Siphonaria capensis Quoy & Gaimard, 1833

Siphonaria capensis Quoy & Gaimard, 1833 View in CoL

( Figs 17L–N View FIGURE 17 , 18F–G View FIGURE 18 )

Siphonaria capensis Quoy & Gaimard 1833: 331 View in CoL , pl. 25, figs 32– 34 (type locality: Cap de Bonne-Espérance, baie de la Table [Table Bay, Cape of Good Hope, South Africa]).— Lamarck 1836: 561; Anton 1838: 26; Lamarck 1839: 206; Jay 1839: 39; Catlow & Reeve 1845: 100; Krauss 1848: 58; Dunker 1853: 3; H. Adams & A. Adams 1855 (in 1853–1858): 271; Hanley 1858b: 151; H. Adams & A. Adams 1863: 271; Paetel 1873: 117; 1883: 178; 1889: 429; Sowerby III 1892: 53; Bartsch 1915: 10; Turton 1932: 10; Hubendick 1947a: 163; Braga 1956: 7, pl. 1 fig. 1; Allanson 1963: 70; Galindo 1977: 416; Richards 1981: 79; Kilburn & Rippey 1982: 134, pl. 32, fig. 13; Villiers & Hodgson 1987: 129; Teske et al. 2007: 223, fig. 2; Pinchuck & Hodgson 2009: 371; Teske et al. 2011: 5026; White & Dayrat 2012: 61.

Siphonaria (Patelliopsis) capensis View in CoL — Hubendick 1945: 70, fig. 20; 1946: 33, pl. 1, figs 40–42, pl. 2, figs 1–4; Allanson 1958: 150, 157, pl. 1, fig. 1; Chambers & McQuaid 1994a: 265, figs 1E, 3A; 1994b: 418; Chambers et al. 1996: 3; 1998: 51.

Siphonaria kowiensis Turton 1932: 10 View in CoL , pl. 4, 84 (type locality: Port Alfred, SA [ South Africa]).— Allanson 1958: 166.

Siphonaria capensis var. lineolata Krauss 1848: 58 View in CoL , pl. 4, fig. 2 (type locality: Tafelbai [Table Bay, SA]); invalid, preoccupied by Sowerby I, 1835).—Sowerby III 1892: 54; Bartsch 1915: 10; Turton 1932: 10; Hubendick 1945: 19; 1947a: 163.

Siphonaria (Patelliopsis) capensis View in CoL forma kraussi Hubendick 1946: 34 View in CoL , pl. 2, figs 1–4 (nom. nov. pro S. lineolata Krauss, 1848 View in CoL not Sowerby I, 1835).— Allanson 1958: 159.

Pachysiphonaria capensis — Trew 1983: 2.

Siphonaria kraussi View in CoL — White & Dayrat 2012: 59, 64.

Material examined. Type material. Lectotype of Siphonaria capensis Quoy & Gaimard, 1833 , present designation, from ‘Cap de Bonne-Espérance, baie de la Table’ [Table Bay, Cape of Good Hope , South Africa] ( MNHN IM 2000-38235 Fig. 17L View FIGURE 17 ); Seven paralectotypes, same data as lectotype ( MNHN-IM-2000-5042 ).

Other, non-type material. Mozambique: Inhaca , Ponta do Farol, 25°58.2’S, 32°59.4’E MM6 ( MNHN IM-2019-1477 p [M584], Fig. 17N View FIGURE 17 ; IM-2019-1481 p [M585], Fig. 17M View FIGURE 17 ) GoogleMaps .

Taxonomic remarks. The lectotype is designated herein for the stabilisation of the name and to ensure the unambiguous identity of this taxon (Art. 74.1 of the Code). Krauss (1848: 58) introduced Siphonaria capensis var. lineolata ; however, this name is preoccupied by S. lineolata Sowerby I, 1835 ( Hubendick 1946: 33; White & Dayrat, 2012: 65) and S. lineolata Orbigny, 1841 ( White & Dayrat, 2012: 65). Hubendick (1946: 33) introduced S. capensis forma kraussi as a replacement name. The taxonomic status of this taxon remains uncertain, but it is synonymized herein because of Hubendick’s treatment as an infrasubspecific taxon (forma). Hubendick (1946: 33) synonymized S. jonasii Dunker, 1846 (probably a juvenile), S. placentula Menke, 1853 , and S. venosa Reeve, 1856 with S. capensis . He also attributed the record of ‘ S. pectinata ’ by Martens (1874) to S. capensis .

Our delineation of this species is based on comparative analyses of the morpho-anatomy and mitochondrial genetics of freshly collected topotypes (e.g., Fig. 17 View FIGURE 17 M-N) and geographic series of additional specimens (Tables S1–2). The taxonomic status of S. placentula , S. oculus , S. venosa and S. jonasii has not been assessed herein. Therefore, Hubendick’s (1946) treatment of these taxa stands. Trew (1983: 2) incorrectly treated S. capensis as a synonym of S. funiculata .

Chambers & McQuaid (1994a, b) reported that S. capensis deposits benthic egg masses from which planktonic veliger larvae hatch.

External morphology (preserved). Animal yellowish/ cream. Irregular, widely spaced dark/black markings/spots along foot wall and cephalic lobes; genital pore conspicuous, located on foot wall posterior to right cephalic fold; mantle edge thick, large lobes.

