Microhabitat Preferences Research Articles

Living benthic foraminiferal assemblages of a transect in the Rockall Trough (NE Atlantic)

Foraminifera are unicellular protists and play a major role in the deep-sea ecosystems. This study focusses on the faunal analysis of living benthic foraminiferal assemblages and their vertical distribution along a transect in the Rockall Trough in the NE Atlantic. Therefore, seven multicorer cores from the Rockall Trough (RT-1 – RT-7), NE Atlantic, were collected at water depths between 1008 and 2205 m on the RRS Discovery cruise DY051 in spring 2016.Surface sediment samples of the collected material were analysed up to 10 cm sediment depth for living (Rose Bengal stained) benthic foraminifera to gain insight into the recent distribution of the foraminiferal fauna. The cores were sliced from 0 to 3 cm into 0.5 cm intervals and from 3 to 10 cm in 1 cm slices. Sediments were divided into the fractions >125 μm and 125–63 μm by wet-sieving. The analysis showed that stations differed in live assemblages, diversity, abundances and vertical distribution. Standing stock values of 92–168 ind./10 cm2 for the total, 54–130 ind./10 cm2 for the calcareous and 24–59 ind./10 cm2 for the agglutinated assemblages were obtained.Living deep-sea foraminiferal assemblages differed between the three shallower (RT-1 – RT-3) and the four deeper sites (RT-4 – RT-7), indicating that the different water masses could be a main factor controlling the deep-sea benthic fauna in the Rockall Trough. This area is characterised by two main water masses: the upper more saline Eastern North Atlantic Water (ENAW) and the lower North Atlantic Deep Water (NADW).Basically, Nonionella iridea occurred at all sites, while Cibicidoides species (except C. wuellerstorfi) and Melonis barleeanus were limited to water depths between 1008 and 1610 m (RT-1 – RT-3). Soft-shelled foraminifera increased sharply with water depth. Saccamminid sp. 1 contributed significantly to this increasing proportion of soft-shelled individuals with its maximum at 1857 m water depth (RT-5). Further characteristics of this transect include a mass occurrence of Uvigerina mediterranea, which was only present at 1008 m (site RT-1) or Globobulimina sp. 1 with its highest densities at 1610 m (RT-4), where it accounted for 20% of the total living foraminiferal fauna. The general microhabitat preferences where consistent with those of other studies, although the Rockall Trough is a very dynamic region considering food supply or other physical parameters.

Occurrence of the Green Shield-Moss Buxbaumia viridis (Moug.) Brid. in the Bieszczady Mountains of Poland

The small-sized gametophytes and sporophytes of the green shield-moss Buxbaumia viridis (Moug.) Brid. make it difficult to study. However, in Europe, there has been increasing interest in this species in the past few years, mostly as a result of the implementation of the Natura 2000 network. In Poland, B. viridis has only been reported in isolated studies that have been limited in terms of area and the number of participating workers. One of the Polish regions where B. viridis was recently recorded is the Bieszczady Mountains, but there have been no large-scale surveys of that region to date. The objective of the current work was to describe the B. viridis population in the Bieszczady Mountains in terms of its spatial distribution and abundance, investigate its selected microhabitat preferences, and evaluate the conservation status of this moss species within the Natura 2000 site Bieszczady PLC180001. The studied region encompassed 93,490.44 ha, including 69,056.23 ha of managed forests and 24,434.21 ha of forests belonging to the Bieszczady National Park. A preliminary survey was conducted in the Cisna Forest District (forest area of 19,555.82 ha) on 15–17 November 2017, while the main survey was performed in selected forest subcompartments of four forest districts—Baligród, Komańcza, Lutowiska, and Stuposiany—as well as the Bieszczady National Park from 5 to 16 November 2018. The field work consisted of searching for B. viridis sporophytes and setae and recording selected population and locality characteristics. The study led to the discovery of 353 new B. viridis localities in 202 study areas, with 9197 diploid individuals (sporophytes or setae only) growing in 545 microhabitats. The number of B. viridis localities discovered in the Bieszczady Mountains during 17 days of survey in 2017 and 2018 was two times higher than the combined number of localities previously found in Poland over more than 150 years (159 localities). Additionally, the number of sporophytes and setae identified was two times greater than their overall number in previous records. In addition, this study provides information about selected microhabitat preferences and the conservation status of this moss in the Bieszczady Natura 2000 site.

