Geomalacus grandis Simroth , 1894
Letourneuxia lusitana Castro, 1873
The KERRY SLUG or KERRY SPOTTED SLUG, scientific name GEOMALACUS
MACULOSUS, is a rare species of medium-sized to large air-breathing
land slug . It is a terrestrial pulmonate gastropod mollusc in the
Arionidae , the roundback slugs.
Kerry slug generally measures 7–8 cm (2.8–3.2 in) in
length and is dark grey or brownish in colour, with yellowish spots.
The internal anatomy of the slug shows some unusual features, and some
characteristic differences from the genus Arion, which is the type
genus of the family Arionidae. The
Kerry slug was described in 1843,
rather late compared to many other relatively large land gastropods
that form a part of the fauna of the
British Isles ; this is one
indication of this slug's rarity and its secretive habits.
Although the distribution of this slug species does include some wild
habitats in southwestern
Ireland (e.g. in
County Kerry ), the species
is more widespread in north-west
Spain and from central to northern
Portugal . However, it is not found anywhere between
Spain. The species appears to require environments that have high
humidity and acidic soil (soil with no calcium carbonate in it). The
slug is mostly nocturnal or crepuscular , although in
Ireland it is
active on overcast days. It feeds on lichens , liverworts , mosses and
fungi , which grow either on boulders or on tree trunks.
This rare species is officially protected by conservation laws in
each of the three countries in which it occurs. However, the survival
Kerry slug is nonetheless threatened because it lives only in
completely wild, unspoiled habitat of a particular type: acidic
woodlands and moorlands that support the species of lower plants on
which the slug relies for food. This habitat type is itself at risk
from a number of different factors, ranging from climate change to the
construction of roads. Attempts have been made to establish breeding
populations in captivity , to help ensure the survival of this slug
species, but with only limited success.
* 1 Taxonomy
* 2 Description
* 2.1 Internal anatomy
* 2.1.1 Shell
* 2.1.2 Various organ systems
* 2.1.3 Muscles
* 2.1.4 Reproductive system
* 2.1.5 Apparatus for feeding
* 3 Distribution
* 3.1.1 Protected sites
* 3.2 Iberia:
* 188.8.131.52 Protected sites
* 4 Behaviour
* 5.2 Feeding
* 5.3 Life cycle
* 6 Threats to the survival of the species
* 7 Conservation measures
* 7.1 International protection
* 7.2 Protection in Iberia
* 7.3 Protection in
* 7.3.1 Monitoring
* 8 References
* 9 Further reading
* 10 External links
Kerry slug is a gastropod , as are all other snails and slugs,
including slugs and snails that live in saltwater, those that live in
freshwater, and those that live on the land. This is a land slug which
breathes air, a pulmonate . It is in the clade
Stylommatophora , which
means that its primitive eyes or eye spots are carried on the tips of
its two upper tentacles . Despite superficial similarities, not all
land slugs are in the same family or superfamily. The
Kerry slug is an
arionid, or round-backed slug; it has no keel on its back, in contrast
to the land slugs in the family
Agriolimacidae . It also
shares numerous internal anatomical features with slug species in
other genera within the family
Arionidae , including the Arion slugs,
which are most typical of the family.
The Kerry slug's scientific name or binomial name is Geomalacus
maculosus. It is in the genus Geomalacus, a name which literally means
"earth mollusc". Its specific name maculosus means "spotted", from the
Latin word macula "spot". The English language vernacular name (or
common name ) is derived from the name of County Kerry, which is the
county in the southwest of
Ireland where this species was first
collected, and which is also the type locality, as mentioned in the
The scientific name of the species is also sometimes written as
Geomalacus (Geomalacus) maculosus. This is because the genus
Geomalacus contains two subgenera: the nominate subgenus (subgenus of
the same name)
Geomalacus and a second subgenus Arrudia Pollonera,
1890. The subgenus
Geomalacus contains only one species, the Kerry
slug. The subgenus Arrudia includes three species.
This slug species was originally described and named from specimens
collected in Ireland. In 1842, an Irish naturalist named William
Andrews (1802–1880) sent material that he had found at Caragh Lake
County Kerry to the Irish naturalist
George James Allman
George James Allman , who
then introduced the slug to science as a new species.
Kerry slug has been included in molecular phylogenetic studies
Colour variation in three individuals, lighter and darker; the
lower two having indistinct banding
The body length of adult slugs of this species is 7–8 cm (2.8–3.2
in). However it is difficult to measure these slugs accurately
because of their unusual startle response (see the section entitled
behaviour ). Kerry slugs can also elongate themselves within crevices
up to 12 cm (4.8 in). "Official" measurements of this species vary;
for example, Kerney et al. (1983) give a range of measurements for
the species: 6–9 cm (2.4–3.6 in). The body of a fixed (preserved)
adult specimen was 7 cm (2.8 in) long with a mantle length of 3 cm
(1.2 in). Colour morphs of G. maculosus. Brown individuals are
typically associated with woodlands; black individuals are found in
open habitats such as blanket bog or heath.
The body of these slugs is glossy, and is covered on the left and
right sides with about 25 longitudinal rows of polygonal granulations
(very small knobs with outlines like polygons).
