Two new species ofAndracantha(Polymorphidae) are described from the intestine of the shagsLeucocarbo chalconotus(Gray) andPhalacrocorax punctatus(Sparrman), and the penguinEudyptula minor(Forster) from southern South Island, New Zealand.Andracantha leucocarboin. sp. is distinguished from its congeners by having no genital or ventral trunk spines, but possessing a scattering of small spines between the anterior fields of spines. This is the first record of a species ofAndracanthafrom a penguin. Circumbursal papillae are illustrated in a scanning electron micrograph for the first time in the polymorphids.Andracantha sigman. sp. is distinguished by the sigmoid shape of its largest proboscis hook, hook VIII, and having the ventral field separated from the posterior disc field by an aspinous gap. A Maximum Likelihood tree fromcox1 and large ribosomal subunit (LSU) data showsA. leucocarboin. sp. to be more closely related toA. gravidathanA. sigman. sp. and the genusAndracanthaas sister toCorynosomaspp. Genetic distances between species ofAndracanthaare comparatively large. A key to the species ofAndracanthais provided.

Nematodes constitute one of the most speciose metazoan groups on earth, and a significant proportion of them have parasitic life styles. Zooparasitic nematodes have zoonotic, commercial and ecological significance within natural systems. Due to their generally small size and hidden nature within their hosts, and the fact that species discrimination using traditional morphological characteristics is often challenging, their biodiversity is not well known, especially within marine ecosystems. For instance, the majority of New Zealand's marine animals have never been the subject of nematode studies, and many currently known nematodes in New Zealand await confirmation of their species identity with modern taxonomic techniques. In this study, we present the results of an extensive biodiversity survey and phylogenetic analyses of parasitic nematodes infecting New Zealand's marine animals. We used genetic data to differentiate nematodes to the lowest taxonomic level possible and present phylogenies of the dominant clades to illustrate their genetic diversity in New Zealand. Our findings reveal a high diversity of parasitic nematodes (23 taxa) infecting New Zealand's marine animals (62 of 94 free-living animal species investigated). The novel data collected here provide a solid baseline for future assessments of change in diversity and distribution of parasitic nematodes.

Parasitic nematodes of the family Mermithidae were found to be infecting the introduced European earwig Forficula auricularia (Dermaptera: Forficulidae) in Dunedin, South Island, New Zealand. Adult females were later collected from various garden plants while depositing eggs. These mermithid specimens were identified morphologically as Mermis nigrescens Dujardin, 1842. A genetic distance of 0.7% between these specimens and a M. nigrescens isolate from Canada (18S rRNA gene), suggests that they have diverged genetically, but there are currently no available comparable sequences for the European M. nigrescens. Two additional nuclear fragments were also amplified, the 28S rRNA and the ribosomal DNA first internal transcribed spacer (ITS1), providing a basis for future studies. Bearing in mind the morphological similarity with other reported M. nigrescens and the lack of sequence data from other parts of the world, we retain the name M. nigrescens, and suggest that the species may be found to represent a complex of cryptic species when more worldwide data are available. Herein, we present a brief description of the post-parasitic worms and adult females, along with an inferred phylogeny using 18S rRNA gene sequences.

A full account of the world's species is important for understanding how natural systems are structured, how they function and how they will respond to natural and anthropogenic pressures in the future. Despite the well‐known importance of parasites in natural systems, they are too often underrepresented from studies on biodiversity and ecological functioning. In this review, we provide a quantitative synthesis of the current state of knowledge of helminth biodiversity within New Zealand's marine environment. We report that records of parasitic helminths within New Zealand marine animals are few and uneven across host taxa. A large proportion of parasite species are taxonomically unresolved, with some differences across parasite taxa. Few parasites have their whole life cycles resolved, and the majority are only reported from one host species at one life stage. Most endemic host species are yet to be investigated for helminths and there is likely an abundance of endemic parasite diversity yet to be discovered. Host species of greater conservation concern are being investigated for helminths less frequently than species of low conservation concern. We conclude that little is known about parasitic helminths in New Zealand's marine environment and make recommendations on how to improve this situation.