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Browsers & Grazers

Photo of a Common WarrenerA major source of food on shores is algae. Some molluscs graze on the fronds of the larger green, brown and red algae. One of these is the Common Warrener, Turbo undulata. It grazes on algae at low shore levels.

Photo of Variegated Limpets

Here are some Common Variegated Limpets, Cellana tramoserica, with a covering of algae on their shells, but no algae on the rock surface. Why is this so ?

It is estimated that for every square centimetre of limpet, about 75 square centimetres of encrusting algae is necessary to maintain its life during its first year of growth.

On many rock surfaces you can see the small round home scars of these limpets, and if you look carefully you can pick out the area which is grazed by them. If you remove the limpets from an area, you will notice that in a short time tiny algae clumps begin to sprout and grow. In areas where the limpets remain, the rock remains bare.

As these molluscs move across the rock they rasp their tongue, called a radula, across its surface. The radula is a file-like ribbon of small horny teeth that all gastropods and some other molluscs possess. It can rasp either vegetable matter, or flesh in some carnivorous species, and convey the particles of food into the mouth.

However, most browsers and grazers do not fed on large macroalgae fronds. They feed on microalgae, algae spores and small plants trying to gain a foothold on the rock surface in moist depressions and pools.

High Shore Browsers and Grazers

Some browsers at the Splash Fringe Level and High Tide Levels are:

Small photo of Tubercled NoddiwinkTubercled Noddiwink, Nodilittorina pyramidalis,
feeds on lichens at high shore levels

Small photo of Blue AustralwinkBlue Australwink, Nodilittorina unifasciata,
feeds on lichens at high shore levels.


Small photo of  Petterd's LimpetPetterd's Limpet, Notoacmea petterdi


Mid Shore Browsers and Grazers

Some grazers and browsers of the mid-tide levels are:

Small photo of  Zebra Top ShellZebra Top Shell, Austrocochlea porcata,


Small photo of Ribbed Top ShellRibbed Top Shell, Austrocochlea constricta


Small photo of Wavy Top ShellWavy Top Shell, Austrocochlea concamerata


Small photo of Black NeriteBlack Nerite, Nerita atramentosa


Small photo of Striped-mouth ConniwinkStriped-mouth Conniwink, Bembicium nanum,


Small photo of Variegated LimpetVariegated Limpet, Cellana tramoserica


Low Shore Browsers and Grazers

Other grazers at the low-tide level and Low Fringe level are:

Small photo of Black Keyhole LimpetBlack Keyhole Limpet, Amblychilepas nigrita


Small photo of Elephant SnailElephant Snail, Scutus antipodes.


Small photo of Common WarrenerCommon Warrener, Turbo undulata



Bennett, I. (1987) W. J. Dakin's classic study: Australian Seashores. p,242, Angus & Robertson, Sydney.

Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. p.88, New Holland, Sydney.

Shepherd, S. A. & Thomas, I. M. (1982) Marine Invertebrates of Victoria, Pt. 2. p. 553, South Australian Government Printer, Adelaide.

Underwood, A. J. & Chapman, M. G. (1993) Seashores: a beachcomber's guide. p.30, New South Wales University Press, Sydney.

Feeding Relationships

Nutrient Absorbers
Grazers & Browsers
Suspension Feeders
Deposit Feeders
Trophic Levels
Energy Pyramid

Home Page
Rocky Shores
Tidal Levels
Intertidal Zonation
Environmental Factors
Biological Factors
Feeding Relationships


photo of Keith DaveyLife on Australian Seashores
by Keith Davey (C) 2000

Learning Consultant - Media
The University of Newcastle

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Scientific Consultant: Phil Colman
site created 01.01.98 : updated 01.04.2000