17 September 2008

Six new Nerite records for Singapore

Like little half-marbles, these snails are quite commonly seen on many of our shores. Nerites (snails of the Family Neritidae) generally have round shells, some with pretty patterns and colours. But what I find most endearing about them are the long elegant 'feelers' that flutter around as the snail wanders. And the delightful pajama-striped body pattern of some of the commonly seen species.

Being common, alas, they are often ignored or overlooked. Fortunately, these snails were a subject of a recent study. Thanks to Tan Siong Kiat and Reuben Clements, the number of Nerite species in Singapore has been expanded to 19, which includes 6 new records! (thanks also to Marcus who alerted on the post on A Snail's Eye View blog)

from Tan, S.K. & Clements, R. (2008) Taxonomy and distribution of the Neritidae (Mollusca: Gastropoda) on Singapore. Zoological Studies 47(4): 481 – 494. Download the PDF.

What I found interesting was the locations of the six new records. Most were not found in exotic faraway shores, but some mainland and overlooked shores, including reclaimed shores.
  • Nerita costata, found at Tanah Merah, Pulau Semakau, Pulau Salu
  • Nerita plicata, found at Pulau Semakau
  • Neritina auriculata, found Sungei Punggol and Berlayar Canal
  • Neritina coromandeliana, found at Marina East
  • Neritina siquijorensis, found at Pasir Ris and Sungei Bedok
  • Neritina sulculosa, found at Sungei Punggol and Berlayar Canal
Sadly, the report noted "Among the Neritina species sampled, Neritina coromandeliana was the rarest with only a single specimen found at Marina East. Subsequent trips to the same location did not yield more samples and unfortunately, construction activities have destroyed and altered much of the original sampling location".

The study also noted that "the high proportion of new records may be attributed to the lack of taxonomical work and undersampling of the local malacofauna. Future surveys, particularly of other locations not covered in this study may reveal species yet to be recorded and increase the distribution ranges of known species".

So yeah, we should pay closer attention to some of our forgotten shores and who knows what we may find!

On a positive note, the study notes "Observations have shown that local Neritids do not appear to be under threat from exotic species or collection. Although major reclamation works over the past few decades have drastically changed the coastal environments of Singapore, populations of most marine Neritids do not appear to be under threat and have rapidly colonized artificial habitats such as breakwaters and seawalls".

However, the study also highlights "Increased habitat alteration, however, may have a disastrous effect on resident populations of Neritina auriculata, Neritina coromandeliana, and Neritina sulculosa as they appear restricted to certain niches within their sampled localities. As such, the conservation of remaining coastal habitats may be vital to the survival of these species in Singapore".

Reuben Clements, one of the authors of this paper is giving an intriguing talk this Friday entitled "Counting (on) snails and tigers for conservation". He asks: How does one count snails and tigers in ecology? How can we "count on" snails and tigers to make a case for the conservation of forest habitats? Come for the talk and find out more!

More details about the talk on the Raffles Museum news blog.


  1. Ok, now I have to memorise this paper so that I can identify the nerites that I find in future.



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