Janthina janthina ( Linnaeus, 1758 )

Beu, Alan G., 2017, Evolution of Janthina and Recluzia (Mollusca: Gastropoda: Epitoniidae), Records of the Australian Museum (Rec. Aust. Mus.) 69 (3), pp. 119-222 : 185-191

Janthina janthina ( Linnaeus, 1758)

Figs 1 , 2A–F , 4A–E , 5A,D , 32–33

Helix janthina Linnaeus, 1758: 772 ; Linnaeus, 1767: 1246 (in part); Born, 1778: 392; Gmelin, 1791: 3645; Dillwyn, 1817: 938.

Janthina violacea Röding, 1798: 75 ; Mörch, 1853: 49; Hedley, 1918: M62; May, 1921: 63; May, 1923: pl. 29, fig. 5; Finlay, 1928: 246; Powell, 1937: 74, pl. 1, fig. 8; Powell, 1946: 77, pl. 1, fig. 8; Allan, 1950: 95, col. pl. 14, fig. 11, text-fig. 22.5; Powell, 1951: 27, fig. 123; Powell, 1957: 98, pl. 1, fig. 8; McMichael, 1960: 72, fig. 143; Powell, 1962: 90, pl. 1, fig. 8; Iredale & McMichael, 1962: 49; Grimmond, 1964: 24; Hodgkin, et al. 1966: 35, pl. 12, fig. 8.

Janthina fragilis Lamarck, 1801: 89 ; Roissy, 1805: 396, pl. 55, fig. 11; Lamarck, 1816, “Liste des objets”: 12, pl. 456, figs 1a–b; Gray, 1827: 495; Lovén, 1847: 190, pl. 3, fig. (radula); Küster, 1868: 4, pl. 1, figs 3–4; Lischke, 1871: 168; Lischke, 1874: 52; Fischer, 1885: 774, fig. 541, pl. 10, fig. 27; Hutton, 1904: 80; Moss, 1908: 28, pl. 7, fig. 2; Pasteur-Humbert, 1962: 52, fig. 73.

Janthina penicephala Péron & Lesueur, 1807 : pl. 27, fig. 1 ( Mörch, 1860: 276), pl. 31 (Sherborn, 1929: 4831).

Janthina communis Lamarck, 1822: 206 ; Payraudeau, 1826: 120; Menke, 1843: 11; Deshayes, 1843: 4; Küster, 1868: 4, pl. 1, figs 1–2; Hutton, 1880: 71; Hutton, 1881: 164, pl. 7, fig. F (radula); Locard, 1898: 1; Suter, 1913: 299, pl. 44, fig. 11.

Ianthina fragilis Lamarck. – G. B. Sowerby I, 1822: 2nd Ianthina page, pl. 191, fig. 1; Reeve, 1842: 145, pl. 205, fig. 1 (repeat of Sowerby’s 1822 fig.); Calder, 1849: 175; Reeve, 1858: pl. 2, figs 6a–b; Benson, 1860: 410; G. B. Sowerby II, 1882: 50, pl. 443, figs 1–4; Tryon, 1887: 36, pl. 10, figs 6–10; Whitelegge, 1889: 261.

Ianthina bicolor Menke, 1828: 84 ; Lesson, 1831: 365, pl. 8, fig. 2.

Janthina vulgaris Gray, 1847b: 148 (nomen nudum); Gray, 1850: 101 (error for J. communis ).

Ianthina planispirata A. Adams & Reeve, 1850: 54 , pl. 11, fig. 10; Benson, 1860: 410.

Ianthina communis Lamarck. – Forbes & Hanley, 1853, vol. 2: 549, pl. 69, figs 6–7; vol. 4: 260, pl. 133, fig. 1; H. Adams & A. Adams, 1854: 87; Reeve, 1858: pl. 1, figs 5a–b; Tenison Woods, 1878: 43; G. B. Sowerby II, 1882: 50, pl. 443, figs 7–8; Pritchard & Gatliff, 1900: 141; Tate & May, 1901: 407.

Ianthina britannica Forbes & Hanley, 1852 , vol. 4: 260 (in synonymy); Reeve, 1858: pl. 3, figs 13a–b; G. B. Sowerby II, 1882: 50, pl. 443, figs 5–6, 14.

Ianthina violacea Röding. – H. Adams & A. Adams, 1854: 86–87, pl. 69, fig. 1; Angas, 1865: 190; Whitelegge, 1889: 261; Verco, 1908: 9; Oliver, 1915: 525; Cotton, 1932: 537; Cotton & Godfrey, 1932: 36, pl. 1, fig. 1; Verco, 1935: pl. 11, fig. 4; Cotton & Godfrey, 1938: 16; Macpherson & Chapple, 1951: 124; Kershaw, 1955: 312; Cotton, 1959: 376.

Ianthina planospirata A. Adams & Reeve. –H. Adams & A. Adams, 1854: 87; Reeve, 1858: pl. 2, figs 9a–b; G. B. Sowerby II, 1882: 50, pl. 443, figs 9–13 (incorrect subsequent spelling of J. planispirata A. Adams & Reeve, 1850 ).

Ianthina striulata Carpenter, 1857: 185 ; Keen, 1968: 408, pl. 59, fig. 79.

Ianthina striulata var. contorta Carpenter, 1857: 186 ; Keen, 1968: 408, pl. 59, fig. 80.

Ianthina affinis Reeve, 1858 : pl. 1, figs 2a–b; Martens, 1904: 142.

Ianthina africana Reeve, 1858 : pl. 2, figs 8a–b.

