Austrolittorina cincta (Quoy & Gaimard, 1833)

Reid, DG & Williams, ST, 2004, The Subfamily Littorininae (Gastropoda: Littorinidae) in the Temperate Southern Hemisphere: The Genera Nodilittorina, Austrolittorina and Afrolittorina, Records of the Australian Museum 56, pp. 75-122 : 96-99

Austrolittorina cincta (Quoy & Gaimard, 1833)

Figs. 4G,H, 12–14

Littorina cincta Quoy & Gaimard, 1833: 481–482 , pl. 33, figs. 20– 21 ( New Zealand; lectotype ( Rosewater, 1970) (fig. 12B) plus 2 paralectotypes,MNHNP,seen). Deshayes, 1843:209–210. Reeve, 1857: Littorina sp. 53, pl. 11, fig. 53. Hutton, 1878: 27. Hutton, 1880: 78. Hutton, 1882: 164, pl. 7, fig. D (radula). Nevill, 1885: 143. Suter, 1901: 214–215.

Litorina cincta .—Philippi, 1847: 202, pl. 4, fig. 18. Weinkauff, 1882: 76, pl. 10, figs. 5, 8. Weinkauff, 1883: 222. Watson, 1886: 574. Bucknill, 1924: 37, pl. 7, fig. 23.

Littorina (Melarhaphe) cincta .—Adams & Adams, 1854: 314 (as Melaraphe ).

Litorina (Melarhaphe) cincta .— Suter, 1913: 187, pl. 38, fig. 27 (as Melaraphe ; as Littorina cincta in Atlas, 1915).

Melarhaphe cincta .— Finlay, 1928: 241 (as Malarhaphe). Powell, 1937: 67, pl. 9, fig. 13. Powell, 1955: 74. Powell, 1962: 83, pl. 9, fig. 13 (as Melarhapha). Dell, 1963: 225 (as Melarapha ).

Littorina (Austrolittorina) cincta .— Rosewater, 1970: 423, 473–474,

pl. 364, figs. 1–6, pl. 365, fig. A (penis), pl. 366 (distribution).

Powell, 1976: 87, pl. 16, fig. 13. Powell, 1979: 87, pl. 23, fig. 10.

Nodilittorina cincta .—Bandel & Kadolsky, 1982: 3. Spencer & Willan, 1996: 18.

Nodilittorina (Nodilittorina) cincta .— Reid, 1989: 99.

Nodilittorina (Austrolittorina) cincta .— Reid, 2002 a: 154.

Austrolittorina cincta .— Williams et al., 2003.

Littorina luctuosa Reeve, 1857 : Littorina sp. 65, pl. 13, fig. 65 ( New Zealand; 3 syntypes BMNH 1968315; Rosewater (1970: pl. 364, figs.3, 4) figured one as “ holotype ”,but this is not a valid lectotype designation, ICZN, 1999: Arts 74.5, 74.6). Hutton, 1880: 79.

Litorina luctuosa .—Weinkauff, 1882: 72, pl. 9, fig. 12.

Littorina (Melarhaphe) mauritiana .— Tryon, 1887: 247, pl. 44, figs.

70, 74 (as Melaraphe ; not Phasianella mauritiana Lamarck, 1822 = Littoraria mauritiana ; includes A. unifasciata , A. antipodum , L. mauritiana , Echinolittorina ziczac ).

Melarhaphe zelandiae Finlay, 1927: 375 ; pl. 18, figs.18–19 ( Dunedin Harbour , New Zealand; holotype Auckland Museum AK 70457 (formerly TM457 ) plus 3 paratypes AK 72526 (formerly TM457 ), not seen).

Taxonomic history. This species is readily recognized by its brown shell and has therefore been correctly identified by most authors. It was redescribed as Littorina luctuosa by Reeve (1857), a species incorrectly synonymized with A. antipodum ( Weinkauff, 1883; Nevill, 1885) until its identity was indicated by Suter (1901, 1913). The species was inadvertently named again by Finlay (1927) as M. zelandiae (see Finlay, 1930; see Taxonomic History of A. antipodum ). This species was included in a very broad concept of L. mauritiana by Tryon (1887; see Taxonomic History of A. unifasciata ).

Diagnosis. Shell moderately large, usually tall-spired, sculptured with incised spiral lines; cream with brown spiral lines, or brown with pale grooves. Penis with bluntly pointed, slightly swollen filament; glandular disc and mamilliform gland on base. Pallial oviduct with two consecutive loops of egg groove, in albumen and capsule glands.

Material examined. 71 lots (17 AMS, 14 USNM, 13 BMNH, 2 IRSNB, 4 NMW, 21 MNZ), including 6 penes, 4 sperm samples, 4 pallial oviducts, 4 radulae.

