Biology subjects

Froehlich, C. Y. M.

Publications and source records attributed to Froehlich, C. Y. M..

9 recordsLinked to original sources

bioRxiv2026

The integrative ecology of the saddleback anemonefish, Amphiprion polymnus, reveals it is a host generalist across multiple ecological axes

Understanding how symbiosis generates biodiversity requires comprehensive insight into the underlying ecology to reveal broad evolutionary patterns, and the clownfish-anemone symbiosis serves as an excellent model. Recently, a new paradigm revealed sea anemone host associations of adult clownfish drove convergent evolution of host specialists and generalists. An alternative study downplayed host specificity in explaining clownfish evolution due partly to an incongruence between the behavior, biology, and host specificity of a single species--Amphiprion polymnus. Previously classified as a host specialist, we revisit the host specificity and ecology of A. polymnus by studying its host associations, behavioral, and dietary ecology compared to a co-occurring host generalist and specialist. By incorporating n = 358 observations, we find A. polymnus associates with five sea anemone species, including a newly documented host, and four at the adult life stage. We show that A. polymnus swim consistently far from their hosts and have broad dietary niches, an ecology that aligns with generalists. Cumulatively, our data indicate A. polymnus is a host generalist, and not a specialist as previously classified. Our findings serve to reconcile previously conflicting studies about A. polymnus, and reinforce the hypothesis that host is the key ecological variable for understanding clownfish evolution. Suitable subject areasbehaviour, ecology, evolution

ecology↗

bioRxiv2025

Population genomics highlight the vulnerability of coral-dwelling gobies to ecological losses due to climatic disturbances

Predicting species resilience to climate change generally focuses on species life history and ecology, overlooking genomic changes following disturbances. After consecutive cyclones and heatwaves, coral-dwelling Gobiodon gobies have experienced extreme population and group size reductions, and slower recovery rates than their coral hosts. To assess genomic contributions to this vulnerability, we analyzed multiple Gobiodon species for population structure (1) among three locations in western Oceania and (2) pre- and post-disturbances at the central location that underwent the same cyclones and heatwaves that reduced populations and group sizes. Species compared among locations all exhibited population structure. Post-disturbances, two species (G. fuscoruber, G. rivulatus) were extirpated, two species (G. histrio, G. quinquestrigatus) exhibited genetic bottlenecks, one species had no change to genetic diversity (G. brochus), and another species had consistently low diversity (G. erythrospilus). Our results highlight that coral-dwelling gobies face compounding ecological and genomic losses from climatic disturbances, warranting targeted conservation.

genomics↗

bioRxiv2025

The ecology and adaptive function of clownfish color patterns

Anti-predator coloration strategies vary widely from conspicuous to cryptic, and everything between. Coloration serves multiple functions, and determining the selective pressures that drive this diversity is a long-standing mystery. Clownfishes display enormous inter- and intra-specific variation in coloration without the influence of sexual selection, providing an excellent system in which to explore these drivers in closely related and sympatric species. Across clownfishes, three color-pattern phenotypes have evolved convergently with host anemone use, implying adaptive functions linked to the hosts physical and chemical properties. Here we conducted a comprehensive study to infer the ultimate functions of clownfish color patterns. By integrating multiple levels of biological organization, including behavior, visual ecology, dietary niche, and microbiome, our data overwhelmingly indicate that specialist and generalist clownfish color patterns have different underlying ecologies and adaptive functions. Specialist clownfishes background match their anemones, remain near hosts, and have specialized diets and microbiomes. Generalists are highly contrasting with their anemones, remain far from hosts, and have variable diets and microbiomes. Taken together, specialist color patterns align with functional expectations of camouflage while generalists align with aposematic or disruptive coloration. Our study provides novel insights into how ecological conditions shape the evolution of multiple anti-predator coloration strategies.

ecology↗

bioRxiv2024

Nemo knows: clownfishes differentiate cryptic host species across fine and broad geographic scales and reveal a potential adaptive radiation in the clownfish-hosting sea anemones.

