''Rathouisia leonina'' is a species of carnivorous air-breathing

land slug Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a sma ...

, 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 ...

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

in the family Rathouisiidae. 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 ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. This slug is

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

and actively preys on

snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

s. It is usually grayish brown to dark gray in color with scattered black spots on the upper surface of the body. The bottom surface of the foot is a light reddish brown. These slugs inhabit environments with high

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...

and shade, such as

foothills Foothills or piedmont are geography, geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an highland, upland area. They are a transition zone between plains and low terrain, relief hill ...

and city gardens, although they are rarely seen.

Taxonomy

''Rathouisia leonina'' was first described by the French

missionary A missionary is a member of a Religious denomination, religious group who is sent into an area in order to promote its faith or provide services to people, such as education, literacy, social justice, health care, and economic development.Thoma ...

and

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Pierre Marie Heude Pierre Marie Heude (25 June 1836 – 3 January 1902) was a French Jesuit missionary and zoologist. Life Born at Fougères in the Department of Ille-et-Vilaine, Heude became a Jesuit in 1856 and was ordained to the priesthood in 1867. He went to ...

in 1882. It is the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'' Rathouisia'', which was named in honor of the

Jesuit The Society of Jesus (; abbreviation: S.J. or SJ), also known as the Jesuit Order or the Jesuits ( ; ), is a religious order (Catholic), religious order of clerics regular of pontifical right for men in the Catholic Church headquartered in Rom ...

Père A name suffix in the Western English-language naming tradition, follows a person's surname (last name) and provides additional information about the person. Post-nominal letters indicate that the individual holds a position, educational degree, a ...

Charles Rathouis who made the original drawings of the specimens for Heude. Heude P. M. (1882–1890)
"Notes sur les Mollusques terrestres de la vallée du Fleuve Bleu"
''Mémoires concernant l'histoire naturelle de l'empire chinois par des pères de la Compagnie de Jésus'', Mision Catholique, Chang-Hai
page 10plate 13
fig. 2
page 100page 131plate 32
Wu M., Guo J.-Y., Wan F.-H., Qin Q.-L., Wu Q. & Wiktor A. (2006). "A preliminary study of the predatory terrestrial mollusk ''Rathouisia leonina''". '' The Veliger'' 48
61
74. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''leonina'' is from

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word "''leo''", which means

lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...

, referring to the predatory nature of the slug.

Distribution

''Rathouisia leonina'' is

. It is found in the following areas: *Eastern China: the foothills of the

Purple Mountain Purple Mountain may refer to: China * Purple Mountain (Nanjing), a mountain in Nanjing, Jiangsu Ireland * Purple Mountain (Kerry), a mountain in County Kerry United States * Purple Mountain (Alaska), a mountain in Alaska * Purple Mountain ...

Nanjing Nanjing or Nanking is the capital of Jiangsu, a province in East China. The city, which is located in the southwestern corner of the province, has 11 districts, an administrative area of , and a population of 9,423,400. Situated in the Yang ...

Jiangsu Jiangsu is a coastal Provinces of the People's Republic of China, province in East China. It is one of the leading provinces in finance, education, technology, and tourism, with its capital in Nanjing. Jiangsu is the List of Chinese administra ...

province *Central China:

Yichang Yichang ( zh, s= ), Postal Map Romanization, alternatively romanized as Ichang, is a prefecture-level city located in western Hubei province, China. Yichang had a population of 3.92 million people at the 2022 census, making it the third most pop ...

Hubei Hubei is a province of China, province in Central China. It has the List of Chinese provincial-level divisions by GDP, seventh-largest economy among Chinese provinces, the second-largest within Central China, and the third-largest among inland ...

province *Southern China:

Shaoguan Shaoguan is a prefecture-level city in northern Guangdong Province ( Yuebei), South China, bordering Hunan to the northwest and Jiangxi to the northeast. It is home to the mummified remains of the sixth Zen Buddhist patriarch Huineng. Its built-u ...

Guangdong ) means "wide" or "vast", and has been associated with the region since the creation of Guang Prefecture in AD 226. The name "''Guang''" ultimately came from Guangxin ( zh, labels=no, first=t, t= , s=广信), an outpost established in Han dynasty ...

province *Southwest China:

Chengkou County Chengkou County () is a county in Chongqing municipality, China, and is the northernmost county-level division of Chongqing, bordering the provinces of Shaanxi and Sichuan to the north and west, respectively. To the northeast, the county borders ...