The slugs have two colour morphs depending on the type of habitat
where they are found, suggesting that they are using camouflage.
There can also be variation in relation to banding. On each side of
the body there can be two bands: one band just below the summit of the
back, and the other band further down the side of the body. When these
bands are present they usually extend the whole length of the body of
the slug, and are overspread by numerous, somewhat oval, yellowish
spots. These yellow spots are distributed more or less in five
longitudinal zones. The caudal end (tail end) of the body
showing supra-pedal grooves and triangular caudal mucous pit
Right view of the tail end of the body.
Behind the animal's head, the "shield" (the shield-shaped outer
surface of the mantle ) is about a third of the length of the body
when the slug is actively crawling and thus extended, but only about
half of that when the slug is motionless and contracted. The shield is
rounded in front, and bluntly pointed behind. The texture of the
surface of this area resembles the underside of undyed leather. It is
spotted with pale buff or whitish spots which are similar to those on
the body, but more uniformly distributed.
The foot-fringe (a band of tissue around the edge of the foot) is not
very distinctly separated: it is very pale and somewhat expanded, with
indistinct lines on it. The sole (the underside) of the foot is a
pale grayish-yellow in colour, and is divided into three indistinct
bands, with the mid-area being somewhat darker and more transparent
than the side bands. There is a caudal mucous pit situated between
the foot and the body on the upper surface of the tip of the tail .
The pit (which collects extra mucus) is not very conspicuous, but it
is triangular in shape and opens transversely (i.e. from side to
side). The mucous pit often carries a transparent yellowish ball of
The upper tentacles are smoky-black or grey, short and thick, with
oval ends, and have the usual eye spots at their tips. The genital
pore (or opening) lies behind and below the right eye-tentacle. The
lower tentacles are pale translucent grey. The skin mucus is usually
pale yellow, and varies in its degree of viscosity (stickiness). The
locomotory-mucus (mucus for crawling on) is tenacious and usually
colourless, but it can be yellowish because of having mixed with the
Most land slugs have, within the mantle, the remnants or residue of
what was, in the evolutionary past, a larger external shell . In most
slugs, this remnant takes the form either of a small internal shell (a
thin shelly plate), or a collection of calcareous (chalky) granules.
In this species there is an internal shell or shell plate which
resembles that found in land slugs of the genus
Limax . In other
words, the shell plate in this species is oval in shape, solid, and
chalky, with a transparent conchiolin (horny) base. The shell plate is
usually somewhat convex above and concave beneath, with a few
indistinct concentric lines of growth, and is covered outwardly with a
very thin transparent periostracum (a protein layer), and with the
nucleus (the oldest growth part) situated near the front. In young
Kerry slugs the shell is very thin and convex, abruptly cut off
behind, and with an extremely thin layer that projects in front and
contains minute granules.
The shell plate has been drawn differently by authors, but do at
least show that it is a solid plate:
The internal shell as drawn by Taylor in 1907
The internal shell as drawn by Godwin-Austen in 1882
Photograph of internal shell of G. maculosus (dorsal view).
Various Organ Systems
Anatomy viewed from below with frontal edge of mantle on the
top. Heart (red) is surrounded by renal organ (yellow). Retractor
muscles (blue) include retractor muscle of left eye tentacle (depicted
on the right), retractor muscle of right eye tentacle and retractor
muscle of odontophore (both on the left). The cerebral ganglia,
a central processing area which is equivalent to the brain within the
nervous system of the slug
The circulatory and excretory system are closely related, in that the
heart is surrounded by the triangular kidney . The kidney has a
lamellate (layered) structure and it has two ureters . In this slug
species, the ventricle of the heart is directed towards, and is very
close to, the anal and respiratory openings. The ventricle of the
heart is further away and further back than it is in species of the
related genus Arion , the type genus of the family Arionidae.
The gland above the foot, the suprapedal gland , is deeply imbedded
in the tissues, and reaches far back. The cephalic (head) gland known
as the Semper\'s organ is well developed, and shows as a pair of
strong flattened lobes. The salivary and digestive glands are the same
as those found in Arion species, but the vestigial osphradium
(kidney-like structure) within the mantle chamber is more distinct
than it is in Arion species.
As for the various muscles within the slug, the cephalic retractors
(muscles for pulling in the head) are very much the same as they are
in Arion species. The right and left tentacular muscles, which pull in
all four of the tentacles , divide early for the upper and lower
tentacles, but only the muscles of the ommatophores (the muscles of
the two upper tentacles, which have eye spots) are darkly pigmented.
The right and left muscles that pull in the eyespot tentacles are
attached at the base to the back edge of the mantle, on the right and
left respectively. The pharyngeal (throat) retractor muscle is, as
usual, furcate (split) for attachment to the back of the buccal bulb
(mouth bulb), and the root of this muscle is fixed on the right side
of the body, just behind where the right tentacular muscle is
Kerry slug is hermaphrodite as all other pulmonates. Its reproductive
system is diagnostic feature. The genus
Geomalacus has a special
feature: the atrium has a diverticulum. This atrial diverticulum is an
elongated part of the atrium. The penis in the genus
reduced and lost as well its penial retractor muscle. The atrial
diverticulum is a secondary penial structure and with its spermatheca
retractor muscle acts as a copulatory organ instead. The other end of
the spermatheca retractor muscle extends to the posterior end of the
body. The atrial diverticulum has been proposed to be the
morphological equivalent (analogy , homoplasy ) of a penis.