Complex patterns of Gondwanan biogeography revealed in a dispersal‐limited arachnid

AbstractAimWe explore the biogeographic history of the Gondwanan lineage Triaenonychidae, a dispersal‐limited arachnid taxon that underwent a recent taxonomic revision based on phylogenomic data. We explicitly test hypotheses related to a biogeographical pattern of ‘common vicariance, rare dispersal’, predicted for dispersal‐limited taxa.LocationContinental landmasses of former temperate Gondwanan terranes (southern South America, southern Africa, Madagascar, Australia, New Zealand, and New Caledonia).TaxonTriaenonychidae, Opiliones, Arachnida.MethodsUtilizing a recently published phylogenomic data set based on ultra‐conserved elements, we conduct Bayesian divergence dating analyses, ancestral area estimation in a likelihood model testing framework, and analyses of macroevolutionary dynamics. Results are correlated with geological history and palaeoclimate reconstructions to infer biogeographic history and distribution.ResultsWe find that divergence dates of ancestral Triaenonychidae pre‐date continental breakup of Gondwana and could be attributed to palaeoclimatic differentiation across Gondwana. There is evidence for two separate expansion routes that span eastern and western Gondwana corresponding to northern warmer climate and southern cooler climate lineages. Many divergences across intercontinental lineages coincide with the timing of continental fragmentation, supporting vicariance as a dominant force. However, some lineages are supported as obvious examples of rare long‐distance dispersal. Biogeographic results support the predicted pattern of common vicariance and rare dispersal for these dispersal‐limited organisms.Main conclusionsVicariance due to continental fragmentation was important in the early diversification of Triaenonychidae. Their unique combination and degrees of dispersal ability and microhabitat preference resulted in complex phylogenetic patterns of geographic distribution not typically seen in other animal taxa. Examining biogeographic patterns across recent studies of arachnid taxa with varying dispersal ability, it is clear that biological characteristics play an important role in the relative importance of dispersal and vicariance (dispersal–vicariance continuum) for any given taxon and can be useful in forming testable a priori hypotheses.

Does trait-based joint species distribution modelling reveal the signature of competition in stream macroinvertebrate communities?

The occupancy and abundance of species are jointly driven by local factors, such as environmental characteristics and biotic interactions, and regional-scale factors, such as dispersal and climate. Recently, it has been shown that biotic interactions shape species occupancies and abundances beyond local extents. However, for small ectothermic animals, particularly for those occurring in freshwater environments, the importance of biotic interactions remains understudied. Species-to-species associations from joint species distribution models (i.e. species associations while controlling for environmental characteristics) are increasingly used to draw hypotheses of which species possibly show biotic interactions. We studied whether species-to-species associations from joint species distribution models show signs of competition using a hypothesis testing framework in stream macroinvertebrate communities at regional extent. We sampled aquatic macroinvertebrates from 105 stream sites in western Finland encompassing a latitudinal gradient of c. 500 kilometres. We hypothesized that if competition drives these associations (H1) functionally, similar species are mostly negatively associated, whereas functionally dissimilar species show random associations. We further hypothesized that the relationship between functional dissimilarity and the strength of association is more pronounced (H2) for abundances rather than occupancies, (H3) at small grain (i.e. stream site) rather than at large grain (i.e. river basin), and (H4) among species having weak dispersal ability than among species with high dispersal ability. Stream macroinvertebrates showed both negative and positive species-to-species associations while controlling for habitat characteristics. However, the negative associations were mostly at large grain (river basin) rather than at small grain (stream site), in occupancy rather than abundance, and not related to species functional dissimilarity or to their dispersal ability. Thus, all our hypotheses considering possible competition (H1-H4) were rejected. Competition does not appear to be a major driving force of stream macroinvertebrate communities at the spatial grain sizes considered. The observed positive associations in occupancy at small grain (stream site) may be attributed to species' similar microhabitat preferences, whereas at large grain (river basin), they may stem from metacommunity dynamics. Our results highlight that species traits were necessary to interpret whether or not species-to-species associations from joint species distribution models resulted from biotic interactions.