Ianthina balteata Reeve, 1858 : pl. 3, figs 11a–b; Lischke, 1871: 168; Lischke, 1874: 53; Hedley, 1900: 141; Pritchard & Gatliff, 1900: 141; Martens, 1904: 142; Macpherson & Chapple, 1951: 124; Cotton, 1959: 376.

Ianthina caeruleata Reeve, 1858 : pl. 2, figs 7a–b; Benson, 1860: 412; Whitelegge, 1889: 261.

Ianthina casta Reeve, 1858 : pl. 1, figs 4a–b.

Ianthina depressa Reeve, 1858 : pl. 3, figs 14a–b.

Ianthina fibula Reeve, 1858 : pl. 4, figs 17a–b.

Ianthina grandis Reeve, 1858 : pl. 1, figs 3a–b.

Ianthina involuta Reeve, 1858 : pl. 3, figs 12a–b.

Ianthina roseola Reeve, 1858 : pl. 1, figs 1a–b.

Ianthina smithiae Reeve, 1858 : pl. 3, figs 15a–b; Benson, 1860: 410; Macpherson & Chapple, 1951: 124.

Ianthina trochoidea Reeve, 1858 : pl. 2, figs 10a–b; G. B. Sowerby II, 1882: 50, pl. 444, fig. 15.

Janthina (Iodes) balteata Reeve. – Mörch, 1860: 274.

Janthina (Iodes) smithiae Reeve. – Mörch, 1860: 274.

Janthina (Iodes) planispirata A. Adams & Reeve. – Mörch, 1860: 274.

Janthina (Iodes) costae Mörch, 1860: 274 .

Janthina (Iodes) caeruleata Reeve. – Mörch, 1860: 275.

Janthina (Iodes) depressa Reeve. – Mörch, 1860: 275.

Janthina (Iodes) casta Reeve. – Mörch, 1860: 275.

Janthina (Iodes) britannica Forbes & Hanley. – Mörch, 1860: 276.

Janthina (Iodes) paenicephala Péron. – Mörch, 1860: 276 (incorrect subsequent spelling of J. penicephala Péron & Lesueur ).

Janthina (Achates) fibula Reeve. – Mörch, 1860: 277.

Janthina (Achates) violacea Röding. – Mörch, 1860: 277.

Janthina (Achates) carpenteri Mörch, 1860: 277 .

Janthina (Achates) orbignyi Mörch, 1860: 277 .

Janthina (Achates) fragilis Lamarck. – Mörch, 1860: 278.

Janthina (Achates) roseola Reeve. – Mörch, 1860: 278.

Janthina (Achates) trochoidea Reeve. – Mörch, 1860: 278.

Janthina (Achates) affinis Reeve. – Mörch, 1860: 278.

Janthina (Achates) africana Reeve. – Mörch, 1860: 279.

Janthina (Achates) grandis Reeve. – Mörch, 1860: 279.

Janthina (Achates) involuta Reeve. – Mörch, 1860: 279.

Janthina ianthina (Linnaeus) .– Angas, 1867: 230.

Ianthina rotundata Leach. – Jeffreys, 1867: 186, frontispiece, pl. 3, fig. 1; Watson, 1886: 134.

Janthina balteata Reeve. – Küster, 1868: 9, pl. 2, fig. 4; Martens, 1904: 142; Suter, 1913: 298, pl. 44, fig. 10; Bucknill, 1924: 49, pl. 5, figs 18–18a; Okutani, 1956: 43, text-figs 3–10; Kira, 1962: 30, pl. 14, fig. 23.

Janthina planispirata A. Adams & Reeve. – Küster, 1868: 8, pl. 2, fig. 3; Iredale & McMichael, 1962: 49.

Janthina depressa Reeve. – Küster, 1868: 8, pl. 2, fig. 9.

Janthina casta Reeve. – Küster, 1868: 8, pl. 2, fig. 8.

Janthina fibula Reeve. – Küster, 1868: 9, pl. 2, fig. 5.

Janthina trochoidea Reeve. – Küster, 1868: 8, pl. 2, figs 1–2; Cossmann, 1925: 157, pl. 6, figs 1–2.

Janthina africana Reeve. – Küster, 1868: 8, pl. 2, figs 10–11.

Ianthina ianthina Linnaeus. – Hutton, 1873a: 6; Iredale, 1910: 71; Hedley, 1916: 192; Morton, 1954: 166, figs 1a–c; Cotton, 1959: 376; Salvat & Rives, 1975: 273, fig. 77.

Janthina bicolor Menke. – Monterosato, 1878: 95; Thiele, 1892: 590, pl. 23, fig. 2.

Janthina bicolor var. conica Monterosato, 1878: 95 .

Janthina bicolor var. major Monterosato, 1878: 95 .

Janthina bicolor var. minor Monterosato, 1878: 95 .

Janthina rotundata Leach. – Monterosato, 1878: 95.

Jodes bicolor (Menke) . – Monterosato, 1884: 105.

Ianthina fragilis var. planispirata A. Adams & Reeve. – Tryon, 1887: 36, pl. 9, figs 94–98.

Ianthina fragilis var. britannica (Leach) Jeffreys. – Tryon, 1887: 37, pl. 9, figs 100.1–5, pl. 10, figs 6–9.

Janthina smithiae Reeve. – Melvill & Standen, 1901: 172.

Janthina auriculata Martens, 1904: 142 , pl. 4, fig. 15.

Janthina costae Mörch. – Martens, 1904: 142.

Janthina fragilis var. planispirata A. Adams & Reeve. – Hutton, 1904: 80.

