Genetic divergence of three freshwater isopod species from southern New Zealand

Aim We examined the biogeography of three freshwater isopod species (Austridotea annectens, A. lacustris, A. benhami), and tested the hypotheses that genetic differences would: (1) exist between geographic locations; and (2) correspond to known geological events (e.g. appearance of islands leading to the availability of habitat). Location Southern New Zealand, including South Island, Stewart Island, Campbell Island and Chatham Islands. Methods We examined specimens throughout the known species range from 12 populations of A. lacustris, five populations of A. annectens, and three populations of A. benhami, using mitochondrial DNA (cytochrome c oxidase I) sequence analyses. Results We resolved three main clades corresponding to the three species, with 16% sequence divergence between A. annectens and A. benhami, and 31% divergence between these species and A. lacustris. Divergence within A. benhami was < 2.0%. However, divergence within A. lacustris reached up to 10% with four main groupings: (1) Chatham Islands; (2) Campbell Island; (3) Fiordland; and (4) east coast South Island and Stewart Island. Divergence within A. annectens reached up to 4.4%, with two main groupings: (1) Chatham Islands and (2) east coast South Island and Stewart Island. Patterns of genetic divergence were most likely the result of geographical isolation among A. lacustris and A. annectens populations. In particular, the divergence of A. lacustris and A. annectens on Chatham Islands may correspond to the availability of this habitat c. 4 Ma, whereas the divergence of A. lacustris on the much older Campbell Island and in Fiordland may indicate either a rare founder event or a change in ocean circulation that resulted in their isolation from a once more widespread gene pool. Main conclusions The three New Zealand species of Austridotea are genetically distinct, with up to 31% divergence between species. Genetic variability was highest between populations of the two most widely distributed species, and divergence was greatest on islands distant from mainland New Zealand and in the discrete Fiordland region. The magnitude of genetic divergence of isopods on the Auckland and Chatham Islands is consistent with these populations having been founded in the Pliocene via oceanic dispersal from mainland New Zealand.     

Crossing the Tasman Sea: Inferring the introduction history of Litoria aurea and Litoria raniformis (Anura: Hylidae) from Australia into New Zealand

Abstract The amphibian fauna of New Zealand consists of three native species (Leiopelma spp.), and three Litoria species introduced from Australia in the last 140 years. We conducted a molecular phylogeographical study that aimed to identify the Australian origins of two species, Litoria aurea and Litoria raniformis. We used partial sequences of the mitochondrial cytochrome oxidase I (cox1) gene from 59 specimens sampled from across the range of both species to identify the probable source populations for the New Zealand introductions, and to describe the current genetic diversity among New Zealand Litoria populations. Our genetic data suggest that L. aurea was introduced into the North Island of New Zealand from two regions in Australia, once from the northern part of coastal New South Wales and once from the southern part of coastal New South Wales. Our data indicate that L. raniformis introductions originated from the Melbourne region of southern Victoria and once established in the South Island of New Zealand, the species subsequently spread throughout both islands. In addition, we found a distinct haplotype in L. raniformis from Tasmania that strongly suggests, contrary to earlier reports, that this species was not introduced into New Zealand from Tasmania. Finally, we identified two very distinctive mitochondrial lineages of L. raniformis within the mainland Australia distribution, which may be previously unrecognized species.     

Mitochondrial DNA structure and colony expansion dynamics of New Zealand fur seals (Arctocephalus forsteri) around Banks Peninsula

New Zealand fur seals are one of many pinniped species that survived the commercial sealing of the eighteenth and nineteenth centuries in dangerously low numbers. After the enforcement of a series of protection measures in the early twentieth century, New Zealand fur seals began to recover from the brink of extinction. We examined the New Zealand fur seal populations of Banks Peninsula, South Island, New Zealand using the mitochondrial DNA control region. We identified a panmictic population structure around Banks Peninsula. The most abundant haplotype in the area showed a slight significant aggregated structure. The Horseshoe Bay colony showed the least number of shared haplotypes with other colonies, suggesting a different origin of re-colonisation of this specific colony. The effective population size of the New Zealand fur seal population at Banks Peninsula was estimated at approximately 2500 individuals. The exponential population growth rate parameter for the area was 35, which corresponds to an expanding population. In general, samples from adjacent colonies shared 4.4 haplotypes while samples collected from colonies separated by between five and eight bays shared 1.9 haplotypes. The genetic data support the spill-over dynamics of colony expansion already suggested for this species. Approximate Bayesian computations analysis suggests re-colonisation of the area from two main clades identified across New Zealand with a most likely admixture coefficient of 0.41 to form the Banks Peninsula population. Approximate Bayesian computations analysis estimated a founder population size of approximately 372 breeding individuals for the area, which then rapidly increased in size with successive waves of external recruitment. The population of fur seals in the area is probably in the late phase of maturity in the colony expansion dynamic.     