Geomalacus maculosus has an atrial diverticulum longer than the
spermatheca duct, while
Geomalacus anguiformis has an atrial
diverticulum shorter than the spermatheca duct.
Various authors have depicted the reproductive system of Kerry slug:
Godwin-Austen (1882), Sharff (1891), Simroth (1891, 1894), Taylor
(1907), Germain (1930), Quick (1960) and Platts & Speight (1988).
Platts "> The reproductive system by Godwin-Austen (1882). The
large mass on the right is albumen gland, the mass on the lower part
right is the ovotestis, the oval shape at the left is the spermatheca.
Mantle edge and atrium is at the top.
Drawing of "male part" of the reproductive system. From lower
left to upper left: genital pore, atrium, atrial diverticulum,
spermatheca duct, spermatheca retractor muscle, spermatheca. On the
top right: epiphallus. Center: vas deferens. Lower right: free
Apparatus For Feeding
The radula is a feeding structure found only in molluscs. Typically
it is a small but strong ribbon-like structure with numerous complex
rows of tiny teeth across it. The radula is situated inside the mouth.
In this species of slug, the radula is 8 mm (5/16 in) long and 2 mm
(1/16 in) wide, and has 240 slightly curved transverse (crosswise)
rows of denticles (tiny teeth). Each row of teeth is composed of one
median tooth and 10 lateral and marginal teeth on each side. The
median teeth are small, and are clearly unicuspid (having one cusp),
though they are slightly shouldered. The lateral teeth are bicuspid
(having two cusps) but the admedian (next to the middle) teeth are
noticeably larger than the median row, and the mesocone (an extra
protrusion in the middle of the tooth) is well developed. There is
however, no distinction between the lateral and marginal series except
that the ectocone (extra little side protrusion) present on the
admedian teeth recedes in position and slightly diminishes in size in
the succeeding teeth up to about the twentieth row on the radula, but
in the marginal series, the ectocone gradually grows in size and
importance as the margin is approached, while the mesocone becomes
almost correspondingly diminished, the outermost teeth showing a more
embryonic (more like that of an embryo) character. One complete
row of teeth in the radula
The jaw , which has broad ribs.
The jaw measures about 1 mm (1/32 in) from side to side, and is
distinctly arcuate (arched) from front to rear, lunate (crescent-moon
shaped) in shape, but very wide, with broad and slightly rounded ends.
The jaw is solid, dark-brown and has about 10 broad flat ribs only in
the middle part of the jaw. These ribs are absent or scarcely
discernible on the side areas. Where the ribs meet the upper edge they
sometimes form crenulations ( a scalloped effect) and may also produce
the same effect on the lower edge of the jaw. In other individuals the
ribs extend all the way across the jaw, making both the upper and the
cutting edges of the jaw clearly denticulate (noticeably toothed in
The alimentary canal of the digestive system forms two loops, as is
true of all species within the family Arionidae.
Distribution map for the species. It shows the "Lusitanian" type
of disjunct distribution , but not the recently discovered Co. Galway
Geomalacus maculosus has what is known as a disjunct distribution (in
other words, it occurs in discontinuous locations). This slug is found
only in southwestern
Ireland , north-west
Spain , and from central
Portugal to northern
Portugal . The presence of this slug in
Ireland might seem anomalous, but similar distribution
patterns have been observed in a few other species of animals and
plants. This particular disjunct distribution (in Iberia and in
Ireland without any intermediate localities) is known as "Lusitanian
There has been speculation that the G. maculosus was introduced to
Ireland from Iberia by prehistoric humans, as appears to have happened
in the case of the
Eurasian pygmy shrew . In support of this, the
genetic diversity of the slug in
Ireland was found to be greatly
reduced compared with the Iberian populations.
Within Ireland, this species of slug is known from areas with
sandstone geology in
West Cork and County Kerry, a total area of
around 5,800 km2 (2,200 sq mi). In 2010, a previously unknown
population of the Kerry
Slug was recorded in a third county, Co.
A significant proportion of the Kerry slug's range in
protected by being included in
Special Areas of Conservation
Special Areas of Conservation (SACs).
Ireland's response to the European environmental legislation
concerning the slug is discussed in greater detail in the Conservation
Measures section below.
A total of seven
Special Areas of Conservation
Special Areas of Conservation have been designated
with the slug as a "selection feature":
Glengarriff Harbour and
* Sheep\'s Head
Killarney National Park
Killarney National Park , Macgillycuddy\'s Reeks and Caragh River
Lough Yganavan and Lough Nambrackdarrig
Cloonee and Inchiquin Loughs, Uragh Wood
Blackwater River (Kerry)
Blackwater River (Kerry) .
In addition, St. Gobnet\'s Wood SAC (which was designated in relation
to other selection criteria) was expanded in 2008 to protect Cascade
Wood, a small area of woodland which is inhabited by the slug.