Sustainability assessment of a lizard assemblage in Pernambuco state, Brazil

Several species of lizards are disappearing around the world. Their populations are declining on a global scale and for carrying out conservation actions, it is necessary to identify the real risks of extinction and the threats that affect the species. Alternative methodologies that are commonly applied and also the use of different approaches are important tools to fill gaps concerning various threats and vulnerabilities of the species. The aim of this study was to test the effectiveness of the “Stobutzki sustainability” method in assessing the degree of vulnerability to extinction of lizards with occurrence registered in Pernambuco, Brazil. 41 species were evaluated by using the “Stobutzki sustainability” method, based on scoring and ranking. The analysis was made from a graphical representation of the factors of "Threats" and "Vulnerabilities" of lizards. The great majority of the species (n = 30) has not shown to be vulnerable. Only 11 lizards were not considered sustainable. The lizards Nothobachia ablephara, Cercosaura ocellata, and Procellosaurinus erythrocercus demonstrated a very high degree of vulnerability to extinction. The gymnophtalmidae family was the least sustainable. A total of 16 threats of anthropogenic origin for the populations of lizards in Pernambuco were detected. Half of the species of lizards (n = 21) have a low number of embryos per litter (<3). Additionaly, this group was considered partially generalist, having an occurrence extension smaller than 40,000 km² and measurements between 100 and 300 mm in total length. Among the top 10 in our Vulnerability Ranking there are six lizards included in threat categories on the list of the Regional Environment Agency of Pernambuco. The "Vulnerabilities" axis was ordered by the fecundity of the species, their distribution and preference for certain microhabitats. Furthermore, for the "Threats" axis, the structuring was based on the situation of the habitats of these species and their distribution in protected areas. The strongest biological predictors of extinction risk for lizards of Pernambuco state were litter size, microenvironmental specificity, and the extent of occurrence. The “Stobutzki Sustainability” method is an important tool to assist the evaluation of vulnerability to extinction in lizard species, as well as the criteria used for researches on other lizard assemblages.

Spatial distribution of six managed tree species is influenced by topography conditions in the Central Amazon

In tropical forests, the spatial distribution of trees may present random, uniform, or grouped patterns that can simultaneously be affected by site and species characteristics. In Central Amazon, topographic gradients and soil water levels drive differences in tree species distribution and in forest dynamics at local scales. Knowing this kind of information can be useful for a forest manager to plan harvesting operations considering the microhabitat preference of merchantable species to reduce the disturbances caused by logging activities. Thus, the spatial variation of tree species is an important information to be considered to support the planning process of forest logging. The present study aims to evaluate the spatial distribution pattern of six species and analyze the relationship between the topography and the population densities and stem size of those species. The study was carried out in a forest production compartment managed by a private company located in the municipality of Silves, state of Amazonas, Brazil. The spatial pattern of the six species was characterized by Ripley's K function. Spatial distribution of diameter at breast height (DBH) and tree density based on kernel incidence calculation were evaluated for topographic classes of slope, elevation, and distance from streams, which were mapped using geographic information systems (GIS). The means of DBH and density of each species were compared among topographic classes by ANOVA and Tukey's test. The results demonstrated the predominance of the aggregate distribution pattern for the six species up to 1105 m (p < 0.01). The tree species Minquartia guianensis Aubl., Protium puncticulatum J.F.Macbr, Manilkara elata (Allemão ex Miq.) Monach, and Caryocar glabrum Aubl. Pers showed an increase in the tree density as the distance from the streams and elevation increased, standing spatially incident on plateaus. Kernel densities of Dinizia excelsa Ducke and Goupia glabra Aubl. were higher closer to streams. The DBH averages followed similar trends of population density for M. guianensis, M. elata, and C. glabrum, and the opposite pattern for D. excelsa, which presented larger individuals in less densely populated areas. P. puncticulatum and G. glabra mean DBH distribution was not affected by the topographic variables analyzed. Topography-related variables showed effects on variations of density and tree size, suggesting that species may be spatially sensitive to the habitat variability available in the study area. In view of logging planning, spatial distribution must be considered in decisions related to cutting down trees and maintenance of remaining trees, especially because some species are more aggregated in smaller scales. Moreover, as topographic variations affect the spatial distribution of size and density, the timber yield will vary spatially in the area, bringing implications for planning logging intensities, roads, skid trails and forest operations. Finally, the procedures and information generated in this study can be reproduced and applied to other species and managed areas to support the planning toward minimizing impacts on the spatial structure of commercial species, as well as to increase the chances of future stock recovery of managed forests in the Amazon.