The symbiosis between clownfishes (or anemonefishes) and their host sea anemones ranks among the most recognizable animal interactions on the planet. Found on coral reef habitats across the Indian and Pacific Oceans, 28 recognized species of clownfishes adaptively radiated from a common ancestor to live obligately with only 10 nominal species of host sea anemones. Are the host sea anemones truly less diverse than clownfishes? Did the symbiosis with clownfishes trigger a reciprocal adaptive radiation in sea anemones, or minimally, a co-evolutionary response to the mutualism? To address these questions, we combined fine- and broad-scale biogeographic sampling with multiple independent genomic datasets for the bubble-tip sea anemone, Entacmaea quadricolor--the most common clownfish host anemone throughout the Indo-West Pacific. Fine-scale sampling and restriction site associated DNA sequencing (RADseq) throughout the Japanese Archipelago revealed three highly divergent cryptic species: two of which co-occur throughout the Ryukyu Islands and can be differentiated by the clownfish species they host. Remarkably, broader biogeographic sampling and bait-capture sequencing reveals that this pattern is not simply the result of local ecological processes unique to Japan, but part of a deeper evolutionary signal where some species of E. quadricolor serve as host to the generalist clownfish species Amphiprion clarkii and others serve as host to the specialist clownfish A. frenatus. In total, we delimit at least five cryptic species in E. quadricolor that have diversified within the last five million years. The rapid diversification of E. quadricolor combined with functional ecological and phenotypic differentiation supports the hypothesis that this may represent an adaptive radiation in response to mutualism with clownfishes. Our data indicate that clownfishes are not merely settling in locally available hosts but recruiting to specialized host lineages with which they have co-evolved. These findings have important implications for understanding how the clownfish-sea anemone symbiosis has evolved and will shape future research agendas on this iconic model system.

evolutionary biology↗

bioRxiv2023

Stable isotopes disentangle niche partitioning and species co-occurrence in a multi-level marine mutualism

Ecologists have long sought general explanations for the co-occurrence of ecologically similar taxa. Niche theory explains co-occurrence via functional differences among taxa that reduce competition and promote resource partitioning. Alternatively, the unified neutral theory of biodiversity and biogeography suggests that co-occurrence can be attributed to stochastic processes, and thus, presupposes that ecologically similar species that occur in sympatry are functionally analogous. We test these alternative hypotheses in multiple dimensions using the most diverse crustacean-sea anemone symbiosis from coral reefs in the Tropical Western Atlantic. {delta}13C and {delta}15N stable isotope analyses of six crustacean symbionts that co-occur around the host anemone Bartholomea annulata exhibit highly differentiated isotopic niche space spanning three trophic levels. As multiple crustacean species within the symbiosis have been documented as cleaners that remove parasites from reef fishes, we extended our investigation into the broader cleaner community. Our stable isotope analyses of cleaners shows that only Pedersons cleaner shrimp Ancylomenes pedersoni exhibits {delta}15N isotopic signatures that are consistent with a dedicated cleaning lifestyle. Co-occurring species that have been previously described to clean reef fishes such as Periclimenes yucatanicus, Stenopus hispidus, and Stenorhynchus seticornis all occupy trophic levels well below An. pedersoni. Taken together, our data are consistent with the expectations of niche theory: co-occurring symbiotic crustaceans have highly partitioned niche space with low levels of functional redundancy. Finally, our findings reinforce and extend the ecological importance of An. pedersoni as likely the only dedicated cleaner shrimp on coral reefs in the Tropical Western Atlantic.

ecology↗

bioRxiv2023

Multi-level framework to assess social variation in response to ecological and social factors: modeled with coral gobies

