Data from: Incomplete datasets obscure associations between traits affecting dispersal ability and geographic range size of reef fishes in the Tropical Eastern Pacific

Dispersal is thought to be an important process determining range size,
especially for species in highly spatially structured habitats, such as
tropical reef fishes. Despite intensive research efforts, there is
conflicting evidence about the role of dispersal on determining range
size. We hypothesize that traits related to dispersal drive range sizes,
but that complete and comprehensive datasets are essential for detecting
relationships between species’ dispersal ability and range size. We
investigate the roles of six traits affecting several stages of dispersal
(adult mobility, spawning mode, pelagic larval duration (PLD), body size,
aggregation behaviour and circadian activity), in explaining range size
variation of reef fishes in the Tropical Eastern Pacific (TEP). All
traits, except for PLD (148 species), had data for all 497 species in the
region. Using a series of models, we investigated which traits were
associated with large range sizes, when analysing all TEP species or only
species with PLD data. Furthermore, using null models, we analysed whether
the PLD-subset is representative of the regional species pool. Several
traits affecting dispersal ability were strongly associated with range
size, although these relationships could not be detected when using the
PLD-data subset. Pelagic spawners (allowing for passive egg dispersal) had
on average 56% larger range sizes than non-pelagic spawners. Species with
medium or high adult mobility had on average a 25% or 33% larger range,
respectively, than species with low mobility. Null models showed that the
PLD-subset was non-representative of the regional species pool, explaining
why model outcomes using the PLD-subset differed from the ones based on
the complete dataset. Our results show that in the TEP, traits affecting
dispersal ability are important in explaining range size variation. Using
a regionally complete dataset was crucial for detecting the theoretically
expected, but so far empirically unresolved, relationship between
dispersal and range size.