Development of larval fish: A multi-species perspective

This thesis progresses from the previous examinations of finfish early life history by first examining the differences and similarities of larval fish development among species, and then building on this knowledge base to test for species similarities based on phylogeny and/or ecology. The first analysis undertaken was a corroboration of external characteristics with internal characteristics (Chapter 2). Second, a detailed analysis of lipids in larval fish across multiple species was completed (Chapter 3). The third analysis chapter (Chapter 4) examines the interplay among developmental processes within larval fish, and how these tradeoffs vary between species. The fifth chapter further extends this question and utilises variation amongst individuals to determine which of these processes are optimised to produce larvae that survive. In the final analytical chapter (Chapter 6), all of this information is incorporated into an exploratory multi-species model.;The contribution of this thesis in its entirety to the field of marine fish ecology is in three general areas: 1) the relevance of body size to larval fish; 2) the potential applicability of a multi-species model of larval fish development; and 3) sources of larval fish mortality. Research within this thesis favoured the use of mass to determine internal state of a larval fish, although to allow comparison across studies, reporting of both mass and length continues to be the most effective approach. Explicitly explaining the similarities and differences observed among species was not assisted by the use of phylogenetic analysis, but ecological patterns such as demersal or pelagic life cycle phases, and season of hatch were somewhat more successful. Additional information about sources of larval fish mortality resulted from highlighting the importance of variables that characterise developmental events during ontogeny (i.e. development progress variables, Chapters 4 and 6) and through the analysis of patterns of intrinsic selection (Chapter 5).