Influence of diet on survivorship and growth in Portia fimbriata, an araneophagic jumping spider (Araneae: Salticidae)

The influence of diet on survival rate and growth was investigated in Portia fimbriata, an araneophagic salticid spider in Queensland. Portia fimbriata spiderlings were reared on one of three different diets: spiders only, insects only, and a mixture of spiders and insects. For each diet, various spider and insect species were used, and the spider diets included as prey both cursorial salticid species and web-building species. Individuals on the insects-only diet did not survive past the fifth instar, whereas juveniles reached maturity when raised on the other diets. Survivorship of P. fimbriata raised on the spiders-only diet was significantly higher when they were fed on the mixed diet. Diet treatment had a significant effect on body dimensions measured at the fourth instar and at maturity. In addition, P. fimbriata reared on the spiders-only diet reached sexual maturity earlier than those reared on the mixed diet. These results suggest that there are fitness-related consequences of prey specialization in P. fimbriata.