Ianthina janthina Linnaeus. – Laursen, 1953: 15, figs 14–18, pl. 1, fig. 1; Macpherson & Gabriel, 1962: 118, fig. 145.

Janthina violaceae [sic] Röding.– Macpherson, 1958: 33, fig. 29.5.

Janthina janthina Linnaeus. – Berry, 1958: 27; Kira, 1962: 30, pl. 14, fig. 22; Bennett, 1966: 40, pl. 8, figs 1–3; Morton & Miller, 1968: 472, fig. 175.4; Keen, 1971: 442, fig. 688; Kuroda et al., 1971: 245, pl. 62, figs 9–10; Cernohorsky, 1972: 197, pl. 3, fig. 8; Abbott, 1974: 113, col. pl. 3, fig. 1178; Powell, 1976: 107, pl. 1, fig. 8; Kay, 1979: 158, fig. 55B; Powell, 1979: 254, pl. 48, fig. 20; Rehder, 1980: 53; Fretter & Graham, 1982: 392, fig. 279; Kilburn & Rippey, 1982: 79, fig. 39, pl. 11, fig. 18; Wells & Bryce, 1986: 60, fig. 152; Wilson, 1993: 281, pl. 44, figs 36a–b; Rios, 1994: 101, pl. 33, fig. 413; Bosch et al., 1995: 111, fig. 440; Giannuzzi-Savelli et al., 1999: 50, 51, fig. 92; Smith, 1998: 813, figs 15.151A, D–F; Okutani, 2000: 319, pl. 158, fig. 1; Redfern, 2001: 75, pl. 36, fig. 314A; Ardovini & Cossignani, 2004: 136; Morley, 2004: 102, back cover; Robertson, 2007a: 5, fig. 3; Beu & Marshall, 2008: 285; Poppe, 2008: 722, pl. 306, figs 4a–b; Spencer et al., 2009: 206; Raven & Bracegirdle, 2010: 28, top right fig.; Willan et al., 2010: 386, text-fig.; Luque, 2011: 209, text-fig.; Grove, 2011: 40, pl. 18, fig. 10; Severns, 2011: 198, pl. 82, fig. 2; Hernández et al., 2011: 98, figs 30E–H; Janssen, 2012: 24, figs 7A–B.

Janthina (Jodes) bicolor Menke. – Priolo, 1959: 185.

Janthina violacia [sic] Röding.–Penniket & Moon, 1970: 24, pl. 9, fig. 3.

Janthina (Janthina) janthina Linnaeus. – Higo et al., 1999:173.

Type material. Laursen (1953: pl. 1, fig. 1) illustrated the four syntypes of Helix janthina in Linnaeus’s collection held by the Linnean Society of London. Linnaeus’s collection is stored in the Linnean Society’s rooms in Burlington House, London , and is not registered. Laursen discussed the identity of these and the two specimens in UPSZTY that formerly belonged to Queen Louisa Ulrika ( Laursen, 1953: 17, pl. 1, fig. 2). He recognized that the specimens in London are Janthina janthina whereas those in Uppsala are J. globosa . In the text Laursen (1953: 17) briefly discussed the identity of Linnaeus’s specimens, noting that “Specimen no. 7 in fig. 15 is identical with the type represented in plate 1, fig. 1, middle”. However, this seems to mean “type” in the sense of “a syntype ” or “a type of specimen” in general, rather than “the type specimen”, as Laursen (1953: 17) provided the following caption to fig. 15: “ Ianthina janthina (Linné) . Variations in the shape of the shell from the type specimen, no. 3, towards the trochoid forms (2‒1) and the flattened forms (4‒12), respectively. Linné’s original material further includes nos. 7 and 12”. It is clear from this that the specimens shown in Laursen’s (1953: figs 1.3, 1.7 and 1.12; Fig. 33 ) are three of Linnaeus’s four syntypes held by the Linnean Society of London. This mention in the caption possibly qualifies as a valid designation of the specimen in Laursen’s (1953: fig. 15.3) illustration as the lectotype of Helix janthina Linnaeus, 1758 under ICZN Article 74.5, as (a) it is clear from the discussion on this page and in the caption to Laursen (1953: pl. 1) that Laursen was aware that Linnaeus’s syntypes included two species, (b) the statement was published before 2000, (c) Laursen used the term “the type”, and (d) the statement referred to an individual specimen. It seems likely that this is a separate specimen from the one mentioned by Laursen (1953: pl. 1, fig. 1, “middle”), which is significantly larger; apparently it is the specimen shown by Laursen (1953: pl. 15.7). However, no formal lectotype designation is included in Laursen’s text, and it is unclear whether the statement in the figure caption was intended as a lectotype designation. Because of doubts about the validity of Laursen’s (1953: 17, caption) lectotype designation, the syntype of Janthina janthina in Linnaeus’s collection housed by the Linnean Society of London and illustrated by Laursen (1953: fig. 15.3; Fig. 33.3 ) is here designated the lectotype of Helix janthina Linnaeus, 1758 . The two paralectotypes in UPSZTY referred to Helix janthina by Linnaeus (1764: 670) are listed above under J. globosa . The lectotype of Helix janthina is here also designated the neotype of Janthina violacea Röding, 1798 , in order to refer this name unambiguously to J. janthina , rather than supplanting a later name. Laursen (1953) did not provide dimensions of the syntypes (which the writer has not seen), but judging from the original scale on Fig. 33 it is c. 25 mm in diameter. Linnaeus (1758: 772) stated its distribution as “Habitat in Europa, Asia, Africa; in M. Mediterraneo frequentior; etiam pelagica”; this wide distribution allows almost any type locality.

