Diaphana lactea ( Jeffreys, 1877 ), Jeffreys, 1877

Ohnheiser, Lena Tina & Malaquias, Manuel António E., 2014, The family Diaphanidae (Gastropoda: Heterobranchia: Cephalaspidea) in Europe, with a redescription of the enigmatic species C olobocephalus costellatus M. Sars, 1870, Zootaxa 3774 (6), pp. 501-522: 507-509

publication ID

http://dx.doi.org/10.11646/zootaxa.3774.6.1

publication LSID

lsid:zoobank.org:pub:1C4C791C-09D7-4711-9D05-1ABE3DB24916

persistent identifier

http://treatment.plazi.org/id/252DDC3C-3522-6801-7D8B-FC74FBF45A41

treatment provided by

Plazi

scientific name

Diaphana lactea ( Jeffreys, 1877 )
status

 

Diaphana lactea ( Jeffreys, 1877)  

( Figs 5 View FIGURE 5 A –D, 6 A –D)

Utriculus lacteus Jeffreys 1877: 334   .

Retusa lactea   — Sykes 1905: 31, pl. 3, fig. 4

Diaphana lactea   — Bouchet & Warén 1979: 229 –231, 237. Høisaeter 1986: 100. Schiøtte 1998: 122, figs 22 A, 24 A –C. Sneli et al. 2005: 96.

Diaphana jonica Geronimo 1974: 151   , 152, pl. 2 fig. 2 (based on Schiøtte 1998).

Diagnosis. Shell external, white to transparent, elongate cylindrical, smooth. Body white. Foot posteriorly bifurcated, cephalic shield with tentacular lobes. Rachidian tooth denticulate, asymmetrical, lateral teeth with minute denticulation, teeth on left side smaller than on the right.

Type locality. Station 12, Valorous expedition.

Material examined. Norwegian Sea, off Trondheim (64 ° 16 ' 54 ’’ N, 00° 11 ' 42 ’’ W), 3 spcs (dissected), ZMBN 85923, H = 3.7, 3.8 mm. SE of Jan Mayen (70 ° 26 ' 12 ’’ N, 06° 31 ' 48 ’’ W), 1 spc (dissected), ZMBN 85934, H = 5.8 mm. Norwegian Sea, Trondheim area (63 ° 58 ' 12 ’’ N, 00° 23 ' 42 ’’ W), 1 spc (dissected), ZMBN 85932, H = 3.9 mm. North of Faroe Islands (63 ° 45 ' 12 ’’ N, 00°07' 60 ’’ W), 1 spc (dissected), ZMBN 85933, H = 3.9 mm. Between Iceland and Jan Mayen (68 ° 46 ' 57 " N, 012° 31 ' 39.6 " W), 3 sh, ZMBN 90574, H = 2.14–2.26 mm.

Shell ( Fig. 5 View FIGURE 5 A –D): Maximum H = 5.8 mm. External, thick; white to whitish transparent; elongate cylindrical in shape, middle part of shell straight, narrowing anteriorly and posteriorly, other side uniformly rounded, aperture wide with thin parietal callus, columellar lip straight, apex sunken, mammillate, but protoconch not protruding top of last whorl, umbilicated; shell surface smooth.

Animal: Body white. Foot posteriorly bifurcated. Cephalic shield with tentacular lobes posteriorly.

Radula ( Fig. 6 View FIGURE 6 A –C): Radular formula 11 x 1.1. 1. Rachidian tooth with two flat denticulate lobes separated by gap with a pointed small cusp, lobes asymmetrical, right lobe larger. Lateral teeth long, inner edge denticulate. Radula asymmetrical with left inner laterals much smaller than the right laterals, one large denticle on tip of left laterals only.

Male reproductive system ( Fig. 6 View FIGURE 6 D): Prostate emerging as undivided lump from penial sheath in a right angle, external seminal groove continuing as open groove through penial sheath.

Ecology. Specimen examined by Schiøtte (1998) were found on mud, sand, silty sand, shell sand, clay, foraminifera, gravel and silt from 559–4268 m depth.

Distribution. Reported from the Norwegian Sea, the Faroe Islands, the Denmark Strait, North Atlantic and the Mediterranean Sea ( Schiøtte 1998; Høisaeter 2009; Sneli et al. 2005; present study).

Remarks. This species was redescribed by Schiøtte (1998). Lemche (1948) did not include Diaphana lactea   in his review of northern Atlantic species. During the present study denticulation of the rachidian tooth was found to be variable from almost absent to coarsely denticulate (fig. 6 F, G). The seminal groove continued as open channel in the penial sheath, which was not the case in the other Diaphana   species studied here. It is most abundant below 2000 m depth and therefore considered a species of abyssal affinities ( Høisaeter 2010).

ZMBN

Museum of Zoology at the University of Bergen, Invertebrate Collection

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Cephalaspidea

Family

Diaphanidae

Genus

Diaphana

Loc

Diaphana lactea ( Jeffreys, 1877 )

Ohnheiser, Lena Tina & Malaquias, Manuel António E. 2014
2014
Loc

Diaphana lactea

Sneli 2005: 96
Schiotte 1998: 122
Hoisaeter 1986: 100
Bouchet 1979: 229
1979
Loc

Retusa lactea

Sykes 1905: 31
1905
Loc

Utriculus lacteus

Jeffreys 1877: 334
1877