to be of primary importance for the survival of toothfish eggs and larvae on the shelf after transport from offshore spawning areas over the Burdwood Bank and southern Chile. Results indicate persistent recruitment hotspots for newly-settled Patagonian toothfish to the north-east, along with opportunistic areas to the south and west of the Falkland Islands, coinciding with the main areas of upwelling and high productivity. During years of low recruitment, juveniles are largely constrained to sheltered inshore regions to the north-west of the Falkland Islands. Spatial distribution patterns during post-settlement ontogenetic migrations are progressive, characterised by age-structured hotspots that differ according to depth, current velocity, oxygen, mixed-layer thickness, the abundance of competitors (icefish – Champsocephalus esox) and prey (rock cod – Patagonotothen ramsayi). The temporal shift in the range and intensity of hotspots is linked to levels of recruitment and subsequent cohort strength, which in turn appears to be driven by oceanographic processes. Understanding the environmental influences on recruitment dynamics is a key step in assessing connectivity within these discrete spatial groups on the Patagonian Shelf, and how their variability can influence the adult population over time.

Despite the fact that tapeworms comprise the bulk of parasite communities of sharks in marine ecosystems, little is known about their life cycles and, more specifically, about the potential intermediate hosts they utilize as transmission routes. In the absence of morphological features required for specific identification of larval tapeworms from potential intermediate hosts, recent molecular advances have contributed to linking larval and adult parasites and, in some instances, uncovering unknown trophic links. Host–parasite checklists are often the first source of information consulted to assess the diversity and host specificity of parasites, and provide insights into parasite identification. However, these host–parasite checklists are only useful if they encompass the full spectrum of associations between hosts and parasites. A checklist of New Zealand fishes and their parasites has been published, but recent parasitological examinations of commercial fish species reveal that the checklist appears to be far from complete. We focused our current study on a comprehensive survey of macroparasites of a commercial species, the New Zealand sole (Peltorhamphus novaezeelandiae) off the coast of Otago, New Zealand. Specifically, we were expecting to recover marine tapeworms using sharks as their definitive hosts that are generally underreported in parasite surveys. The parasites recovered included tapeworms, flukes, round worms and thorny-headed worms. Surprisingly, a large proportion of the non-tapeworm parasites we recovered were not previously reported from this fish species. A discussion on the potential ecological roles played by this fish species in the transmission of parasites is included.

Despite their very different historical origins as scientific disciplines, parasitology and marine ecology have already combined successfully to make important contributions to our understanding of the functioning of natural ecosystems. For example, robust assessments of the contribution of parasites to ecosystem biomass and energetics, and of their impact on community-wide biodiversity and food web structure, have all been made for the first time in marine systems. Nevertheless, for the marriage between parasitology and marine ecology to remain fruitful, several challenges must first be overcome. We discuss seven such challenges on the road to a greater synergy between these disciplines: (1) Raising awareness of parasitism as an ecological force by increasing the proportion of articles about parasites and diseases in marine ecology journals; (2) Making greater use of theory and conceptual frameworks from marine ecology to guide parasitological research; (3) Speeding up or at least maintaining the current rate at which marine parasites are found and described; (4) Elucidating a greater proportion of life cycles in all major groups of marine parasites; (5) Increasing the number of host–parasite model systems on which our knowledge is based; (6) Extending parasitological research offshore and into ocean depths; and (7) Developing, as needed, new epidemiological theory and transmission models for the marine environment. None of these challenges is insurmountable, and addressing just a few of them should guarantee that parasitology and marine ecology will continue to join forces and make further substantial contributions.

This study examines the use of peer review in an undergraduate ecology programme, in which students write a research proposal as a grant application, prior to carrying out the research project. Using a theoretical feedback model, we compared teacher and student peer reviews in a double blind exercise, and show how students responded to feedback given by each group. In addition, students wrote a rebuttal for every feedback point before re-drafting and submission. Despite students claiming they could tell if the reviewer was a teacher or student, this was not always the case, and both student and teacher feedback was accepted on merit. Analysis of feedback types and rebuttal actions showed similar patterns between students and teachers. Where teachers differed slightly was in the use of questions and giving direction. Interviews with students showed the rebuttal was a novel experience, because it required a consideration of each comment and justification as to why it was accepted, partially accepted...

Most parasites from known host species are yet to be discovered and described, let alone those from host species not yet known to science. Here, we use tapeworms of elasmobranchs to identify factors influencing their discovery and explaining the time lag between the descriptions of elasmobranch hosts and their respective tapeworm parasites. The dataset included 918 tapeworm species from 290 elasmobranch species. Data were analysed using linear mixed-effects models. Our findings indicated that we are currently in the midst of the greatest rate of discovery for tapeworms exploiting elasmobranchs. We identified tapeworm size, year of discovery of the type host, host latitudinal range and type locality of the parasite influencing most on the probability of discovery of tapeworms from elasmobranchs and the average time lag between descriptions of elasmobranchs and their tapeworms. The time lag between descriptions is decreasing progressively, but, at current rates and number of taxonomic experts, it will take two centuries to clear the backlog of undescribed tapeworms from known elasmobranch species. Given that the number of new elasmobranch species described each year is on the rise, we need to re-assess funding strategies to save elasmobranchs (and, thus, their tapeworm parasites) before they go extinct.

Parasites are important components of natural systems, and among their various roles, parasites strongly influence the flow of energy between and within food webs. Over 1000 tapeworm species are known to parasitise elasmobranchs, although full life cycles are resolved for fewer than 10 of them. The lack in resolution stems from the inability to distinguish larval from adult stages using morphology alone. Molecular elucidation of trophic transmission pathways is the next step in understanding the role of hosts and parasites within food webs. We investigated the parasite assemblage of New Zealand’s rough skate, Zearaja nasuta. Skates and their prey items (obtained from the skates’ stomachs) were dissected for the recovery of adult and larval tapeworms, respectively. A fragment of the 28S rDNA region was amplified for worm specimens with the aim to confirm species identity of parasites within rough skates and to uncover trophic transmission pathways that exploit the predation links between rough skates and their prey. We identified seven species of tapeworms from four tapeworm orders. Four trophic transmission pathways were resolved between three prey items from skates stomachs and skates, and one pathway between larval tapeworm sequence from a New Zealand sole and skate, i.e. a genetic match was found between larval tapeworms in prey and adult worms in skates. We report the first case of an adult trypanorhynch parasitising rough skate. These findings contribute to our limited understanding of cestode life cycles as well as providing insights into the importance of predator-prey relationships for parasite transmission.