Temporal variation in small nonvolant mammal (Cricetidae and Didelphidae) microhabitat associations in the Upper Paraná Atlantic Forest

Many questions concerning habitat preferences of Neotropical small mammals remain unanswered. These questions include where the animal lives within and among the available habitats, and the temporal (seasonal and interannual) variation in the habitat associations. The objectives of this research were: (1) to determine the associations of non-volant small mammal species (Rodentia and Didelphimorphia) with specific microhabitat characteristics including vegetation structure in an area near the western boundary of the Upper Paraná Atlantic Forest, and (2) to evaluate seasonal and interannual variation in those associations. Three grids were sampled in three seasons (Dry, Wet, Variable) during two years (2015-2017). The four predominant small mammal species (Gracilinanus agilis, Akodon montensis, Hylaeamys megacephalus, and Oligoryzomys nigripes) were evaluated for seasonal and interannual variation in habitat preferences. Each of the four exhibited seasonal and/or interannual variation in microhabitat preferences for three to six of the 17 environmental variables analyzed. This is the first study to explicitly evaluate temporal variation in habitat associations of small mammals in the Atlantic Forest ecoregion. The temporal patterns of habitat association among these four predominant species reveal a complex spatially and temporally dynamic composition and structure in this small mammal community.

Invertebrate functional responses to hydro­morpho­logical degradation in Mediterranean Croatian rivers

Hydromorphological alterations are among the most widespread anthropogenic pressures in rivers andstreams. They comprise channelization, damming, water abstraction etc. resulting in habitats alteration and subsequentchanges in aquatic community composition. Aim of this study was to test to what extent hydromorphologicalalterations influence aquatic macroinvertebrates as one of the best bioindicators to anthropogenic pressures. Our researchtook place in the Mediterranean part of Croatia. We sampled 40 sites which include perennial rivers varyingin catchment size and altitude with similar environmental conditions along river reaches. Large rivers were omittedfrom this research because of their different functional group representation to the rivers covered used in this study.We used the functional approach to hydromorphological alteration by testing the following traits: reproductionstrategy, functional feeding group and microhabitat (substrate type) preference. From the feeding standpoint shredderswere the most affected group by hydrological alteration. Moreover, taxa confined to a specific relatively lesscommon habitat e.g. phytal, pelal and lithal were the most negatively affected by morphological degradation due,mostly, to it leading to a homogenization of the substrate. Finally, the smaller and faster reproductive taxa weremore resilient to hydromorphological degradation. We found that the functional approach to bioassessment complementsthe common biocenotical approach, at the same time it may provide sound ecological knowledge.

