Effect of substrate size and depth on macroalgal communities in unstable marine rocky bottoms

2021 ◽  
pp. 103411
Author(s):  
Carlos Sangil ◽  
Julio Afonso-Carrillo ◽  
Marta Sansón
Keyword(s):  
Substrate Size ◽  
Rocky Bottoms

Temporal dynamics of encrusting communities during the Late Devonian: a case study from the Central Devonian Field, Russia

Paleobiology ◽  
2017 ◽  
Vol 43 (4) ◽  
pp. 550-568 ◽  
Author(s):  
Michał Zatoń ◽  
Tomasz Borszcz ◽  
Michał Rakociński
Keyword(s):  
Temporal Dynamics ◽  
Small Sample ◽  
Time Interval ◽  
Faunal Turnover ◽  
Central Devonian Field ◽  
Before And After ◽  
Substrate Size ◽  
Mass Extinction Event ◽  
Diversity Dynamics

AbstractIn this study we focused on the dynamics of encrusting assemblages preserved on brachiopod hosts collected from upper Frasnian and lower Famennian deposits of the Central Devonian Field, Russia. Because the encrusted brachiopods come from deposits bracketing the Frasnian/Famennian (F/F) boundary, the results also shed some light on ecological differences in encrusting communities before and after the Frasnian–Famennian (F-F) event. To explore the diversity dynamics of encrusting assemblages, we analyzed more than 1300 brachiopod valves (substrates) from two localities. Taxon accumulation plots and shareholder quorum subsampling (SQS) routines indicated that a reasonably small sample of brachiopod host valves (n=50) is sufficient to capture the majority of the encrusting genera recorded at a given site. The richness of encrusters per substrate declined simultaneously with the number of encrusting taxa in the lower Famennian, accompanied by a decrease in epibiont abundance, with a comparable decrease in mean encrustation intensity (percentage of bioclasts encrusted by one or more epibionts). Epibiont abundance and occupancy roughly mirror each other. Strikingly, few ecological characteristics are correlated with substrate size, possibly reflecting random settlement of larvae. Evenness, which is negatively correlated with substrate size, shows greater within-stage variability among samples than between Frasnian and Famennian intervals and may indicate the instability of early Famennian biocenoses following the faunal turnover. The occurrence distribution of encrusters points to nonrandom associations and exclusions among several encrusting taxa. However, abundance and occupancy of microconchids remained relatively stable throughout the sampled time interval. The notable decline in abundance (~60%) and relatively minor decline in diversity (~30%) suggest jointly that encrusting communities experienced ecological collapse rather than a major mass extinction event. The differences between the upper Frasnian and lower Famennian encrusting assemblages may thus record a turnover associated with the F-F event.

scholarly journals Citizen science via social media revealed conditions of symbiosis between a marine gastropod and an epibiotic alga

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Osamu Kagawa ◽  
◽  
Shota Uchida ◽  
Daishi Yamazaki ◽  
Yumiko Osawa ◽  
...  
Keyword(s):  
Social Media ◽  
Heat Stress ◽  
Environmental Factors ◽  
Citizen Science ◽  
Bayesian Model ◽  
Symbiotic Relationship ◽  
Hierarchical Bayesian Model ◽  
Symbiotic Interaction ◽  
Intertidal Gastropod ◽  
Substrate Size

AbstractEnvironmental factors promote symbiosis, but its mechanism is not yet well understood. The alga Pseudocladophora conchopheria grows only on the shell of an intertidal gastropod Lunella correensis, and these species have a close symbiotic relationship which the alga reduces heat stress of the gastropod. In collaboration with general public, we investigated how environmental conditions alter the symbiotic interaction between the alga and the gastropod. Information about the habitats of each gastropod and images of shells was obtained from the Japanese and Korean coasts via social media. We constructed the hierarchical Bayesian model using the data. The results indicated that the proportion of shell area covered by P. conchopheria increased as the substrate size utilized by the gastropod increased. Meanwhile, temperature did not affect the proportion of P. conchopheria on the shell. These suggested that the alga provides no benefits for the gastropod on small substrates because gastropod can reduce the heat stress by diving into the small sediment. Further, the gastropod’s cost incurred by growing the alga on the shell seems to be low as the algae can grow even in cooler places where no benefits of heat resistance for gastropods. Different environments can yield variable conditions in symbiosis.