Larval horsehair worms (Nematomorpha) from the tissues of native freshwater fish in New Zealand

Abstract

Encysted larval horsehair worms (Phylum Nematomorpha) were recovered from the tissues of upland bullies (Gobiomorphus breviceps) and a galaxiid (Galaxias vulgaris) from the Seaward River, Canterbury. The cysts were mostly in the alimentary submucosa. A few occurred in the liver. An adult digenean fluke (Coitocaecum sp.), parasitic within the gut of a bully, also contained nematomorph larvae in its tissues. It is suggested that the fish became infected by eating nematomorph larvae or egg strings.     

Phylogenetic relationships of New Zealand Asteraceae inferred from ITS sequences

Forty-five sequences from members of all genera of Asteraceae indigenous to New Zealand and 50 published sequences representing the tribal diversity in the family were analyzed to assess the utility of ITS sequences to resolve phylogenetic relationships. Previous studies using chloroplast DNA sequences and morphology provided support for several clades in the Asteraceae, yet the relationships among some of these were uncertain. The results from ITS analysis were largely consistent with these earlier studies. The New Zealand species are included in at least six clades, most of these corresponding to recognized tribes. Our results have also clarified the tribal affinities of a few anomalous genera. Haastia, previously aligned with the Gnaphalieae or the Astereae, is nested in the Senecioneae. Centipeda, previously included in the Astereae or Anthemideae, emerges near the Heliantheae. The relationships of Abrotanella remain unresolved. Received August 8, 2001 Accepted November 6, 2001     

Epiphytic dinoflagellates in sub-tropical New Zealand,in particular the genus Coolia Meunier

Macroalgae growing in New Zealand's sub-tropical waters were sampled for epiphytic microalgae, in particular dinoflagellates. Four new Coolia isolates collected from sites throughout Northland in January/February 2013 were all identified as C. malayensis as determined by large subunit ribosomal DNA (LSU rDNA) sequence analysis and scanning electron microscopy. C. malayensis, a common dinoflagellate species in New Zealand, was previously reported as C. monotis and isolates held in the Cawthron Institute Culture Collection of Microalgae have now been reclassified based on the DNA sequence data. Toxicity studies of the New Zealand C. malayensis isolates (as determined by intraperitoneal (i.p.) injection of mice) resulted in an LD₅₀ of 80.0 mg/kg for isolate NLD 12 (95% CI: 63.8–101.0 mg/kg) compared to a Malaysian isolate which exhibited low toxicity, with transient effects at 900 mg/kg, but which resulted in the enlargement of the test animal's spleen. Ostreopsis siamensis, a common epiphytic bloom former in northern New Zealand, was found in association with Coolia at sites across Northland. Densest cell concentrations were collected from macroalgae throughout the Bay of Islands. Four new isolates of O. siamensis all produced palytoxin-like compounds (LC–MS analysis). Also isolated from Northland macroalgae were Amphidinium thermaeum (non-toxic by i.p. injection of mice) and Gambierdiscus cf. yasumotoi, with the latter producing a putative maitotoxin analogue (MTX-3) as determined by LC–MS.     

New species of Euptyctima (Acari,Oribatida) from New Zealand

Abstract

Oribotritia contortula n. sp., O. contraria n. sp., O. teretis n. sp., Rhysotritia bifurcata n. sp., Microtritia contraria n. sp., M. glabrata n. sp., Hoplophthiracarus bisulcus n. sp., Austrophthiracarus pulchellus n. sp., and Notophthiracarus claviger n. sp. are described from New Zealand.

The genera of Oribotritia Jacot, Rhysotritia Märkel & Meyer, Hoplophthiracarus Jacot, and Austrophthiracarus Balogh & Mahunka are new records for New Zealand.     

