Distribution of Uncinaria among the Lower Animals

Abstract

The ocean sunfishes have a long and confusing taxonomic legacy, clouding the global zoogeography of each species and hindering fisheries bycatch assessments. The traditional view of Mola mola as the most common sunfish species worldwide is challenged by our findings from Australia and New Zealand, revealing that three large sunfishes, Masturus lanceolatus, Mola alexandrini and Mola tecta, dominate the tropical/subtropical, warm-temperate and cold-temperate waters here, respectively, while Mola mola – both Pacific and Atlantic clades – is relatively rare. These findings were based on phylogenetic (mtDNA D-loop) and/or morphological species identification of sunfish from longline bycatches (n = 106), natural history museum collections (n = 45) and other sources (n = 12), informed by recent advances in the taxonomy of the genus Mola. Furthermore, separation in species distributions were seen when comparing sampling latitude and sea surface temperature. The findings imply that the longline fisheries observer sunfish data from Australia and New Zealand is a mix of species, and not dominated by M. mola as previously assumed. Mean catch per unit Effort (2001–13) in 1° latitude/longitude grids off Pacific Australia and New Zealand were predominantly < 1 sunfish.1000 hooks−1 (up to 6.5 in some areas) with no statistical significant upwards or downwards trends detected over time in four fishing ground subareas, each presumably dominated by either Masturus lanceolatus, Mola alexandrini or Mola tecta. Widespread specimen identification errors had previously obscured a more complex Molidae zoogeography in the area, highlighting that phylogenetic analyses of sunfish bycatch globally would benefit species-level conservation status evaluations.