Janthina communis , three syntypes examined, formerly NHMG 1094/79 , now catalogued as NHMG-INVE 41376 , without locality. These are also the syntypes of J. fragilis , which was simply renamed J. communis by Lamarck; Lamarck (1822: 206) listed “ Janthina fragilis . Encyclop. Pl. 456. F.1.a.b” (the proposal of J. fragilis ) in the synonymy of J. communis .All three specimens are conspecific. The locality was stated by Lamarck (1822: 206) as “l’Océan Atlantique et la Méditerranée”. However, Y. Finet ( NHMG pers. comm. 27 Sep 2012) pointed out that, as with J. exigua, Rosalie de Lamarck’s annotation on Lamarck’s copy of Animaux sans vertèbres states that there was only one specimen in Lamarck’s collection, so two of these specimens evidently are not original syntypes. The drawings in Lamarck (1816: pl. 456, fig. 1) are not accurate enough to distinguish specimens, so it is not possible to determine which syntype is the original. Janthina penicephala , from near the Cape of Good Hope ( Mörch, 1860: 16), no type material in MNHN, location of type material not known. The lectotype of Helix janthina designated above in Linnaeus’s collection housed by the Linnean Society of London is here also designated the neotype of Janthina penicephala Péron & Lesueur, 1807 , in order to refer this name unambiguously to J. janthina , rather than supplanting a later name. Janthina affinis , 3 syntypes NHMUK 1972018 , without locality, ex Cuming collection. Janthina africana , 3 syntypes NHMUK 1976163 , from “ Zanzibar ”, ex Cuming collection. Janthina balteata , 3 syntypes NHMUK 1976164 , from “Cape of Good Hope”, ex Cuming collection. Janthina casta , 3 syntypes NHMUK 1972020 , without locality, ex Cuming collection. Janthina caeruleata , 3 syntypes NHMUK 1976162 , without locality, ex Cuming collection. Janthina depressa , 2 syntypes NHMUK 1976166 , without locality, ex Cuming collection. Janthina fibula , 3 syntypes NHMUK 1976169 , without locality, ex Cuming collection. Janthina grandis , 3 syntypes NHMUK 1972019 , without locality, ex Cuming collection. Janthina involuta , 3 syntypes NHMUK 1976165 , without locality , ex Cuming collection; these are unusual, distorted specimens of J. janthina . Mörch (1860: 279) stated that he had found the distorted condition in other species, and attributed it to “implantations d’Anatifes”, i.e., Lepas specimens attached to the Janthina shell. Janthina planispirata , 3 syntypes NHMUK 1951.3.14.1–3 , from “Atlantic Ocean”, ex Cuming collection. Janthina roseola , 3 syntypes NHMUK 1973003 , from “Nicobar”, ex Cuming collection, 3 normal, faintly pinkish-mauve specimens of J. janthina . Janthina smithiae , 3 syntypes NHMUK 1976167 , from Glamorganshire, UK, ex Cuming collection. J. trochoidea , 2 syntypes NHMUK 20130060 , without locality, from the V.W. MacAndrew collection, purchased from G. B. Sowerby (K. Way, NHMUK, pers. comm. 19 Feb 2013), and so probably ultimately from the Cuming collection; 3 possible syntypes also in NMV, purchased from H. Cuming. No specimens considered to be original material of Iodes angularis Leach or Janthina britannica of Leach or Jeffreys are present in NHMUK (K. Way, NHMUK, pers. comm. 05 Feb 2013).

As noted above under Janthina globosa, Keen (1968: 408 , 410, pl. 59, figs 78a–80) recorded and illustrated the type material of all three of Carpenter’s (1857) Janthina names in NHMUK, recording 37 syntypes of I. striulata on Carpenter’s tablets 868–876 (nine tablets) and two syntypes (only one then still preserved) of I. striulata var. contorta on tablet 877. All illustrated specimens are clearly J. janthina , as concluded by Keen (1968), although the illustrated syntype of I. striulata var. contorta is an unusual specimen with a folded columella. Type material of all three names is still present in NHMUK ; I. striulata , 9 syntypes NHMUK 1857.6.4.868 – 876 ; I. striulata var. contorta , 1 syntype NHMUK 1857.6.4.877 (K. Way, NHMUK, pers. comm. 05 Feb 2013). All are from Mazatlan, Mexico.

The writer is not aware of the location of type material of Janthina bicolor , stated to be from Jamaica; R. Janssen ( SMF pers. comm. 18 Aug 2015) confirmed that there is no type material of J. bicolor in the remnants of Menke’s collection in SMF. However, J. bicolor is an earlier name than either J. pallida Thompson, 1840 or J. umbilicata Orbigny, 1841 , so it is desirable to clarify its application with a neotype to avoid it supplanting later names. The lectotype of Helix janthina Linnaeus, 1758 and neotype of Janthina violacea Röding, 1798 designated above, the syntype of Helix janthina in Linnaeus’s collection housed by the Linnean Society of London and illustrated by Laursen (1953: fig. 15.3), is here designated the neotype of Janthina bicolor Menke, 1828 .