Reproductive cycling and fecundity estimation in the upland bully

The upland bully is a prolific and widespread member of New Zealand freshwater fish communities that may mature at age 1 (or earlier). It begins spawning in spring, laying as many as eight clutches of eggs over the spring and summer, at periods as brief as 13 days. Ovaries contain two modes of maturing oocytes, so that oogenesis must be continual during the spawning season. This poses difficulties in fecundity estimation, which were solved by captive rearing. The ovoid eggs are about 2 mm long; egg size declines with clutch number during the summer, but increases with fish size. Clutch size varied, in 70 spawnings, from 121 to 880 eggs, with total seasonal fecundity up to >5000 eggs. The production of multiple clutches greatly increases seasonal fecundity and may explain the success of this species in sometimes unreliable or harsh environments.     

Population structure and biogeography of Hemiphaga pigeons (Aves: Columbidae) on islands in the New Zealand region

Aim The New Zealand avifauna includes lineages that lack close relatives elsewhere and have low diversity, characteristics sometimes ascribed to long geographic isolation. However, extinction at the population and species levels could yield the same pattern. A prominent example is the ecologically important pigeon genus Hemiphaga. In this study, we examined the population structure and phylogeography of Hemiphaga across islands in the region. Location New Zealand, Chatham Islands and Norfolk Island. Methods Mitochondrial DNA was sequenced for all species of the genus Hemiphaga. Sixty‐seven individuals from mainland New Zealand (Hemiphaga novaeseelandiae novaeseelandiae), six of the Chatham Islands sister species (Hemiphaga chathamensis), and three of the extinct Norfolk Island subspecies (Hemiphaga novaeseelandiae spadicea) were included in this study. Novel D‐loop and cytochrome b primers were designed to amplify DNA from museum samples. Additionally, five other mitochondrial genes were used to examine placement of the phylogenetic root. Results Analyses of mitochondrial DNA sequences revealed three Hemiphaga clades, consistent with the allopatric populations of recognized (sub)species on oceanic islands. Of the 23 D‐loop haplotypes among 67 New Zealand pigeons (Hemiphaga n. novaeseelandiae), 19 haplotypes were singletons and one haplotype was common and widespread. Population genetic diversity was shallow within and between New Zealand populations, indicating range expansion with high inter‐population exchange. Tentative rooting of the Hemiphaga clade with cyt b data indicates exchange between mainland New Zealand and the Chatham Islands prior to colonization of Norfolk Island. We found low genetic divergence between populations on New Zealand, the Chatham Islands and Norfolk Island, but deep phylogenetic divergence from the closest living relatives of Hemiphaga. Main conclusions The data are consistent with the hypothesis of population reduction during the Pleistocene and subsequent expansion from forest refugia. Observed mobility of Hemiphaga when feeding helps explain the shallow diversity among populations on islands separated by many hundreds of kilometres of ocean. Together with comparison of distribution patterns observed among birds of the New Zealand region, these data suggest that endemicity might represent not long occupancy of an area, but descent from geologically recent colonizations. We consider the role of lineage pruning in creating the impression of old endemicity.     

Phylogeography of the New Zealand cicada Maoricicada campbelli based on mitochondrial DNA sequences: ancient clades associated with cenozoic environmental change

New Zealand's isolation, its well-studied rapidly changing landscape, and its many examples of rampant speciation make it an excellent location for studying the process of genetic differentiation. Using 1520 base pairs of mitochondrial DNA from the cytochrome oxidase subunit I, ATPase subunits 6 and 8 and tRNA(Asp) genes, we detected two well-differentiated, parapatrically distributed clades within the widespread New Zealand cicada species Maoricicada campbelli that may prove to represent two species. The situation that we uncovered is unusual in that an ancient lineage with low genetic diversity is surrounded on three sides by two recently diverged lineages. Using a relaxed molecular clock model coupled with Bayesian statistics, we dated the earliest divergence within M. campbelli at 2.3 +/- 0.55 million years. Our data suggest that geological and climatological events of the late Pliocene divided a once-widespread species into northern and southern components and that near the middle of the Pleistocene the northern lineage began moving south eventually reaching the southern clade. The southern clade seems to have moved northward to only a limited extent. We discovered five potential zones of secondary contact through mountain passes that will be examined in future work. We predict that, as in North American periodical cicadas, contact between these highly differentiated lineages will exist but will not involve gene flow.     

