Common name. Square top –snail.

Size. Maximum shell height 12 mm⁽¹⁾.

Remarks. Occurs on protected mudflats⁽¹⁾.

Distribution. East African distribution including Madagascar. Common in Mozambique extending south to Durban in South Africa⁽¹⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1987 (NMSA). Only dead shells collected in 2012 from Fani’s Island (South Lake).

Common name. Brown nerite or Zebra nerite.

Size. Maximum shell height 22 mm⁽²⁾.

Remarks. Occurs on stones in streams that are tidally influenced⁽²⁾.

Distribution. Southeastern coast of Africa from Mozambique to Mzamba in the Eastern Cape Province of South Africa⁽³⁾. Also reported from the Comoro Islands, Madagascar and Seychelles⁽²⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1988 from the St Lucia Mouth (NPB). Not found during the recent survey.

Common name. Spotted nerite.

Size. Maximum shell height 20 mm⁽²⁾.

Remarks. Reportedly occurs within mangroves⁽²⁾ and on Phragmites stems in estuaries.

Distribution. East African coast from Somalia extending south to the Umzimkulu River on the KwaZulu-Natal coast of South Africa⁽²⁾. Also reported from the Mtamvuna River⁽³⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1924 and 1987 (NMSA) from False Bay. Not recorded in the recent survey.

Common name. Red-rimmed melania.

Size. Maximum shell height 45 mm⁽³⁾.

Remarks. Predominantly parthenogenetic species⁽³⁾ which inhabits fresh and brackish water⁽²⁾.

Distribution. Natural Indo-Pacific distribution includes much of Africa with a southern limit at Port Elizabeth⁽²⁾ and extending east to southern Asia and northern Australia⁽³⁾. Introduced to regions of North America⁽⁴⁾ and New Zealand⁽⁵⁾.

St Lucia records. Reported in 2012⁽⁶⁾ from Shark Basin (St Lucia Mouth). Recently recorded from the Mpophomeni Stream (False Bay).

Common name. Quilted melania⁽⁷⁾.

Size. Maximum shell height 29.5 mm⁽⁷⁾.

Remarks. Alien invasive species first recorded in northern KwaZulu-Natal in 1999⁽⁸⁾. Indigenous to southeastern Asia⁽⁷⁾ but has also been introduced to the Caribbean⁽⁹⁾, the Americas^{(4, 10)} and Israel⁽¹¹⁾.

St Lucia records. Reported from St Lucia in 2006⁽¹²⁾, 2007⁽¹³⁾ and between 2010 and 2013^{(6, 13, 14)}. Reported in the recent survey from the mangroves at the St Lucia Bridge (Narrows) as well as Makakatana, Catalina Bay and Charter’s Creek (South Lake).

Common name. White-studded cerith.

Size. Up to 30.5 mm.

Remarks. Dead shells collected at Lister’s Point in March 2012.

Distribution. Indo-Pacific distribution with southwestern reports from Mozambique⁽¹⁵⁾, Madagascar⁽¹⁶⁾ and Mauritius⁽¹⁷⁾. South African distrubution restricted to coastline from Kosi Bay to Durban⁽¹⁸⁾.

St Lucia records. Not previously reported.

Common name. Pinnated litiopid.

Size. Maximum shell height 11 mm⁽¹⁾.

Remarks. Common estuarine species which varies in plumpness⁽¹⁾.

Distribution. Still Bay to Zululand coast⁽¹⁾.

St Lucia records. Not previously reported from St Lucia; collected at Charter’s Creek (South Lake) in 1967 and 1987 respectively (NMSA). Not found in the recent survey.

Common name. Truncated mangrove snail⁽¹⁹⁾.

Size. Maximum shell height 36 mm⁽¹⁾.

Remarks. Common mangrove climbing whelk also found in salt marshes on mud beneath vegetation⁽¹⁾, although less abundant⁽¹⁹⁾. Shells tend to have a characteristically decollated apex.

