Journal Articles

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

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    A contribution to the anatomy of two rare cetacean species: The hourglass dolphin (Cephalorhynchus cruciger) and the spectacled porpoise (Phocoena dioptrica)
    (Wiley Periodicals LLC on behalf of American Association for Anatomy, 2025-10-22) Graïc J-M; Gerussi T; Cozzi B; Boys RM; Kot BCW; Perrott MR; Fleury K; Chung TYT; Tsui HCL; Burns E; Webster T; Hunter S; Betty EL; Howarth O; Loch C; White S; Dawson S; Rayment W; Cole R; Cox D; Waterhouse T; Hendriks H; van Helden A; Johnstone M; Stewart RO; Fordyce RE; Stockin KA
    The anatomical description of the hourglass dolphin (Cephalorhynchus cruciger) and the spectacled porpoise (Phocoena dioptrica) remains largely unexplored, due to limited specimen availability and preservation challenges. This study employed digital imaging techniques, conventional histology, and computed tomography to provide visualization of anatomical structures for a detailed analysis. We present a comprehensive analysis of the gross macroscopical and microscopical morphology of two hourglass dolphins and four spectacled porpoises. Morphometric measurements and skeletal characteristics aligned with the literature, while internal anatomy (organs and systems) was similar to other odontocetes. Precise and consistent lung measurements were challenging; qualitative assessments indicated relatively large lungs with respect to body size. The spectacled porpoise dorsal fin was uniquely large with a well-developed blood supply; this is hypothesized to act as a thermoregulatory window, though it may also play a role in sexual display in the case of males. Overall, this study provides new data on the anatomy of the hourglass dolphin and spectacled porpoise, contributing insights that may influence future research on these rare species. The findings highlight the importance of anatomical studies as a basis for explaining evolutionary relationships within cetaceans and their ecological roles in the Southern Ocean ecosystems.
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    Teat and udder morphology and pathology of New Zealand dairy ewes.
    (Taylor and Francis Group, 2025-02-12) Chambers G; Lawrence KE; Ridler AL; Laven RA
    AIMS: To describe the morphology and prevalence of teat and udder pathology of New Zealand dairy ewes. METHODS: A repeated cross-sectional study was conducted on 20 commercial New Zealand dairy sheep farms over the 2022-2023 season. Approximately 15 randomly selected ewes were examined on each farm in early, mid, and late lactation. Four udder morphology measures were scored on a 5-point scale: depth (1 = pendulous, 5 = compact udder), suspension (ratio of width at abdominal attachment to height, 1 = low, 5 = high), gland separation (1 = zero, 5 = maximum separation), and teat placement (1 = distally located, vertically oriented, 5 = laterally located, horizontally oriented teats). Teat length and width were measured, and the presence of supernumerary teats, asymmetry, visible teat/udder inflammation, and lesions were recorded. Teats and glands were palpated for consistency, gland-nodules, teat canal thickening, and patency, and teat ends scored for hyperkeratosis. Teat and gland-level pathological variables were converted to ewe-level scores. The presence of involuted, non- or minimally lactating glands was recorded. Data were analysed using descriptive statistics. RESULTS: Across the three visits, 893 observations were made on 882 unique ewes. Mean teat length and width were 27.5 (95% CI = 27.2-27.7) and 15.8 (95% CI = 15.7-15.9) mm. Udder depth, separation, suspension, and teat placement had modal scores of 4, 3, 3, and 3 respectively, and varied across visits and age groups. Asymmetrical udder prevalence was 39% (95% CI = 35.5-42%) overall and increased with age (27% for 1-year-olds, 38% for two-year-olds, 43% for mixed age ewes). Supernumerary teats were observed in 15% (95% CI = 13-17.9%) of ewes. There was between-farm variation in all udder morphology variables. Ewe-level prevalences of teat end hyperkeratosis (any degree of severity), gland/teat inflammation, lesions, palpable defects, and involuted glands were all < 6%. CONCLUSIONS: Morphological observations resembled those from overseas dairy sheep. Teat dimensions, udder depth, separation, suspension, teat placement, and presence of supernumerary teats varied between farms. Udder depth, separation, and suspension scores decreased with age, while teat placement score and the prevalence of asymmetry increased with age. Teat and udder pathology were rare. CLINICAL RELEVANCE: This is the first systematic study of teat and udder morphology and pathology in New Zealand dairy ewes. The data will be useful for farmers and industry partners, providing a comparison with their own flocks, identifying areas for improvement, and informing and contrasting with future studies.