Chlorophyll-nutrient relationships in North Island lakes (New Zealand)

A model for the prediction of chlorophyll a in the near surface waters (1 m) of North Island lakes was developed using data from the literature and our own study of 12 North Island lakes. Annual geometric mean concentrations of chlorophyll a, total nitrogen and total phosphorus were used since no distinct growing season was discernable. Annual mean ratios of total nitrogen to total phosphorus in the near surface waters ranged between 10 and 59 (by weight). Strong correlations were obtained between log-transformed values of chlorophyll a and total nitrogen (r² = 0.53, n = 16), chlorophyll a and total phosphorus (r² = 0.71, n = 21), and between total nitrogen and total phosphorus (r² = 0.69, n = 16). However, after correcting for the high interdependency between total nitrogen and total phosphorus, only total phosphorus was found to be important in predicting chlorophyll concentrations. Much of the variance in the chlorophyll-phosphorus relation was attributable to differences in mean lake depth. Lakes with mean depths less than 11 m had significantly more chlorophyll a per unit of total phosphorus ( = 0.54 µg · µg^–1, SE = 0.05, n = 6) than lakes of greater mean depth ( = 0.17 µg · µg^–1, SE = 0.02, n = 14). When the effect of mean depth was taken into account, 89% of the variance in chlorophyll a was explained compared with 71% for the simple linear regression on total phosphorus alone.     

Calanoid copepod biogeography in New Zealand

The distribution of four calanoid copepod species of Boeckella in New Zealand are mapped and described. An explanation of their distribution patterns based on panbiogeographic methods is compared to an explanation based on dispersalist concepts. The panbiogeographic explanation is simpler, and is consistent with explanation of distribution patterns among other genera of plants, invertebrates, amphibians and birds. This revised version was published online in July 2006 with corrections to the Cover Date.     

新西兰鸟类入侵成功的有关因素

了解外来入侵物种（alien invasive species,AIS)的生物学涉及纯生物学及应用生物学的问题,但是靠预先设计的实验来加深人们的了解显然是不可能的,然而我们可以研究现有的入侵,这也是一个很好的途径,本文利用新西兰历史上的一些记录,探讨了物种在新环境中成功定居的因素,令人惊奇的是,物种间的生物学差异对成功的定居几乎没有什么作用,相反,真正起作用的是一个物种被引入新环境的频率及数量。     

Species of the genus Crotonia (Acari: Cryptostigmata) from New Zealand

Five new species of Crotonia from New Zealand ( C. cervicorna, C. cupulata, C. longibulbula, C. tuberculata and C. reticulata ) are described as new, and two species ( C. cophinana (Michael 1908) and C. caudatis (Hammer 1966)) are redescribed. Five species groups of the genus are characterized and a key to the adequately described species of the world is presented.     

Host specificity in parasitic mistletoes (Loranthaceae) in New Zealand

1. We quantify the degree of host specificity for the five extant New Zealand loranthaceous mistletoes ( Alepis flavida, Ileostylus micranthus, Peraxilla colensoi, Peraxilla tetrapetala and Tupeia antarctica ).
2. Host specificity is highest for A. flavida, P. colensoi and P. tetrapetala which primarily parasitize species of Nothofagus , and lowest for T. antarctica and especially I. micranthus which parasitize a wide range of host species.
3. These patterns of host specificity support the suggestion that relative host abundance is a key factor determining the degree of host specialization in mistletoes (resource fragmentation hypothesis). While evolutionary history may be important in the specificity of the mistletoe–host relationship in some situations, our data suggest that for New Zealand mistletoes evolutionary history simply reflects the temporal component of relative host abundance.
4. We conclude that it is the stability of host availability through time and space which is the dominant factor determining host specificity patterns.     

Hookworm infection,anaemia and genetic variability of the New Zealand sea lion

Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in the New Zealand sea lion, a threatened otariid that has low levels of genetic variability and high hookworm infection rates. Using a panel of 22 microsatellites, we found that average allelic diversity (5.9) and mean heterozygosity (0.72) were higher than expected for a small population with restricted breeding, and we found no evidence of an association between genetic variability and hookworm resistance. However, similar to what was observed for the California sea lion, homozygosity at a single locus explained the occurrence of anaemia and thrombocytopenia in hookworm-infected pups (generalized linear model, F = 11.81, p < 0.001) and the effect was apparently driven by a particular allele (odds ratio = 34.95%; CI: 7.12–162.41; p < 0.00001). Our study offers further evidence that these haematophagus parasites exert selective pressure on otariid blood-clotting processes.     

