Siphonaria kurracheensis Reeve, 1856

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 : 90-93

Siphonaria kurracheensis Reeve, 1856

( Figs 33I–N, Q–R, V , 34E–G )

Siphonaria kurracheensis Reeve 1856 : pl. 5, species 20 (type locality: Kurrachee, Scinde [Karachi, Pakistan]).— Hanley 1858b: 152; Issel 1869: 320; Fischer 1870: 167; Paetel 1873: 117; Fischer 1883 (in 1880–1887):Index, pl.11, fig.25 (ventral only); Paetel 1883: 178; 1889: 428; Melvill & Standen 1901: 457; Melville & Abercrombie 1893: 24; Hubendick 1946: 54, pl. 2, figs 36, 39, 40; Berry 1977: 210; Anon 1980: 11; Trew 1983: 6; Jones 1986: 130, pl. 23; White & Dayrat 2012: 64.

Siphonaria cochleariformis —Cooke 1886a: 133 (not S. cochleariformis Reeve, 1856 ).

Siphonaria luzonica —Cooke 1886a: 133 (not S. luzonica Reeve, 1856 ).

Siphonaria natalensis —Cooke 1886a: 133 (not S. natalensis Krauss, 1848 ).

Siphonaria siquijorensis —Cooke 1886a: 133 (not S. siquijorensis Reeve, 1856 ).

Siphonaria kurrachensis Cooke 1886a: 133 ; 1886b: 383; Galindo 1977: 416 (incorrect subsequent spelling of kurracheensis ).

Siphonaria diemenensis —Smythe 1982: 80 (not S diemenensis Quoy & Gaimard, 1833 ).

Siphonaria savignyi — Dayrat et al. 2014: 261, ‘unit 28’, fig. 5 E, F (not S. savignyi Krauss, 1848 ).

Material examined. Type material. Lectotype of Siphonaria kurracheensis Reeve, 1856 , present designation, from Kurrachee [Karachi], Scinde, [ Pakistan] ( NHMUK 1979167 /1, Fig. 33I ). Three paralectotypes, same data as lectotype ( NHMUK 1979167/2-4 , Fig. 33J– L ).

Other, non-type material. Pakistan: Karachi , Bubiji Beach, 24°53’N, 67°01’E ( WAM S72336 p,WAM S74134 p [SK148]); French Beach, 24°50.367’N, 66°49.387’E PA01-1 ( AM C.585741 4p, C.585848 p [M240], C.585849 p [M241], C.585850 p [M484], C.585852 p [M485, SK304]); Clifton Beach, 24°45.500’N, 67°05.968’E PA02-1 ( AM C.585107 p [SK008], C.585744 p [SK045], C.585856 p [M229], C.585857 p [M230],C.585858 p [M231]) .

Taxonomic remarks. The largest syntype with clearest external sculpture ( Fig. 33I ) is herein designated as the lectotype of S. kurracheensis for the stabilisation of the name (Art. 74.1 of the Code). The shell figure in Reeve’s (1856) original description provides a ventral view only. Our delineation of this species is based on comparative analyses of the morpho-anatomy and mitochondrial genetics of freshly collected topotypes ( Fig. 33N, M, Q ) and geographic series of additional specimens (Table S1). We do not accept Hubendick’s (1946) extended concept of S. kurracheensis , which included several extralimital nominal taxa (e.g., S. belcheri , S. depressa , S. luzonica , S. savignyi , S. siquijorensis and S. zebra ), all of which represent distinct species. Therefore, the accepted distribution of this species is much smaller than previously stated.

Morrison (1972: 56–58) synonymized S. kurracheensis with S. laciniosa based on similarity in shell form and a ‘common reproductive development’. This synonymy is rejected herein based on examination of types and topotypes. The species identified as ‘ S. kurracheensis ’ in WA by various authors is shown herein to be morphologically and genetically distinct and is described as a new species, Siphonaria restis sp. nov. (unit 54) below.

External morphology. External parts evenly pale cream without black pigmentation apart from faint shading at centre of cephalic folds; mantle weakly lobed, translucent, narrower than foot wall, covers exposed inner shell lip; genital pore inconspicuous, located on foot wall to right anterior of right cephalic fold; single small black epithelial eye spots centralised on two centrally touching cephalic folds; pneumostomal lobe under the mantle, unpigmented, between the right anterior and right posterior ADMs.

Shell ( Fig. 33I–N, Q, R ; Table S9). Small sized (max sl mean = 11.5 mm, SD = 1.7 mm, n = 7), ovate, height low to medium; shell thickness thin to medium, apex offset weakly posterior and left, apical sides weakly convex, protoconch direction undetermined, shell whorl dextral; growth striae indistinct; rib count (mean = 42, SD = 4, n = 7), primary ribs pale white, fairly straight, unraised, flat, ridge rounded; secondary ribs even whitish; ribs increasingly widen to shell lip; more primary than secondary ribs; rib interstices very narrow brown, marking on side of primary ribs; siphonal ridge low prominent; shell lip uneven, weakly scalloped, corrugated by primary ribs. Interior mottled red brown blotches on margin; spatula golden to pale brown/whitish; clearly demarked from margin by siphonal groove similar colour paler fairly prominent; irregular narrow brown rays from shell lip to spatula; brown interstices show through shell lip; ADM scar indistinct, CMS convex. Smaller and tall specimens with thicker shells, tend to show dark brown rays on shell margin. Thickening of shell margin and variability in shell height occurs in larger specimens in this species.