New range records and life history observations of insects (Diptera: Dryomyzidae, Chironomidae; Coleoptera: Staphylinidae) associated with barnacles (Balanomorpha: Balanidae, Chthamalidae) on the Pacific coasts of North America and Japan

AbstractInsects are usually considered to be excluded from the marine environment. A small number of species, however, are considered to be marine, due to spending some portion of their life cycle in salt water. We use natural history collection specimens, in-field observations, and molecular analysis to generate new locale records and natural history data for seven insect species. All seven species are associated with barnacles (Balanomorpha: Balanidae, Chthamalidae) along the Pacific coast of Canada, the United States of America, or Japan. Use of DNA barcode analysis confirms the monophyly of three species of Oedoparena (Diptera: Dryomyzidae). Natural history collection specimens expand the geographical range and illuminate the phenology of Oedoparena spp. In-field observations record direct associations between three species of Thalassosmittia (Diptera: Chironomidae), Diaulota densissima (Casey) (Coleoptera: Staphylinidae), and intertidal barnacles from various locations in British Columbia, Canada. Barnacle host associations and microhabitat preferences are proposed for all species. A new definition of what constitutes a marine insect is offered.

Habitat niches suggest that non-crop habitat types differ in quality as source habitats for Central European agrobiont spiders

Non-crop habitats in agricultural landscapes may differ in their potential to serve as source habitats for natural enemies. To determine this potential for different habitat types, it is crucial to understand habitat preferences and the habitat niche width of natural enemies. In addition, populations of natural enemies are affected by management practices depending on their preferences for habitat strata. Here we analysed agrobiont spider preferences (very common species in arable fields) for different microhabitats (ground, herbaceous, and shrub strata) and non-crop habitats (agroecosystems, forests, scrub, meadows, steppe, and wetlands). We compared guild-specific preferences of cursorial and web-building spiders that inhabit pome fruit orchards and cereal fields using two databases on Central European spider preferences. The majority of agrobiont spiders showed a moderate niche width. Agrobiont spiders from orchards preferred the shrub stratum while spiders from cereal fields preferred the ground and herbaceous strata across habitats. Agrobiont spiders primarily utilized non-crop habitats that were structurally similar to a particular agroecosystem: spiders from orchards utilized mostly woody vegetation while spiders from cereal fields utilized mostly meadows. Moreover, cursorial and web-building spider species from cereal fields differed in their preferences for different non-crop habitats. The results highlight that non-crop habitats have different potential as sources of agrobiont spiders. The composition of non-crop habitats in agricultural landscapes may affect the functional composition and pest control potential of spider communities. Further studies focusing on the effects that landscapes have on natural enemies in local agroecosystem need to account for the identity of non-crop habitats.

Ecological aspects of the interactions between Centruroides limbatus and Tityus ocelote (Scorpiones: Buthidae) in a Caribbean forest of Costa Rica

Scorpion species often occur in sympatry, especially in tropical forests. Here, we analyse aspects of the intraguild interactions occurring between Centruroides limbatus (Pocock, 1898) and Tityus ocelote Francke & Stockwell, 1987 (Buthidae) in a tropical forest of Costa Rica. We divided the study in 2 areas: north and south. Results show differences in abundance and distribution of C. limbatus (north = 16, south = 8) and T. ocelote (north = 2, south = 37); a major frequency of females for both species (74% ♀ and 26% ♂ in C. limbatus , 78% ♀ and 22% ♂ in T. ocelote ; 55 sexed scorpions); similar microhabitat preferences (trees with vines, palms) and significant differences ( p = 0.037) in the height at which both species were located above ground in each zone. Significant differences in height between zones showed disparity in habitat selection (north and south), whereas non-significant differences in height between species indicated niche overlap in those areas where they coexist, confirmed by the Morisita index for niche overlap in the southern zone (M-NO = 0.686). Cannibalism was reported in C. limbatus . These intraguild interactions indicate the existence of some level of competition between these scorpions.

Exploratory Study of Fatty Acid Profile in Two Filmy Ferns with Contrasting Desiccation Tolerance Reveal the Production of Very Long Chain Polyunsaturated Omega-3 Fatty Acids.

