scholarly journals Variaciones adaptativas en la talla de la megafauna bentónica de fondos blandos tropicales en función de parámetros bióticos y abióticos

2017 ◽  
Vol 65 (3) ◽  
pp. 1002
Author(s):  
Luis Alfonso Gómez ◽  
Camilo Bernando García
Keyword(s):  
Body Size ◽  
Deep Sea ◽  
Coastal Upwelling ◽  
Abiotic Factors ◽  
Food Limitation ◽  
Additive Models ◽  
Optimal Size ◽  
Bathymetric Range ◽  
Physicochemical Changes ◽  
Magdalena River

Understanding and predicting adaptations in body size of megabenthic invertebrates remains a major challenge in marine macroecology. This study was conducted in order to investigate size variations of benthic megafauna in the tropics and to identify the effect of biotic and abiotic factors that may produce changes to these organisms, testing unresolved hypothesis and paradigms of deep sea ecology from subtropical and temperate areas. The study area covered the continental shelf of the Colombian Caribbean. The samples were collected during 1998, 2001 and 2005, using semi-globe demersal net for a water depth of 10 to 500 m. The most common species were selected for further study: Eudolium crosseanum, Cosmioconcha nitens, Nuculana acuta (mollusks), Astropecten alligator, Brissopsis atlantica, B. elongata (equinoderms), Anasimus latus, Chasmocarcinus cylindricus and Achelous spinicarpus (crustaceans). Generalized Additive Models were used to detect significant changes in size and to infer the effects of biotic and environmental factors on organisms’ size. The dependent variable was size and the predicting model variables were depth, temperature, intraspecific density, interspecific density, richness, latitude, and longitude. A total of 7 000 individuals were measured. Six species showed an increase in body size towards deeper and colder sites. These species inhabit shallow and deep environments that exceed a variation in temperature of 10 °C. There was a remarkable size reduction in areas affected by the Magdalena River, possibly due to major physicochemical changes caused by the river. This region has the lowest planktonic primary productivity within the study area. An increase in sizes was observed north of the Magdalena River (long 74°W - 71°W & lat of 11°N - 13°N), which may be attributable to the coastal upwelling occurring in this part of Colombia. The relationship between the density of benthic organisms and size was not clear. However, five species showed an inverse relation with intraspecific density and three with interspecific density. Temperature and depth were the variables that best explained the variations in size. Most of the studied species showed an increase in body size when temperature dropped along the bathymetric range. The trend of increasing size in deeper zones is contrary to the prediction of the optimal size theoretical model (but consistent with recent studies), which indicates a reduction in organisms’ size in the deep sea, due to food limitation with increasing depth. It is possible that this increase in size is an adaptation to maximize energy, which is frequently observed in the coldest habitats of several species. Future studies in Caribbean should examine variations in size of benthic megafauna towards deeper zones (more than 500 m), were temperature is less variable and then other factors can play a more important role determining the size of these organisms.

scholarly journals Variaciones adaptativas en la talla de la megafauna bentónica de fondos blandos tropicales en función de parámetros bióticos y abióticos

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Luis Alfonso Gómez ◽  
Camilo Bernando García
Keyword(s):  
Body Size ◽  
Deep Sea ◽  
Coastal Upwelling ◽  
Abiotic Factors ◽  
Food Limitation ◽  
Additive Models ◽  
Optimal Size ◽  
Bathymetric Range ◽  
Physicochemical Changes ◽  
Magdalena River

Understanding and predicting adaptations in body size of megabenthic invertebrates remains a major challenge in marine macroecology. This study was conducted in order to investigate size variations of benthic megafauna in the tropics and to identify the effect of biotic and abiotic factors that may produce changes to these organisms, testing unresolved hypothesis and paradigms of deep sea ecology from subtropical and temperate areas. The study area covered the continental shelf of the Colombian Caribbean. The samples were collected during 1998, 2001 and 2005, using semi-globe demersal net for a water depth of 10 to 500 m. The most common species were selected for further study: Eudolium crosseanum, Cosmioconcha nitens, Nuculana acuta (mollusks), Astropecten alligator, Brissopsis atlantica, B. elongata (equinoderms), Anasimus latus, Chasmocarcinus cylindricus and Achelous spinicarpus (crustaceans). Generalized Additive Models were used to detect significant changes in size and to infer the effects of biotic and environmental factors on organisms’ size. The dependent variable was size and the predicting model variables were depth, temperature, intraspecific density, interspecific density, richness, latitude, and longitude. A total of 7 000 individuals were measured. Six species showed an increase in body size towards deeper and colder sites. These species inhabit shallow and deep environments that exceed a variation in temperature of 10 °C. There was a remarkable size reduction in areas affected by the Magdalena River, possibly due to major physicochemical changes caused by the river. This region has the lowest planktonic primary productivity within the study area. An increase in sizes was observed north of the Magdalena River, between a longitude of 74°W and 71°W and latitude of 11°N y 13°N, which may be attributable to the coastal upwelling occurring in this part of Colombia. The relationship between the density of benthic organisms and size was not clear. However, five species showed an inverse relation with intraspecific density and three with interspecific density. Temperature and depth were the variables that best explained the variations in size. Most of the studied species showed an increase in body size when temperature dropped along the bathymetric range. The trend of increasing size in deeper zones is contrary to the prediction of the optimal size theoretical model (but consistent with recent studies), which indicates a reduction in organisms’ size in the deep sea, due to food limitation with increasing depth. It is possible that this increase in size is an adaptation to maximize energy, which is frequently observed in the coldest habitats of several species. Future studies in Caribbean should examine variations in size of benthic megafauna towards deeper zones (more than 500 m), were temperature is less variable and then other factors can play a more important role determining the size of these organisms.