Janthina costae ( Mörch, 1860: 274) was identified by a long list of published references, the first two pre-Linnean, followed by “ Janthina bicolor O. Costa. Cat. syst. (1829), p. CVI, no 27” (Mörch did not italicize generic names in this paper) and a further 14 references; Mörch apparently thought this was a species distinct from J. bicolor , i.e., J. janthina . He provided the locality “Méditerranée (Costa)”. Kathe Jensen (ZMUC pers. comm. 18 Aug 2015) stated that there are three specimens in ZMUC identified as “ possible syntypes ” of J. costae, ZMUC GAS-719 , with an early label reading “ Janthina costae Mörch I. Canar [Canary Islands] McAndrew 1865 ii 8 ” (presumably collected by the naturalist Robert McAndrew). This is the only known possible type material. If the date is a collection date, it is unlikely that these are syntypes, but McAndrew likely collected them during his only visit to the Canary Islands in 1852 ( MacAndrew, 2008: 72), Mörch saw them in McAndrew’s collection, McAndrew sent them to Mörch, and they were received on 8 Feb 1865. They are assumed to be authentic syntypes. Janthina carpenteri ( Mörch, 1860: 277) was proposed for “ Janthina striulata Carp. Reig. , p. 185.— fragilis Reeve , fig. 6. Var. contorta Carpenter , Cat. p. 186”, i.e., J. janthina ; no reason was given for renaming it. Kathe Jensen (ZMUC pers. comm. 21 Aug 2015) stated that there are at least three syntypes of J. carpenteri with animal tissue in one phial in the wet collection, ZMUC GAS-1501 , from the Pacific Ocean off Valparaiso, Chile, collected on 23–26 Mar 1847 by Reinhardt during the first Galathea Expedition.

Janthina orbignyi ( Mörch, 1860: 277) was proposed for “ Janthina fragilis D’Orb. Amér. , t. 61, fig. 8”, i.e., again J. janthina . Kathe Jensen (ZMUC pers. comm. 18 Aug 2015) stated that she was unable to find any type material in ZMUC. This is not surprising, as the specimens of J. janthina illustrated under the name J. fragilis by d’Orbigny constitute the syntypes of J. orbignyi , and are in d’Orbigny’s collection of South American Mollusca in NHMUK. Seven syntypes are present, NHMUK 1854.12.4.399 – 400 , bearing the locality “Atlantic Ocean”, and labelled “illustrated in d’Orbigny, 1840. Voy. Amer. Meridian. Moll., 5: 413, pl. 61, figs. 8–10”. Photographs of the four largest specimens were sent by Andreia Salvador (NHMUK pers. comm. 16 Feb 2016), demonstrating that all are specimens of J. janthina . The largest specimen ( Figs 32E–F ), NHMUK 1854.12.4.399a , is here designated the lectotype of Janthina orbignyi . Ianthina auriculata holotype ZMB 60008 (C. Zorn, ZMB pers. comm. 8 Sep 2015); from the Indian Ocean, Valdivia Station 258, near East Africa, 2°58'N 46°50'E, “ein Stück”, i.e., it is the holotype. The illustration ( Martens, 1904: 142, pl. 4, fig. 15) shows a typical trochiform specimen of J. janthina (not seen).

Laursen (1953: 16) listed “ Ianthina fragilis var. spiraelata Mörch, 1860 ” in the synonymy of Janthina janthina . However, Mörch (1860: 278) listed “ Ianthina fragilis … var. spira elata ”, i.e., a variety with an elevated spire, and did not intend to propose a new name.

Other material examined. Holocene fossils: trench excavated through uplifted Holocene terraces, Table Cape, Mahia Peninsula, central E North Island , New Zealand; from north-south transect, terrace 2 (1850±50 years old), basal sediment 117 m inland from high-tide line and 5.5 m above mean sea-level ( GS 15077 , Y19/f062, grid ref. Y19/422212; 1, blue juvenile with low spire and diagnostic axial ridgelets; Beu, 2016: fig. 5P).

Present-day samples from Australia and New Zealand: Australia: Western Australia: Sunday I., Derby ( WAM); Broome ( NMV); Abrolhos Islands ( SAM); Esperance ( NMV); Cape Naturaliste (N2069, N2070, WAM); Leighton Beach ( WAM 249-250); Cheyne Beach ( WAM 2998); Cottesloe (C69307, AMS); Fremantle (N4021, WAM; NMV; AMS); Point Peron, Fremantle ( WAM 367-40); Rottnest I. ( NMV; WAM.909/10-31); Yalingup (N2072, N2073, N2459, N2461, WAM); Windy Harbour, Cape D’Entrecasteaux ( WAM 213-65); Salmon Holes Beach, King George Sound (C69333, AMS); Albany (C56995, AMS; NMNZ M259093, 2). South Australia: Sleaford Bay ( SAM). Victoria: Phillip I. ( NMV); Gabo I. ( NMV); Mallacoota ( NMV). New South Wales: Narooma ( NMV); Woody Head, Iluka (C70070, AMS); Minnie Waters (C70011, AMS); Port Stephens ( NMV, AMS); Port Danger (C5332, AMS); Flat Rock, Richmond River (C50827, AMS); beach E of Bergalia, Moruya ( AMS); Budgewai Beach (C70041, AMS); Nambuca Heads ( NMV); Norah Head (C73966, AMS); Maroubra (C51089, C83051, AMS); Merimbula ( NMV); Broulee, Bateman’s Bay ( NMV; C75537, AMS); Wooli ( NMV, AMS); Manly Beach ( NMV, AMS); Long Reef, Collaroy (C69101, C73827, AMS); Collaroy Beach (C79167, C 77764, AMS); Curl Curl Beach, Sydney (C50583, AMS); Bondi Beach ( AMS); Harbord ( AMS); Coogee, Sydney ( NMV); Cronulla ( AMS); Botany Bay (C83050, AMS); Broken Bay ( NMV); Putty Beach, Kilcare ( AMS); Newcastle ( NMV); Wreck Bay, Sussex Inlet ( AMS); Bombo, near Kiama ( AMS); Port Kembla ( AMS); Shellharbour ( NMV); Ulladulla ( AMS); Twofold Bay (C64284, AMS). Queensland: Darnley I., Torres Strait (C51507, AMS); Two Isles ( WAM); NE Herald Cay, Coral Sea (C69064, AMS); West Cay, Diamond Islets (C69165, AMS); North Keppell I. ( NMV); Frederick Reef (C68587, AMS); Tawnum Beach ( AMS); Caloundra ( NMV; C12497, AMS); Lady Elliott I. ( WAM; C72669, C72994, C69177, AMS); Heron I. ( NMV); Keppell Bay (C320, AMS); Point Lookout, Stradbroke I. ( WAM 159-59; AMS); outer beach, Stradbroke I. ( NMV; C13059, AMS); Moreton Bay ( NMV). Tasmania: Beach End (C11220, AMS); Falmouth (M210983, NMNZ); Frederick Henry Bay ( AMS); Clarke I. ( NMV).