Sichuan Sichuan is a province in Southwestern China, occupying the Sichuan Basin and Tibetan Plateau—between the Jinsha River to the west, the Daba Mountains to the north, and the Yunnan–Guizhou Plateau to the south. Its capital city is Cheng ...

province, along the

Yangtze River The Yangtze or Yangzi ( or ) is the longest river in Eurasia and the third-longest in the world. It rises at Jari Hill in the Tanggula Mountains of the Tibetan Plateau and flows including Dam Qu River the longest source of the Yangtze, i ...

Description

''Rathouisia leonina'' has a cylindrical and elongated body, with a resting length of less than . The body color usually ranges from light grayish-brown to dark gray, rarely reddish. The bottom surface (sole) is light reddish brown. The upper surface of the body has scattered black oblong spots. The

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s are short and black in color. ''Rathouisia leonina'' is larger than its two congeners, '' Rathouisia pantherina'' and '' Rathouisia tigrina''. Adults weigh from 0.18 to 1.02 g. Their

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

is very sticky.

Ecology

Habitat

''Rathouisia leonina'' often inhabits areas with high humidity and shade, but can also live in open habitats and in dry environments. These slugs are usually found in limestone hills, foothills, and city gardens, though they are not often seen. They commonly rest under thick litter and rocks during the dry season. They only move on

laterite Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolo ...

soil (without litter) during the humid season. They are actively crawling at temperatures of .

Feeding habits

''Rathouisia leonina'' is a predatory carnivorous slug. It exclusively preys on

s, which it attacks through their

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

. The common natural prey species of ''Rathouisia leonina'' include the following: *

Camaenidae Camaenidae is a Family (biology), family of air-breathing land snails, terrestrial molluscs, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea, the typical snails and their allies. This is one of the most diverse families i ...

: '' Bradybaena similaris'', '' Acusta ravida'', '' Trichobradybaena submissa''. It also eats the eggs of the mentioned species of Camaenidae. * Subulinidae: '' Opeas arctipsirale'' *

Succineidae Succineidae are a family of small to medium-sized, air-breathing land snails (and slug Slug, or land slug, is a common name for any apparently shell-less Terrestrial mollusc, terrestrial gastropod mollusc. The word ''slug'' is also often ...

Barker G. M. (2004). ''Natural Enemies of Terrestrial Molluscs''. CABI Publishing, 644 pp.
page 337
In laboratory experiments, this slug also preyed upon '' Cathaica fasciola'' (

), ''

Cornu aspersum ''Cornu aspersum'' (syn. ''Helix aspersa'', ''Cryptomphalus aspersus''), known by the common name garden snail, is a species of land snail in the family Helicidae, which includes some of the most familiar land snails. Of all terrestrial molluscs, ...

'' (

Helicidae Helicidae is a large, diverse family of western Palaearctic, medium to large-sized, air-breathing land snails, sometimes called the "typical snails." It includes some of the largest European land snails, several species are common in anthropoge ...

), and ''

Achatina fulica ''Lissachatina fulica'' is a species of large land snail that belongs in the subfamily Achatininae of the family Achatinidae. It is also known as the giant African land snail. It shares the common name "giant African snail" with other species of ...

'' (

Achatinidae Achatinidae (New Latin, from Greek "''agate''") is a family of medium to large sized tropical land snails, terrestrial pulmonate gastropod mollusks from Africa. Well known species include '' Achatina achatina'' the Giant African Snail, and '' L ...

). It does not prey on other slugs.

Life cycle

''Rathouisia leonina'' lays clutches of 10 to 49 eggs. The eggs are spherical or ellipsoidal in shape, with a diameter of . The eggs are a translucent light smoke-blue or light pink in color. Juveniles hatch from the eggs after 25 to 29 days when kept in temperatures of .

References

External links

* {{Taxonbar, from=Q18753243 Rathouisiidae Gastropods of Asia Molluscs of China Endemic fauna of China Gastropods described in 1882 Taxa named by Pierre Marie Heude