scholarly journals Environmental Effects on the Spatiotemporal Variability of Fish Larvae in the Western Guangdong Waters, China

2021 ◽  
Vol 9 (3) ◽  
pp. 316
Author(s):  
Yuting Feng ◽  
Lijun Yao ◽  
Hui Zhao ◽  
Jing Yu ◽  
Zhaojin Lin
Keyword(s):  
Environmental Effects ◽  
Coastal Upwelling ◽  
Fish Larvae ◽  
Additive Models ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Spatiotemporal Variability ◽  
Aquatic Life ◽  
Positive Effects ◽  
Fishery Resources

Spawning grounds occupy an important position in the survival and reproduction of aquatic life, which plays an important role in the replenishment of fishery resources, especially in the China coasts where fishery resources are depleting. This study investigated environmental effects on the spatiotemporal variability of fish larvae in the western Guangdong waters (WGWs), on the basis of generalized additive models (GAMs) and center of gravity (CoG). Satellite data including sea surface salinity (SSS), sea surface temperature (SST), and in situ observations for fish larvae from April to June in 2014–2015 were used. Results showed that 40.3% of the total variation in fish larvae density was explained. SST, SSS, and depth showed positive effects in 23–24 °C and 27–30 °C, 24–32 PSU, and 0–60 m, and showed negative effects in 24–27 °C, 32–34.2 PSU, 60–80 m. Based on the stepwise GAMs, the most important factor was month, with a contribution of 10.6%, followed by longitude, offshore distance, depth, and latitude, with contributions of 7.0%, 7.0%, 6.3%, 4.2%, 3.9%, and 1.3%, respectively. Fish larvae CoG shifted northward by 0.6° N and eastwards by 0.13° E from April to June. The distribution of fish larvae in the WGWs was affected by complex submarine topography in the Qiongzhou Strait, coastal upwelling in the WGWs, and runoff from the Pearl River.

Potential Deep-Sea Petroleum Source Beds Related to Coastal Upwelling

1983 ◽  
pp. 467-483 ◽  
Author(s):  
Jürgen Rullkötter ◽  
Vassil Vuchev ◽  
Karl Hinz ◽  
Edward L. Winterer ◽  
Peter O. Baumgartner ◽  
...  
Keyword(s):  
Deep Sea ◽  
Coastal Upwelling

scholarly journals Deconstructing bathymetric body size patterns in deep-sea gastropods

2005 ◽  
Vol 297 ◽  
pp. 181-187 ◽  
Author(s):  
CR McClain ◽  
MA Rex ◽  
R Jabbour
Keyword(s):  
Body Size ◽  
Deep Sea

Deep-Sea Faunal Zonation of Benthos along Beaufort-Bermuda Transect in the North-western Atlantic

1972 ◽  
Vol 73 ◽  
pp. 183-194 ◽  
Author(s):  
Robert Y. George ◽  
Robert J. Menzies
Keyword(s):  
Deep Sea ◽  
Abiotic Factors ◽  
Global Scale ◽  
Species Level ◽  
Red Clay ◽  
Generic Level ◽  
Western Atlantic ◽  
The North ◽  
Shelf Slope ◽  
Abyssal Zone

SynopsisIn this paper the subject of faunal zonation in the ocean floor from the intertidal, and over the continental shelf, slope and rise and to the abyssal plain is examined on the basis of faunal change at the generic and species level. The region investigated over a period of five years aboard R/V Eastward is a Beaufort-Bermuda transect, approximately 75 kilometres wide and 500 kilometres long and bounded between 32° and 36°N latitude and 64° and 79°W longitude. A new method, involving numerical indices reflecting changes in the composition of taxa, endemism and diversity between adjacent depth levels, was developed for defining faunal boundaries. Isotherms and isobaths utilised by earlier authors for characterising deep-sea boundary on a global scale do not coincide with natural faunal boundaries. This study analyses the vertical distribution of 128 species of isopod crustaceans and 28 species of large epibenthic invertebrates. The zonation patterns seem to correspond with correlations in environmental conditions such as currents, topography and sediments.We suggest four major vertical faunal provinces, characterised at the generic level, namely (1) the Intertidal Faunal Province; (2) the Shelf Faunal Province; (3) the Archibenthal Zone of Transition; and (4) the Abyssal Faunal Province and internal zones within these characterised at the species level. The main aspects of interest include the presence of a narrow ‘meso abyssal zone’ with a species maximum, the demonstration of the true transitional nature of the Archibenthal Zone in biotic and abiotic factors and the characteristic low-biomass Red Clay environment showing definite faunal isolation from the continental margin.

