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The TimeFISH database provides the first public time-series dataset on reef fish assemblages in the southwestern Atlantic (SWA), comprising 15 years of data (2007-2022) based on standardized Underwater Visual Censuses (UVCs). The rocky reefs covered by our dataset are influenced by pronounced seasonal cycles of ocean temperatures with warm tropical waters from the Brazil Current in the summer (~27°C) and colder waters from the La Plata River Plume discharge and upwelling from the South Atlantic Central Water in the winter (~18°C). These oceanographic conditions characterize this area as the southernmost tropical-subtropical climatic transition zone in the Atlantic Ocean. As a result, reef fish assemblages are comprised of both tropical and subtropical species. All records included in TimeFISH were collected using UVCs, a nondestructive method that allows the estimation of fish species richness, abundance, and body size distributions. UVCs were performed through 40 m2 belt transects by scuba diving in nine locations along the southern Brazilian coast (25-29°S). Four of these locations lie within the boundaries of the no-entry Arvoredo Marine Biological Reserve, where fishing and recreational activities are forbidden, and the remaining locations are unprotected from these activities. During each belt transect, a diver swam at a constant depth above and parallel to the reef, identifying fish species, counting the number of individuals, and estimating the total body length (Lt in cm) of all detected individuals. All fish individuals in the water column (up to 2 m above the substratum) and at the bottom were targeted. In total, 202,965 individuals belonging to 163 reef fish species and 53 families were recorded across 1857 UVCs. All survey campaigns were funded by either public or mixed capital (private-public) sources, including seven grants from the Brazilian federal and Santa Catarina state governments. Part of the data has already been used in multiple MS.c. and Ph.D. theses and scientific articles. TimeFISH represents an important contribution for future studies aiming to examine temporal and spatial variations of reef fish assemblages in transition zones. No copyright restrictions apply to the use of this data set, other than citing this publication.

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Functional traits have been fundamental to the evolution and diversification of entire fish lineages on coral reefs. Yet their relationship with the processes promoting speciation, extinction and the filtering of local species pools remains unclear. We review the current literature exploring the evolution of diet, body size, water column use and geographic range size in reef-associated fishes. Using published and new data, we mapped functional traits on to published phylogenetic trees to uncover evolutionary patterns that have led to the current functional diversity of fishes on coral reefs. When examining reconstructed patterns for diet and feeding mode, we found examples of independent transitions to planktivory across different reef fish families. Such transitions and associated morphological alterations may represent cases in which ecological opportunity for the exploitation of different resources drives speciation and adaptation. In terms of body size, reconstructions showed that both large and small sizes appear multiple times within clades of mid-sized fishes and that extreme body sizes have arisen mostly in the last 10 million years (Myr). The reconstruction of range size revealed many cases of disparate range sizes among sister species. Such range size disparity highlights potential vicariant processes through isolation in peripheral locations. When accounting for peripheral speciation processes in sister pairs, we found a significant relationship between labrid range size and lineage age. The diversity and evolution of traits within lineages is influenced by trait-environment interactions as well as by species and trait-trait interactions, where the presence of a given trait may trigger the development of related traits or behaviours. Our effort to assess the evolution of functional diversity across reef fish clades adds to the burgeoning research focusing on the evolutionary and ecological roles of functional traits. We argue that the combination of a phylogenetic and a functional approach will improve the understanding of the mechanisms of species assembly in extraordinarily rich coral reef communities.

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Estimating population parameters is essential for understanding the ecology of species, which ultimately helps to assess their conservation status. The seahorse Hippocampus reidi is directly exposed to anthropogenic threats along the Brazilian coast, but the species still figures as Data Deficient (DD) at IUCN's Red List. To provide better information on the ecology of this species, we studied how population parameters vary over time in a natural subtropical environment. By combing mark-recapture models for open and closed populations, we estimated abundance, survival rate, emigration probability, and capture probability. We marked 111 individuals, which showed a 1:1 sex ratio, and an average size of 10.5 cm. The population showed high survival rate, low temporary emigration probability and variable capture probability and abundance. Our models considering relevant biological criteria illuminate the relatively poorly known population ecology and life history of seahorses. It is our hope that this study inspires the use of mark-recapture methods in other populations of H. reidi in a collective effort to properly assess their conservation status.(AU)