1.Understanding variation in social organization that does not have a strong phylogenetic signal represents a key focus of research in behavioural and evolutionary ecology. In light of this, we established a sociality framework that identifies four categories of variation in social organisation that range from large-scale to fine-scale and can each be related to various ecological factors: (1) forms of sociality, (2) degree of sociality, (3) social plasticity, and (4) within-group plasticity. We modelled this framework by quantifying the four categories of variation over time, space and disturbance regime using multiple species of coral-dwelling gobies from the genus Gobiodon. Gobies are a particularly interesting model system as they vary in social structure, have within-group cooperation and form mutualistic relationships with their coral hosts which are vulnerable to climatic disturbances. We found that gobies varied in forms of sociality - from being solitary, to paired or group-living depending on location and disturbance regime. Only low or moderate degrees of sociality were observed in gobies, and this was influenced by location or disturbance regime depending on species. Gobies were more often solitary or pair-forming than group-forming (which became extremely rare) in a high disturbance regime whereas they were more often found in groups in a moderate disturbance regime. The size of coral hosts affected the social plasticity of gobies, and corals were smaller due to climatic disturbances. Gobies did not exhibit within-group social plasticity, as there were no changes to the structure of size-based hierarchies or sex allocation patterns with location or disturbance regime. Lastly, by combining the four categories of variation, we find that there is a high loss of sociality in coral-dwelling gobies due environmental disturbances, which likely affects overall goby survival as living in groups can improve survival and fitness. By using our structured framework, we identified which categories of social variation were influenced by ecological factors like location and disturbance. This framework therefore provides an excellent tool for predicting future responses of animal societies to environmental stressors.

ecology↗

bioRxiv2022

Delayed recovery and host specialization may spell disaster for coral-fish mutualism

Mutualisms are prevalent in many ecosystems, yet little is known about how symbioses are affected by multiple disturbances. Here we show delayed recovery for 13 coral-dwelling goby fishes (genus Gobiodon) compared with their host Acropora corals following 4 consecutive cyclones and heatwaves. While corals became twice as abundant 3 years post-disturbances, their symbiotic gobies were only half as abundant relative to pre-disturbances and half of the goby species disappeared. Although goby species preferred particular coral species, surviving goby species shifted hosts to newly abundant coral species when their preferred hosts became rare. As host specialization is key for goby fitness, shifting hosts may have negative fitness consequences for gobies and corals alike and affect their survival in response to environmental changes. Our study demonstrates that mutualist partners do not respond identically to multiple disturbances, and that goby host plasticity, while potentially detrimental, may be the only possibility for early recovery.

ecology↗

bioRxiv2021

Habitat size, health and saturation do not alter movement decisions or the preference for familiarity in a social coral-reef fish

While habitat is often a limiting resource for group-living animals, we have yet to understand what aspects of habitat are particularly important for the maintenance of sociality. As anthropogenic disturbances rapidly degrade the quality of many habitats, site-attached animals are facing additional stressors that may alter the trade-offs of moving or remaining philopatric. Here we examined how habitat health, size and saturation affect movement decisions of a coral-dwelling goby, Gobiodon quinquestrigatus, that resides within bleaching-susceptible Acropora coral hosts. To assess effects of habitat health, we translocated individuals far from their home corals into dead corals with the choice of adjacent healthy corals. To assess effects of habitat size and saturation, we manipulated coral sizes and the number of residents in healthy corals. Remarkably, 55% of gobies returned home regardless of treatment, 7% stayed in the new coral, and the rest were not found. Contrary to expectations, habitat factors did not affect how costs of movement influence group-living decisions in this species. These site-attached fishes preferred to home instead of choosing alternative habitat, which suggests a surprising awareness of their ecological surroundings. However, disregarding alternative high-quality habitat is concerning as it may affect population persistence under conditions of rapid habitat degradation.

animal behavior and cognition↗

bioRxiv2021

Uneven declines between corals and cryptobenthic fish symbionts from multiple disturbances

With the onset and increasing frequency of multiple disturbances, the recovery potential of critical ecosystem-building species and their mutual symbionts is threatened. Similar effects to both hosts and their symbionts following disturbances have been assumed. However, we report unequal declines between hosts and symbionts throughout multiple climate-driven disturbances in reef-building Acropora corals and cryptobenthic coral-dwelling Gobiodon gobies. Communities were surveyed before and after consecutive cyclones (2014, 2015) and heatwaves (2016, 2017). After cyclones, coral size and goby group size decreased similarly by 28-30%. After heatwave-induced bleaching, coral size decreased substantially (47%) and the few gobies recorded mostly inhabited corals singly. Despite several coral species still occurring after bleaching, all goby species declined, leaving 78% of corals uninhabited. These findings suggest that gobies, which are important mutual symbionts for corals, are unable to cope with consecutive disturbances. This disproportionate decline could lead to ecosystem-level disruptions through loss of key symbiotic services to corals.

ecology↗