Scaled Worm Snail (Scaly Tube Snail)

Thylacodes squamigerus (Serpulorbis squamigerus)

These marine gastropods belong in the Vermetidae family, characteristic for their irregular shell shape due to warping and losing the snail’s common spiral form. Unlike other snails, the shell is adhered onto the substrate (rock) either individually or in cluster among others who filter feed through their mucus net secretion. (3) An adult commonly has a length of 125mm and a diameter of 12mm (4).  It is preyed upon by the seastar Pisater giganteus as part of the echinoderm’s primary diet but the Scaly Tube Snail is subjected to other predators  (4). Larvae settlement is selective through recruitment by bryozoans onto a designated substrate and the post-settlement mortality, both which affect distribution of this species (2). Invertebrates of the Cheilostoma clade often recruit larvae onto their calcium carbonate skeleton, providing a surface for settlement and growth of the snail up to three months where it can then escape predation independently (2).


(1) Holmes, S. J. (1900). The early cleavage and formation of the mesoderm of Serpulorbis squamigerus Carpenter. The Biological Bulletin, 1(3), 115-121.

(2) Osman, R. W. (1987). Interactions between the vermetid Serpulorbis squamigerus (Carpenter) and several species of encrusting bryozoans. Journal of experimental marine biology and ecology, 111(3), 267-284.

(3) Hadfield, M. G. (1970). Observations on the anatomy and biology of two California vermetid gastropods. The Veliger, 12, 301-309.

(4) Hughes, R. N. (1978). The biology of Dendropoma corallinaceum and Serpulorbis natalensis, two South African vermetid gastropods. Zoological journal of the Linnean Society, 64(2), 111-127.


(Photograph) Tai Ray-Jones. Scaled Worm Snail