Lord Howe Island: ( WAM; C13803, C29233 , C80906, AMS; NMNZ M213985, 14);Anson Bay ( NMNZ M212602, 6); Middleton Reef ( NMNZ M171237, 1). Norfolk Island: (C59407, C31040, AMS; observed, AGB, collection of Mrs M. Hoare, Norfolk); Emily Bay ( WM 11213, GNS); Cemetery Bay ( NMNZ M212604, 5). Kermadec Islands: Raoul Island ( NMV; AWM; C36652, AMS; GNS WM15297, 73; NMNZ M202861, 60; M202870, 5; M214376, 70).

New Zealand: NW of Three Kings Islands ( NMNZ M020819, 1); W Norfolk Ridge, W of Cape Reinga ( NMNZ M171032, 2; M172330, 5); Te Werahi Beach, Cape Maria van Diemen ( NMNZ M277691, 2); Tapotupotu, E of Cape Reinga ( GNS RM4697, 1; RM6154, 12); Spirits Bay ( NMNZ M277687, 2; M277689, 3); Tom Bowling Bay ( NMNZ M011904, 2); Te Paki, Ninety Mile Beach ( NMNZ M277686, 3); N end of Ninety Mile Beach ( NMNZ M277690, 12; GNS RM4636, 5); The Bluff, Ninety Mile Beach ( GNS RM4058, 3; NMNZ M277693, 4); Paua, Parengarenga Harbour ( NMNZ M277692, 1); Tokerau Beach, Doubtless Bay ( NMNZ M277688, 1); Cavalli Islands, Whangaroa ( NMNZ M308660, 1); Takou Bay ( GNS RM4442, 2; NMNZ M277685, 2); Russell, Bay of Islands ( NMNZ M087141, 2); Whangarei Heads ( NMNZ M02758 , 3; AWM 18331; AWM 30529);Te Henga,WAuckland (M216304, NMNZ);Waitakere West, W Auckland ( AWM 18160); Piha Beach, W Auckland ( NMNZ M090620, 5; GNS RM5309, 24); Bethells Beach, W Auckland ( NMNZ M016304, 30; M087139, 40); Muriwai Beach, W Auckland ( GNS RM330, 10; NMNZ M02757 , 70; M011903, 4; M087144, 100; M160082, 8; AWM 18330; AWM 29270);Whatipu, Manukau Harbour,W Auckland ( NMNZ M087142, 1); Pataua, Auckland ( GNS RM5313, 1); W coast Awhitu Peninsula, SW of Waiuku,W Auckland ( NMNZ M087143, 50; M277679, 1; M277680, 1; M277681, 7; M277682, 3; M 277684, 1; M277697, 6; M277698, 6; GNS RM5315, 2); Kaitoke Beach, Great Barrier I. ( NMNZ M090518, 2); Tairua, Coromandel ( NMNZ M090519, 7); Thames ( AWM 18329); Matakana Island, Bay of Plenty ( AWM 18328; AWM 33270); Papamoa Beach, Bay of Plenty ( NMNZ M120139, 150); Boulder Bay, Motuhora (Whale) Island, Bay of Plenty ( NMNZ M040063, 18); Ohope Beach, Whakatane ( NMNZ M040064, 50); Opotiki ( AWM 18327); beach E side Waitaki River, 5 km W of Opotiki ( GNS RM5561, 1); platform E of Te Araroa, East Cape ( GNS RM4900, 1); Aotea Harbour, W coast North Island ( GNS RM4057, 8); S of Karioi mouth, W coast North Island ( GNS RM4062, 11); beach S of Raglan ( GNS RM4062, 1); Wainui Beach, Gisborne ( NMNZ M308659, 6); Nukumaru Beach, Whanganui ( GNS RM5625, 166); Foxton Beach ( GNS RM5319, 2); Waitarere Beach, Levin ( GNS RM2967, 45; NMNZ M014282, 8); Otaki Beach, W Wellington ( NMNZ M102500, 2); Te Horo Beach, W Wellington ( GNS RM5314, 8); Waikanae Beach, W Wellington ( NMNZ M01128 , 13; M018827, 25; M160083, 200; M303126,3; M308073, 5; GNS RM5844, 80; RM5893, 120); Kapiti Island,W Wellington ( NMNZ M02756 , 30); Paraparaumu Beach, W Wellington ( NMNZ M284746, 40); beach S of Opau Stream, W Wellington ( GNS RM6716, 4); Swamp Bay, Greville Harbour, D’Urville Island ( GNS RM4060, 1); Ocean Beach, Farewell Spit ( NMNZ M023155, 5); Carters Beach, Westport ( GNS RM5316, 3; RM5317, 5); Cape Foulwind, Westland ( GNS RM4059, 1); Punakaiki Beach, Westland ( NMNZ M131404, 1); Wakapatu Beach, N of Nugget Pt, Otago ( NMNZ M111368, 3); Mason Bay, Stewart Island ( GNS RM6717, 1; NMNZ M219479,20); Chatham Islands ( NMNZ M05151 ,5; AWM 16429); beach NW coast of Mangere I., Chatham Islands ( GNS RM6012, 1).

