Labropoulou et al : Habitat selection and (diet of juvenile Pagrus pagrus 



505 



A Numerical abundance 



0.9 ^ 



0.8 



0.7 



0.6 



0.5 



0.4 



0.3 



0.2 



0.1 







0.9 

 0.8 

 0.7 + 

 0.6 

 0.5 

 0.4 - 

 0.3 

 0.2 

 0.1 

 



f \ 



Aug Sep Oct Nov Dec Feb Mar Apr May Jun .lul 



B Biomass 



H h 



Aug Sep Oct Nov Dec Feb Mar Apr May Jun Jul 



Figure 6 



Monthly variations of Pagrus pagrus dietary breadth: numerical abundance (A): 

 biomass (Bi. Error bars are 95'^r bootstrap confidence intervals. 



their results showed pronounced seasonal changes 

 in the diet of red porgy. It is possible that these dif- 

 ferences in feeding habits between juvenile and ma- 

 ture individuals are associated with habitat change 

 from soft bottom to hard substrates. Manooch ( 1977 ) 

 stated that red porgy is an opportunistic browser 

 feeding on a variety of invertebrates as well as small 

 fish. He also noted that its diet appeared to be de- 

 pendent on species availability, rather than prefer- 

 ence or selection. These differences between our re- 

 sults and those of the previous studies may be due 

 in part to the fact that in both studies dietary analy- 

 sis was based on mature specimens, probably reflect- 

 ing the distinct spatial zones occupied by juvenile 

 and mature specimens. 



According to our results, habitat of juvenile red 

 porgy appears to be well separated from that of adult 

 specimens. The absence of mature individuals in the 

 trawlable fishing grounds indicates that recruitment 

 in shallow waters is followed by an ontogenetic move- 

 ment to a new habitat, at the time they reach sexual 

 maturity. Further examination of this phenomenon 

 is important from a biological, as well as from a man- 

 agement, point of view. Red porgy have previously 

 been described as a food generalist obtaining most 

 of its food from the benthos and epibenthos as well 



as a habitat generalist occupying a variety of habi- 

 tats (Manooch, 1977; Manooch and Hassler, 1978; 

 Pajuelo and Lorenzo, 1996). Patterns observed in the 



