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Marine slugs

Lamellaria latens. Lateral view of moving specimen. Low profile. Unobtrusive small tubercles. Length 10mm. In Laminaria holdfast, LWS, Menai Strait, Wales. February 2011.
Lamellaria latens
Lamellaria perspicua. 20 mm long (excluding projection of foot). Mantle curved into respiratory siphon. Dome is rarely depressed lower than in this picture, while L. latens always has a lower profile than this. LWS Menai Strait, Anglesey, Feb. 2011.
Lamellaria perspicua
Philine punctata. Length 4mm. m: mantle covering shell. a: abrasion through mantle exposing shell. c: cephalic shield. p: parapodial lobe. On 10cm long stone encrusted with organisms. LWS, Menai Strait, Wales. April 2011.
Philine punctata
Runcina coronata. Foot distinctly separated from fused mantle/cephalic-shield, which folds down over its anterior margin. Posterior of foot and gill extended behind mantle. Weymouth, England. April 2012.
Runcina coronata
Elysia viridis 2. Green parapodial lobes with dendritic digestive gland closely resemble a leaf. On red algae in rock pool. Lower shore, Dorset. January 2011.
Elysia viridis
Placida dendritica
Hermaea bifida. Translucent white with maroon-red surface pigment on the head, along the flanks below the cerata, and on long slender metapodium. Internal pink-red patch (buccal mass?) visible below eye patch. Portland Harbour. April 2012.
Hermaea bifida (Montagu, 1816)
Limapontia capitata. Length 3mm. Metapodium (tail), eye areas, rhinophoral crests and central area of back, all white. Small greenish patches with a few reflective flecks of green. Menai Strait, Wales. April 2011.
Limapontia capitata
Limapontia depressa. L. 5mm. Chrome-yellow. 1: side of foot. 2: edge of mantle. 3: pale patch marks bursa copulatrix. 4: point of penis eversion. 5: head overhanging anterior. 6: eye-patch rib in profile. Dee Estuary, Cheshire. July 2011.
Limapontia depressa
Limapontia senestra. Length 4.3mm. Pale patches weakly developed on dorsum and subdorsally. Pale digitiform rhinophores, eye patches and metapodium (tail). Medial notch in tip of metapodium. Yellowish penis below right eye. Orkney. March 1975.
Limapontia senestra
Akera bullata. 1: shell. 2: Parapodial lobe, pale inner surface visible anteriorally. 3: Curved expansion of cephalic disc to form ear-like lobes with white rims. 4: Eye. In soakaway pond of marine aquarium, Oban, Scotland. April 2010.
Akera bullata
A. depilans; “finger test”. Cornwall, England. December 2014. Leg. D. Fenwick
Aplysia depilans
Length 25mm. Flamborough, England. September 2014. Leg. S.Taylor.
Aplysia punctata
Berthella plumula with gill well exposed and oral veil expanded. Eastbourne, East Sussex, England. October 1988.
Berthella plumula
Doto coronata. Body length 12mm. Genital papilla below first ceras. White upper surface of foot protudes all around body. 5 circles of tubercles on some cerata (maximum often 4). February 2013. Menai Strait. Wales.
Doto coronata
Doto koenneckeri. L. 9mm. Unpigmented pale subdorsal lines. Single row of five cerata each side of body leaving dorsum fully exposed. No cnidosacs. LWS, Menai Strait, Wales. August 2010.
Doto koenneckeri
Doto sarsiae. Length 8.5 mm. Large specimen with yellowish tinted epithelium and orange-red viscera. Tiny seventh pair of cerata concealed by sixth pair. On Garveia nutans, LWS, Menai Strait, Wales. April 2011. Conf. B. Picton.
Doto sarsiae
Lateral view of Goniodoris castanea. Length 10mm. Erect rim and medial ridge on the reduced mantle. Gills partially expanded. LWS, Menai Strait, Wales. April 2011.
Goniodoris castanea
Lateral view of Goniodoris nodosa. Length 12mm. Colourless gills. Mantle does not conceal sides of body. On rocky shore exposed to strong currents, ELWS, Menai Strait, Wales. March 2011. Found by spawn.
Goniodoris nodosa
Ancula gibbosa. Length 10mm. Sides of head extended into short oral tentacles, but no propodial tentacles on foot. Two forward pointing elongate papillae at base of each rhinophore. Extreme low water spring tide, Menai Strait, Wales. March 2011.
Ancula gibbosa
Onchidoris bilamellata. Length 13mm. Round-headed, large and small club-shape tubercles cover mantle. Up to 16 oblique lamellae on rhinophores. Gills unipinnate. February 2013. Menai Strait, Wales.
