Maoristylus ambagiosus

This snail has a large (43–97 millimetres or 1.7–3.8 inches long)^[6] shell, which is heavily calcified. The size of the adult shell is habitat dependent,^[6] but the shell shape is not plastic.^[5] Maoristylus ambagiosus is highly valued by Te Aupōuri me Ngāti Kurī (the indigenous people of northern New Zealand) as a food source, musical instrument and in the past this snail provided alarm calls at night warning of approaching invaders.^[7]

This land snail species occurs in New Zealand. It is restricted to a small fragmented area of Northland Region, including the Aupouri Peninsula and Motuopao Island.^[8] In the past local Māori moved and propagated populations of Maoristylus ambagiosus,^[9][10] so today at least three extant populations are found on old pā sites (fortified settlements), along with other species that were cultivated such as karaka (Corynocarpus laevigatus) and harakeke (Phormium tenax).^[11][12]

This snail feeds at night on fallen leaves on the forest floor.^[6] A favorite plant species is hangehange (Geniostoma ligustrifolium). Maoristylus ambagiosus needs year round moisture provided by deep leaf-litter. Eggs are laid in clutches (average 43 eggs) in the shallow hollows in the soil.^[6] The species is slow-growing with a lifespan of 10–22 years and strong site fidelity^[13] The same individual snail has been found under the same food plant for 12 years.^[6] The species is endangered due to predation from rats^[14] and birds,^[15] habitat damage by pigs and horses and competition from introduced snails.^[14]

Based on molecular phylogeny (mtDNA) and shell morphology research it was suggested in 2011 by Buckley et al.^[16] that there are no subspecies of Maoristylus ambagiosus.^[16] However, in the past, what were thought to be eight extant subspecies and a number of undescribed but distinct populations, were named;^[8] six of these "subspecies" are now extinct^[17] (marked with a †); conservation statuses were given according to the New Zealand Threat Classification System for the extant taxa: "nationally critical" and "nationally endangered":^[18] At least five subspecies of Maoristylus ambagiosus can be recognised using shell shape (not size or location) of individuals snails suggesting these represented distinct populations that require protection.^[5]

• Maoristylus ambagiosus "Herangi Hill" †
• Maoristylus ambagiosus "nouvelle" - nationally endangered
• Maoristylus ambagiosus "Haupatoto" - nationally critical
• Maoristylus ambagiosus "Kauaetewhakapeke Stream" - nationally critical
• Maoristylus ambagiosus "Kohuronaki" - nationally critical
• Maoristylus ambagiosus "Poroiki" - nationally critical
• Maoristylus ambagiosus "Te Paki" - nationally endangered
• Maoristylus ambagiosus "Tirikawa" - nationally critical
• Maoristylus ambagiosus ambagiosus Suter, 1906 - nationally critical
• Maoristylus ambagiosus annectens Powell, 1938 2
• Maoristylus ambagiosus consobrinus Powell, 1938 - nationally critical
• Maoristylus ambagiosus gardneri †
• Maoristylus ambagiosus hancoxi 1
• Maoristylus ambagiosus hinemoa †
• Maoristylus ambagiosus keenorum Powell, 1938 - nationally endangered
• Maoristylus ambagiosus lesleyae †
• Maoristylus ambagiosus michiei Powell, 1951 - nationally endangered
• Maoristylus ambagiosus pandora Powell, 1951 - nationally critical
• Maoristylus ambagiosus paraspiritus Powell, 1951 - nationally endangered
• Maoristylus ambagiosus priscus †
• Maoristylus ambagiosus spiritus †
• Maoristylus ambagiosus watti Powell, 1947 - nationally critical
• Maoristylus ambagiosus whareana Powell, 1951 - nationally critical
• Maoristylus ambagiosus worthyi †