Distribution. Janthina janthina is much the most common Janthina species in beach strandings in most parts of the world, although towards the southern limit of the Pacific range of Janthina in southern New Zealand (from Wellington west coast beaches southwards) small specimens of J. exigua are more common than J. janthina . It occurs throughout the world tropical to cool-temperate ocean, although Berry (1958) noted that it is “extremely rare” in California. Judged by specimens cast ashore, specimens of J. janthina are smaller around southern than northern New Zealand, and those collected on more oceanic islands (e.g., Lord Howe Island and the Kermadec Islands) are larger than any cast ashore in New Zealand, indicating that it reaches a larger size both in warmer water and in a more strictly oceanic environment than elsewhere. Savilov (1969: 399) reported specimens captured at 215 of the 393 Vitya z stations where Janthina was collected in the Pacific, with a winter northern boundary at about 40°N, where the sea surface temperature falls to 10°C. It was also observed near the North Island of New Zealand. “Very large concentrations of young I. janthina , up to 5 mm long, were noted during the Vityaz cruise in … the N subtropical circulation, including the Kuroshio [Current], and in the eastern areas of the North Trade Wind Current … It was almost absent in the Trade Wind Countercurrent area. However, this species reappeared in large numbers in the South Trade Wind Current, especially in its eastern part” ( Savilov, 1969: 399).

One Holocene fossil is recorded above from New Zealand. Jung (1975: 119, figs 51–53) also recorded “ Janthina sp. 1”, probably based on larval shells of J. janthina , in late Pleistocene–Holocene core-tops from DSDP Site 147, drilled in the Cariaco Basin, Venezuela. His “ Janthina sp. 2” ( Jung, 1975: figs 54–55) is taller and more narrowly conical and probably represents a benthic Epitonium species. Janssen (2007b: 150, pl. 14, figs 3–4) also recorded Holocene fossils of “ Janthina sp.” from core-tops collected in the Red Sea. The larval shell illustrated shows no characters to distinguish it from the most common living species, J. janthina , although several other Janthina species are recorded as living in the Red Sea ( Janssen, 2007b). As noted under J. globosa, Janssen (2012) also recorded late Pleistocene–Holocene fossils of J. janthina from 19 core-tops in the Mediterranean Sea.

Dimensions. See Table 7 .

Diagnosis. Largest Janthina species, diameter reaching almost 50 mm; spire very low (mainly in small specimens) to moderately tall; height highly variable, but without consistent allometry; last whorl weakly angled at periphery, sutural ramp and base only weakly inflated, producing weakly trochiform teleoconch shape. Sculpture of many fine, close, irregular spiral threads, and a few low spiral folds on base of some specimens; most specimens with obvious, fine, closely spaced axial ridgelets on first 1–1.5 teleoconch whorls. Sinus occupying entire height of outer lip, wide, shallow, V-shaped, deeper in lower part of lip than higher up, apex in centre of lip; i.e., dorsal limb of lip curving forwards from sinus apex more strongly than ventral limb. Most specimens counter-shaded, darker violet on ventral surface and paler on dorsal surface, some with pale zone around centre of base; highly variable in all characters. Broods eggs in oviduct, releasing rapidly bursting packets of veligers.

Remarks. The huge number of specimens of Janthina janthina in collections all over the world exhibits a wide range of variation in both shape and colour. Failure to recognize this as the variation of a single species led to the recognition of many nominal species by early authors, particularly Reeve (1858). Laursen (1953: fig. 15) provided a useful figure of specimen outlines ( Fig. 33 ) revealing the completely intergrading variation in shape, particularly in spire height, anterior columellar shape and the degree of angulation at the periphery of the last whorl, demonstrating that all these forms are part of the variation of one species. In collections the writer has examined, specimens resembling Laursen’s (1953: fig. 15) numbers 5–9 are the most common shape, and juvenile specimens all resemble Laursen’s numbers 10–12; extremely tall-spired forms such as Laursen’s numbers 1–2 are rare. Wilson and Wilson (1956) & Wilson (1958) also compared the dimensions of a large number of stranded southern British specimens graphically, again demonstrating their intergradation. Specimens from near the southern limit of its range in New Zealand bear obvious, fine, close, axial ridgelets similar to those of Janthina exigua on the initial 1–1.5 teleoconch whorls, whereas the rest of the teleoconch surface is essentially smooth, with weak growth lines and many weak, irregular spiral threads. Laursen (1953: 18) described this sculpture as “The first 1½ whorls may have sharp, regular striae, which pass into a fainter, irregular striation”, it was illustrated by Robertson (1971: pl. 5, fig. 17; 2007a: 8, upper left fig.), and this axial sculpture occurs on most specimens throughout its range. The remainder of the surface in J. janthina is not as smooth and polished as in J. globosa and J. pallida . Spiral coiling is rather irregular. A small proportion of adult shells also bears low spiral folds and grooves below the shoulder angulation, producing sculpture not unlike the more prominent and much more consistently present spiral folds of J. typica and J. chavani , although the folds are much fewer and weaker in J. janthina ( Figs 2A, D , 4A , 5A ). The radular teeth of J. janthina ( Laursen 1953: figs 16–18) are moderately long and moderately strongly hooked, much longer than those of J. pallida , but similar to those of J. exigua and J. umbilicata . They vary significantly in length within one radula.