Distribution. Indo-pacific mangrove species. South African distribution extends from Knysna along southeastern coast into Mozambique⁽¹⁹⁾.

St Lucia records. Reported in previous surveys from 1948–51⁽²⁰⁾, 1964–65⁽²¹⁾. Found in the recent survey at Shark Basin, at the Mfolozi Back Channel (St Lucia Mouth), and at the St Lucia Bridge (Narrows).

Common name. African periwinkle⁽¹⁹⁾.

Size. Shell height 5–8 mm⁽¹⁹⁾.

Remarks. Typical high intertidal species which occurs in large numbers usually on exposed rocks⁽¹⁾.

Distribution. Southwestern Indian Ocean⁽²²⁾ from Durban to southern Mozambique⁽¹⁹⁾ as well as southeastern Madagascar⁽²²⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1971 from “St Lucia River Estuary” (NMSA). Not recorded in the recent survey.

St Lucia synonyms. Littorina glabrata Philippi, 1846.

Common name. Striped periwinkle⁽¹⁹⁾.

Size. Maximum shell height 24 mm⁽¹⁾.

Remarks. High resistance to desiccation⁽¹⁹⁾ enables habitation of exposed regions⁽¹⁾ above high spring-tide level in sub-tropical regions.

Distribution. Tropical and subtropical Indian Ocean distribution⁽¹⁾ with a southern limit at Port Elizabeth⁽¹⁾ on the South African coast.

St Lucia records. Not previously reported from St Lucia; collected in 1971 (NMSA) from the St Lucia Estuary. Not found during the recent survey.

Common name. Estuarine periwinkle⁽¹⁹⁾.

Size. Shell height 14–26 mm⁽²³⁾.

Remarks. Associated with roots and trunks of Rhizophora and occasionally Bruguiera mangrove trees⁽²³⁾.

Distribution. Tropical and subtropical Indo-Pacific distribution from the east African coast including the Red Sea and east to Polynesia⁽²³⁾, with a southern limit at Port Elizabeth on the Eastern Cape coast of South Africa⁽¹⁹⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1971 and 1987 (NMSA) from St Lucia Estuary and Shark Basin respectively. Only dead shells retrieved recently from Shark Basin (St Lucia Mouth).

Common name. Pale periwinkle

Size. Shell height 15–25 mm⁽²³⁾.

Remarks. Commonly occurs on the leaves of Rhizophora in mangrove forests⁽²³⁾.

Distribution. Tropical to sub-tropical Indo-Pacific distribution extending from east African coast to Samoa⁽²³⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1987 (NMSA) from the St Lucia Estuary. Not found during the recent survey.

Common name. Aldabra periwinkle.

Size. Shell height 13–34 mm⁽²³⁾.

Remarks. Occurs in mangroves and marsh grass habitats as well as on sheltered rocks⁽²³⁾.

Distribution. Coastal Indian Ocean distribution from Aden, Yemen⁽²³⁾, in the north to the Swartkops River mouth⁽²⁴⁾ at Port Elizabeth, South Africa. Range extends east to Mauritius, Maldives and Cocos Islands⁽²³⁾.

St Lucia records. Not previously reported from St Lucia; collected by NMSA at unknown date. Not found during the recent survey.

Common name. Mangrove periwinkle.

Size. Shell height 25–35 mm⁽²³⁾.

Remarks. Characteristic mangrove and estuarine species found above high water⁽¹⁾. Usually found on trunks, roots⁽²³⁾ and branches of mangrove trees⁽¹⁾.

Distribution. Tropical and sub-tropical Indo-Pacific distribution extending from the eastern African coast across to Samoa and Hawaii⁽²³⁾. The southern limit of the species is Algoa Bay at Port Elizabeth in South Africa^{(1, 19)}.

St Lucia records. Reported from St Lucia in 1948–51⁽²⁰⁾, 1964–55⁽²¹⁾ and 1972–73⁽²⁵⁾ however the species has not been recorded recently.

