The red triangle slug (''Triboniophorus graeffei'') is a

species In biology, a species is the basic unit of 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 the appropriate s ...

of large 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 smal ...

, 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 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 includ ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

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 e ...

in the family

Athoracophoridae Athoracophoridae, common name the leaf-veined slugs, are a family of air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the infraorder Stylommatophora, the stalk-eyed snails and slugs. Many of the species have an attractive pat ...

, the leaf-veined slugs. This large (up to ), often colorful and striking-looking species is found in eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It is Australia's largest native land slug.''Red Triangle Slug Fact File''
Australian Museum, 2009, accessed 22 February 2009. It is a common part of the

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. Zoo ...

. ''Triboniophorus graeffei'' is the

type species In 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 species that contains the biological type specimen ...

of the genus '' Triboniophorus''.Solem A. 1959
''Systematics of the land and fresh-water mollusca of the New Hebrides''
Fieldiana Zoology, volume 43, number 1, Chicago Natural History Museum
page 45
46 A closely related species is the as-yet-unnamed ''Triboniophorus'' sp. nov. 'Kaputar'.

Distribution

This slug species occurs on the east coast of Australia, from

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

.(June) 2004
''Red Triangle Slug Diversity''
An Australian Museum Website, Australian Museum, accessed 22 February 2009. An affiliated bright pink species, '' Triboniophorus aff. graeffei'', are found exclusively on

Mount Kaputar Mount Kaputar, a mountain with an elevation of above sea level, is located near Narrabri in northern New South Wales. It is part of the Nandewar Range and has been preserved within the Mount Kaputar National Park. The mountain is a prominent l ...

. Solem (1959) mentioned a possible introduction of this species to the

New Hebrides New Hebrides, officially the New Hebrides Condominium (french: link=no, Condominium des Nouvelles-Hébrides, "Condominium of the New Hebrides") and named after the Hebrides Scottish archipelago, was the colonial name for the island group ...

, but no material was available to confirm it.

Habitat

Red triangle slugs are found in damp situations in various habitats, including city gardens,

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

and

heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler ...

Life habits

These slugs graze on

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

which grows on the surface of the smooth bark of some

eucalyptus tree ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...

s and on rocks. Sometimes the slugs enter houses and have been known to graze on the

mold A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...

that grows on bathroom walls. This species of slug has been found to have an unusual defensive mechanism. It can secrete a kind of sticky mucus (different from the slippery slime secreted when it moves) that is strong enough to glue predators down for days. The glue is strongest in wet conditions and becomes less sticky as it dries. The cells responsible for secreting the glue are located across the dorsal surface.

Description

Red triangle slugs have two, not four,

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, and like other leaf-vein slugs, they have an indented pattern on their dorsum which resembles that of a leaf. The body length is up to 14 cm. They are very variable in color. Individual slugs can be white, off-white, yellow, dark or light grey, beige, pink, red, or olive green. Each of the color forms have a red (possibly orange, magenta, or maroon) triangle on the mantle surrounding the

pneumostome The pneumostome or breathing pore is a respiratory opening of the external body anatomy of an air-breathing land slug or land snail. It is a part of the respiratory system of gastropods. It is an opening in the right side of the mantle of a ...

, and a red line at the edge of the foot. The texture of the dorsum of the slug can be smooth or very rough. Juveniles lack the typical red foot border and red triangle of the adults but have three dark grey stripes running down the dorsal surface of their body and have the triangular mantle shield outlined with grey.pers. comm. Michael Shea, Australian Museum Research is currently being carried out in an attempt to determine if some of the different colourations may actually represent different species or subspecies.

Gallery

Various shots of ''Triboniophorus graeffei'' on the bark of Sydney Blue Gums, near

Dungog Dungog is a country town on the Williams River in the Hunter Region of New South Wales, Australia. Located in the middle of dairy and timber country, it is the centre of the Dungog Shire local government area and at the 2016 census it had a po ...

, showing color variation, varying degrees of contraction and body shape. Image:Triboniophorus graeffei - Dungog7.jpg, Close-up of a pale pink individual with the

open and a narrow body, tentacles fully extended Image:Triboniophorus graeffei - Dungog1.jpg, An off-white individual with a very pale "red triangle" Image:Triboniophorus graeffei - Dungog2.jpg, A beige individual with a very wide body and a pale orange "triangle" and foot edge. Tentacles partially retracted Image:Triboniophorus graeffei - Dungog4.jpg, Two individuals, one fully contracted and with pneumostome closed Image:Triboniophorus graeffei - Dungog5.jpg, Same two individuals from the side showing the body shape in profile Image:Triboniophorus graeffei - Dungog6.jpg, Same two individuals, the previously contracted one has retreated to a less exposed position among old flakes of bark Image:Triboniophorus_graeffei_juvenile.jpg, Juvenile Red Triangle Slug on moist

Hawkesbury Sandstone Sydney sandstone is the common name for Sydney Basin Hawkesbury Sandstone, one variety of which is historically known as Yellowblock, and also as "yellow gold" a sedimentary rock named after the Hawkesbury River north of Sydney, where this ...

Chatswood West Chatswood West is a suburb on the Lower North Shore (Sydney), Lower North Shore of Sydney, in the state of New South Wales, Australia. Chatswood West is located 11 kilometres north-west of the Sydney central business district, in the Local gover ...

References

External links

Photographs on the life history etc.:
Photo of about-to-hatch eggs and newly hatched juvenile, from Bill Rudman's site

Feeding tracks on a tree trunk

Showing detail of the head and triangle with pneumostome open
Photographs of the various different color forms:
A mating pair of the white form on a tree trunk

A yellow one with magenta markings, in the contracted state

A dark yellow or orange individual with dark red markings

* ttps://www.flickr.com/photos/phanimals/2905885581/ A photo showing a wide red margin of the foot on a cream-colored individual
A cream-colored individual wrapped around a twig with pneumostome closed

A beige individual with orange markings

A solidly bright red individual
{{Taxonbar, from=Q3075433 Athoracophoridae Gastropods described in 1863