Parâmetros populacionais são essenciais para compreender a ecologia das espécies, além de auxiliar a avalição do seu status de conservação. Dentre as espécies de cavalo-marinho que ocorrem no Brasil, Hippocampus reidi é a mais abundante, o que expõe suas populações a frequentes ameaças antropogênicas. Entretanto, esta espécie ainda consta como Deficiente em Dados (DD) na lista vermelha da IUCN. Considerando esta falta de informações sobre populações de H. reidi, utilizamos métodos de marcação e recaptura para avaliar como parâmetros de uma população de ambiente subtropical variam ao longo do tempo. Baseado em históricos de captura individuais, combinamos modelos de populações abertas e fechadas para estimar abundância, taxa de sobrevivência, probabilidade de emigração e probabilidade de captura. Ao todo, marcamos 111 indivíduos, em proporção sexual de 1:1, e tamanho médio de 10,5 cm. Esta população relativamente pequena apresentou alta taxa de sobrevivência, baixa probabilidade de emigração temporária e probabilidade de captura e abundância variáveis. A partir dos nossos modelos que consideraram critérios biológicos relevantes, fornecemos estimativas de parâmetros chave que auxiliarão a compreensão da ecologia e da história de vida de cavalos-marinhos. Nossa expectativa é que este método passe a ser amplamente utilizado em outras populações, em um esforço coletivo para avaliar o estado de conservação desta espécie.(AU)

Assuntos

RESUMO

Estimating population parameters is essential for understanding the ecology of species, which ultimately helps to assess their conservation status. The seahorse Hippocampus reidi is directly exposed to anthropogenic threats along the Brazilian coast, but the species still figures as Data Deficient (DD) at IUCN's Red List. To provide better information on the ecology of this species, we studied how population parameters vary over time in a natural subtropical environment. By combing mark-recapture models for open and closed populations, we estimated abundance, survival rate, emigration probability, and capture probability. We marked 111 individuals, which showed a 1:1 sex ratio, and an average size of 10.5 cm. The population showed high survival rate, low temporary emigration probability and variable capture probability and abundance. Our models considering relevant biological criteria illuminate the relatively poorly known population ecology and life history of seahorses. It is our hope that this study inspires the use of mark-recapture methods in other populations of H. reidi in a collective effort to properly assess their conservation status.(AU)

Parâmetros populacionais são essenciais para compreender a ecologia das espécies, além de auxiliar a avalição do seu status de conservação. Dentre as espécies de cavalo-marinho que ocorrem no Brasil, Hippocampus reidi é a mais abundante, o que expõe suas populações a frequentes ameaças antropogênicas. Entretanto, esta espécie ainda consta como Deficiente em Dados (DD) na lista vermelha da IUCN. Considerando esta falta de informações sobre populações de H. reidi, utilizamos métodos de marcação e recaptura para avaliar como parâmetros de uma população de ambiente subtropical variam ao longo do tempo. Baseado em históricos de captura individuais, combinamos modelos de populações abertas e fechadas para estimar abundância, taxa de sobrevivência, probabilidade de emigração e probabilidade de captura. Ao todo, marcamos 111 indivíduos, em proporção sexual de 1:1, e tamanho médio de 10,5 cm. Esta população relativamente pequena apresentou alta taxa de sobrevivência, baixa probabilidade de emigração temporária e probabilidade de captura e abundância variáveis. A partir dos nossos modelos que consideraram critérios biológicos relevantes, fornecemos estimativas de parâmetros chave que auxiliarão a compreensão da ecologia e da história de vida de cavalos-marinhos. Nossa expectativa é que este método passe a ser amplamente utilizado em outras populações, em um esforço coletivo para avaliar o estado de conservação desta espécie.(AU)

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The disparity in species richness among evolutionary lineages is one of the oldest and most intriguing issues in evolutionary biology. Although geographical factors have been traditionally thought to promote speciation, recent studies have underscored the importance of ecological interactions as one of the main drivers of diversification. Here, we test if differences in species richness of closely related lineages match predictions based on the concept of density-dependent diversification. As radiation progresses, ecological niche-space would become increasingly saturated, resulting in fewer opportunities for speciation. To assess this hypothesis, we tested whether reef fish niche shifts toward usage of low-quality food resources (i.e. relatively low energy/protein per unit mass), such as algae, detritus, sponges and corals are accompanied by rapid net diversification. Using available molecular information, we reconstructed phylogenies of four major reef fish clades (Acanthuroidei, Chaetodontidae, Labridae and Pomacentridae) to estimate the timing of radiations of their subclades. We found that the evolution of species-rich clades was associated with a switch to low quality food in three of the four clades analyzed, which is consistent with a density-dependent model of diversification. We suggest that ecological opportunity may play an important role in understanding the diversification of reef-fish lineages.

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