Diversity in coral reef fishes is not evenly distributed and tends to accumulate in the Indo-Malay-Philippines Archipelago (IMPA). The comprehension of the mechanisms that initiated this pattern is in its infancy despite its importance for the conservation of coral reefs. Considering the IMPA either as an area of overlap or a cradle of marine biodiversity, the hypotheses proposed to account for this pattern rely on extant knowledge about taxonomy and species range distribution. The recent large-scale use of standard molecular data (DNA barcoding), however, has revealed the importance of taking into account cryptic diversity when assessing tropical biodiversity. We DNA barcoded 2276 specimens belonging to 668 coral reef fish species through a collaborative effort conducted concomitantly in both Indian and Pacific oceans to appraise the importance of cryptic diversity in species with an Indo-Pacific distribution range. Of the 141 species sampled on each side of the IMPA, 62 presented no spatial structure whereas 67 exhibited divergent lineages on each side of the IMPA with K2P distances ranging between 1% and 12%, and 12 presented several lineages with K2P distances ranging between 3% and 22%. Thus, from this initial pool of 141 nominal species with Indo-Pacific distribution, 79 dissolved into 165 biological units among which 162 were found in a single ocean. This result is consistent with the view that the IMPA accumulates diversity as a consequence of its geological history, its location on the junction between the two main tropical oceans and the presence of a land bridge during glacial times in the IMPA that fostered allopatric divergence and secondary contacts between the Indian and Pacific oceans.

We analyzed stomach contents and muscle isotopic composition (δ 13 C, δ 15 N) of yellowstripe goatfish Mulloidichthys flavolineatus from a coral reef to investigate size-related dietary changes and resource or habitat partitioning. Juveniles (<12 cm total length [TL]), young adults (12 ≤ TL < 17 cm) and adults (≥17 cm TL) showed a high diet overlap, especially between juveniles and young adults. According to stomach contents analysis, M. flavolineatus widens its prey spectrum with increasing size from a common prey pool that includes polychaetes, tanaids and harpacticoid copepods. We observed a significant increase in δ 13 C values (from -17.1 ± 0.5 ‰ for juveniles to -10.7 ± 0.8 ‰ for adults), which were correlated to fish size. Adults (δ 15 N mean of 11.1 ± 1.8 ‰) were one trophic level above juveniles and young adults (7.7 ± 0.5 and 7.4 ± 0.5 ‰, respectively). These patterns of isotopic changes confirmed ontogenetic dietary shifts. However, trophodynamics can be influenced by physiological factors such as growth and sexual maturity. M. flavolineatus shift from a pelagic to a macrobenthic diet, which is equilibrated at the adult stage. Results from combined stomach contents (prey volume) and stable isotope analyses suggested a dominant contribution of polychaetes (macrofauna), possibly through selective feeding. Conversely, on the basis of prey volume and stable isotope data, meiofauna did not feature significantly in the diet despite their high abundance in stomachs. Two adult groups were distinguished based on their δ 15 N values (11.9 ± 0.8 and 7.8 ± 0.6 ‰), indicating possible stage-specific partitioning in habitat use inside the reef. KEY WORDS: Yellowstripe goatfish · Ontogenetic diet shift · Stomach contents · Stable isotopes · Mixing model · Southwestern Indian Ocean Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 386: [181][182][183][184][185][186][187][188][189][190][191][192][193][194][195] 2009 Knowledge of the trophic interactions between fish and their food resources is of immediate significance to understanding processes that structure shallow-water tropical communities. A number of studies on goatfish diets are reported from the Pacific (Sorden 1982, Lukoschek & McCormick 2001, Sampey et al. 2007), the tropical West Atlantic (Munro 1976, Humann & DeLoach 2002, the Mediterranean and the Red Sea (Ben-Eliahu & Golani 1990, Golani & Galil 1991, Wahbeh 1992. Published data from the Indian Ocean are scarce and concern only the genus Upeneichthys (Platell et al. 1998). Sympatric mullid species can greatly differ in their depth distribution, foraging substratum selection and feeding modes (Gosline 1984, McCormick 1995, Platell et al. 1998. While main food items vary widely among species, all Mullidae are benthic carnivores, using their sensory hyoid barbels to drive out prey. Mulloidichthys flavolineatus is considered to be a specialist benthic predator, foraging mainly on sediments around reefs (McCormick 1995). Past studies from the Hawaiia...

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International audienceWe isolated and characterized 26 microsatellite loci for Macrorhynchia phoenicea (Busk, 1852), a rather common tropical hydrozoan from the Indo-Pacific. The number of alleles per locus ranged from 4 to 24. The observed heterozygosity ranged from 0.000 to 0.970 and the expected heterozygosity from 0.029 to 0.833. Ten loci were at HardyeWeinberg equilibrium. No pair of loci presented linkage disequilibrium. Transferability of up to 18 loci was positive across four other Aglaopheniidae species from different genera. These loci will be used in studying reef population connectivity for these particular species at the scale of the Indo-Pacific, a promising but little explored research field