''Quantula striata'', also known as ''Dyakia striata'', 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, air-breathing, tropical land snail. It is a

terrestrial Terrestrial refers to things related to land or the planet Earth. 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 or near the ground, as opposed to ...

, pulmonate, gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...

in the family

Dyakiidae Dyakiidae is a family of air-breathing land snails terrestrial pulmonate gastropod mollusks in the superfamily Trochomorphoidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Some of the species in this family are s ...

. This species appears to be unique among terrestrial gastropods in that it is

bioluminescent Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some b ...

: Its eggs glow in the dark, and juveniles and most adults give off flashes of green light. It is the only species in the genus ''Quantula''.Tumpeesuwan C., Naggs F. & Panha S. (31 August 2007) "A new genus and new species of dyakiid snail (Pulmonata: Dyakiidae) from the Phu Phan range, northeastern Thailand". ''

Raffles Bulletin of Zoology ''The Raffles Bulletin of Zoology'' is a peer-reviewed open-access scientific journal published by the Lee Kong Chian Natural History Museum at the National University of Singapore. It covers the taxonomy, ecology, and conservation of Southeast ...

'
55(2)
: 363-369
PDF
/ref>

Distribution

This species occurs in

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

,Daston M. M. & Copeland J. (1993) "The luminescent organ and sexual maturity in ''Dyakia striata''". ''

Malacologia ''Malacologia'' is a peer-reviewed scientific journal in the field of malacology, the study of mollusks. The journal publishes articles in the fields of molluscan systematics, ecology, population ecology, genetics, molecular genetics, evolution, a ...

'' 35(1):
9
19
abstract
/ref>

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailan ...

, the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, Fiji, and some islands in the Rhio Archipelago.

Shell description

The shell of this species is dextral (right-handed) in coiling. The shell of an adult snail is 16–27 mm in width. The

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy * ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus urbis Romae The ...

is narrow.Asia and the Pacific Islands - The World of Snails
The color of the shell is brown, shading to white underneath.

Anatomy

The length of the body is up to 5–6 cm. The dorsal part of the head and foot is dark brown in color. The ventral parts are creamy white in color. The eye tentacles are long, and the eye spots are large.

Bioluminescence

''Quantula striata'' is the only terrestrial gastropod known to exhibit bioluminescence. This was not discovered until 1942, when it was reported by Dr. Yata Haneda (see also Haneda 1946), probably because the flashes are quite dim. The purpose of the snail's bioluminescence is not yet fully understood, but it is thought to have some relation to

animal communication Animal communication is the transfer of information from one or a group of animals (sender or senders) to one or more other animals (receiver or receivers) that affects the current or future behavior of the receivers. Information may be sent int ...

. Light is emitted by an organ known as the "organ of Haneda," located in the head-foot region of the adult snail. This organ consists of a 0.5 mm-wide cluster of giant cells and is a part of the

suprapedal gland The suprapedal gland or mucous pedal gland is an anatomical feature found in some snails and slugs. It is a gland located inside the front end of the foot of gastropods.Barker G. M. (2001) "Gastropods on Land: Phylogeny, Diversity and Adaptive ...

. The snail flashes while it is moving, and half as intensely when it is feeding, and does not flash when it is inactive. Flashes lasts 0.5–6.0 s. The light produced is yellow-green, with a

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...

of about 515 nm. The substance which produces it has not yet been identified.Isobe M., Yuakul D., Sigurdsson J. B., Goto T. & Lam T. J. (1991) "Fluorescent Substance in the Luminous Land Snail, ''Dyakia striata''". '' Agricultural and Biological Chemistry'' 55(8): 1947-1951
abstract and PDF
Isobe at al. (1991) stated that the fluorescent substance "may be similar to flavin". The eggs of this species glow, and so do newly hatched snails. Juveniles can produce flashes of light, as can most, but not all, adults.

Ecology

In Singapore these snails live in a variety of disturbed habitats, such as lawns, walkways and rubbish dumps, and like most land snails, they are observed more often after rain."On ''Quantula striata'' (Gray, 1834) a bioluminescence snail with a compilation of related works". Online Last change: 30 January 2007, accessed 27 November 2009. These snails feed on vegetation, fruit and vegetables, and also on the decaying flesh of already dead animals. In captivity the snails can feed on cucumber, lettuce, carrots, apple, and boiled eggs. The snails can eat chalk for calcium, and commercially available rat food for protein.

References

External links

Photo of the live snailImage of the shellFour views of one shellMore shell images''Quantula striata''
at

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. T ...

(NCBI) {{Commons category Dyakiidae Bioluminescent molluscs Invertebrates of Malaysia Gastropods described in 1834 Taxa named by John Edward Gray Molluscs of the Philippines Fauna of Singapore Invertebrates of Cambodia Fauna of Indonesia