Sinployea kaipara

Family	Charopidae
Authority	Climo, Mahlfeld & Roscoe, 2025
Threat status	Proposed in 2025, see Conservation below
Shell	Shell small, thin, and fragile, 2.2 mm wide and 1.22 mm high at three whorls, moderately finely ribbed, loosely coiled, narrowly umbilicate and low spired (spire 250 μm high).

Distribution

Sinployea kaipara is known only from two sites north of Auckland, which are ~ 20 km apart. Considering the distributions of the other Sinployea species in the Northland and Auckland area, it is likely that S. kaipara is restricted to the Kaipara area.

Habitat

Sinployea kaipara is known only from forests dominated by kauri (Agathis australis (D.Don) Lindl. ex Loudon).

The name

After Kaipara district, north of Auckland.

Conservation

North Island collections of land snails are shown in Figure 2; only two of those have produced shells of S. kaipara. The species has not been re-collected since the mid-1980s. A collecting trip made by K.M. and D.J.R. in kauri forest near Kaukapakapa in September 2015 was not successful in detecting this species. There is no information available on population size or trend. Most northern NZ Sinployea species occur in very low numbers and are rarely collected, and it appears that this species occurs in low numbers at few localities in the Kaipara area. Any impact of the current kauri dieback (caused by Phytophthora agathidicida) on land snail diversity and on this particular species is unknown. It is 37 years since the species was last found. Because it was not collected in any of the other samples taken from the area, and because many Sinployea species are allopatric, it seems most likely that this species occurs in a few small, scattered populations and is a naturally uncommon Kaipara endemic. The last assessment (2010 NZTCS panel meeting; Mahlfeld et al. 2012) ranked this species as ‘Data Deficient’, with the qualifier ‘one locality’ (OL). A change in ranking from ‘Data Deficient’ to ‘Naturally Uncommon’, with the qualifiers ‘Data Poor: Size and Trend’ and ‘Biologically Sparse’, is therefore proposed here. A further change to ‘Nationally Critical’ might follow, if further surveys fail to detect this species.

Sources

• Described in: Mahlfeld, K., Climo, F. & Roscoe, D. (2025). Systematics, conservation status, and biogeography of 16 new species of Sinployea Solem, 1983 (Gastropoda: Charopidae) from New Zealand. Zoological Journal of the Linnean Society 204(1). Publication details
• Treatment on Plazi (CC0). Distribution, habitat, name and conservation text are quoted from it.

This record was compiled from published, public data. A full factsheet for this species has not been written yet.