Middle and Late Jurassic terebratulides from New Zealand

Terebratulide brachiopods are found throughout the New Zealand Mesozoic, and by the Jurassic are second only to rhynchonellides in abundance and diversity. Only two species have been described from the Late Jurassic, Kutchithyris hendersoni Marwick, 1953 and Holcothyris (?) kaiwaraensis Campbell, 1965. In this study, one new genus and 14 new species are described, and three additional forms placed in open nomenclature.Nearly all the material comes from the Murihiku Terrane on the west coast of the North Island south of Auckland, and most from a small number of shellbeds with diverse faunas. Two key localities for Middle Jurassic (Bajocian–Bathonian) brachiopods are Opuatia Cliff at Port Waikato, and a quarry in the Marokopa Valley. Two species of fairly large terebratulide, Loboidothyris waitomoensis n. sp. and L. grantmackiei n. sp. are tentatively assigned to the genus Loboidothyris. A further species which may also belong to this genus, L. awakinoensis n. sp. is found in the Awakino Valley to the south. Two species of Zeilleria, Z. opuatiaensis n. sp. and Z. waiohipaensis n. sp. and one of Aulacothyris, A. waikatoensis n. sp. are also recognised. A new species of Kutchithyris, K. marokopaensis n. sp., less strongly folded than K. hendersoni, is also present.Captain King's Shellbed is a metre-thick Oxfordian shellbed that can be traced from Kawhia to the Awakino Valley. It has a rich and diverse fauna in which terebratulides are prominent. Kutchithyris hendersoni is the most abundant, followed by Crispithyris nauarchus n. gen. n. sp. The fauna also includes the same two species of Zeilleria as in the Middle Jurassic, and the costellate terebratulide Terebratulina leeae n. sp.Brachiopods are much less common in the later part of the Jurassic (Kimmeridgian and Tithonian). A further species of Kutchithyris, K. challinori n. sp., a second species of Terebratulina, T. putiensis n. sp. and one of Zeilleria (Z. sp.) are present. A rare form is the small subcircular Disculina mancenidoi n. sp. Holcothyris kaiwaraensis is known only from the Late Jurassic Pahau Terrane of North Canterbury, but a second species of Holcothyris, H. campbelli n. sp. is present in the Late Oxfordian and Kimmeridgian of the Kawhia area.Aulacothyris, Terebratulina, and Zeilleria are cosmopolitan. Kutchithyris and Holcothyris are Tethyan. Loboidothyris is more widely distributed but generally Tethyan. Disculina is described from Southern England and France, but has since been recognised in the Caucasus and Japan, and may also have a Tethyan distribution.     

新西兰果园规范化栽培技术及发展趋势

报道了新西兰水果主产区果园普遍采用的规范化栽培技术系统,包括果园布局、果树定植与枝条定向牵引、果产品全程质量管理、果园生态环境管理等技术,并分析了该技术的特点、目的和作用,对新西兰果园近年在栽培技术上的优化和创新进行了总结,提出了新西兰果园栽培的发展趋势。     

Campylobacter jejuni inactivation in New Zealand soils

AIM: The study was undertaken to determine the inactivation rate of Campylobacter jejuni in New Zealand soils. METHODS AND RESULTS: Farm dairy effluent (FDE) inoculated at c. 10(5) ml(-1) with C. jejuni was applied to intact soil cores at a rate of 2 l m(-2). Four soils were used: Hamilton (granular); Taupo (pumice); Horotiu and Waihou (allophanic). After FDE application cores were incubated at 10 degrees C for up to 32 days. For all four soils all the FDE remained within the cores and at least 99% of C. jejuni were retained in the top 5 cm. Campylobacter jejuni had declined to the limit of detection (two C. jejuni 100 g(-1)) by 25 days in Hamilton and Taupo soils and by 32 days in Waihou soil. In contrast, in Horotiu soil the decline was only three orders of magnitude after 32 days. Simulated heavy rainfall was applied 4 and 11 days after FDE application and only about 1% of the applied C. jejuni were recovered in leachates. CONCLUSIONS: This study demonstrated that at least 99% of applied C. jejuni were retained in the top 5 cm of four soils where they survived for at least 25 days at 10 degrees C. SIGNIFICANCE AND IMPACT OF THE STUDY: Soil retention of C. jejuni is efficient at FDE application rates that prevent drainage losses. The low infectious dose of C. jejuni and its ability to survive up to 25 days have implications for stock management on dairy farms.     

New species of the genus Cyamops Melander from New Zealand (Diptera, Periscelididae, Stenomicrinae)

Two new species of the genus Cyamops (Diptera: Periscelididae), the first from New Zealand, are described. The two newly described species are: Cyamops alessandrae and Cyamops crosbyi. A key to the genera of the subfamily Stenomicrinae and to the species of Cyamops from the Australasian/Oceanian Region and detailed illustrations of structures of the male terminalia are provided.