''Struthiolaria papulosa'', whose

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contra ...

is the ostrich foot snail or ostrich foot shell, or Tākai in

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of medium-sized sea snail native to

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

Description

''Struthiolaria papulosa'' has an average body length of 77 mm, a body volume of 26.9 cm³ and a wet body mass of 47 g. The shell is dextrally coiled. The upper part of the shell is small and cone-shaped made of two swirls, called the

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also calle ...

. On this protoconch there are fine lines very close to each other. The opening of the shell has an oval shape with thick, turned-out and wavy lips with a thickened area at the top of the opening.

Geographic Distribution

''S. papulosa'' is native to New Zealand but can also be found in certain places along the south and east coast of Australia. In New Zealand, ''S. papulosa'' is found along the coast in both the North and

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasma ...

Habitat

''S. papulosa'' prefers shallow salt water or on sand flats in sheltered or open coasts.

Life cycle

The life cycle of ''S. papulosa'' is divided in four stages: egg,

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

, juvenile and adult. Adult ''S. papulosa'' release their sperm and eggs into the water, which can take up to 1 hour. Fertilization occurs externally, after which the fertilized egg starts developing. The egg starts forming a larval shell 9-10 hours after fertilization and, around 3 days later, the larvae grow into juvenile sea snails. ''S. papulosa'' live an average of 5 years but can live up to 25 years.

Ecology

Diet

''S. papulosa'' is a filter feeder that feeds on algae, plankton and other small marine animals. It filters suspended matter from the water with a specialized filtering structure, or uses its tooth-lined tongue to graze seaweed from the bottom of the sea.

Predators, parasites and diseases

''S. papulosa'' has many predators including fish, birds and

reptiles Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephali ...

. The egg and larva stage are eaten by many

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cr ...

feeders but the most common ''S. papulosa'' predator is

Asteroidea Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish a ...

, especially starfish. ''S. papulosa'' protects itself from being eaten by

by repeatedly doing somersaults.

Ecology

Although the origin of this snail is unclear, it is believed that ''S. errata'' is a possible ancestor.

References

{{Taxonbar, from=Q3169255 Struthiolariidae Gastropods of New Zealand Gastropods described in 1784 Taxa named by Thomas Martyn (zoologist)