The species has also been recorded at other SACs where it is not a
selection feature, for example Derryclogher Bog in County Cork.
IBERIA: SPAIN AND PORTUGAL
Despite its first "discovery" at Caragh Lake, and its English common
name of "Kerry slug",
Ireland is not at the centre of this slug
species' distribution; instead the distribution of this slug is
centred in continental Iberia . This slug has been known from
Spain since 1868, and from northern
Portugal since 1873. It
was once reported as occurring in France, but this was never
confirmed, and so that record is considered suspect.
The southernmost locality where this species is found is the mountain
Serra da Estrela
Serra da Estrela in Portugal. Other Portuguese localities
include the provinces Beira Alta ,
Douro Litoral , Minho ,
Trás-os-Montes e Alto Douro and the
Peneda-Gerês National Park
Peneda-Gerês National Park , a
The distribution of this species in
Spain includes coastal locations
in Galicia , and extends through the
Cantabrian Mountains as far east
Ganekogorta in the Basque Country . The localities in
question fall within the boundaries of various autonomous communities
Castile and León
Castile and León (provinces of
León , Palencia and Zamora ), and the Basque Country (provinces of
Álava ). There have been unconfirmed findings of this
slug reported from
Natura 2000 sites for this species in
Spain include 48 localities
(listed below, grouped by region). As at 2017 some of these sites have
yet to be designated as
Special Areas of Conservation:
Muniellos ; Ponga —
Amieva ; Redes ;
Camesa river ;
Special Area of Conservation; Liébana
Special Protection Area ); "Upper valleys of the Nansa and Saja and
Alto Campoo ");
* Castile and León
Vegacervera ; Lake Sanabria and its vicinities; Montes
Site of Community Importance );
Montes Aquilanos y Sierra
de Teleno (SPA); Natural Park of Fuentes Carrionas and Fuente
Cobre-Montaña Palentina (SAC);
Sierra de la Cabrera (SCI partially
overlapping with a SPA of the same name).
Anllóns river ; Baixa Limia ; Baixa Limia - Serra do
Xurés ; Baixo Miño ; Bidueiral de
Montederramo ; Carballido, a yew
A Fonsagrada ;
Carnota - Monte Pindo;
Cíes Islands ; Costa
Costa da Morte
Costa da Morte - two areas,
Costa da Morte
Costa da Morte and Costa da
Morte (Northern); Cruzul-Agüeira; Encoro de
Abegondo -Cecebre ; Eo
river (included among the Galician sites although the estuary forms
the boundary with Asturias); Costa de
Valdoviño ; Fragas
do Eume ; Macizo Central,
Ourense (province) ;
Monte Aloia ; Monte
Negueira ; Pena
Trevinca ; Pena Veidosa; Serra do Candán;
Serra do Cando; Serra do Xistral; Sil river canyon ; Sobreirais do
Arnego ; Tambre - two areas, the river and its estuary; Támega river
; Ulla-Deza river system
* More than one region
ANCARES - This district is divided between Galicia and Castile and
León . Sierra de los Ancares is a mountain range which forms the
boundary between the two autonomous communities, and which gives its
name to a
Natura 2000 site in the province of León. On the Galician
side of the sierra are two relevant sites - Ancares (protected under
the Birds Directive) and Ancares-Courel (protected under the Habitats
Directive). PICOS DE EUROPA - This mountain range is divided
between three autonomous communities. The three sites listed (Picos de
Picos de Europa
Picos de Europa (Asturias),
Picos de Europa
Picos de Europa en Castilla y
León) include protected areas in the
Picos de Europa
Picos de Europa National Park ,
and a regional park in Castile and Leon which is also called Picos de
The alarm response posture, which is found only in this species
This species of slug is primarily nocturnal , in other words it is
usually only active at night. During the daylight hours, these slugs
are usually hidden in crevices of rocks and under loose bark on trees.
In Iberia, juvenile slugs of this species become active during
twilight , and adults become active at night, especially on rainy or
very humid nights.
Ireland however is much further north, so the
temperatures there are considerably cooler, there is more rain, and
the air is often quite damp; in
Ireland this slug is sometimes active
in the daytime as long as the weather is humid and overcast.
Kerry slug has a defensive behavior that is very unusual in
slugs. When attacked, most land slugs will simply retract the head and
contract the body, but stay firmly attached to the substrate . In
contrast, when this slug is threatened, it retracts its head, lets go
of the substrate, rolls up completely, and stays contracted in a
ball-like shape. This is a unique feature among all the Arionidae,
and among all slugs in Ireland.
Kerry slug eats liverworts , probably including this
Pellia epiphylla , which is found in localities where the slug
occurs in Ireland. Two individuals among lichen patches on a
rock are not easy to see because of their protective colouration .
Geomalacus maculosus lives only in wild habitats and thus it is
never an agricultural pest, unlike some other slugs in the family
Ireland this slug inhabits wild woodland with oak trees, and
oligotrophic open moorlands , as long as there are boulders covered
with lichens and mosses in these habitats. In
Spain it usually occurs
in granite mountains.