Priolo (1959: 185–186) provided a list of numerous usages in the literature on Mediterranean molluscs of the name Janthina bicolor , which he evidently considered to apply to a species distinct from J. janthina .

Time range. Holocene fossils and living only.

Figures

Figure 1. Living specimens of Janthina janthina (Linnaeus) in life position in an aquarium, suspended beneath their floats, redrawn from photographs in Wilson & Wilson (1956: pl. 1, figs 1–2) and Yonge & Thomson (1976: pl. 5, lower); bubbles in float shown schematically. (A) left (anatomically right) lateral view, showing float, attached to mesopodium and located against propodium (at left end of float); partially extended snout; black-tipped right cephalic tentacle, not fully visible here; smooth, almost circular right epipodium (centre); digitateposterior edge of left epipodium, at rear between shelland mesopodium; and rear end of float disintegrating.(B) dorsal(anatomically ventral) view of another specimen forming a new float bubble, showing odontophore and radula partly everted out of mouth at tip of snout; black-tipped, forked cephalic tentacles; cupped propodium with black lining, in process of enclosing an air bubble; shell (right edge); and epipodium (left edge; anatomically on right). Scale bar 10 mm.

Figure 2 (facing page 123). Shells of the five living species of Janthina and two species of Recluzia recognized in this work; apertural views, and left lateral views showing outer lip sinus.(A–F) Janthina janthina (Linnaeus);A–B, D, GNS RM4442, two specimens, beach, Takou Bay, Northland, New Zealand; C, GNS WM15986, “bicolor” form, San Lourenço Beach, Santa Maria I., Azores, Atlantic; E, GNS RM6735, “bicolor” form, Ohope Beach, Whakatane, New Zealand; F, GNS WM15297, beach between Hutchinson Bluff and Rayner Point, Raoul I., Kermadec Islands. (G–J) Janthina globosa (Swainson); G, GNS WM15254, beach, Mauritius, Indian Ocean; H–J, GNS RM5321, two specimens, Muriwai Beach, West Auckland, New Zealand. (K–L) Janthina pallida Thompson, GNS WM15256, beach, Windy Harbour, Cape D’Entrecasteaux, southern Western Australia.(M, O) Janthina exigua Lamarck, GNS RM5626, Nukumaru Beach, Whanganui, New Zealand. (N, Q) Janthina umbilicata d’Orbigny, GNS RM5627, Nukumaru Beach, Whanganui, New Zealand. (P, R) Recluzia johnii (Holten), GNS WM17360, ventral and dorsal views; trawled in sediment, 130–180 m, Swain Reefs, SE Queensland, Australia (shortest specimen, last entryin Table 12).(S–T) Recluzia lutea (Bennett), GNS RM6748,beach, Great Exhibition Bay,Northland, New Zealand (from same sample as Figs 36M–P). Scale bar 10 mm, applies to all figures.

Figure 4 (facing page 129). Living animals in aquaria. (A) Janthina janthina (Linnaeus) (centre) and J. pallida Thomson (left, and part of another float at right) together, showing different bubble sizes in floats, and J. janthina feeding on pink eggs of J. pallida beneath float; collected at Arina Beach, Heraklion, Crete. (B) Janthina janthina, collected on beach in northern New South Wales, Australia, clearly showing forked cephalic tentacles;(C–E) Janthina janthina, all data as for Fig.4A; C, showing forked cephalic tentacles, lack of eyes, and teeth and odontophore protruding from mouth at end of extended snout; D–E, showing extended head and snout, odontophore visible in mouth, and partially expanded right epipodium lying over shell (A, C–E, reproduced with permission of Dimitris Poursanidis, Heraklion, Crete; B, reproduced with permission of Denis Riek, Brunswick Heads, New South Wales). Scale bars 10 mm.

Figure 5. (See facing page 131 for caption).

Figure 32. Specimens of Janthina janthina (Linnaeus). (A–D) GNS RM5844, Waikanae Beach, west Wellington, New Zealand; SEM, 2 specimens; apical views showing steeply inclined protoconch, slightly irregular teleoconch coiling, weak irregular spiral sculpture, and prominent axial riblets on early teleoconch whorls; B, protoconch of A enlarged; D, apex of protoconch of C enlarged. (E–F) NHMUK1854.12.4.399a,lectotype designated here ofJanthina orbignyi Mörch,“Atlantic Ocean”; largest of seven syntypes in d’Orbigny’s South American collection, illustrated by d’Orbigny (1841: 413, pl. 61, figs. 8–10); NHMUK photos sent by A. Salvador. Scale bars:A, C, 4 mm; B, 500 µm; D, 300 µm; E–F, 10 mm.

Figure 33. Janthina janthina (Linnaeus), range of variation in shell shape; copy at published size of Laursen (1953: fig. 15); numbers on figure as published by Laursen.Fig. 33.3, lectotype designated here of Helix janthina Linnaeus, 1758; Figs 33.7, 33.12, paralectotypes of Helix janthina; all three in collection of Linnean Society of London. Original scale bar included = 20 mm (i.e., figures reduced slightly).