DOI: 10.5061/dryad.04qh2
title: Data from: Larval traits carry over to affect post-settlement behaviour in a common coral reef fish

description: Most reef fishes begin life as planktonic larvae before settling to the
 reef, metamorphosing, and entering the benthic adult population. Different
 selective forces determine survival in the planktonic and benthic life
 stages, but traits established in the larval stage may carry over to
 affect post-settlement performance. We tested the hypothesis that larval
 traits affect two key post-settlement fish behaviours: social
 group-joining and foraging. Certain larval traits of reef fishes are
 permanently recorded in the rings in their otoliths. In the bluehead
 wrasse (Thalassoma bifasciatum), prior work has shown that key larval
 traits recorded in otoliths (growth rate, energetic condition at
 settlement) carry-over to affect post-settlement survival on the reef,
 with higher-larval-condition fish experiencing less post-settlement
 mortality. We hypothesized that this selective mortality is mediated by
 carry-over effects on post-settlement anti-predator behaviours. We
 predicted that better-condition fish would forage less and be more likely
 to join groups, both behaviours that would reduce predation risk. We
 collected 550 recently settled bluehead wrasse (Thalassoma bifasciatum)
 from three reef sites off St. Croix (USVI), and performed two analyses.
 First, we compared each settler's larval traits to the size of its
 social group to determine whether larval traits influenced group-joining
 behaviour. Second, we observed foraging behaviour in a subset of focal
 grouped and solitary fish (n = 14) for 1-4 days post-settlement. We then
 collected the fish and tested whether larval traits influenced the
 proportion of time spent foraging. Body length at settlement, but not
 condition, affected group-joining behaviour; smaller fish were more likely
 to remain solitary or in smaller groups. However, both greater length and
 better condition were associated with greater proportions of time spent
 foraging over four consecutive days post-settlement. Larval traits
 carry-over to affect post-settlement behavior, though not as we expected:
 higher-quality larvae join groups more frequently (safer) but then forage
 more. Foraging is risky but may allow faster post-settlement growth,
 reducing mortality risk in the long run. This shows that behaviour likely
 serves as a mechanistic link connecting larval traits to post-settlement
 selective mortality.
description: SL_Zero_Day_Old_Otolith_DataThis data was collected in the lab from photos of otoliths taken with Leica Aquire software. The measurements were calculated with ImageJ software.SL_Zero_Day_Old_Otolith_data.csvZero_Day_Old_Otolith_DataThis data was collected in the lab from photos of otoliths taken with Leica Aquire software. The measurements were calculated with ImageJ software. This file includes data for Standard Length analysis when otolith rings were unreadable.Behavioural_DataThis data includes otolith (collected in the lab) and behavioral (collected in the field) data. Photos of otoliths taken with Leica Aquire software and otolith measurements were calculated with ImageJ software.Behavioral_Data.csv