Kerry slug usually prefers acidic soil and high humidity
environments, living on moss and lichen -covered rocks and trees
(mainly the chestnut
Castanea sativa and some species of oak), under
fallen wood and under bark of rotten wood. It may also occur in open
areas, such as hydrophilic pastures near oligotrophic water bodies.
The food of
Geomalacus maculosus includes lichens , liverworts ,
mosses, fungi (
Fistulina hepatica ) and bacteria that grow on
boulders and on tree trunks.
In captivity , this species has been fed on porridge , bread ,
dandelion leaves, lichen
Cladonia fimbriata and various vegetables :
(carrot , cabbage , cucumber , lettuce ). It can be also carnivorous
in captivity, and has been documented as devouring the snail Vitrina
A cluster of eggs deposited in captivity
The mating of this species is in head-to-head position with genital
openings facing each other. Atria are shaped as a funnel with fluted
edges after mating. As in Arion, sperm is transferred in a
spermatophore . Eggs are laid in July to October in the wild, and
from February to October in captivity.
Self-fertilisation is also
possible in this species. The eggs are laid in clusters of 18 to 30,
and held together by a film of mucus . The egg masses are about 3.5 ×
2 cm in overall size.
The eggs are very large compared with the size of the animal, but
vary within certain limits. The largest eggs are more elongate, being
8.5 × 4.25 mm; the smallest eggs are more regularly oval, and are
only 6 × 3 mm. All are semitranslucent milky-white or opalescent when
fresh, although some of the larger and more elongate ones show a
somewhat transparent area at the smaller end. The opalescent (the
color changes with the light direction like an opal) lustre becomes
lost in a few days, and the eggs turn yellowish, and later brown, or
The young appear to hatch in from 6 to 8 weeks, at which period the
spots on the body of the animal are barely present. However, the
lateral bands are distinct and black, much more conspicuous than they
are in mature slugs of this species. In juveniles the shield shows
lyre -shaped markings, as is the case in slugs of the genus Arion.
However these lyre-shaped markings become indistinct as the slugs grow
larger. The slugs probably pass the winter in the sexually immature
stage. The body of preserved juvenile specimens is up to 3 cm (1.2
in) long with a mantle length of 10 mm. Juveniles reach maturity in 2
years, at a length about 2.6 cm. The life span of Geomalacus
maculosus in the wild is up to seven years, but the lifespan in
captivity is rarely over three years. In numerous different
localities in Spain, it was consistently found to be the case that no
more than a very few individuals of the species were observed at any
There were not known natural enemies of
Geomalacus maculosus up to
2014. Predators of
Geomalacus maculosus include larvae of the third
instar of the fly
Tetanocera elata .
THREATS TO THE SURVIVAL OF THE SPECIES
One threat to the habitat of this slug is the invasive plant
Rhododendron ponticum , as shown flowering here in Killarney
National Park .
The most serious threat to the species is probably modification of
the habitat , which reduces its lichen and moss food sources. This
can lead to the local disappearance of the species, which was
documented in Spain. Other threats include: intensification of land
use (land reclamation , using of pesticides , overgrazing by sheep ,
removing of shrubs , building gardens, burning, and building roads and
highways), tourism , general development pressure, coniferous forest
plantations , the spread of invasive species of plants such as
Rhododendron ponticum and habitat fragmentation (see also Moorkens
Other potential dangers to the species include climate change and air
pollution , because these negatively affect the lichens which are a
food source for the slug.
Climate change will probably affect the
Iberian populations more seriously, because the climate there is
already on the hot and dry side relative to Ireland, which is
generally rather cool and damp.
Because of its perceived rarity and its restricted distribution,
Geomalacus maculosus is protected under the Convention on the
Conservation of European Wildlife and Natural Habitats (Bern
Convention), EIS Bern Invertebrates Project. This decision was backed
by studies of its distribution and ecology in
Ireland which concluded
that evidence of a decline in Iberia, plus uncertainty over its status
in Ireland, tended to support its inclusion in the Convention. Since
Geomalacus maculosus has been considered a least concern species
IUCN Red List
IUCN Red List , however, during 1994 to 2006 the slug was
rated as vulnerable .
Geomalacus maculosus is also protected by the European Union's
Habitats Directive (which was a response to the Bern Convention) and
has been listed as an Annex II and Annex IV species since 1992. There
are two principal mechanisms used by the Directive to protect habitats
* the creation of
Special Areas of Conservation
Special Areas of Conservation (SACs)
* the protection of species independently of their habitats by other
Seven SACs have been designated for this species in
Ireland and 49
SCIs in Spain. It is probably in areas not specifically protected as
SACs that threats to the
Kerry slug will be greatest. The Habitats
Directive protects the
Kerry slug outside the SACs by Article 12 (1),
which obliges European Union member states to:
* establish ‘a system of strict protection’ for listed species
* prohibit deliberate capture or killing
* prohibit ‘deliberate disturbance … particularly during the
period of breeding, rearing, hibernation and migration’
* prohibit ‘deliberate destruction or taking of eggs from the
* prohibit the deliberate or non-deliberate ‘deterioration or
destruction of breeding sites or resting places’.