Substrate size effect at off-axis laser deposition of multicomponent films

1996 ◽  
Vol 96-98 ◽  
pp. 717-720
Author(s):  
M.R. Predtechensky ◽  
O.M. Tukhto ◽  
A.N. Smal ◽  
S.A. Vasil'eva
Keyword(s):  
Size Effect ◽  
Laser Deposition ◽  
Substrate Size

A comparison of bryophyte species diversity and niche structure of montane streams and stream banks

1987 ◽  
Vol 65 (9) ◽  
pp. 1824-1837 ◽  
Author(s):  
Janice M. Glime ◽  
Dale H. Vitt
Keyword(s):  
New York ◽  
Species Diversity ◽  
Water Surface ◽  
Niche Overlap ◽  
Niche Width ◽  
Vertical Distance ◽  
Substrate Size ◽  
Species Cover ◽  
Montane Streams ◽  
Stream Substrate

Eleven alkaline western Canadian montane streams were sampled by transects to compare the bryophyte species cover, diversity, frequency, richness, niche width, and niche overlap in three vertical zones (relative to water level) with the same parameters in four acidic streams on Slide Mountain in the Adirondack Mountains of New York. Resources for niche width and overlap include vertical distance from water surface, aspect in stream, substrate size, and percent bare substrate. Species cover, richness, and diversity increase from the submerged zone 1 (< −5 cm) to the terrestrial zone 3 (10–30 cm). Brillouin species diversity increases from 1.98 to 3.03 (means per stream) along the same gradient. All species except one from zone 1 also occur in zone 3. The niche widths for aspect in stream, substrate size, and vertical distance from water surface are all negatively correlated with their chi-square values, indicating that the width values are most reliable for small widths and become increasingly less reliable for large niche widths. Niche overlap is high among most species for at least one resource parameter.

Is it possible to predict habitat use by spawning salmonids? A test using California golden trout (Oncorhynchus mykiss aguabonita)

1999 ◽  
Vol 56 (9) ◽  
pp. 1576-1584 ◽  
Author(s):  
Roland A Knapp ◽  
Haiganoush K Preisler
Keyword(s):  
Oncorhynchus Mykiss ◽  
Water Depth ◽  
Parametric Model ◽  
Water Velocity ◽  
Habitat Characteristics ◽  
Nonparametric Model ◽  
Habitat Features ◽  
Substrate Size ◽  
Depth Water ◽  
Spawning Sites

It is widely believed that stream salmonids select spawning sites based on water depth, water velocity, and substrate size. Attempts to predict spawning locations using these habitat features have met with little success, however. In this study, we used nonparametric logistic regression to determine what habitat features were associated with the locations chosen by spawning California golden trout (Oncorhynchus mykiss aguabonita). From this nonparametric model, we developed a parametric model that incorporated the habitat features most strongly associated with spawning sites and used this model to calculate the probability of use by spawning golden trout for specific stream locations. The overall nonparametric model was highly significant and explained 62% of the variation in spawning location. Four of the eight habitat variables, substrate size, water depth, water velocity, and stream width, had highly significant effects and alone explained 59% of the variation in spawning location. The results of a cross-validation procedure indicated that the parametric model generally provided a good fit to the data. These results indicate that location-specific probabilities of use were predictable based on easily measured habitat characteristics and that nonparametric regression, an approach still rarely used in ecological studies, may have considerable utility in the development of fish-habitat models. Given the escalating pace at which fish habitats are being altered, such models are increasingly important in predicting the effects of these alterations on populations.

scholarly journals Diet and feeding strategy of the dusky grouper Mycteroperca marginata (Actinopterygii: Epinephelidae) in a man-made rocky habitat in southern Brazil

2011 ◽  
Vol 9 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Mario V. Condini ◽  
Elisa Seyboth ◽  
João P. Vieira ◽  
Alexandre M. Garcia
Keyword(s):  
Feeding Strategy ◽  
Marine Species ◽  
Southern Brazil ◽  
Patos Lagoon ◽  
Additional Tool ◽  
Rocky Habitat ◽  
Dusky Grouper ◽  
Dietary Shifts ◽  
Rocky Habitats ◽  
Rocky Bottoms

The dusky grouper (Mycteroperca marginata) is a marine species usually associated with rocky bottoms and reefs. The present work investigated the diet and feeding strategy of a dusky grouper population inhabiting a 4.5 km long pair of rocky jetties located in the mouth of Patos Lagoon estuary. No prior research has been conducted in such man-made habitat and the current study provides a basis for comparative studies on the diet of the dusky grouper populations inhabiting natural vs. man-made rocky habitats. Similarly with previous studies on natural substrates, crabs and fishes were the main food categories consumed (%IRI = 85.1 and %IRI = 12.6, respectively), whereas shrimps and mollusks had lower importance in the diet (%IRI = 1.9 and 0.4, respectively). As previously reported for dusky grouper populations inhabiting reefs and rocky bottoms, the present work revealed conspicuous size related dietary shifts. Blue crabs and fishes become increasingly important food items in the diet of larger individuals (> 500 mm, TL). Finally, it was found that the studied dusky population has a generalist feeding strategy with a high between-individual variation in prey consumption. Such strategy remained similar across the size increment of the species. Our findings suggest that man-made rocky substrates provide suitable feeding grounds for the dusky grouper in southern Brazil and could be used as an additional tool in the conservation efforts of this endangered species.

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