Reproductive system ( Figs 34E, F; n = 3). Positioned within coelom under the respiratory cavity, hermaphroditic glands positioned to posterior against right foot wall and over foot sole, epiphallic parts positioned between BM and to side of RAM; AO medium, broad, tip bluntly hooked, merges with MA, joins to upper end of small GA; ED very short, centrally twisted, bent, joins to side of GA; EG folded may be large; single wide looped flagellum F1 joins as an extension of broader ED; AO, GA and ED all muscular white tissue; BD and CD with opposing connections (bulbous at CD) into GA between ED, AO and GP; BD longer and narrower than CD with a prominent distal loop, top of loop attached via a long MA to inner foot wall in front of BM; both BD and CD smooth, similar thickness and pass together through RAM connecting into folds of MG ( BD above CD), BC small, translucent test and bulbous drop shaped; HD brownish, narrow coils, links AG to a small elongated narrow brownish granulated HG; dark SV embedded within AG / MG; MG and AG small folded soft white tissue, similar size, sides match curvature of inner foot wall at right posterior quarter of coelom.

Spermatophore ( Fig. 34G ). Thread-like, test thin, translucent (length = 7.2 mm, n = 1, AL = 9 mm); head section cylindrical, centrally coiled, rounded tip; test thin, smooth, featureless, translucent, contains a white core, tapers into flagellum; head longer, wider than translucent flagellum (head length = 5.5 mm, ~ 76 % of total length, head width = 172 μm, flagellum width = 17 μm, n = 1); SPM tightly coiled in yellowish gel in BC of one specimen.

Comparative remarks. In our mitochondrial phylogeny ( Figs 1–4 ), S. kurracheensis (atra group, unit 28) forms a clade with S. alternata from the Caribbean and Gulf of Mexico as well as S. striata sp. nov. from Madagascar ( Figs 1 , 2 ). These species differ from S. kurracheensis by COI distances of ≥ 7.1% ( S. alternata , unit 29) and ≥ 8.6% ( S. striata sp. nov., unit 74) (Table S5). For a comparison with S. striata sp. nov. refer to comparative remarks under that species. Siphonaria kurracheensis occurs in sympatry with four congeners in Karachi, Pakistan. Siphonaria asghar has weaker, finer edge scalloping, less prominent siphonal groove, darker interior, a smaller AO, a shorter, wider DB, and a larger BC. Siphonaria belcheri has a darker exterior and interior, a larger, wider AO, a longer, narrower BD, and a larger F1. Siphonaria perexigua sp. nov. has a smaller, taller shell with less raised ribbing, a smaller AO, larger BC, and longer, wider ED. For comparison with Siphonaria crenata refer to comparative remarks under that species. Shell sculpture and geometry of S. kurracheensis resembles that of S. zelandica (flat, fine ribs); however, this resemblance is convergent since both species are not closely related with each other. Both species have non-overlapping distributions.

A record of ‘ S. kurracheensis ’ from SA in Adcock (1893: 11, in synonymy of S. luzonica ) is based on a misidentification of S. zelandica . A record of ‘ S. kurracheensis ’ from the Suez Canal in Moazzo (1939: 280, fig. 2) is a misidentification of S. belcheri (also noticed by Hubendick 1946: 54), the shell closely resembles the weakly ribbed paralectotype of S. belcheri . SPM and RS of ‘ S. kurracheensis ’ and ‘ S. kurracheensis var. siquiorensis ’ depicted in Hubendick (1945: figs 51–52) are here attributed to S. japonica and probably S. javanica , respectively. Hubendick (1946: 54) treated five taxa as varieties of S. kurracheensis (i.e., S. savignyi , S. luzonica , S. zebra , S. belcheri , S. depressa and S. siquijorensis ). None of these treatments are accepted herein and these taxa are all removed from the concept of S. kurracheensis as delineated herein. Hence, the distribution of S. kurracheensis outlined in Hubendick (1946: 54), which includes locations well beyond Karachi and Persian Gulf (i.e., Java Sea, Philippines, Qld, and Port Jackson), is also disputed.