PROTECTION IN IBERIA
Conservation status reports from
Portugal and from
Spain were not yet
available in August 2009.
Its conservation status in
Spain for the IUCN criteria is vulnerable.
PROTECTION IN IRELAND
In 1988 Platts and Speight noted that only three of the Irish sites
where the slug occurred were protected:
Glengariff Forest , West Cork;
Uragh Wood Nature Reserve , South Kerry; and
Killarney National Park
Killarney National Park ,
North Kerry. They concluded that the species could not be adequately
safeguarded with only three sites, and therefore they supported its
inclusion in the Bern list, to which the Irish government is a
Habitats Directive was transposed into Irish law by:
* The EC (Natural Habitats) Regulations 1997. This was the
principal legislation transposing the
Habitats Directive and upgraded
the protection of the Kerry slug's habitat by the designation of
Special Areas of Conservation
Special Areas of Conservation (as listed in the distribution section
* Adapting existing legislation. The
Kerry slug has been protected
since 1990 under the Irish Wildlife Act of 1976 ; it was added to the
list of protected species by
Statutory Instrument 112/1990, and was
the only gastropod so protected. The treatment of the Kerry
been cited in the media as an example of hyperprotectionism
(specifically, in the context of delays to a by-pass). However, The
Wildlife Act does not protect the slug from authorised or unauthorised
indirect damage, but only from wilful direct damage such as
The Irish National Parks and Wildlife Service published a Species
Action Plan for the
Kerry slug in January 2008. Efforts were made to
protect the slug from indirect damage arising, for example, from
commercial forestry. However, following a legal challenge to
Ireland's transposition and implementation of the Habitats Directive,
the Action Plan was superseded in May 2010 by a Threat Response Plan .
The Threat Response Plan addressed issues which arose when the
European Court of Justice
European Court of Justice held that
Ireland was not protecting the
Kerry slug with the strictness that the directive required in respect
of a species listed in annex 4.
In a report to the
European Commission covering 1988–2007, the
conservation status of the species in
Ireland was declared "favourable
(FV)" in all evaluated criteria (range, population, habitat and future
prospects). However, the validity of this assessment was put into
question by the
European Court of Justice
European Court of Justice ruling discussed above,
which held that
Ireland was not monitoring the slug properly.
The need to improve monitoring was discussed by the NPWS Threat
Response Plan of 2010, which recognised that population statistics
were still deficient, particularly outside the SACs. As the Threat
Response Plan noted, species monitoring is a process in which
distribution and status of the subject are evaluated systematically
over time. Under this definition no monitoring of the Kerry
yet been undertaken in
Ireland as of May 2010. In order to take
matters forward, the Kerry
Slug Survey of Ireland, a collaboration
between the National Parks and Wildlife Service and the Applied
Ecology Unit at the
National University of Ireland, Galway
National University of Ireland, Galway ,
researched a "suitable monitoring protocol" for the species. The
Slug Survey's investigations resulted in the publication of a
guide to the population dynamics of the Kerry slug; this guide was
published as part of the Irish Wildlife Manual series in 2011.
Since 1990, the species has been successfully bred in captivity. The
Wildfowl -webkit-column-width: 40em; column-width: 40em;
* ^ A B "
Geomalacus maculosus". 2006
IUCN Red List
IUCN Red List of Threatened
Species. Retrieved 18 July 2007. External link in work= (help )
* ^ A B Allman, G. J. (1843). "On a new genus of terrestrial
gasteropod". The Athenaeum. London (829): 851.
* ^ A B Simroth, H. (1894). "Beiträge zur Kenntniss der
portugiesischen und der ostafrikanischen Nacktschnecken-Fauna".
Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft (in
German). Frankfurt am Main. 18 (3): 289–307, table 1, figure 1,
table 2, figure 1–3.
* ^ Castro, J. da Silva (1873). "Mollusques terrestres et
fluviatiles du Portugal. Espèces nouvelles ou peu connues". Jornal de
sciencias mathematicas, physicas, e naturaes (in French). Lisboa. 4:
* ^ "
Geomalacus maculosus General Information". EUNIS biodiversity
European Environment Agency
European Environment Agency (EEA). Retrieved 27 June 2010.
* ^ Simpson, D. P. (1979). Cassell's Latin Dictionary (5 ed.).
London: Cassell Ltd. ISBN 0-304-52257-0 .
* ^ Wade, C. M., Mordan, P. B. & Clarke, B. (2001). "A phylogeny of
the land snails (Gastropoda: Pulmonata)" . Proceedings of the Royal
Society B: Biological Sciences . 268 (1465): 413–422. doi
:10.1098/rspb.2000.1372 . PMC 1088622 . PMID 11270439 . CS1 maint:
Multiple names: authors list (link )
* ^ A B C D E F G H I J K L M N O . Conservation Status Assessment
Report. National Parks & Wildlife Service, Department of the
Environment, Heritage and Local Government, Ireland. February 2008.
Missing or empty title= (help ); contribution= ignored (help ) 9 pp.