Lipids are fundamental components of cell membranes and play a significant role in their integrity and fluidity. Alteration in lipid composition of membranes has been reported to be a major response to abiotic environmental stresses. This work was focused on the characterization of frond lipid composition and membrane integrity during a desiccation–rehydration cycle of two filmy fern species with contrasting desiccation tolerance: Hymenophyllum caudiculatum (less tolerant) and Hymenophyllum plicatum (more tolerant). The relative water content decreased without differences between species when both filmy ferns were subjected to desiccation. However, H. plicatum reached a higher relative water content than H. caudiculatum after rehydration. Fatty acids profiles showed the presence of a very long chain polyunsaturated fatty acid during the desiccation–rehydration cycle, with eicosatrienoic acid being the most abundant. Additionally, propidium iodide permeation staining and confocal microscopy demonstrated that, following the desiccation–rehydration cycle, H. plicatum exhibited a greater membrane integrity than H. caudiculatum. The lack of some very long chain fatty acids such as C22:1n9 and C24:1n9 in this species contrasting with H. plicatum may be associated with its lower membrane stability during the desiccation–rehydration cycle. This report provides the first insight into the fatty acid composition and dynamics of the membrane integrity of filmy ferns during a desiccation–rehydration cycle. This could potentially play a role in determining the different levels of desiccation tolerance and microhabitat preferences exhibited by Hymenophyllaceae species.

Paleobiogeography of the Middle Jurassic (Bathonian-Callovian) benthic foraminifera

Evaluating what governs the distribution patterns of an organism, enables better understanding of the role of biotic and abiotic factors that influences these patterns, thus, giving a better insight into their paleobiogeographical distribution. A total of 168 benthic foraminiferal genera (782 species) were analyzed from 39 Bathonian-Callovian localities, across the globe. Nonmetric Multidimensional Scaling (NMDS) and Analysis of Similarities (ANOSIM) were used to analyze the benthic foraminiferal distribution patterns. Analyses revealed statistically significant differences in the foraminiferal distribution patterns between Laurasia and Gondwanaland and further between North and South Gondwanaland in the Bathonian, attributed to their response to global eustatic lowstands. In contrast, the Callovian is marked by a lack of differentiation between Gondwanaland and Laurasia, reflecting a foraminiferal response to global eustatic highstands. But, the continued significant differentiation between North and South Gondwanaland is attributed to a combination of differing paleotemperatures due to their paleolatitudinal positions, coupled with the opening of the Mozambique Corridor that probably played a far greater role at the subprovincial level, as compared to sea level, for the Province. The taxa were also categorized based on their ecological traits such as oxygen availability, life-habit, and shell composition. Statistically significant differences on the geographic patterns based on life-habit (epifaunal and infaunal) and marginally on shell composition (calcareous and agglutinated) were noted, but not for their oxygen preference (oxic, suboxic and dysoxic). Examining the Bathonian-Callovian global occurrence data revealed that both species duration and species diversity greatly influenced the geographic distribution of the benthic foraminifera, where longer duration and higher species diversity ensured wider geographic distribution. • 782 benthic foraminiferal species from 39 localities were analyzed using NMDS and ANOSIM. • Laurasia and Gondwanaland were similar in the Callovian but they differ significantly in the Bathonian. • Eustasy, paleotemperatures and paleolatitude played a major role in the distribution patterns. • Microhabitat preference and shell composition have played a minor role. • Species duration and diversity determine the geographic range of a given taxon.

Effects of soil substrate on the ecological features of the sand pit-building Antlions Myrmeleon formicarius Linnaeus, 1767 (Neuroptera: Myrmeleontidae) larvae in the Amanos Mountains of Turkey

The hunting behavior of antlion larvae is unique in the insect world and soil characteristics may strongly affect their microhabitat selection. Therefore, the substrate type of sand pit construction is expected to have an important role in their traps. Different types of soil substrates can be inhabited by Myrmeleon formicarius Linnaeus, 1767 larvae. This study was conducted during 2018-2019 June-August in the Amanos Mountains of Turkey to examine assess the relationship between the microhabitat preference of larvae of M. formicarius. In this study, five substrate types were determined as particularly according to their habitat preference. In this study, the preference of fine-grained soils is found more adaptive because of the pits are constructed in these substrates are more functional for longer periods and they are much more successful in trapping their preys than the coarse-grained soil pits. Furthermore, it was found that there is a direct relationship between the pit size and substrate particle structure. Therefore, the detection and selection of microhabitats under more convenient ecological conditions, which increase capture success and elucidate the hunting strategy, may be carried out during strong soil substrate selection for Myrmeleon Linnaeus species. It was concluded that there is no strong relationship between the soil substrate type, pH, and trap diameter.