The SPM depicted herein differs from that of ‘ S. kurracheensis ’ figured in Hubendick (1945: 31, fig. 51) and reproduced by Berry (1977: fig. 19) by being longer and without barbs on flagellum. A specimen figured as S. kurracheensis from the Suez Canal ( Barash & Danin 1972: fig. 14) is S. savignyi . Dayrat et al. (2014: 261, fig. 5 E) misidentified unit 28 as S. savignyi ; it is in fact S. kurracheensis based on the clustering with sequences of that species. Similarly, they misidentified unit 27 as S. kurracheensis , but the correct identification is S. belcheri . Specimens figured as ‘ S. kurracheensis ’ from Mubarak Village, Karachi ( Bosch et al. 1995: fig. 863; Ali et al. 2011: fig. 1B) and from Dwarka Coast, Gujarat ( Vakani & Rahul Kundu 2021: figs 2d, 3d) are misidentifications and are likely specimens of S. crenata based on size, ribbing and extension of siphonal ridge.

Distribution and habitat. Recorded from Muscat, Gulf of Oman, Karachi, Pakistan and Gujarat, India ( Fig. 25 ). In the present study found in sheltered positions on exposed rocky intertidal marine shores, upper to mid littoral level.

Figures

FIGURE 1. Maximum Likelihood phylogram based on analyses of a concatenated sequence data set of 16S and COI. Branches are collapsed at the species level. Branch labels give unit numbers and accepted species names. Numbers on branches indicate branch support employing 10,000 ultrafast bootstraps.Available genus-group names are shown next to their type species. Scale bar indicating modelled sequence divergence.

FIGURE 2. Maximum Likelihood phylogram (partial, species not collapsed). Clades G–I (atra group) of the tree shown in Fig. 1. Branch labels give specimen identifiers for new sequences or Genbank accession numbers for imported sequences from other studies and geographic regions (seeTables S1–S2 for details). Identical haplotypes are merged into single tips. Numbers on branches indicate branch support by employing 10,000 ultrafast bootstraps. Clade names give unit numbers and accepted species names. Scale bar indicating modelled sequence divergence. Figure spread over two pages.

FIGURE 3. Maximum Likelihood phylogram (partial, species not collapsed). Clades J–L (laciniosa and plicata groups) of the tree shown in Fig. 1. Branch labels give specimen identifiers for new sequences or Genbank accession numbers for imported sequences from other studies and geographic regions (see Tables S1–S2 for details). Identical haplotypes are merged into single tips. Numbers on branches indicate branch support by employing 10,000 ultrafast bootstraps. Clade names give unit numbers and accepted species names. Scale bar indicating modelled sequence divergence.

FIGURE 4. Maximum Likelihood phylogram (partial, species not collapsed). Clades C–F (normalis, lateralis and pectinata groups) of the tree shown in Fig. 1. Branch labels give specimen identifiers for new sequences or Genbank accession numbers for imported sequences from other studies and geographic regions (see Tables S1–S2 for details). Identical haplotypes are merged into single tips. Numbers on branches indicate branch support by employing 10,000 ultrafast bootstraps. Clade names give unit numbers and accepted species names. Scale bar indicating modelled sequence divergence.

FIGURE 25. Known occurrence records of S. viridis, S. normalis, S. radians, S. scabra, S. funiculata, S. kurracheensis and S. carbo.

FIGURE 33. Shells of S. funiculata and S. kurracheensis. A–H, O–P, S–U. S. funiculata. A. Lectotype NHMUK 1979027/1. B. Tas, d’Entrecasteaux Channel, TS, AM C.585268 [M135, SK049]. C. Holotype of S. virgulata AM C.39858. D. Holotype of S. blainvillei NHMUK 1907.10.28.90, E. Holotype of S. oblivirgulata UUZM 1575. F. NSW, Sydney Harbour, TS of S. oblivirgulata AM C.585035 [M162]. G. Tas, Dodges Ferry, TS of S. funiculataAM C.584883 [SK138]. H. NSW, Sydney Harbour,AM C.585068 [M185]. O. NSW, Terrigal, TS of S. virgulata AM C.585056 [M224]. P. Tas, Bridport, AM C.585251 [M174]. S. Tas, in situ. T. Tas, animal, U. Protoconch AM C.585332 [SK026]. I–N, Q–R, V. S. kurracheensis, I. Lectotype NHMUK 1979167/1, J–L. Paralectotypes NHMUK 1979167/2-4. M. Pakistan, Karachi, TS, AM C.585857 [M230, SK192]. N. Karachi, TS, WAM S72336 [SK148]. Q. AM C.585856 [M229]. R. AM C.585849 [M241]. V. Karachi, in situ. Unlabelled scale bars = 10 mm.

FIGURE 34. Reproductive morphology of S. funiculata and S. kurracheensis. A–D. S. funiculata. A. Tas, d’Entrecasteaux Channel, TS, AM C.585268 [M135, SK049]. B–C. NSW, Kiama, B. AM C.585280 [SK048]. C. AM C.584884 [SK384]. D. NSW, Sydney Harbour, TS of S. obvirgulata AM C.585035 [M162, SK035]. E–G. S. kurracheensis, Pakistan, Karachi, TS. E. WAM S74134 [SK148]. F. AM C.585857 [M230, SK192]. G. WAM S72336 [SK516]. Scale bars = 1 mm.