* ^ A B Kerney, M. P; Cameron, A. D.; Jungbluth, J. H. (1983). Die
Landschnecken Nord- und Mitteleuropas (in German). Hamburg and Berlin:
Verlag Paul Parey. p. 138. ISBN 3-490-17918-8 .
* ^ A B O'Hanlon, A.; Feeney, K.; Dockery, P.; Gormally, M. J.
(2017-07-10). "Quantifying phenotype-environment matching in the
protected Kerry spotted slug (Mollusca: Gastropoda) using digital
photography: exposure to UV radiation determines cryptic colour
Frontiers in Zoology . doi :10.1186/s12983-017-0218-9 .
* ^ A B C D E F G H I J K L M N O P Q R S T U V W X Taylor, J. W.
(1907). Monograph of the land and freshwater Mollusca of the British
Isles. Testacellidae. Limacidae. Arionidae. pt 8–14. Leeds: Taylor
brothers. pp. 253–259.
* ^ A B Scharff, R. F. (1891). The slugs of Ireland. The Scientific
Transactions of the Royal Dublin Society, volume IV., series II.
Royal Dublin Society
Royal Dublin Society ; London, Williams Speight, M. C. D.
(1988). "The taxonomy and distribution of the
Kerry slug Geomalacus
maculosus Allman, 1843 (Mollusca: Arionidae) with a discussion of its
status as a threatened species". Irish Naturalists\' Journal . 22
* ^ A B Pilsbry H. A. (1898). "Phylogeny of the genera of
Proceedings of the Malacological Society of London 3:
* ^ A B C Godwin-Austen, H. H. (1882). Land and freshwater mollusca
of India, including South Arabia, Baluchistan, Afghanistan, Kashmir,
Nepal, Burma, Pegu, Tenasserim, Malaya Peninsula, Ceylon and other
islands of the Indian Ocean; Supplementary to Masers Theobald and
Hanley's Conchologica Indica. Plates to Volume I. Taylor and Francis,
London. Plate XII, figure 5.
* ^ (in German) Simroth, H. (1891). "Die nacktschnecken der
portugiesisch-azorischen fauna in ihrem Verhältnis zu denen der
paläarktischen region überhaupt". Nova Acta Academiae Caesareae
Leopoldino-Carolinae Germanicae Naturae Curiosorum 56(1): 201–424,
Tab. IX-XVIII. Halle.
Geomalacus maculosus is on page 351–355.
* ^ (in French) Germain L. (1930). Mollusques terrestres et
fluviatiles. Première partie. Faune Fr., lechevalier, Paris, 21: 477
* ^ Quick H. E. (1960). "British slugs (Pulmonata; Testacellidae,
Arionidae, Limacidae". Bulletin of the British Museum (Natural
History). Zoology 6(3): 103-226.
* ^ "Family summary for Arionidae".
AnimalBase , last change
12-06-2009, accessed 4 August 2010.
* ^ A B C D E F "Plano Sectorial da Rede Natura 2000. "Fauna,
Invertebrados"" (PDF) (in Portuguese). Portugal: Instituto de
Conservação da Natureza e da Biodiversidade. 2006. Archived from the
original (PDF) on 26 December 2009. Retrieved 25 September 2009.
* ^ A B Viney, Michael (May 5, 2010). "Problems with plan for
protection of slugs".
Irish Times . Retrieved May 2, 2012.
* ^ Mascheretti, S.; Rogatcheva, M.B.; Gündüz, İ.; Fredga, K.;
Searle, J.B. (2003). "How did pygmy shrews colonize Ireland? Clues
from a phylogenetic analysis of mitochondrial cytochrome b sequences"
. Proceedings of the Royal Society B. 270: 1593–1599. doi
:10.1098/rspb.2003.2406 . PMC 1691416 . PMID 12908980 .
* ^ Reich, I.; Gormally, M.; Allcock, A.L.; Mc Donnell, R.;
Castillejo, J.; Iglesias, J.; Quinteiro, J; Smith, C.J. (2015).
"Genetic study reveals close link between Irish and Northern Spanish
specimens of the protected Lusitanian slug
Biological Journal of the Linnean Society. 116: 156–168. doi
* ^ Genetic study reveals close link between Irish and Northern
Spanish specimens of the protected Lusitanian slug Geomalacus
The Linnean Society of London , Biological Journal of
the Linnean Society
* ^ A B C D E F G H I J K L M
Species Action Plan. Kerry Slug.
Geomalacus maculosus (PDF). Ireland: National Parks ">(PDF) on
2007-12-18. 9 pp.
* ^ Kearney, Jon (2010). "
Kerry slug (
Geomalacus maculosus Allman
1843) recorded at Lettercraffroe, Co. Galway". Irish Naturalists
Journal . 31: 68–69.
* ^ A B C
Geomalacus maculosus. EUNIS (European Nature Information
System), European Topic Centre on Biological Diversity, European
Environment Agency . Retrieved 2017-06-17.
* ^ A B Ketch, Catherine (2012), Kerry
Slug researcher visits Baile
Bhúirne and Beara,
* ^ A B C Threat Response Plan, Ireland: National Parks & Wildlife
Service. Retrieved 24 June 2012
* ^ Castillejo, J. (1998). Guia de las babosas Ibericas (in
Spanish). Santiago de Compostela: Real Academia de Ciencias. 154 pp.