Common name. Sea elephant.

Size. Up to 34 mm.

Remarks. Pelagic marine species related to Charonia spp. (Ranellidae). The species is expected to occur more frequently in the system as the marine connection is maintained.

Distribution. Circumtropical distribution including the Gulf of Mexico⁽²⁶⁾, the Mediterranean Sea⁽²⁷⁾ and the North Atlantic⁽²⁸⁾.

St Lucia records. Not previously reported from St Lucia; recorded in the recent survey in 2013 from the Mfolozi-St Lucia Beach Spillway (St Lucia Mouth).

St Lucia synonyms. Assiminea bifasciata Nevill, 1880; Coriandria durbanensis (Tomlin, 1916); Rissoa capensis Sowerby, 1892.

Common name. False sentinel.

Size. Up to 2.22 mm.

Remarks. Taxon under revision. Provisional name based on genetics and shell morphometrics⁽²⁹⁾. Small size and sympatric occurrence with Assiminea spp. caused previous confusion and misidentification. Forms dense aggregations on firm mud. Distribution. East coast of southern Africa.

St Lucia records. Probably combined in the 1948–51⁽⁴⁾ survey with Assiminea spp. Reported in 2012 as Coriandria durbanensis (Tomlin 1916)⁽⁶⁾ from Lister’s Point (False Bay). Found in the recent survey from Charter’s Creek (South Lake), Hell’s Gate (North Lake) and Lister’s Point (False Bay).

St Lucia synonyms. Assiminea bifasciata Nevill, 1880; Assiminea cf. ovata (Krauss, 1848); Syncera sp. Gray, 1821;

Common name. Sentinel snail.

Size. Maximum shell height 7 mm^{(1, 19)}.

Remarks. Dominant in estuaries on the east coast⁽¹⁹⁾ forming large colonies on firm mud sheltered by mangroves or salt marsh⁽¹⁹⁾. Species listed as “capensis” following the recommendation of W. Ponder, as the taxonomy of this group is currently under review.

Distribution. Southern African species extending from Langebaan to Mozambique⁽¹⁹⁾.

St Lucia records. Previous records in 1948–51⁽²⁰⁾, 1981–2⁽³⁰⁾ and 2005⁽¹²⁾ probably comprised both Assiminea cf. capensis and “Assiminea” aff. capensis. Reported as Syncera sp. in 1964–5⁽²¹⁾ and Assiminea durbanensis in 1993⁽³¹⁾. Identified as Assiminea cf. ovata in 2007–9⁽¹⁴⁾ following Appleton 1996⁽³⁾. Reported as Assiminea cf. capensis in 2012⁽⁶⁾ and found during the recent survey from the Mfolozi Back Channel (St Lucia Mouth), Catalina Bay and Charter’s Creek (South Lake) as well as Lister’s Point (False Bay).

Common name. Checkerboard bonnet.

Size. Maximum shell height 69 mm⁽¹⁾.

Remarks. Inhabits sandy environments, known to bury itself in the substrate⁽¹⁾. Subtidal species which was most likely washed into the system.

Distribution. Indo-Pacific distribution including the KwaZulu-Natal coast⁽¹⁾. Reported from Mozambique⁽¹⁵⁾ and Tanzania⁽³²⁾.

St Lucia records. Not previously reported from St Lucia; single specimen collected from the St Lucia Mouth by NMSA at an unspecified date. Not reported in the recent survey.

St Lucia synonyms. Nassa kraussiana (Dunker, 1846).

Common name. Tick shell⁽¹⁹⁾.

Size. Shell height 7.5–10 mm⁽¹⁾.

Remarks. Characteristic estuarine species found in salt marshes and lagoonal mudbanks⁽¹⁹⁾ where it forms dense colonies. Occurs within shallow pools often among eelgrass⁽¹⁾.

