Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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Author: search.filters.author.Aguirre JDSubject: search.filters.subject.06 Biological Sciences

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    Introduced alien, range extension or just visiting? Combining citizen science observations and expert knowledge to classify range dynamics of marine fishes
    (1/07/2021) Middleton I; Aguirre JD; Trnski T; Francis M; Duffy C; Liggins L
    Aim: Despite the unprecedented rate of species redistribution during the Anthropocene, there are few monitoring programmes at the appropriate spatial and temporal scale to detect distributional change of marine species and to infer climate- versus human-mediated drivers of change. Here, we present an approach that combines citizen science with expert knowledge to classify out-of-range occurrences for marine fishes as potential range extensions or human-mediated dispersal events. Innovation: Our stepwise approach includes decision trees, scoring and matrices to classify citizen science observations of species occurrences and to provide a measure of confidence and validation using expert knowledge. Our method draws on peer-reviewed literature, knowledge of the species (e.g. contributing to its detectability, and potential to raft with, or foul, man-made structures or debris) and information obtained from citizen science observations (e.g. life stage, number of individuals). Using a case study of suspected out-of-range marine fishes in Aotearoa New Zealand, we demonstrate our approach to defining species’ ranges, assigning confidence to these definitions and considering the species detectability to overcome the data deficiencies that currently hinder monitoring the range dynamics of these species. Our classification of citizen science observations revealed that six of ten species had out-of-range occurrences; one of these was classified as an extralimital vagrant, four species had potentially extended their ranges and one species occurrence was likely due to human-mediated dispersal. Conclusion: The case study of marine fishes in New Zealand validates our approach combining citizen science observations with expert knowledge to infer species range dynamics in real time. Our stepwise approach helps to identify data deficiencies important in informing scientific inferences and management actions and can be refined to suit other data sources, taxonomic groups, geographic settings or extended with new steps and existing tools.
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    Morphological and genetic divergence supports peripheral endemism and a recent evolutionary history of Chrysiptera demoiselles in the subtropical South Pacific
    (1/06/2022) Liggins L; Kilduff L; Trnski T; Delrieu-Trottin E; Carvajal JI; Arranz V; Planes S; Saenz-Agudelo P; Aguirre JD
    The delineation of species and their evolutionary relationships informs our understanding of biogeography and how regional faunas are assembled. The peripheral geography and local environment of reefs in the subtropical South Pacific likely promotes the allopatric and adaptive divergence of taxa colonising from the tropics; however, the fauna of this region has been relatively understudied. Here, we address the taxonomic and evolutionary relationships among Chrysiptera taxa of the subtropical South Pacific. We use meristic counts, morphometrics and genetic markers to characterise the similarities and differences among four taxa restricted to the South Pacific region that have strikingly different colouration: C. notialis, a taxon restricted to eastern Australia, New Caledonia, Lord Howe Island and Norfolk Island; C. galba, found in the Cook Islands, southern French Polynesia and Pitcairn Islands; and the two disjunct populations of C. rapanui, found in the eastern Pacific around Rapa Nui (Isla de Pascua or Easter Island) and Motu Motiro Hiva (Salas y Gómez) and in the South-western Pacific around Rangitāhua (Kermadec Islands). Our morphometric analysis confirmed that these four taxa, including the two disjunct populations of C. rapanui, are morphologically distinct. However, our genetic analysis revealed that only C. rapanui from Rapa Nui was genetically differentiated, whereas C. rapanui of Rangitāhua, C. galba and C. notialis all shared a common haplotype. Furthermore, none of the taxa could be consistently differentiated based on individual meristic features. Our study reconciles a formerly perplexing and disjunct distribution for C. rapanui, to reveal that C. rapanui is an endemic of Rapa Nui and that the Chrysiptera of French Polynesia, Rangitāhua, and the South-western Pacific have only a very recent history of divergence. Our analyses suggest these subtropical taxa have diverged from a predominantly tropical Chrysiptera genus in morphological features important in determining colonisation success, locomotion and feeding ecology.