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Freshwater-limited fish populations are often tightly constrained by river drainage boundaries. As a case in point, the distribution of lineages within New Zealand's diverse Galaxias vulgaris complex is broadly structured by geographic barriers, reflecting tectonic processes. However, several drainages of the Central Otago region have been locally modified by past gold-mining activities, with artificial water races connecting formerly isolated headwaters of distinct river drainage systems. Here we synthesise published genetic data to highlight the role of anthropogenic catchment modification in redistributing fish diversity. These data show that several local phylogeographic anomalies for stream-resident Galaxias fishes are closely linked to anthropogenic connections across major drainage divides. While these anthropogenic translocations may parallel natural geologically-driven mixing events that occur on deeper time scales, they nevertheless have potential conservation implications given the increasing fragmentation of native fish populations. Our review also highlights the role of sub-catchment units in shaping the hierarchical structure of intraspecific biodiversity. [ABSTRACT FROM AUTHOR]

We integrate multidisciplinary observations to provide a regional-scale synthesis of river drainage reconfiguration in Southland (New Zealand) between the Miocene and the Holocene. Distributions of sedimentary clasts, including alluvial gold, garnets and chromite, are combined with freshwater fish genetics, surface geomorphology, and basement geology to constrain river drainage directions and interconnections through time. River evolution in much of the South Island has been dominated by localised tectonic uplift linked to distant Alpine Fault tectonism. In the southeast, the rise of ranges between Central Otago and Southland severed initial long-distance southward drainage and gold transport and isolated fish species. Plio-Pleistocene range uplift caused the recycling of older alluvial gold deposits into the new Southland river systems. The most significant Southland drainage reorientations have occurred through the Pleistocene, in parallel with similar processes in Central Otago. In particular, the Pomahaka River has evolved geomorphologically from a Southland-linked catchment to become a major tributary of the Clutha catchment, with associated biological evolution of distinctive endemic freshwater fish. [ABSTRACT FROM AUTHOR]

Late Holocene earthquake activity on the reverse Akatore Fault of southeastern South Island has caused uplift along >20 km of nearby coastline, with the last major earthquake event c. 800 years ago. Fault-related uplift has exposed a prominent rocky and sandy terrace along the coastline. We used a combination of approaches including land-based observations, LIDAR remote sensing, and radiocarbon dating of shell deposits, to reveal the extent and nature of past uplift in the region. Cumulative uplift of this terrace varies laterally from <1 m at the northern and southern ends to possibly exceed 5 m in the central portion. The coastal terrace lies below a steep fossil sea cliff. Caves at the base of this cliff contain shells with radiocarbon ages <500 years old, implying persistence of large wave incursion right across the terrace after uplift. A major uplift event of ∼2 m along the whole 20 km of shoreline caused extirpation of some intertidal kelps that now have genetically distinct lineages in the uplift zone. [ABSTRACT FROM AUTHOR]

Island ecosystems can be severely affected by climate change as they provide limited opportunities for species to track their habitat. Studying the population dynamics of keystone species from these ecosystems can shed a light on climate – ecosystem interactions. Southern beeches are such keystone species in New Zealand with beech forests constituting the most abundant forest cover on the two main islands. Here we use 2.4 kilobase pairs of chloroplast genetic markers from four species of southern beech across their geographic distribution to help elucidate the Pleistocene history of New Zealand forests, and the processes that led to the present-day distribution of southern beech diversity. Broadly concordant phylogeographic patterns were observed across all beech species analysed. The centre of genetic diversity in silver beech was in the northern South Island, with unique haplotypes in the southern South Island, and southern and northern North Island, separated by known 'beech gaps'. Significantly less genetic diversity was evident in the subgenus Fuscospora (red, hard, black/mountain beech). All three species shared a single haplotype in the southern South Island, and a unique haplotype north of the central South Island 'beech gap'. Our study indicates that the present-day distribution of southern beech diversity in New Zealand is largely a result of Plio-Pleistocene environmental changes, with survival in cryptic southern South Island and multiple North Island in situ microrefugia throughout recent glacial cycles. By contrast, the northern South Island was likely the only New Zealand region that supported large (silver) beech populations throughout the Pleistocene. With beech species in New Zealand being keystone forest species, the distribution of the genus throughout the Pleistocene provides a proxy for forest cover at different times. It helps understand the ecological challenges the New Zealand forest fauna and flora were exposed to during the climate oscillations of the ice ages. [ABSTRACT FROM AUTHOR]

A new wing-reduced species of the stonefly genus Zelandoperla Tillyard is described from Otago, New Zealand. Zelandoperla maungatuaensis sp. n. differs from a related species, Z. denticulata, primarily by lacking full wing development. We used morphological, geographical, and genetic evidence to assess the proposed status of Z. maungatuaensis sp. n. and Z. denticulata as separate monomorphic species, as opposed to conspecific members of a polymorphic species. High genetic divergence was found between distinctly allopatric populations, supporting the status of Z. maungatuaensis sp. n. as a distinct monomorphic species. [ABSTRACT FROM AUTHOR]

Stenoperla helsoni is an endemic New Zealand stonefly characterised by distinctive sexually dimorphic wing loss. Previous distribution records indicated that this species was restricted to the South Island's Southern Alps, although our recent collections of wing-reduced specimens from a site in the Tararua Ranges suggest that this species may extend into the lower North Island. We amplified the mitochondrial COI gene to confirm the identity of North Island specimens, and to assess phylogeographic structuring within the species and genus. North Island specimens were confirmed as S. helsoni, indicating that this species has a much wider geographic range than previously thought. This broad distribution, combined with low levels of intraspecific divergence, suggests that female S. helsoni may be strong fliers, despite males being flightless. Distinct North Island and South Island populations were identified, with a 1.5% divergence between the two populations. [ABSTRACT FROM AUTHOR]

Recent genetic analyses have revealed evidence for the existence of two distinct lineages of Little Penguin (genusEudyptula), one endemic to New Zealand (E. minor), and the other widespread along the coasts of Australia and south-east New Zealand (E. novaehollandiae). Here we present the first comprehensive morphometric analysis of completeEudyptulaskeletons. We show that variability inEudyptulabody and bill size is associated with sea surface temperature gradients, suggesting that thermoregulatory processes underpin morphological variation in these seabirds. More importantly, we detect osteological differentiation between New Zealand and Australian specimens, providing further support for the taxonomic separation of these behaviourally and genetically distinct lineages. Broadly, our study shows the value of multivariate osteological analyses in helping to resolve the status of genetic lineages that appear morphologically ‘cryptic’ when considering external morphometrics and plumage features alone. [ABSTRACT FROM AUTHOR]

Plecoptera (stoneflies) are an anciently derived order of freshwater insects with two divergent suborders Antarctoperlaria in the southern hemisphere and Arctoperlaria primarily in the northern hemisphere. In this paper, we present the first published mitochondrial genome of an Antarctoperlarian stonefly: the New Zealand stonefly Zelandoperla fenestrata. The Z. fenestrata mitochondrial genome is 16,385 bp, with the typical insect mitogenome complement of 13 protein-coding genes, 22 tRNAs, and two rRNA genes, along with a A + T rich control region. This mitogenome will be of interest to the study of evolutionary divergence within Polyneoptera, and will aid in phylogeographic studies of this species. [ABSTRACT FROM AUTHOR]