Onchidoris bilamellata
Onchidoris depressa. Length 4mm. Depressed profile. Long soft colourless tubercles. Rhinophores faintly yellowish, with oblique lamellae. Translucent gills on right of image. Menai Strait, Wales. September 2011.
Knoutsodonta depressa (Alder & Hancock, 1842)
Onchidoris inconspicua. Length 6mm. Seen from directly above against dark viscera, pale dorsal tubercles form light halos around their apical spots. Orkney. March 1975. det. Bernard Picton
Knoutsodonta inconspicua (Alder & Hancock, 1851)
Onchidoris muricata. Length 8mm. Translucent gills on left of image. Ten oblique lamellae on rhinophores. Club-shape tubrcles with broad rounded tops on mantle. Menai Strait. March 2012.
Onchidoris muricata
Onchidoris sparsa. 7.5mm (longer when extended). 1: Ground colour pinkish, seen in lines dissecting brown pigment. 2: Pale lines alternate with dark blocks around periphery. Click “View image details” for 3 –8.
Knoutsodonta sparsa (Alder & Hancock, 1846)
Acanthodoris pilosa. Length 11mm. Soft, tall, thin, conical tubercles on mantle give shaggy appearance. Menai Strait, Wales. March 2015.
Acanthodoris pilosa
Adalaria proxima. Image from Alder & Hancock, as Doris aspera. Yellow form most frequent in southern Britain.
Adalaria proxima
Aegires punctilucens. Gill concealed by three tuberculated lobes. Upper surface of foot periphery forms translucent white band sprinkled with opaque white around base of body. Menai Strait, Wales. March 2012.
Aegires punctilucens
Polycera quadrilineata. Yellow pigment on raised mantle rim and flanks. Grey dorsal line on anterior. Some black on gills and rhinophore stems. Yellow propodial tentacle at bottom right of image. Menai Strait. August 2010
Polycera quadrilineata (O. F. Müller, 1776)
Palio nothus. Length 10.5mm. o: folded, flattened, rectangular, lateral oral-lobe. p: extended propodial expansion. Menai Strait, Wales. March 2012.
Palio nothus
Length 11.5mm. Menai Strait.
Thecacera pennigera
Cadlina pellucida. Elliptical outline, low profile. Ample, soft, translucent, white mantle covers whole body. Gills partially contracted. July 2012 .Sublittoral. Setúbal, Portugal.
Cadlina pellucida
Rostanga rubra. Length 10mm. Perimeter of mantle beaded with white spots. Unipinnate gills rise to form narrow cylinder. Foot extends at posterior when moving. Rhinophores thickened by large lamellae. Menai Strait, Wales. February 2013.
Rostanga rubra
Doris ocelligera. Length 13mm. Low rounded tubercles, some with fine dark apical spots. Two spatulate guard-tubercles on rim of rhinophore pit. Gills much darker than mantle, tilted backwards. August 2012. Sublittoral 0.6m. Split, Croatia.
Doris ocelligera
Doris verrucosa. Unpigmented specimen. Translucent rhinophores and unipinnate gills similar colour to, but a bit paler than, mantle. October 2005. Lorient, Brittany, France. Det. J. Prkić. Conf. M. Poddubetskaia.
Doris verrucosa
1 Archidoris pseudoargus. Length 60mm. Ample mantle covers whole body. Surface has blunt spiculose tubercles, variable size, many large. Firm and stiff to touch. Rhinophores slender cone-shape. Menai Strait, Wales. March 2012.
Doris pseudoargus Rapp, 1827
Geitodoris planata. Length 30mm. Pale vaguely stellate areas, each radiating from large pale papilla. Small partially tripinnate gills are pale fawn marked with brown . LWS, Menai Strait, Wales. February 2013.
Geitodoris planata
Jorunna tomentosa. Length 60mm. s: stepped profile (varies). c: raised collar around extended gills. f: pale foot extends beyond mantle at posterior. Gills tripinnate. Orkney. April 1975.
Jorunna tomentosa
Lateral view of Janolus hyalinus. Length 15mm. Foot nearly transparent with pigment flecks on dorsal surface. Metapodium extending from posterior tapers rapidly to fine point. In water’s edge, LWS, Menai Strait, Wales. April 2011.
Janolus hyalinus
Coryphella browni. Length 35mm. Cerata rise from raised ridge of white flesh. Opaque white ovotestis in posterior half. Brown hind gut leads to anus on right flank. On rocky shore exposed to strong currents, LWS, Menai Strait, Wales. February 2011.
Fjordia browni (Picton, 1980)
Coryphella gracilis. Length 8.5mm. White pigment distally on rhinophores and oral tentacles. Medial line on tail reduced to a few opaque white dots. Thin subterminal white pigment band on cerata. LWS, Menai Strait, Wales. April 2011.
