Quantula striata

{{Short description|Species of gastropod}} {{Speciesbox | image =Naturalis Biodiversity Center - RMNH.MOL.283935 - Quantula striata (Gray, 1834) - Dyakiidae - Mollusc shell.jpeg | taxon = Quantula striata | authority = (Gray, 1834) | synonyms = *''Nanina striata'' Gray, 1834 (basionym) *''Ariophanta striata'' (J. E. Gray, 1834) *''Helix naninoides'' Benson, 1842 *''Hemiplecta leechi'' de Morgan, 1885 | synonyms_ref = <ref>{{cite WoRMS |db=MolluscaBase |year=2024 |title=''Quantula striata'' (J. E. Gray, 1834) |id=1252851 |access-date=11 April 2024 }}</ref> }}

'''''Quantula striata''''', also known as ''Dyakia striata'', is a species of medium-sized, air-breathing, tropical land snail. It is a terrestrial, pulmonate, gastropod mollusc in the family Dyakiidae. This species appears to be unique among terrestrial gastropods in that it is bioluminescent: Its eggs glow in the dark, and juveniles and most adults give off flashes of green light.

== Distribution == This species occurs in Singapore, Malaysia,<ref name="Daston 1993">{{Cite journal |last1=Daston |first1=M. M. |last2=Copeland |first2=J. |year=1993 |title=The luminescent organ and sexual maturity in ''Dyakia striata'' |journal=Malacologia |volume=35 |issue=1 |pages=9–19 |url=https://archive.org/stream/malacologia351993inst#page/8/mode/2up }}</ref> Cambodia, the Philippines, Fiji, and some islands in the Rhio Archipelago.<ref name="Isobe 1991"/>

== 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.<ref name="Counsilman 1988"/> The umbilicus is narrow.<ref>[http://www.freewebs.com/worldofsnails/asiaandthepacificislands.htm Asia and the Pacific Islands - The World of Snails] {{webarchive |url=https://web.archive.org/web/20100404001248/http://www.freewebs.com/worldofsnails/asiaandthepacificislands.htm |date=April 4, 2010 }}</ref> The color of the shell is brown, shading to white underneath.<ref name="Counsilman 1988">{{Cite journal | last1 = Counsilman | first1 = J. J. | last2 = Ong | first2 = P. P. | doi = 10.1007/BF02348856 | title = Responses of the luminescent land snail ''Dyakia (Quantula) striata'' to natural and artificial lights | journal = Journal of Ethology | volume = 6 | pages = 1–8 | year = 1988 | s2cid = 12203232 }}</ref>

== Anatomy == The length of the body is up to 5–6 cm.<ref name="Counsilman 1988"/> The dorsal part of the head and foot is dark brown in color.<ref name="Counsilman 1988"/> The ventral parts are creamy white in color.<ref name="Counsilman 1988"/> The eye tentacles are long, and the eye spots are large.<ref name="Counsilman 1988"/>

== Bioluminescence == ''Quantula striata'' is the only terrestrial gastropod known to exhibit bioluminescence.<ref name="Isobe 1988">{{Cite journal | last1 = Isobe | first1 = M. | last2 = Uyakul | first2 = D. | last3 = Goto | first3 = T. | last4 = Counsilman | first4 = J. J. | title = ''Dyakia'' bioluminescence—1. Bioluminescence and fluorescence spectra of the land snail, ''D. striata'' | doi = 10.1002/bio.1170020204 | journal = Journal of Bioluminescence and Chemiluminescence | volume = 2 | issue = 2 | pages = 73–79 | year = 1988 | pmid = 3213594 }}</ref> This was not discovered until 1942, when it was reported by Dr. Yata Haneda (see also Haneda 1946),<ref name="Copeland 1989"/> probably because the flashes are quite dim.<ref name="Counsilman 1988"/> The purpose of the snail's bioluminescence is not yet fully understood, but it is thought to have some relation to animal communication.<ref name="Copeland 1989"/> Light is emitted by an organ known as the "organ of Haneda,"<ref name="shell.kwansei.ac.jp"/> located in the head-foot region of the adult snail. This organ consists of a 0.5 mm-wide cluster of giant cells<ref name="Isobe 1991"/> and is a part of the suprapedal gland.<ref name="Isobe 1991"/> The snail flashes while it is moving, and half as intensely when it is feeding, and does not flash when it is inactive.<ref name="Copeland 1989">{{cite journal |author1=Copeland J. |author2=Daston, M. M. |year=1989 |title=Bioluminescence in the terrestrial snail ''Dyakia'' (''Quantula'') ''striata'' |journal=Malacologia |volume=30 |issue=1–2 |pages=317–324 |url=https://archive.org/stream/malacologia301989inst#page/316/mode/2up }}</ref> Flashes lasts 0.5–6.0 s.<ref name="Copeland 1989"/>