A decade-long study on mayfly emergence patterns

Mayfly assemblage structure, microhabitat preference and emergence patterns were studied over a decade in two types of karst freshwater habitats, namely, a spring and two tufa barriers. Mayfly adults were collected using pyramidal emergence traps. A total of nine species was recorded. Tufa barriers had a higher species richness but a lower abundance than did the spring. All sites were dominated by species typical of the rhithral zone. The spring had the highest share of grazers, whereas gatherers (collectors and filter feeders) dominated at tufa barriers, with minimal changes through the years. Mayfly abundance at the spring was higher in years with a higher discharge. The opposite was recorded for tufa barriers, which could be related to drift and food availability. Mayflies emerged from the spring between March and November, most probably being triggered by the photoperiod. Emergence from tufa barriers was seasonal and related to changes in water temperature. Some species exhibited typical central European emergence patterns, whereas, in some others, certain discrepancies were recorded. Several taxa showed preference towards emergence from a particular microhabitat. The present study showed that for fine ecological data on aquatic insects, long-term studies are essential.

Heat wave effects on the behavior and life-history traits of sedentary antlions.

Research on the behavioral responses of animals to extreme weather events, such as heat wave, is lacking even though their frequency and intensity in nature are increasing. Here, we investigated the behavioral response to a simulated heat wave in two species of antlions (Neuroptera: Myrmeleontidae). These insects spend the majority of their lives as larvae and live in sandy areas suitable for a trap-building hunting strategy. We used larvae of Myrmeleon bore and Euroleon nostras, which are characterized by different microhabitat preferences—sunlit in the case of M. bore and shaded in the case of E. nostras. Larvae were exposed to fluctuating temperatures (40 °C for 10 h daily and 25 °C for the remaining time) or a constant temperature (25 °C) for an entire week. We found increased mortality of larvae under heat. We detected a reduction in the hunting activity of larvae under heat, which corresponded to changes in the body mass of individuals. Furthermore, we found long-term consequences of the simulated heat wave, as it prolonged the time larvae needed to molt. These effects were pronounced in the case of E. nostras but did not occur or were less pronounced in the case of M. bore, suggesting that microhabitat-specific selective pressures dictate how well antlions handle heat waves. We, thus, present results demonstrating the connection between behavior and the subsequent changes to fitness-relevant traits in the context of a simulated heat wave. These results illustrate how even closely related species may react differently to the same event.

White-handed gibbons (Hylobates lar) alter ranging patterns in response to habitat type.

Small apes are often characterized as inhabiting small home ranges and being dependent on evergreen forest due to their dietary specialization on ripe fruits. Yet few primate studies, particularly those with gibbons, have considered intraspecific variations in ranging behaviors in response to local ecological conditions. This study examines Endangered white-handed gibbon (Hylobates lar) ranging patterns in a heterogeneous landscape. We conducted 13months of behavioral observations on four white-handed gibbon groups living in Huai Kha Khaeng Wildlife Sanctuary in western Thailand, and combine these data with group location and transect-based productivity data. We compare home range area, site fidelity, and microhabitat preferences. Home range (HR) area varied considerably among the four groups (17-61 hectares). Site fidelity was higher in one of the groups with more evergreen forest in the HR (0.72 ± 0.1) than one of the groups with very little evergreen forest in the habitat (0.47 ± 0.07). While groups with more evergreen forest in the HR preferred evergreen forest areas, groups with very little evergreen forest within the HR demonstrated less preference for evergreen forest areas. We conclude that gibbons at this site exhibit a considerable degree of behavioral variation in response to local ecological conditions. These findings suggest that while gibbons exhibit significant ecological flexibility, this flexibility may be limited by habitat type and key food resources.