Distribution. Southern African distribution from the Namaqualand coast⁽²⁾ extending along KwaZulu-Natal⁽¹⁹⁾. Also reported from southern Mozambique⁽¹⁵⁾.

St Lucia records. Reported in 1948–51⁽²⁰⁾, 1972–73⁽²⁵⁾ and 2010⁽³³⁾. Recorded in 1964–65⁽²¹⁾ as Nassa kraussiana. Dead shells retrieved during the recent survey from South and North Lake shores, as well as False Bay.

Common name. Heptagonal rock snail.

Size. Maximum shell length 30 mm⁽¹⁾.

Remarks. Common under rocks or logs on muddy sand of estuarine bays⁽¹⁾.

Distribution. Indo-pacific distribution including the KwaZulu-Natal coast⁽¹⁾ extending to Mozambique as well as Madagascar⁽¹⁵⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1987(NMSA) from the Mfolozi Link Canal (St Lucia Mouth). The specimen collected was probably exposed after excavation of the Link Canal as it is a Pleistocene subfossil. Not found during the recent survey, however the species may re-colonize St Lucia if the marine connection is maintained.

Common name. Short spined murex⁽¹⁹⁾.

Size. Maximum shell height 82 mm⁽¹⁾.

Remarks. Occurs on protected intertidal sandbanks, often among eelgrass^{(1, 19)}. Forms dense mating aggregations⁽¹⁹⁾.

Distribution. Indian Ocean distribution along the eastern coast of Africa extending from Kenya to Durban^{(1, 15, 19)}.

St Lucia records. Not previously reported from St Lucia; only dead shells retrieved from Lister’s Point (False Bay) and Fani’s Island (South Lake) in the recent survey.

Common name. Toad purpura.

Size. Maximum shell height 70 mm.

Remarks. Common in rock pools on the KwaZulu-Natal coast. Specimen illustrated is a sub-adult.

Distribution. Tropical and sub-tropical Indian Ocean^{(15, 32)} with southern limit in the eastern Transkei^{(1, 19)}.

St Lucia records. Not previously collected or reported from St Lucia. Only one dead shell was found at False Bay during the recent survey.

St Lucia synonyms. Haminoea petersi (Martens, 1879); Haminoea gracilis (Sowerby, 1897); Cylichna africana Bartsch, 1915; Cylichna tubulosa Gould, 1859.

Common name. Natal bubble shell.

Size. Maximum shell length 19 mm⁽¹⁾.

Remarks. Inhabits shallow water including tidal rock pools⁽³⁴⁾.

Distribution. On the South African coast, replaces Haminoea alfredensis from the Transkei into northern KwaZulu-Natal⁽¹⁾. Occurs from Port Alfred to Mozambique and is likely synonymous with other Indo-Pacific species⁽³⁴⁾.

St Lucia records. Probably misidentified in 1972–73⁽²⁵⁾ as Cylichna africana, as misspelled Haminea gracilis in 1964–65⁽²¹⁾ and as misspelled Haminea petersi in 1981–82⁽³⁰⁾. Reported in 1948–51⁽²⁰⁾, as well as in 2006⁽¹²⁾ and 2007⁽¹⁴⁾. Only dead shells retrieved during the recent survey.

St Lucia synonyms. Barnardaclesia cirrhifera (Quoy & Gaimard, 1832); Notarchus cirrhifera (Quoy & Gaimard, 1832).

Common name. Shaggy Sea Hare, Ragged Sea Hare.

Size. Maximum length 130 mm⁽³⁴⁾.

Remarks. Common estuarine species which also occurs in tide pools⁽¹⁹⁾.

Distribution. Cicumtropical species reported from the east coast of Africa⁽¹⁹⁾, the Mediterranean Sea⁽²⁷⁾, the North Atlantic region⁽²⁸⁾ as well as the Caribbean⁽³⁵⁾.

St Lucia records. Reported as Barnardaclesia cirrhifera in 1948–51⁽²⁰⁾ and as Notarchus cirrhifera in 1964–65⁽²¹⁾. Not recorded during the recent survey.