Shell ( Fig. 12). Mature shell height 8.9–20.2 mm. Shape high-turbinate to tall-spired, occasionally patulous or globular (H/B = (1.11)1.29–1.79; SH = (1.26)1.47–2.34); spire outline straight; whorls rounded, suture impressed, periphery slightly angled; solid. Columella pillar straight or slightly concave; columella excavated; eroded parietal area usually present. Sculpture of 8–12 approximately equidistant primary spiral grooves (incised lines) above periphery, continuing on base; grooves occasionally obsolete; rarely, ribs between grooves become raised and prominent at periphery; microstriae faint or absent; surface, especially spire, often eroded; growth lines weak. Protoconch rarely preserved, about 3 whorls, 375–425 µm length, sculptured by spiral rows of minute tubercles ( Pilkington, 1971). Colour cream with pale to dark brown spiral lines (corresponding to spaces between grooves); rarely, lines are faint or narrow ( Fig. 12F); occasionally entirely brown with pale grooves on base only; occasionally cream with a broad peripheral brown band and few spiral brown lines on base ( Fig. 12D); juveniles black or brown with one or more spiral white lines on base; aperture dark brown with basal white band.

Animal. Head, tentacles and sides of foot black. Opercular ratio 0.44–0.54. Penis ( Fig. 13A–D): filament 0.5 total length of penis, smooth or slightly wrinkled, bluntly pointed, slightly swollen, reddish coloration at base of filament when live; sperm groove opens terminally; single mamilliform gland and adjacent large flap of penial glandular disc borne together on broad lateral branch of base; penial base often with black pigment. Euspermatozoa 79–86 µm; paraspermatozoa ( Fig. 13G,H) spherical, 10–13 µm diameter, containing large spherical granules and a curved, twisted or torus-shaped rod body. Pallial oviduct ( Fig. 13E) with simple loop of albumen gland, followed by large, almost circular loop of capsule gland, within which portion adjacent to egg groove (translucent capsule gland) is differentiated as a ring; copulatory bursa large, opening near anterior end of straight section, extending back beneath capsule gland.

Spawn and development. Spawn ( Fig. 13F) a transparent pelagic capsule 250 µm diameter, containing a single ovum 80 µm diameter, capsule with domed upper surface sculptured by 3 concentric rings, peripheral ridge and a basal circumferential flange; development planktotrophic; spawning season November to March (at Otago; Pilkington, 1971).

Radula ( Fig. 4G,H). Relative radular length 3.5–5.6. Rachidian: length/width 1.18–1.30; major cusp elongate, rounded to slightly pointed at tip. Lateral and inner marginal: major cusps large, elongate, bluntly rounded to slightly pointed at tip. Outer marginal: 7–9 cusps.

Habitat. This species is most abundant in the southern areas of New Zealand, where it occupies a vertical range from the littoral fringe to the barnacle zone, and may even extend to the kelp (Durvillea) zone (at Otago; Batham, 1958; Morton & Miller, 1968). There is some downward migration during the spawning season ( Pilkington, 1971). Although its upper vertical limit is below that of the frequently sympatric A. antipodum , it has a wider range of habitat; it reaches further down the shore, is common in sheltered and exposed sites, and extends further into turbid bays ( Batham, 1956; Morton & Miller, 1968). Further north in South Island, its tidal range is more restricted than that of A. antipodum and its distribution is centred on more sheltered shores than that species, being most frequent on irregular rock with numerous crevices (at Banks Peninsula; Knox, 1953). In North Island, it is sparse on the east coast of Auckland, where it is restricted to open coasts, but more common on the Auckland west coast (Morton & Miller, 1968).

Range ( Fig. 14). New Zealand, Auckland Islands, Chatham Islands. This species occurs throughout the two main islands of New Zealand (northernmost record: The Bluff , Ninety- Mile Beach , 34°41'S 172°54'E, AMS C406343 ), on Stewart Island ( Port Pegasus , 47°09'S 167°42'E, MNZ M026145 ), Snares Islands (Rima Islet, 48°02'S 166°38'E, MNZ M058350 ), Auckland Islands ( Rose Island , 50°31'S 166°15'E, MNZ M155923 ) and Chatham Islands ( Waitangi Bay , 43°57'S 176°33'W, MNZ M110471 ; Powell, 1933b) .

Remarks. The shell shows considerable variability in both shape and colour. Shape ranges from elongate to globular or even patulous. Possible correlation with environmental variables has not been recorded but, by analogy with other species (e.g., A. unifasciata ) the wide-mouthed forms might be found on more exposed coasts.

Of the two species of Austrolittorina in New Zealand, A. cincta has the darker coloration and more southerly (i.e. higher latitude) distribution, whereas A. antipodum has a paler shell and more northerly distribution. This might be an example of climatic selection, with dark, heat-absorbing shells in cooler climates. A similar case has been noted in the intraspecific variation of A. araucana ( Reid, 2002 a) and another in the pair Afrolittorina africana and A. knysnaensis (described below).

This species is sympatric with A. antipodum throughout most of its range; however, its distribution is more southern, for it is more common in the south of its range ( Suter, 1913) and extends to the Auckland Islands (where A. antipodum does not occur). In the north it does not reach the Three Kings Islands or the Kermadec Islands, in contrast to A. antipodum . The two species are readily discriminated by the brown colour or lined pattern of A. cincta ; when, rarely, the pattern is faint or reduced to a peripheral band only, the base still retains a few brown lines close to the columella, and the spiral grooves are more pronounced than in A. antipodum . Anatomically, there is only a slight difference in the penial shape, the filament being slightly more pointed in A. cincta .