Host specificity and microhabitat preference of symbiotic copepods (Cyclopoida: Clausiididae) associated with ghost shrimps (Decapoda: Callichiridae, Callianideidae).

We examined the host specificity of two ectosymbiotic Clausidium Kossman, 1874 copepods (Cyclopoida: Clausiididae) on two co‐occurrence species of host ghost shrimps. Our results revealed that both species of symbiotic copepod demonstrated extremely high host specificity. Moreover, within a single host shrimp species, each symbiont species displayed strong spatial patterns in microhabitat selection on their hosts’ bodies. Clausidium persiaensis Sepahvand & Kihara, 2017, was only found on the host Callianidea typa Milne Edwards, 1837 and almost exclusively within the host shrimp gill chamber, while C. iranensis Sepahvand, Kihara, & Boxshall, 2019 was only found on the host Neocallichirus jousseaumei (Nobili, 1904) and showed extremely strong preferences for the chelae and anterior walking legs. We also found that while the number of symbionts tends to increase with the host size, the two host species differed in the degree of symbiont infestation, with large C. typa hosting approximately 7× as many symbionts as the similarly sized N. jousseaumeia. The mechanisms resulting in the observed differences in infestation levels and microhabitat preferences of clausidium copepods among their hosts, including differences in physiology, burrowing pattern, and host grooming behavior should be further investigated.

Microhabitat preference of the Banggai Cardinalfish (Pterapogon kauderni): a behavioural experimental approach

The Banggai cardinalfish Pterapogon kauderni is an endangered endemic species with an exceptionally small native distribution and an unusual life history. A paternal mouthbrooder with direct development, symbiosis with benthic organisms (referred to as microhabitat), is crucial to its survival. This is especially so for postflexion larvae (recruits), after their release from the male parent’s buccal cavity. Microhabitat preference in P. kauderni has been studied empirically based on a survey of wild populations. This study adopted an ex-situ experimental approach to P. kauderni microhabitat preference using two well established behavioural trial methods: choice flume and choice tank. The experimental animals were sourced from the introduced P. kauderni population in Palu Bay, Central Sulawesi, Indonesia. The choice flume method was applied at the Central Sulawesi Marine and Fisheries Service Hatchery in Mamboro, Palu, with microhabitats Diadema setosum and D. savignyi. The choice box method was applied at the Universitas Hasanuddin Centre for Research and Development in Makassar, South Sulawesi, Indonesia, with microhabitats Heteractis crispa, Entacmaea quadricolor, D. savignyi and D. setosum. The results indicate the most to least preferred preference hierarchy of D. savignyi, D. setosum, H. crispa, E. quadricolor. While the preference for the sea anemone H. crispa compared to E. quadricolor is consonant with empirical in situ studies on P. kauderni, the observed preference for D. savignyi over D. setosum was unexpected, and points to the need for further research. Observations made during the trials also raise the possibility that imprinting may occur and influence subsequent microhabitat preference.

Does color matter? Molecular and ecological divergence in four sympatric color morphs of a coral reef fish.

Non‐sex‐linked color polymorphism is common in animals and can be maintained in populations via balancing selection or, when under diversifying selection, can promote divergence. Despite their potential importance in ecological interactions and the evolution of biodiversity, their function and the mechanisms by which these polymorphisms are maintained are still poorly understood. Here, we combine field observations with life history and molecular data to compare four sympatric color morphs of the coral reef fish Paracirrhites forsteri (family Cirrhitidae) in the central Red Sea. Our findings verify that the color morphs are not sex‐limited, inhabit the same reefs, and do not show clear signs of avoidance or aggression among them. A barcoding approach based on 1,276 bp of mitochondrial DNA could not differentiate the color morphs. However, when 36,769 SNPs were considered, we found low but significant population structure. Focusing on 1,121 F ST outliers, we recovered distinct population clusters that corresponded to shifts in allele frequencies with each color morph harboring unique alleles. Genetic divergence at these outlier loci is accompanied by differences in growth and marginal variation in microhabitat preference. Together, life history and molecular analysis suggest subtle divergence between the color morphs in this population, the causes for which remain elusive.