Common name. Lined Sea Hare.

Size. 28 mm⁽³³⁾.

Remarks. Occurs in sheltered pools and estuaries, often sympatric with Bursatella leachii.

Distribution. Circumtropical distribution including Cape Verde⁽³⁶⁾ and the Caribbean Sea⁽³⁵⁾. Southern African distribution extends from Mngazana in the Eastern Cape to southern Mozambique⁽³⁴⁾.

St Lucia records. Recorded in 2007⁽¹⁴⁾ after the overtopping and mouth breaching event. Not reported in the recent survey.

Common name. Eyed false-limpet⁽¹⁹⁾.

Size. Maximum length 33 mm⁽¹⁾.

Remarks. Locally common species which is found on sheltered rocks in lagoons and estuaries⁽¹⁾.

Distribution. Southern African distribution extends along the coast from False Bay in the Western Cape Province to Mozambique⁽¹⁾.

St Lucia records. Reported in 1948–51⁽²⁰⁾ and 1964–65⁽²¹⁾ from the St Lucia Mouth. Not recorded in the recent survey.

Common name. Natal bladder snail

Size. 9.6 × 8.5 mm (depressed form) 9.5 × 6.5 mm (high spired form)⁽²⁾.

Remarks. Wide range of habitats including small pools, slow flowing rivers and lakes⁽²⁾.

Distribution. East African distribution extending from Ethiopia to the northern coastal region of KwaZulu-Natal⁽²⁾ where it occurs predominantly on the eastern lowlands⁽²⁴⁾.

St Lucia records. Not previously reported from St Lucia; recorded in the recent survey at Catalina Bay (South Lake) in 2012.

Common name. Tropical bladder snail.

Size. 12.3 × 7.8 mm (slender form), 10.6 × 8.3 mm (more globose form)⁽²⁾.

Remarks. Commonly occurs in small earth dams and residual pools of seasonally flowing streams⁽²⁾.

Distribution. Eastern and southern Africa, extending from Ethiopia to Namibia and the Western Cape of South Africa. Not commonly found on the eastern coastal region of South Africa⁽²⁾.

St Lucia records. Reported in 1948⁽²⁰⁾, 1964–65⁽²¹⁾ and 2002–03⁽³⁷⁾. Only dead shells retrieved from the lake shores at Lister’s Point (False Bay), Hell’s Gate (North Lake), Fani’s Island (South Lake) and Mpate Mouth (Narrows) during the recent survey.

Common name. Forskål’s bladder snail.

Size. 17 × 5.4 mm⁽²⁾.

Remarks. Ability to aestivate allows this species to commonly inhabit seasonal pools⁽²⁴⁾.

Distribution. Afrotropical distribution extending south from the Egyptian Mediterranean region to Namibia⁽²⁾. Also reported from Madagascar⁽²⁾.

St Lucia records. Reported in 2002–03⁽³⁷⁾ from the South Lake Eastern Shores. Not reported during the recent survey.

Common name. Slender bladder snail⁽⁷⁾.

Size. 15 × 8 mm⁽³⁾.

Remarks. Alien species introduced from South America⁽³⁾. Commonly colonizes lentic waterbodies and the backwaters of rivers⁽²⁴⁾. Recent work assigns this species to the genus “Aplexa” rather than “Physa”⁽³⁸⁾.

Distribution. Occurs in isolated populations in KwaZulu-Natal, Mpumalanga and Limpopo⁽²⁴⁾.

St Lucia records. Reported in 2005⁽³⁹⁾ from a pan on the Western Shores (South Lake). Recorded in 2009⁽¹³⁾, 2010⁽¹⁴⁾ and in the recent survey in 2012 from Catalina Bay (South Lake).

Common name. Natal pond snail.

Size. Maximum shell height 25 mm⁽²⁾.