Microchlamylla gracilis (Alder & Hancock, 1844)
Coryphella lineata juvenile, 5mm long. Opaque white pigment line on oral tentacle, rhinophore, dorsum, flank and ceras (two lines). LWS, Menai Strait, September 2011.
Fjordia lineata (Lovén, 1846)
Coryphella verrucosa rufibranchialis. Length 6.5mm. Internal pink diagonal band below rhinophores appears as a V in dorsal view. Several small cerata at bases of ceratal groups. Continuous white line on tail, but dorsal line not developed on this one.
Coryphella verrucosa
Flabellina pedata. Length 16mm. On rocky shore exposed to strong currents, LWS, Menai Strait, Wales. April 2011. Pale blobs of ovotestis visible.
Edmunsella pedata
Flabellina pellucida (as Eolis pellucida) from Alder & Hancock. Long tapering translucent oral tentacles attached dorso-laterally to head; have white pigment distally.
Carronella pellucida (Alder & Hancock, 1843)
Catriona gymnota. Length 6mm. Form with powdery distal area of cerata white only. At base of Tubularia on rocky shore exposed to strong currents, ELWS, Menai Strait, Wales. March 2011.
Catriona gymnota
Cuthona caerulea. Length 4mm. Olive green digestive gland. Only vestiges of orange bands below blue band. Apical orange is internal orange cnidosac plus orange surface pigment. LWS, Menai Strait, Wales. March 2012
Trinchesia caerulea (Montagu, 1804)
Cuthona foliata. Length 6mm. Rhinophores densely covered in freckles of white pigment except for an encircling band of dull translucent orange. On rocky shore exposed to strong currents, LWS, Menai Strait, Wales. April 2011.
Trinchesia foliata (Forbes & Goodsir, 1839)
Cuthona nana. Length 6mm. Part grown, so cerata do not extend in front of rhinophores. On Hydractinia echinata on shell of Hermit crab on shore with rocks and muddy sand. LWS, Menai Strait, Wales. March 2010.
Cuthona nana
Tergipes tergipes. Length 3mm. Cerata arranged singly, white cnidosacs inside tips. Rhinophores much longer than oral tentacles. White ovotestis in body. April 2011. LWS, Menai Strait, Wales
Tergipes tergipes
Eubranchus exiguus. Cerata in groups of 1 large & 1 small; apical band of brown and white, with white band below. Two indistinct bands of brown flecks lower down, with scatter of white flecks. Peach digestive gland. LWS, Menai Strait, Wales. March 2011.
Eubranchus exiguus
Eubranchus farrani. Length 10mm. Orange pigment on rhinophores distally. Distal yellow on cerata. Body pigment restricted to tip of tail on this specimen. Cerata on anterior half lack usual inflation. February 2013. LWS, Menai Strait, Wales.
Amphorina farrani (Alder & Hancock, 1844)
Eubranchus pallidus. Translucent inflated white cerata; pale-brown internal digestive gland, mahogany and white flecks, distally white with sub-apical gold ring . Mahogany band and flecks on rhinophores and oral tentacles. Orkney. February 1975.
Amphorina pallida (Alder & Hancock, 1842)
Facelina auriculata. Length 19mm. Iridescence well developed on head and cerata. White splashes down front of cerata. Yellow lamellae on rhinophores. On rocky shore exposed to strong currents, ELWS, Menai Strait, Wales. March 2011.
Facelina auriculata
Facelina bostoniensis. L.18mm. Foot much wider than body. Cerata long, linear, rather untidy and lack iridescence . Lamellated rosy fawn rhinophores. Internal mouthparts and oesophagus rose-pink. Laxford, Scotland. October 1975.
Facelina bostoniensis
Aeolidia papillosa. Length 26mm. Pink body with pale flecks, and orange-brown cerata (short and stout as at rest). Differences from Aeolidiella glauca: broad gap between oral tentacles, eyes barely visible behind rhinophores. Mersey Estuary. Oct. 2010.
Aeolidia papillosa
Aeolidiella alderi. Typical specimen; white body and tentacles with distal pigment. Brown-filled cerata, except white anterior ruff. No pigment on dorsum. Triangular propodial tentacle continues curve of foot. Lough Hyne, Co. Cork, Ireland.
Aeolidiella alderi
Aeolidiella glauca. Length 20mm. Translucent orange rhinophores with distal white stipple. Anterior cerata form white ruff similar to that of A. alderi, but dorsum has stipple of A. glauca and animal stouter than A. alderi. Low water spring tide, Menai St
Aeolidiella glauca
Aeolidiella sanguinea. Orange specimen with orange-brown internal digestive gland, and distinct white tips on cerata. No surface pigment. Blood-red specimens also occur. LWS, Menai Strait, Wales. Sept. 2009.
Aeolidiella sanguinea