Chemically mediated behavior of recruiting corals and fishes: A tipping point that may limit reef recovery

Coral reefs are in global decline, converting from dominance by coral to dominance by seaweed. Once seaweeds become abundant, coral recovery is suppressed unless herbivores return to remove seaweeds, and corals then recruit. Variance in the recovery of fishes and corals is not well understood.We show that juveniles of both corals and fishes are repelled by chemical cues from fished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Chemical cues of specific seaweeds from degraded reefs repulsed recruits, and cues from specific corals that are typical of healthy reefs attracted recruits. Juveniles were present at but behaviorally avoided recruiting to degraded reefs dominated by seaweeds. For recovery, degraded reefs may need to be managed to produce cues that attract, rather than repel, recruiting corals and fishes

The reproductive season of scleractinian corals in Socotra, Yemen

Determining when corals reproduce has clear management and economic implications. Here we document the reproductive condition of corals in the genus Acropora on the island of Socotra in Yemen during February 2014. Twenty percent of colonies (n = 143) contained mature gametes and 28% had immature gametes indicating that spawning will occur in both February and March in 2014, confirming previous anecdotal reports of coral spawning at this time in Socotra. Acropora typically reproduce in synchrony with many other broadcast spawning scleractinian corals, and we therefore predict that many other species are reproductively active at this time of year

The reproductive season of Acropora in Socotra, Yemen

© 2014 Baird AH et al. Determining when corals reproduce has clear management and economic implications. Here we document the reproductive condition of corals in the genus Acropora on the island of Socotra in Yemen during February 2014. Twenty percent of colonies (n = 143) contained mature gametes and 28% had immature gametes indicating that spawning will occur in both February and March in 2014, confirming previous anecdotal reports of coral spawning at this time in Socotra. Acropora typically reproduce in synchrony with many other broadcast spawning scleractinian corals, and we therefore predict that many other species are reproductively active at this time of year

Utjecaj proteina graha lima na funkcionalna svojstva škroba

The functional properties of starches determine their potential applications in food systems. These properties depend largely on granular and molecular structure and can be physically, chemically or enzymatically modified. One way of modifying starch functional properties is by interaction with other food components, such as proteins. Starch-protein interactions are frequent in plant foods, particularly cereals and legumes, which are formed mainly of starches and proteins. An evaluation has been done of changes in the functional properties of three native starches (corn, Zea mays L.; cassava, Manihot esculenta; and lima bean, Phaseolus lunatus L.) when blended with lima bean protein concentrate. The gelatinization temperature of each blend increased compared to its corresponding native starch. The cassava starch/lima bean protein blend had the highest overall swelling power and water absorption capacity values at all temperatures. Maximum viscosity for each blend was higher than for the corresponding native starches. The blends of lima bean protein with cassava and corn starches did not exhibit syneresis. The lima bean starch/lima bean protein blend had the highest gel firmness values, followed by the blends with corn and cassava starches. The protein-starch mixtures are an alternative in the improvement of the starch functional properties which are useful in the development of nutritional products.O funkcionalnim svojstvima škroba ovisi njegova primjena u proizvodnji hrane. Ta svojstva uglavnom ovise o strukturi zrna i molekula. Mogu se modificirati fizikalnim, kemijskim ili enzimskim postupcima, a jedan od njih je i interakcija s ostalim sastojcima hrane (npr. proteinima). Interakcije škroba i proteina su česte u hrani biljnog podrijetla, osobito u žitaricama i leguminozama koje se uglavnom sastoje od te dvije komponente. U radu je ispitana promjena funkcionalnih svojstava škroba izoliranog iz kukuruza (Zea mays L.), manioke (Manihot esculenta) i lima graha (Phaseolus lunatus L.), nakon miješanja s koncentratom proteina iz graha lima. Temperatura se želiranja svake mješavine škroba i proteina povećala u usporedbi s izvornim škrobom. Mješavina škroba manioke i proteina graha lima imala je najbolji kapacitet bubrenja i upijanja vode na svim temperaturama. Maksimalna je viskoznost mješavina bila veća od viskoznosti samog škroba svake vrste, pri čemu mješavine proteina graha lima sa škrobom manioke i kukuruza nisu pokazale jače zgrušavanje. Najveću je čvrstoću gela imala mješavina škroba i proteina graha lima, zatim mješavina škroba kukuruza i proteina, te naposljetku škroba manioke i proteina graha lima. Mješavine su škroba i proteina alternativni način poboljšavanja funkcionalnih svojstava škroba u proizvodnji hrane

The Status of Spotted Seatrout (\u3ci\u3eCynoscion nebulosus\u3c/i\u3e) As a Technologically Feasible Species for U.S. Marine Aquaculture