Remarks. Occurs in permanent streams⁽²⁾. Major intermediate host of the giant liver fluke, Fasciola gigantica⁽³⁾. Debated whether this species should be assigned to the genus Radix.

Distribution. East African distribution including the highlands of Ethiopia⁽²⁾. Southern range includes the Orange, Okavango and Zambezi Rivers⁽²⁴⁾.

St Lucia records. Not previously reported from St Lucia; collected in 1982 (NPB). Reported in the recent survey from Catalina Bay (South Lake) in 2012.

Common name. Reticulate pond snail.

Size. 17 × 9 mm⁽²⁾.

Remarks. Alien species introduced from North America. Occurs on damp mud at the water-air interface⁽²⁴⁾. Intermediate host for Fasciola hepatica and Fasciola gigantica⁽²⁴⁾.

Distribution. Widely introduced to many areas, including Puerto Rico, Europe and New Zealand. First reported from Africa in 1944 from the Western Cape Province of South Africa⁽²⁾.

St Lucia records. Reported in 2009⁽¹³⁾ from freshwater seepage area in Catalina Bay (South Lake). Not recorded in the recent survey.

Common name. Twisted amber snail⁽⁴⁰⁾.

Size. Maximum shell length 10 mm⁽³⁾.

Remarks. Typically occurs on emergent vegetation alongside water⁽³⁾.

Distribution. Southern African distribution includes Mozambique, northern Botswana and Zimbabwe⁽¹⁷⁾. Found on the KwaZulu-Natal coastal belt between Park Rynie and Lake Sibaya⁽⁴⁰⁾.

St Lucia records. Reported in 2002–03⁽³⁷⁾ from South Lake Eastern Shores. Not recorded in the recent survey.

Common name. Keeled coffee-bean snail.

Size. 12 × 7.5 mm⁽²⁾.

Remarks. Typically found on the surface of firm mud in mangroves and salt marshes⁽²⁴⁾.

Distribution. East African coastal distribution from the Massawa region of the Red Sea to Port Elizabeth in South Africa⁽²⁾.

St Lucia records. Reported in 1964–65⁽²¹⁾ as well as during the recent survey at the mangroves near the St Lucia Estuary Mouth.

Common name. Common coffee-bean snail⁽⁴⁰⁾.

Size. Maximum shell height 18 mm⁽⁴⁰⁾.

Remarks. Reported as Melampus ordinarius Melvill & Ponsonby, 1901 from deep vertical cracks in high level outcrops at Mission Rocks⁽⁴⁰⁾.

Distribution. Tropical to subtropical Indian Ocean distribution extending from East London north along the KwaZulu-Natal coast⁽⁴⁰⁾.

St Lucia records. Reported in 1964–65⁽²¹⁾. Not recorded in the recent survey.

Common name. Dwarf coffee-bean snail⁽⁴⁰⁾.

Size. Maximum shell height 13 mm⁽⁴⁰⁾.

Remarks. Found on firm mud in lagoons and estuaries where individuals form dense colonies⁽⁴⁰⁾.

Distribution. Tropical Indo-Pacific distribution including Indian Ocean islands. South African distribution extends from KwaZulu-Natal to Port Alfred⁽⁴⁰⁾.

St Lucia records. Not previously reported from St Lucia; recorded from the mangroves at Shark Basin (St Lucia Mouth) in the recent survey.

Common name. Half-grooved coffee-bean snail⁽⁴⁰⁾.

Size. Maximum shell height 12 mm⁽⁴⁰⁾.

Remarks. Mangrove species which occurs in the burrows of crabs up to a depth of 150 mm as well as on the surface of the mud⁽²⁴⁾.

Distribution. East African distribution ranging from the Giuba River in Tanzania to the Umkomaas River on the southern coast of KwaZulu-Natal in South Africa⁽²⁾.

St Lucia records. Reported in St Lucia in 1964–65⁽²¹⁾ as well as in the recent survey from the mangroves at Shark Basin (St Lucia Mouth) in 2012.