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Title: The environmental physiology of Bufo bufo L. and Bufo calamita Laur. tadpoles.
Author: Nicolle, Philip David.
Awarding Body: Liverpool Polytechnic
Current Institution: Liverpool John Moores University
Date of Award: 1989
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Using spawncollected from the north ~rseyside sand dune system, the effects of tenperature on growth, developrent, rretabolism and rretamorphosis in B. bufo and B. calamita tadpoles were investigated, together with a limited study on the effects of L-thyroxine. The effects of density on growth, developteI1t and rretarnorphosis were examined. Physiological and behavioural effects of B. bufo tadpoles on B. calamita tadpoles were also studied. B. calamita spawnand tadpoles survive at higher temperatures than B. bufo. Below20°CB. bufo spawn, and below 15°Ctheir, develop at a greater rate than B. calamita. B. calamita spawnand tadpoles' growth and developrent is faster at higher temperatures. B. calamita tadpoles have higher rretabolic rates than B. bufo across the terrperature range 15-30°C. Faster rates of rretabolism and developnent in B. calamita result in smaller tadpoles and toadlets than B. bufo. B. calamita mayconpensate for this with increased rretamorphic efficiency in tenns of energy. It is speculated that differences in tadpole thyroid physiology could account for observed differences. ~tamorphic efficiency was greatest, and rates of developrent and growth maximised/at the tadpoles' preferred body terrperature. Increased density reduced growth-and developteI1t of tadpoles, but influenced different stages in the two species. ~tamorphosis in all B. bufo tadpoles was delayed, whereas in B. calamita a proportion of the population rretarnorphosedapparently unaffected by increased density. The responses of tadpoles to temperature and density were related to the species' prefered spawningenvironrrents. In the presence of B. bufo tadpoles, B. calamita growth, developrent and rretabolism was suppressed. The pattern of developrent and timing of rretamorphosis in B. calamita becamesimilar to that of B. bufo. Inhibition was not relieved by L-thyroxine, and did not effect tadpole behaviour. Mass specific food consurrption was increased. It is speculated that the i.nh.ibitor is a parasite or a substance which affects assimilation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Ecology Ecology Zoology