Culture models and facilities for large-scale, commercial production of popular Gulf of Mexico species are unavailable. The spotted seatrout (Cynoscion nebulosus) is one of the most popular recreational fishes in the Gulf of Mexico. Seatrout culture techniques were adapted from red drum (Sciaenops ocellatus) protocols developed in the 1970s. Broodstock husbandry, spawning, and extensive pond rearing techniques using fertilized and bloomed brackish ponds were well-established by the 1980s. By 2018, approximately 80 million 25–30-day old seatrout had been produced, mainly for stock enhancement. Cannibalism and poor nutrition hindered intensive tank culture. Between 2005 and 2015, an intensive tank-rearing protocol that reduced cannibalism and intracohort variability and increased average survival to almost 50% was developed using algal concentrate, rotifers, brine shrimp (Artemia sp.), and microencapsulated feeds. Preliminary results suggested that a 500 g fish could be produced in approximately 10 months. Nevertheless, interest in commercialization has remained low. Zootechnical performance throughout the latter stages of culture, the economics of production, consumer preferences/perceptions, and market capacity must be documented to complete the assessment of the spotted seatrout as a species for commercial aquaculture. The optimization of aquafeeds specific for seatrout and a domestication program is warranted to further facilitate industry growth

Genomic and transcriptomic signals of thermal tolerance in heat-tolerant corals (Platygyra daedalea) of the Arabian/Persian Gulf

© 2018 John Wiley & Sons Ltd Scleractinian corals occur in tropical regions near their upper thermal limits and are severely threatened by rising ocean temperatures. However, several recent studies have shown coral populations can harbour genetic variation in thermal tolerance. Here, we have extended these approaches to study heat tolerance of corals in the Persian/Arabian Gulf, where heat-tolerant local populations experience extreme summer temperatures (up to 36°C). To evaluate whether selection has depleted genetic variation in thermal tolerance, estimate potential future adaptive responses and understand the functional basis for these corals’ unusual heat tolerance, we conducted controlled crosses in the Gulf coral Platygyra daedalea. Heat tolerance is highly heritable in this population (h 2 = 0.487–0.748), suggesting substantial potential for adaptive responses to selection for elevated temperatures. To identify genetic markers associated with this variation, we conducted genomewide SNP genotyping in parental corals and tested for relationships between paternal genotype and offspring thermal tolerance. Resulting multilocus SNP genotypes explained a large fraction of variation in thermal tolerance in these crosses (69%). To investigate the functional basis of these differences in thermal tolerance, we profiled transcriptional responses in tolerant and susceptible families, revealing substantial sire effects on transcriptional responses to thermal stress. We also studied sequence variation in these expressed sequences, identifying alleles and functional groups of differentially expressed genes associated with thermal tolerance. Our findings demonstrate that corals in this population harbour extensive genetic variation in thermal tolerance, and heat-tolerant phenotypes differ in both gene sequences and transcriptional stress responses from their susceptible counterparts

Enhancing the heat tolerance of reef-building corals to future warming

Reef-building corals thriving in extreme thermal environments may provide genetic variation that can assist the evolution of populations to rapid climate warming. However, the feasibility and scale of genetic improvements remain untested despite ongoing population declines from recurrent thermal stress events. Here, we show that corals from the hottest reefs in the world transfer sufficient heat tolerance to a naïve population sufficient to withstand end-of-century warming projections. Heat survival increased up to 84% when naïve mothers were selectively bred with fathers from the hottest reefs because of strong heritable genetic effects. We identified genomic loci associated with tolerance variation that were enriched for heat shock proteins, oxidative stress, and immune functions. Unexpectedly, several coral families exhibited survival rates and genomic associations deviating from origin predictions, including a few naïve purebreds with exceptionally high heat tolerance. Our findings highlight previously uncharacterized enhanced and intrinsic potential of coral populations to adapt to climate warming

How to make more out of community data? A conceptual framework and its implementation as models and software

Community ecology aims to understand what factors determine the assembly and dynamics of species assemblages at different spatiotemporal scales. To facilitate the integration between conceptual and statistical approaches in community ecology, we propose Hierarchical Modelling of Species Communities (HMSC) as a general, flexible framework for modern analysis of community data. While non-manipulative data allow for only correlative and not causal inference, this framework facilitates the formulation of data-driven hypotheses regarding the processes that structure communities. We model environmental filtering by variation and covariation in the responses of individual species to the characteristics of their environment, with potential contingencies on species traits and phylogenetic relationships. We capture biotic assembly rules by species-to-species association matrices, which may be estimated at multiple spatial or temporal scales. We operationalise the HMSC framework as a hierarchical Bayesian joint species distribution model, and implement it as R-and Matlab-packages which enable computationally efficient analyses of large data sets. Armed with this tool, community ecologists can make sense of many types of data, including spatially explicit data and time-series data. We illustrate the use of this framework through a series of diverse ecological examples.Peer reviewe