4.3.6 Epiphytes 



4.4 INVERTEBRATES 



Many species of algae occur 

 epiphytically, some as obligates on other 

 species of algae. Even though it is an 

 annual , Nereocystis may have many 

 epiphytes, the commonest of which are the 

 reds Porphyra nereocystis and 

 Antithamnionella pacifica , and the green 

 Enteromorpha linza (Abbott and Hollenberg 

 1976) . P. nereocystis and A. pacifica may 

 be found on the stipes of plants, while E. 

 linza is usually found at the lower 

 junctions of fronds. Microcladia 

 cal ifornica is commonly found on Egregia 

 menziesi i in the low intertidal, while M. 

 coul teri (Figure 17) occurs on many 

 species of red algae as well as on large 

 brown algae (Abbott and Hollenberg 1976). 



During the summer, species of the 

 brown alga Coilodesme may be found 

 abundantly on Cystoseira . Coilodesme 

 cal ifornica is particularly abundant on _C. 

 osmundacea . Diatoms (see Section 4.2.1 

 above) and many other algal species such 

 as Myriogramme caespitosa , Pterochondria 

 woodii , and Microcladia coul teri may occur 

 on Macrocystis and other kelps. 



Epiphytic algae seem to become 

 particularly abundant as fronds senesce. 

 This is probably not due to the epiphytes 

 actually overwhelming plants and causing 

 their demise, but to the general 

 deterioration of host plants at this time. 

 Fil ion-Myklebust and Norton (1981) 

 reported that the intertidal brown seaweed 

 Ascophyl Turn nodosum sheds its epidermis, 

 which may remove epiphytes. Moss (1982) 

 found that continuous shedding of the 

 outermost layers of meristoderm cell walls 

 occurred in the perennial alga Hal idrys 

 sil iquosa , and suggested that this might 

 be a general occurrence in the Fucales. 

 These sorts of events may be especially 

 important for long-lived perennial 

 species, which have a longer exposure to 

 potential epiphytes. It has also been 

 suggested that the abundant small 

 Crustacea that inhabit the fronds of large 

 brown algae may benefit plants by removing 

 epiphytes (Schiel and Choat 1980). 

 Limpets that live on the surface of stipes 

 may provide similar benefits (Dayton et 

 al. 1984). Most of these ideas have yet 

 to be tested. 



4.4.1 Introduction 



Giant kelp forests are inhabited by 

 an abundant and species-rich invertebrate 

 fauna found in a variety of habitats 

 (Figure 6). In giant kelp holdfasts 

 alone, Andrews (1945) found over 23,000 

 individuals representing nine phyla in 

 five holdfast collections from the 

 Monterey, California area (exact size of 

 collections unspecified). McLean (1962) 

 identified 204 species of invertebrates 

 seen during 30 SCUBA dives in a primarily 

 Nereocystis luetkeana forest south of 

 Monterey ("site described in Chapter 3). 

 Pequegnat (1964) found over 300 species on 

 a shallow rocky reef in southern 

 California. The diversity of sizes, 

 morphologies, feeding types, and behaviors 

 is also high, making even an overview of 

 conspicuous species and their ecology a 

 difficult task. 



Unfortunately, there is no single 

 reference equivalent to that for the algae 

 by Abbott and Hollenberg (1976) describing 

 subtidal marine invertebrates in 

 California. However, because many species 

 range into the low intertidal zone, the 

 recent intertidal survey by Morris et al . 

 (1980) is very helpful, as are Ricketts et 

 al. (1968), and for central California, 

 Smith and Carlton (1975). These books, as 

 well as MacGinitie and MacGinitie (1968), 

 also include natural history information. 

 Popular books (North 1976a, Gotshall and 

 Laurent 1979) summarize information on the 

 more common subtidal invertebrates likely 

 to be found in giant kelp forests. We 

 will discuss some of these below, 

 particularly species that are common, and 

 for which there is some ecological 

 information. 



We have organized groups of 

 invertebrates functionally by feeding 

 type, rather than taxonomically , in an 

 attempt at ecological relevance. Feeding 

 type distinctions, however, are often 

 unclear as a particular species such as 

 the sea urchin Strongylocentrotus 

 franciscanus may graze attached plants 

 (grazer) , catch drift (detritus feeder), 

 consume animals (predator), and perhaps 

 use dissolved organic matter (DOM). Where 



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