III-E-28 



Odum, W.E. 1970. Utilization of the direct grazing and plant detritus 

 food chains by the striped mullet Mugil cephalus . Pages 222-240 in 

 J.H. Steele, ed., Marine food chains. University of California Press, 

 Berkeley. 



Zooplankton are not the most important herbivore link in secondary 

 production. In most cases, food chains are based on detritus derived 

 from marsh grasses, sea grasses, macro-algae, and mangroves, or 

 directly on the benthic and epiphytic microflora. Animals that are 

 able to utilize such energy sources replace zooplankton as the critical 

 herbivore link. 



The striped mullet, Mugil cephalus , typically feeds either by sucking 

 up the surface layer of mud or by grazing on submerged rock and plant 

 surfaces. Studies have shown that the major stomach contents fall into 

 three categories: (1) micro-algae, including epiphytic and benthic 

 forms: (2) decaying plant detritus; and (3) inorganic sediment particles, 

 which appear to function as a grinding paste in the degradation of plant 

 cell walls in the pyloric stomach. There has not been a concerted 

 attempt to analyze feeding habits in relation to the food available 

 in the environment and how this relationship varies from one area 

 ■to another. 



For this study seven different environmental systems were chosen, 

 and the mullet's diet analyzed for each system. Findings showed that 

 M. cephalus is able to utilize either plant detritus or live plant 

 material, depending on which is easier to exploit in a given situation. 

 When faced with a choice between these two resources, M. cephalus 

 fed almost exclusively on live plant material. (B.W.) 



Keywords: fishes, food chains, zooplankton, detritus, food habits, 

 California 



III-E-29 



Tenore, K.R. 1971. A technique for measuring detrital utilization by 

 deposit feeding benthos. Page 237 j£ D.S. Gorsline, ed.. Second 

 national coastal and shallow water research conference; abstract vol. 

 University of Southern California, Los Angeles. (Abstr.) 



Many workers have emphasized the nutritive role of detritus in 

 coastal systems, and any study of the energetics of the benthos must 

 take into account this detrital energy flow. The consensus of benthic 

 ecologists is that detritus, derived chiefly from the decay of shallow 

 water rooted vegetation, is the basic nutritional source of shallow 

 water benthos. Our knowledge of such functional relations is scant 

 and investigations should aim at determining energy flow rates of the 

 benthos. 



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