* ^ A B C D Castillejo, J.; Iglesias, J. (2007). Geomalacus
(Geomalacus) maculosus Allman, 1843. Libro Rojo de los Invertebrados
de España (PDF) (in Spanish). pp. 351–352.
* ^ Sierra de los Ancares, Urugallo cantábrico website (LIFE
Programme : Capercaillie Project)
* ^ "Ancares (ES0000374)". EEA. Retrieved 21 July 2016.
* ^ "Ancares-Courel (ES1120001)". EEA. Retrieved 22 July 2016.
* ^ A B C D E Ramos, M. A. (1998). "Implementing the habitats
directive for mollusc species in Spain". Journal of Conchology.
Molluscan Conservation: A Strategy for the 21st Century, Special
Publication (2): 125–132.
* ^ A B C D E F G H I Wiesniewski, P. J. (2000). "Husbandry and
breeding of Kerry spotted slug". International Zoo Yearbook. 37 (1):
319–321. doi :10.1111/j.1748-1090.2000.tb00736.x . (subscription
* ^ Rodriguez,, T.; Ondina, P.; Outeiro, A.; Castillejo, J. (1993).
"Slugs of Portugal. III. Revision of the genus
Geomalacus Allman, 1843
(Gastropoda:Pulmonata: Arionidae)" (PDF). Veliger. 36 (2): 145–159.
Retrieved 7 March 2016.
* ^ Rogers, T. (1900). "The eggs of the Kerry
maculosus, Allman". Irish
Naturalist . 9: 168–170, plate 5.
* ^ A B Giordani I.; Hynes T.; Reich I.; Mc Donnell R. J.; Gormally
M. J. (2014). "
Tetanocera elata (Diptera: Sciomyzidae) Larvae Feed on
Geomalacus maculosus (Gastropoda: Arionidae):
First Record of Predation". Journal of Insect Behavior . 27 (5):
652–656. doi :10.1007/s10905-014-9457-1 .
* ^ A B . Conservation Status Assessment Report. National Parks &
Wildlife Service, Department of the Environment, Heritage and Local
Government, Ireland. 25 February 2008. Missing or empty title= (help
); contribution= ignored (help )
* ^ A B "Checklist of protected ">(PDF). National Parks & Wildlife
Service, Department of the Environment, Heritage and Local Government,
Ireland. 7 January 2009. 15 pp., cited page: p. 12.
* ^ Eionet (European Environment Information and Observation
Network), European Topic Centre on Biological Diversity. "Geomalacus
maculosus". Retrieved 18 August 2009.
* ^ SI 94/1997 as amended by EC (Natural Habitats) (Amendment)
Regulations SI 233/1998 and SI 378/2005.
* ^ "Wildlife Act, 1976 (Protection of Wild Animals) Regulations,
1990". Retrieved August 30, 2012.
* ^ "By the Time We\'ve Saved the Slugs, the Snails and Those
Viking Graves, Who Will Save the Commuter?".
Daily Mail (London).
McClatchy-Tribune Information Services. 2007. Retrieved July 21, 2014
HighBeam Research (subscription required)
* ^ Bruce, Helen (January 2008). "On the wild frontier; (1) Under
threat: The otter is a perennial favourite for children and nature
enthusiasts, with its expressive features, dog-like playfulness, grace
in the water and furry coat (2) Image problem: Not as cuddly as the
otter but the Kerry
Slug is still in need of our help". Daily Mail
(London). McClatchy-Tribune Information Services. HighBeam Research
(subscription required). Retrieved August 30, 2012.
* ^ "Kerry
Slug and Otter Guidelines". The Forest Service,
Department of Agriculture, Fisheries and Food . 2009. Retrieved
October 9, 2012.
* ^ Commission v
Ireland C-183/05. (The court case did not just
involve the Kerry slug, but considered wider transposition failures by
* ^ Kerry
Slug Survey of
Ireland (Official Website) Retrieved 3
* ^ Mc Donnell, R.J. and Gormley M.J. (2011). Distribution and
population dynamics of the Kerry Slug, Irish Wildlife Manual No 54,
National Parks and Wildlife Service, Department of Arts, Heritage and
the Gaeltacht , Dublin
* Allman, G. J. (1844). "On a new genus of terrestrial gastropod".
Report of the
British Association for the Advancement of Science
British Association for the Advancement of Science 1843:
* Allman, G. J. (1846). "Description of a new genus of pulmonary
Annals and Magazine of Natural History 17: 297–299,
* Boycott A. E., Oldham C. (1930). "The food of Geomalacus
maculosus". Journal of Conchology. 19: 36.
* Oldham, C. (1942). "Notes on Geomaculus maculosus". Proceedings of
The Malacological Society of London 25.
* Heynemann, D. F. (1873). "On the French species of the genus
Geomalacus". Annals and Magazine of Natural History, pages 271–275.
* (in German) Heynemann, D. F. (1869). "Zur Kenntniss von
Geomalacus". Nachrichtsblatt der Deutschen Malakozoologischen
Gesellschaft, pages 165–168.
* (in German) H