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. Porti a fimbriata spiderlings were reared on one of three different diets: s piders only, insects only, and a mixture of spiders and insects. For e ach diet, various spider and insect species were used, and the spider diets included as prey both cursorial salticid species and web-buildin g species. Individuals on the insects-only diet did not survive past t he 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. Di et treatment had a significant effect on body dimensions measured at t he fourth instar and at maturity. In addition, P. fimbriata reared on the spiders-only diet reached sexual maturity earlier than those reare d on the mixed diet. These results suggest that there are fitness-rela ted consequences of prey specialization in P. fimbriata.