Dr. Martin Hendricks

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https://hdl.handle.net/10566/1543

Dr. Martin Hendricks

Position: Associate Researcher
Department: Biodiversity and Conservation Biology Programme
Faculty: Faculty of Natural Science
Qualifications: M.Sc.
Tel: 021 959 2041
Fax: 021 959 2312
Email: mhendricks@uwc.ac.za

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Browsing by Author "Wilby, Deborah"

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    The role of encrusting coralline algae in the diets of selected intertidal herbivores
    (Springer Verlag, 2006) Maneveldt, Gavin; Wilby, Deborah; Potgieter, Michelle; Hendricks, Martin G.J.
    Kalk Bay, South Africa, has a typical south coast zonation pattern with a band of seaweed dominating the mid-eulittoral and sandwiched between two molluscan-herbivore dominated upper and lower eulittoral zones. Encrusting coralline algae were very obvious features of these zones. The most abundant herbivores in the upper eulittoral were the limpet, Cymbula oculus (10.4 + 1.6 m-2; 201.65 + 32.68 g.m-2) and the false limpet, Siphonaria capensis (97.07 + 19.92 m-2; 77.93 + 16.02 g.m-2). The territorial gardening limpet, Scutellastra cochlear, dominated the lower eulittoral zone, achieving very high densities (545.27 + 84.35 m-2) and biomass (4630.17 + 556.13 g.m-2), and excluded all other herbivores and most seaweeds, except for its garden alga and the encrusting coralline alga, Spongities yendoi (35.93 + 2.26 % cover). For the upper eulittoral zone, only the chiton Acanthochiton garnoti 30.5 + 1.33 % and the limpet C. oculus 2.9 + 0.34 %, contained encrusting coralline algae in their guts. The lower eulittoral zone limpet, Scutellastra cochlear also had a large percentage of encrusting coralline algae in its gut with limpets lacking gardens having higher (45.1 + 1.68 %) proportions of coralline algae in their guts than those with gardens (25.6 + 0.8 %). Encrusting coralline algae had high organic contents, similar to those of other encrusting and turfy algae, but higher organic contents than foliose algae. Radula structure, grazing frequencies as a percentage of the area grazed (upper eulittoral 73.25 + 3.60 % d-1; lower eulittoral 46.0 + 3.29 % d-1), and algae organic content provided evidence to support the dietary habits of the above herbivores. The data show that many intertidal molluscs are actively consuming encrusting coralline algae and that these seaweeds should be seen as an important food source.