The light produced is yellow-green, with a wavelength of about 515 nm. The substance which produces it has not yet been identified.<ref name="Isobe 1991">{{cite journal |last1=Isobe |first1=Minoru |last2=Uyakul |first2=Duangchan |last3=Sigurdsson |first3=Jon B. |last4=Goto |first4=Toshio |last5=Lam |first5=Toong J. |title=Fluorescent substance in the luminous land snail, ''Dyakia striata'' |journal=Agricultural and Biological Chemistry |date=1991 |volume=55 |issue=8 |pages=1947–1951 |doi=10.1080/00021369.1991.10870892|doi-access=free }}</ref> Isobe at al. (1991)<ref name="Isobe 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.<ref name="Counsilman 1988"/>

== 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.<ref name="shell.kwansei.ac.jp">{{cite web|url=http://shell.kwansei.ac.jp/~shell/life/e_striata.html |title=On ''Quantula striata'' (Gray, 1834) a bioluminescence snail with a compilation of related works |work=Micro shells |access-date=November 24, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20091106022643/http://shell.kwansei.ac.jp/~shell/life/e_striata.html |archive-date=November 6, 2009 }}</ref>

These snails feed on vegetation, fruit and vegetables, and also on the decaying flesh of already dead animals.<ref name="Counsilman 1988"/><ref name="Copeland 1989"/>

In captivity the snails can feed on cucumber, lettuce, carrots, apple, and boiled eggs.<ref name="Isobe 1991"/><ref name="Counsilman 1988"/><ref name="Copeland 1989"/> The snails can eat chalk for calcium, and commercially available rat food for protein.<ref name="Counsilman 1988"/>

== See also == * ''Latia neritoides'', a freshwater snail from New Zealand, is the only other pulmonate gastropod that shows bioluminescence.

==References== {{Reflist}}

== Further reading == * {{Cite journal | last1 = Copeland | first1 = J. | title = Optic nerve responses to light stimulation in the bioluminescent terrestrial snail, ''Dyakia'' (''Quantula'') ''striata'' | doi = 10.1016/0300-9629(88)91046-8 | journal = Comparative Biochemistry and Physiology A | volume = 89 | issue = 3 | pages = 391–400| year = 1988 }} * {{cite journal | last1 = Copeland | first1 = J. | last2 = Counsilman | first2 = J. J. | year = 1986 | title = Neuroethological Studies of Behavior in the Land Snail ''Dyakia'' (''Quantula'') ''striata'' | journal = International Society for Neuroethology Abstracts | volume = 1 | page = 93 }} * {{cite journal | last1 = Copeland | first1 = J. | last2 = Counsilman | first2 = J. J. | last3 = Loh | first3 = D. | last4 = Chan | first4 = S. Y. | last5 = Tan | first5 = W. H. | last6 = Maneri | first6 = M. | year = 1987 | title = Factors Affecting the Rate of Flashing and Loss of Luminescence in an Asian Land Snail ''Dyakia striata'' | journal = Veliger | volume = 29 | pages = 394–439 }} * {{cite journal | last1 = Haneda | first1 = Y | year = 1946 | title = A luminous land snail, ''Dyakia striata'', found in Malaya | journal = Seibutsu | volume = 1 | pages = 294–298 }}

==External links== {{Commons category}} *[https://web.archive.org/web/20091106022643/http://shell.kwansei.ac.jp/~shell/life/e_striata.html Photo of the live snail] *[http://www.femorale.com.br/shells/photo.asp?idconcha=46900&cod=5076&url=%2Fshells%2Fspecies.asp%3Ffamily%3DARIOPHANTIDAE%26cod%3D5076 Image of the shell] *[https://web.archive.org/web/20110716025437/http://www.seashellhub.com/Ariophantidae/QuantulastriataIpoh.JPG Four views of one shell] *[https://web.archive.org/web/20110616092307/http://shell.kwansei.ac.jp/~shell/pic_book/img04/hikarimm.jpg More shell images]

Category:Dyakiidae Category:Gastropods of Asia Category:Molluscs of Cambodia Category:Molluscs of Indonesia Category:Molluscs of Malaysia Category:Molluscs of the Philippines Category:Bioluminescent molluscs Category:Gastropods described in 1834 Category:Taxa named by John Edward Gray