Trumpet-mouthed hunter snail (Gulella salpinx)
|Size||Shell length: up to 7.6 mm (2)|
The trumpet-mouthed hunter snail is classified as Critically Endangered (CR) on the IUCN Red List (1).
The rather flamboyant common name of the trumpet-mouthed hunter snail (Gulella salpinx) refers to the flaring, trumpet-like opening of its distinctive shell. The shell is unusual, being white in colour, with strongly defined whorls and grooves, appearing to be thrown off to the left of the snail’s body. The semi-translucent body is pale buff, while the tentacles are bright orange (2).
This recently discovered, narrow-range endemic is known only from a single limestone outcrop of the Marble Delta in the KwaZulu-Natal province of South Africa (1) (2). The KwaZulu-Natal south coast is a relatively well studied area, but the species has not been found at any other locations in the region. All the specimens collected to date have come from an area of less than an estimated 1,000 square metres, but the total area of the limestone outcrop to which it is probably restricted is around 40 km² (1).
The trumpet-mouthed hunter snail’s confinement to limestone deposits implies that it requires areas of lime-rich soil (2). The species has been found amongst the leaf-litter of dense valley thicket and woodland on south-facing slopes (1) (2).
As a recently discovered species, relatively little is known about this snail’s biology. Unusually for snails, however, it is known to be ovoviviparous, with developing eggs brooded internally within the uterus before hatching. The female then ‘gives birth’ to minute juvenile snails (2).
The ‘hunter’ part of this species’ common name refers to its carnivorous habits, a behaviour that is common to the whole Streptaxidae family, which primarily feed upon soft-bodied invertebrates such as other snails and worms (3).
The marble deposit, to which the species is endemic, is extensively mined by two companies (1) (2). The area is also heavily invaded by non-native plants (1) (2).
Once informed of this critically endangered snail’s existence, the two mining companies operating in the area have expressed their willingness to cooperate in its conservation. They have even offered to support a survey of additional habitat within the marble deposit to search for further populations (1).
For more information on the trumpet-mouthed hunter snail:
- Herbert, D.G. & Kilburn, R.N. (2004) Field guide to the land snails and slugs of eastern South Africa. 340pp. Natal Museum, Pietermaritzburg.
Authenticated (13/07/2006) by Dr. Dai G. Herbert, Chief Curator: Mollusca, Natal Museum, and member of the IUCN/SSC Southern African Invertebrate, and Mollusc Specialist Groups.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Ovovivipary: method of reproduction in which the eggs are retained within the adult, the well developed embryos ultimately hatching inside the parent, which then appears to give birth to living young.
- Whorls: in molluscs,the spiral coils of the shell of a snail.
IUCN Red List (June, 2006)
Inland Invertebrate Initiative: Database of Threatened Invertebrates of South Africa (July, 2006)
The Open Earth Project (July, 2006)