DOI: 10.5061/dryad.ns5m4kg
title: Data from: Incomplete datasets obscure associations between traits affecting dispersal ability and geographic range size of reef fishes in the Tropical Eastern Pacific

description: 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.
description: Alzateetal_2018_EE_data_finalData on geographic distribution of 497 reef fish species was obtained from the Shorefishes of the Tropical Eastern Pacific (SFTEP), Online Information System (Robertson & Allen, 2016) and the IOBIS data base (to complete the distributions of species that are not endemic to the TEP). We restricted our study to the distribution of tropical reef-associated bony fishes in the TEP region (sensu Robertson & Allen, 2016). We included only tropical species, whose main distribution occurs in the Pacific Ocean. Range size was calculated using the geographical coordinates of all records reported in the region. Range size was measured as the maximum linear distance (in kilometres) between any two points where a species has been recorded. In addition, we collated information on several species traits potentially affecting dispersal from the literature and online databases: body size, adult mobility, spawning mode, PLD, circadian activity and aggregation behaviour. All of these factors have been suggested as possible drivers of range size in reef fishes.