''Newcombia canaliculata'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of air-breathing

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Achatinellidae Achatinellidae is a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea. Taxonomy It was previously the only family in the superfamily Achatinelloidea (according to the tax ...

. This species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

Taxonomy

The ''Newcombia'' genus is divided into three series: # ''Newcombia plicata'' # '' Newcombia philippiana'' # '' Newcombia cumingi''

Distribution & Habitat

These mollusks have been found in the

Hawaiian Archipelago The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kure Atoll. Formerly c ...

, on

Halawa Hālawa () is a census-designated place (CDP) in the ‘Ewa District of Honolulu County, Hawaii, United States. Hālawa Stream branches into two valleys: North and South Hālawa; North Hālawa is the larger stream and fluvial feature. Their c ...

Molokai Molokai or Molokai ( or ; Molokaʻi dialect: Morotaʻi ) is the fifth most populated of the eight major islands that make up the Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its g ...

and Wailau, Maui. Though rarely seen, they can be found resting at higher, mesic elevations. Commonly they camouflage as pieces of a tree branch. They live on

lehua Lehua Island is a small, crescent-shaped island in the Hawaiian Islands, north of Niihau, Niʻihau, 18 miles due west of Kauai, Kauaʻi. This uninhabited, barren islet was one of the first five islands sighted by James Cook, Captain James ...

trees, as well as

lantana ''Lantana'' () is a genus of about 150 species of perennial plant, perennial flowering plants in the verbena family, Verbenaceae. They are native to tropics, tropical regions of the Americas and Africa but exist as an introduced species in num ...

trees.

Description

''Newcombia canaliculata'' has a long,

sinistral Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different ...

, thin textured spiral shell, made up of calcium carbonate that ranges in varieties of brown tones. Shells may be solid colors completely, or have multiple tinges/patterns of neutral colors like white, black and brown. What makes the ''Newcombia canaliculata'' so unique is its thin spiral ribbing coiled around the shell. Additionally some snails may have zigzag patterns on a single

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

and oftentimes appear “blurred.”

Conservation

''Newcombia canaliculata'' on the

IUCN Red list The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

. They were recently thought to be extinct until a recent discovery on the island of Molokai.

Threats

These mollusk are at risk to predation by rats ''(

Rattus rattus The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is ...

Rattus exulans The Polynesian rat, Pacific rat or little rat (''Rattus exulans''), or , is the third most widespread species of rat in the world behind the brown rat and black rat. Contrary to its vernacular name, the Polynesian rat originated in Southeast Asia ...

, and Rattus nowegicus)'' and Chameleons ('' Chamaeleo jacksonii).'' Predation as well as low reproductive rates and inbreeding are all threats to ''Newcombia canaliculata.''

References

C Biota of Molokai Molluscs of Hawaii Endemic fauna of Hawaii Endangered fauna of Hawaii Gastropods described in 1905 Taxonomy articles created by Polbot {{Achatinellidae-stub