Shell ( Figs 17L–N View FIGURE 17 ; Table S9). Small to medium sized, ovate, thick, medium height (max sl mean = 23.1 mm, SD = 3.3 mm, n = 13), exterior grey/light brown, fairly even, apical sides convex, almost straight on posterior; apex offset to left and posterior, often eroded, protoconch direction undetermined, body whorl dextral, growth striae clear with faint external colour banding aligning with growth stages; primary ribs touching, raised fairly evenly spaced, straight, broaden to shell edge, ridges rounded to flat, rib count (mean = 42.6, SD = 5.8, n = 13), few to no secondary ribs; ribs project weakly beyond shell edge, siphonal ridge indistinct, weakly raised, formed by multiple ribs; rib interstices dark brown, weakly furrowed; shell edge weakly corrugated and scalloped. Interior glossy, edge and margin chocolate brown to black at shell edge with white /cream rays aligning under ribs, extending and narrowing from shell edge over margin to ADM scar, spatula pale blue/tan, siphonal groove apparent, same as interior colour, CMS straight.

Reproductive system ( Fig. 18F; n View FIGURE 18 = 3). Positioned within coelom under the respiratory cavity and intestine, over foot muscle, against right side of foot wall; epiphallic parts positioned over BM and between RAM; single conspicuous GP, opening from GA through foot wall posterior to right cephalic fold, junction of AO, GA and ED close distinct; AO large broad and flat, larger than GA, thicker than ED; GA bulbous proximal to ED and BD / CD junctions, ED relatively long and twisted; EG very large, broad, lobed, flagellum (F1) indistinct; BD and CD closely coupled, of similar length and thickness, connect in parallel close together into GA between ED and GP, BD without distal loop or MA; both ducts smooth, featureless, pass together partially through RAM connecting into soft curved folds of MG, CD wider and dorsal to BD; CD connects to small, bulbous, thin test BC, partially embedded into folds of MG; HD short thick, brown markings, coiled, links AG to elongated narrow yellowish granulated HD; HG larger than AG, MG and AG folded, soft white tissue; SV embedded on left side of AG.

Spermatophore ( Fig. 18G View FIGURE 18 ). Very small, drop-like with short flagellum (length = 0.41 ± 0.037 mm, n = 3); head section bulbous, rounded (head length = 0.31 ± 0.04 mm, head ~76% of SPM length, head width = 230 ± 37 μm; flagellum width = 17 ± 0 μm, n = 3), body and flagellum test fur-like, opaque, tapering to a pointed end; both sections featureless; 4 SPM in brown gelatinous mass in one BC ( MNHN IM-2019-1481 [M585]) embedded in white gelatinous mass.

Radula. Dentition formula: 42:1:42 ( Hubendick 1946: 34).

Comparative remarks. Analyses of mtDNA sequences supported a sister relationship of S. capensis (unit 96) with unit 4 (= S. pectinata from Spain and Ghana + S. naufragum from Trinidad and Tabago; not reviewed herein, see Giribet & Kawauchi 2016). Distances between units 96 and 4 were ≥ 10.7% in COI (Table S8). We found two sympatric congeners in Mozambique: Siphonaria carbo has a darker shell with a more central apex and finer ribbing, an indistinct AO, larger, elongate BC and longer, larger SPM. Siphonaria plana has a smaller, paler shell with coarser ribbing and a flared siphonal ridge, smaller AO, twisted ED, BD with bursal and distal loops, a larger BC and a longer, thread-like SPM. For comparisons with South African siphonariids, such as S. serrata ( Fischer, 1807) , S. concinna Sowerby I, 1825 , S. oculus Krauss, 1848 and S. carbo Hanley, 1858 , which occur within the distributional range of S. capensis , refer to the studies of Allanson (1958), Chambers & McQuaid (1994a) and Teske et al. (2007, 2011).

The RS figured in Hubendick (1945: 18, fig. 20) closely resembles the RS of S. capensis figured herein ( Fig. 18F View FIGURE 18 ) except for one detail in the junctions of the CD / BD / GP / GA, which Hubendick portrays as wider and with ducts more separated. Apart from the absence of an AO, the RS of S. capensis figured in Allanson (1958: 165, fig. 10) matches well the RS figured herein ( Fig. 18F View FIGURE 18 ). Figured specimens of ‘ S. capensis’ and ‘ S. capensis v. kraussi’ in Hubendick (1946: pl. 1, figs 40–42 from Cape, South Africa; pl. 2, figs 1–4 from Port Natal, respectively) corresponds well with shells shown herein ( Fig. 17L–N View FIGURE 17 ). Similarly, specimens figured in Krauss (1848: 58, pl. 4, fig. 2), Braga (1956: 7, pl. 1 fig. 1), Allanson (1958: 150, 157, pls 1a–b, 2a–b), Kilburn & Rippey (1982: 134, pl. 32, fig. 13) and Chambers & McQuaid (1994a: 256, figs1E, 3A) correspond well with typical features of this species.

Distribution and habitat. Endemic to SE coast of Africa ( Fig. 28 View FIGURE 28 ). During this study, collected on intertidal rocks in Baie de Maputo, Mozambique.