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    Three new species of flat mites (Acari: Tetranychoidea: Tenuipalpidae) from alpine New Zealand
    (Acarologia, 2025-01-27) Khaustov AA; Minor MA; Auger P
    Female, male and deutonymph of Acaricis brevicaudus sp. nov., female and deutonymph of Dolichotetranychus tuberculatus sp. nov., and female of Pentamerismus corniger sp. nov. are described and illustrated from alpine cushion fields in New Zealand. Both A. brevicaudus sp. nov. and D. tuberculatus sp. nov. are associated with the cushion-forming ultra-dwarf shrub Dracophyllum muscoides Hook. f. (Ericaceae). The host plant for P. corniger sp. nov. is currently unknown. The diagnosis of Acaricis Beard and Gerson is modified. Additionally, Pentamerismus is recorded from New Zealand for the first time.
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    Cultural divergence and morphological variation of isolated remnant populations of the endangered Floreana mockingbird
    (CSIRO Publishing, 2024-07-22) Reyes EMR; Roper MM; Sevilla C; Rueda D; Brunton DH; Smith ANH; Ortiz-Catedral L; Davis R
    Context: Cultural divergence refers to changes over time in behavioural traits. These cultural changes could have important implications for conservation planning, and impact the success of conservation efforts such as translocations. Aims: Here, we investigate the extent, and potential impacts, of cultural divergence in two isolated populations of the Floreana mockingbird (Mimus trifasciatus) on the Galápagos Islands. Methods: Using contemporary recordings of vocalisations we test for spatial vocal differentiation between mockingbird populations. Furthermore, we explore the potential drivers of change using morphological measurements and historical recordings of the species. Key results: We found evidence of spatial and temporal differentiation in vocalisations between the two populations of the Floreana mockingbird. We accurately classified over 75% of the birds to the correct populations based on multivariate measures of audio recordings using canonical analysis of principal coordinates (CAP). We also found significant differences in morphometrics between populations specifically, beak depth was associated with frequency modulation, an acoustic measure that is significantly different between populations. Furthermore, we found evidence of change in the complexity of the vocalisations over a period of 57 years. Conclusions: Cultural divergence was found in the two remaining populations of this endangered species. Factors such as changes in morphology and cultural drift might have been influenced the change in vocalisation across time and populations. Implications: We highlight the importance of considering behavioural factors when planning reintroductions of endangered species where there is a need to minimise the risk of assortative mating so as to maximise genetic diversity.
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    High functional diversity in deep-sea fish communities and increasing intraspecific trait variation with increasing latitude.
    (2021-08) Myers EMV; Anderson MJ; Liggins L; Harvey ES; Roberts CD; Eme D
    Variation in both inter- and intraspecific traits affects community dynamics, yet we know little regarding the relative importance of external environmental filters versus internal biotic interactions that shape the functional space of communities along broad-scale environmental gradients, such as latitude, elevation, or depth. We examined changes in several key aspects of functional alpha diversity for marine fishes along depth and latitude gradients by quantifying intra- and interspecific richness, dispersion, and regularity in functional trait space. We derived eight functional traits related to food acquisition and locomotion and calculated seven complementary indices of functional diversity for 144 species of marine ray-finned fishes along large-scale depth (50-1200 m) and latitudinal gradients (29°-51° S) in New Zealand waters. Traits were derived from morphological measurements taken directly from footage obtained using Baited Remote Underwater Stereo-Video systems and museum specimens. We partitioned functional variation into intra- and interspecific components for the first time using a PERMANOVA approach. We also implemented two tree-based diversity metrics in a functional distance-based context for the first time: namely, the variance in pairwise functional distance and the variance in nearest neighbor distance. Functional alpha diversity increased with increasing depth and decreased with increasing latitude. More specifically, the dispersion and mean nearest neighbor distances among species in trait space and intraspecific trait variability all increased with depth, whereas functional hypervolume (richness) was stable across depth. In contrast, functional hypervolume, dispersion, and regularity indices all decreased with increasing latitude; however, intraspecific trait variation increased with latitude, suggesting that intraspecific trait variability becomes increasingly important at higher latitudes. These results suggest that competition within and among species are key processes shaping functional multidimensional space for fishes in the deep sea. Increasing morphological dissimilarity with increasing depth may facilitate niche partitioning to promote coexistence, whereas abiotic filtering may be the dominant process structuring communities with increasing latitude.