Siphonaria laciniosa ( Linnaeus, 1758 )

Jenkins, Bruce & Köhler, Frank, 2024, Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda), Megataxa 13 (1), pp. 1-217 : 201-202

Siphonaria laciniosa ( Linnaeus, 1758)

( Fig. 84A )

Patella laciniosa Linnaeus 1758: 781 (type locality: ‘ Habitat in India’ ).— Linneaus 1767: 1258.

Taxonomic remarks. Utter confusion exists regarding the existence of a possible type specimen, the type locality, and the identity of S. laciniosa . Linnaeus (1758: 781) provided a brief description (‘ribs raised unequal, the darker outwardly blunted’) and a type locality (‘India’) referring to figures in pre-Linnean works, such as Rumphius (1705: 121, pl. 40, fig. C, 1711: 8, 1741: 121; pl. 40, fig. C) and D’Argenville (1757: 184, pl. 2, fig. O). The shells depicted in both works are of the ‘ atra group’. Linnaeus (1767: 1258) and Gmelin (1791: 3695) expanded the original description and stated that P. laciniosa ‘lives in Indian seas’ (translation), re-citing the engravings of Rumphius and D’Argenville but adding references to Knorr (1789: 11, pl. 30, figs 2–4, 7–8), showing patellids but not siphonariids, and Martini & Chemnitz (1769 [in 1769–1829]: pl. 10, fig. 81), showing a modified copy of Rumphius’ (1705: 121) engravings. We conclude that Linneaus was uncertain of the identity of P. laciniosa and how it related to shells described by pre-Linnean authors as these represented different species.

The alleged type specimen of Patella laciniosa Linneaus, 1758:781 UUZM # 912 (specimen label without locality and provenance; Fig.84A )has been accessioned by the UUZM with the following information: “Protologue: 1758: 781. Donation: Gustav IV Adolf. Preparation: dry. Swartz label: laciniosa ”. It is a shell of the ‘ laciniosa group’ and clearly a distinct from the species figured by Rumphius’ as ‘two-eyed spotted species’, which is of the ‘ atra group’ ( Fig. 6N ).

Dillwyn (1817: 1021) and Hanley (1855: 417) opined that the name P. laciniosa was essentially based on the figure of Rumphius (1705 – 1741). This would mean that the UMMZ specimen cannot be a type. Hanley (1855) was uncertain of the identity of the shell figured in Rumphius (1741). According to Sherborn (1940), Benthem Jutting (1959) and Dance (1967), most of Rumphius’ specimens have been lost. We could not trace any information on a specimen of ‘ Patella tertia ’ or ‘two-eyed spotted’ figured by Rumphius (1741). It is possible, perhaps even likely, that Rumphius’ depicted a shell from Indonesia. Dillwyn (1817: 1021) stated that the species ‘inhabits the coasts of Amboyna’ [ Ambon, Indonesia]. This might be the type locality of P. laciniosa if Linneaus’s statement on the origin of this species was a reference to Rumphius. Morrison (1972: 58) suggested that the ‘Eye spots’ are likely due to erosion of the shell apex, a feature confirmed herein to be commonly observed in species of the ‘ atra group’. Hubendick’s (1946) was the first to attribute type status to the UUMZ specimen mentioned above. Hubendick (1946: 48) stated that ‘the type of S. laciniosa is in the keeping of the Zool. Mus., Uppsala’, but confusingly identified it as a specimen of S. laciniosa forma exigua referring to a name introduced by Sowerby I, 1823. Subsequently, Dance (1967: 80) stated that no type specimen of P. laciniosa was found in the Linnaean collection and considered it to be lost. However, according to Odhner (1954: 26) and Wallin (2001: 89) there is a type of P. laciniosa in the UUZM catalogue of Linnaean type specimens.

The identity of this alleged type of P. laciniosa cannot be ascertained. It is likely a siphonariid of the ‘ laciniosa group’, but its features are insufficient to identify this species. Moreover, the generic type locality ‘India’ may refer to any place in the Tropical parts of the Indian Ocean, including the Indonesian archipelago and is too vague to allow to narrow the selection down to a single species.

Morrison (1972) considered Hubendick’s claim of a type specimen as an invalid type designation stating that ‘Linne didn’t indicate that he had ever seen a specimen up to 1767’. Alternatively, Morrison (1972: 58) designated the non-binomial ‘the two-eyed spotted species’ figure in Rumphius (1705: 125, pl. 40, fig. C; Fig. 84B ) as ‘the type of laciniosa ’. This type designation has subsequently been acceptedbyChristiaens(1980a:78).However,Hubendick’s and Morrison’s type concepts are irreconcilable with each other contributing to the confusion around this name. If we accept Hubendick’s claim that the UMMZ specimen is the type, then S. laciniosa is an unidentifiable species in the ‘ laciniosa group’ and distinct from the species depicted by Rumphius. However, if we accept Morrison’s view, then S. laciniosa is an unidentifiable species of the ‘ atra group’ possibly from Indonesia.

We are of the view that the ambiguity surrounding this name cannot be resolved without a ruling of the commission and therefore we treat the name P. laciniosa herein as a nomen dubium. This name has been used throughout the body of taxonomic literature, but because of the ambiguity surrounding its identity, subsequent uses invariably were hypothetical and often contradictory. The earliest taxonomists effectively reiterated the name referring to the original description of Linnaeus (1758: 380) without contributing any clarification of the original concept (e.g., Schrӧter 1784: 403; Röding 1798: 5; Roissy 1805: 214; Dillwyn 1817: 1021; Lamarck 1819: 325; Sowerby I 1825: 29; Hanley 1855: 417). Pilsbry (1892 [in 1891–1892]: 160) listed P. laciniosa as ‘unidentified Patellidae ...possibly = P. stellaeformis ’. Eventually, Hubendick (1946: 47) transferred the species to Siphonaria based on examination of the probable type. However, his delimitation of the species is speculative and not accepted herein. Specimens identified as ‘ S. laciniosa’ by Hubendick (1946: 47) are not from the type locality and many examples comprise mixed lots.

Figures

FIGURE 6. Relationships of genetic K-2-P distances in COI and 16S for sequences form the same individuals.

FIGURE 84. Siphonaria laciniosa. A. Alleged holotype of Patella laciniosa UUZM # 912. B. Reproduction of ‘the twoeyed spotted species’ in Rumphius (1705: pl. 40, fig. C).