Bathyconchoecilla, a new genus of deep plankto-benthic halocyprids (Ostracoda, Myodocopa) from the northern Pacific and an overview of Bathyconchoeciinae

Crustaceana ◽  
2018 ◽  
Vol 91 (11) ◽  
pp. 1291-1317
Author(s):  
Vladimir G. Chavtur ◽  
Alexander G. Bashmanov
Keyword(s):  
Body Size ◽  
Deep Sea ◽  
Morphological Analysis ◽  
New Genus ◽  
Heterogeneous Group ◽  
Species Complexes ◽  
Northern Pacific

Abstract Plankto-benthic ostracods of the subfamily Bathyconchoeciinae constitute an extremely heterogeneous group of species, as well in body size, as well as in the shape and structure of carapace and limbs. At present, their fauna contains 35 known (described) species, belonging to four genera. Besides that, about 50 species with still open nomenclature were noted in the literature and have been found in material from our collections. A preliminary morphological analysis of the bathyconchoeciines allowed, in addition, to single out 13 species complexes (= putative genera). One of these genera is described herein as Bathyconchoecilla gen. nov., from the deep-sea zone of the Kurile-Kamchatka Trench. The new genus differs from other genera in this subfamily by the shape and sculpture of the carapace, the location of the left hook on the second antenna in the male, and the structure of the coxale and basale of the mandible and the endites of the maxilla.

scholarly journals Biology, not environment, drives major patterns in maximum tetrapod body size through time

2012 ◽  
Vol 8 (4) ◽  
pp. 674-677 ◽  
Author(s):  
Roland B. Sookias ◽  
Roger B. J. Benson ◽  
Richard J. Butler
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Abiotic Factors ◽  
Logistic Models ◽  
Growth Curves ◽  
Maximum Size ◽  
Generalized Least Squares ◽  
Least Squares Regression ◽  
Geological Time ◽  
Cenozoic Mammals

Abiotic and biological factors have been hypothesized as controlling maximum body size of tetrapods and other animals through geological time. We analyse the effects of three abiotic factors—oxygen, temperature and land area—on maximum size of Permian–Jurassic archosauromorphs and therapsids, and Cenozoic mammals, using time series generalized least-squares regression models. We also examine maximum size growth curves for the Permian–Jurassic data by comparing fits of Gompertz and logistic models. When serial correlation is removed, we find no robust correlations, indicating that these environmental factors did not consistently control tetrapod maximum size. Gompertz models—i.e. exponentially decreasing rate of size increase at larger sizes—fit maximum size curves far better than logistic models. This suggests that biological limits such as reduced fecundity and niche space availability become increasingly limiting as larger sizes are reached. Environmental factors analysed may still have imposed an upper limit on tetrapod body size, but any environmentally imposed limit did not vary substantially during the intervals examined despite variation in these environmental factors.

scholarly journals Evidence for benthic body size miniaturization in the deep sea

2006 ◽  
Vol 86 (6) ◽  
pp. 1339-1345 ◽  
Author(s):  
Janne I. Kaariainen ◽  
Brian J. Bett
Keyword(s):  
Body Size ◽  
Deep Sea ◽  
Size Structure ◽  
Size Class ◽  
The Body ◽  
Significant Shift ◽  
Individual Biomass ◽  
Wet Weight ◽  
Accumulation Curves ◽  
Average Individual

The benthic body size miniaturization hypothesis states that deep-sea communities are dominated by organisms of smaller body size, although some field studies have produced contradictory results. Using appropriate sample sets, this study tests this hypothesis by contrasting the benthic communities of the Fladen Ground (North Sea, 150 m) and the Faroe–Shetland Channel (1600 m). Samples were collected for large (500 μm) and small macrofauna (250–355 μm), meiofauna (45 μm) as well as an intermediate sized ‘mesofauna’ (180 μm) to ensure comprehensive coverage of the full meio- and macro-faunal body size-range. The body size structure of the benthos was compared using two methods. The more widely used average individual biomass method involves dividing the total sample biomass by sample abundance. Additionally, body size accumulation curves were constructed by assigning all specimens into a logarithmic size-class and then plotting the cumulative percentage of individuals present in each size-class. The results seem to support the hypothesis that the deep-sea environment is a small organism habitat. Although these findings only represent two locations, the overall body size accumulation curves clearly display a statistically significant shift towards smaller body sizes at the deeper site. The magnitude of the effect is appreciable with median metazoan body size reducing from 14.3 μg wet weight in the Fladen Ground to 3.8 μg wet weight in the Faroe–Shetland Channel. The average individual biomass measurements are shown to be of limited value and can lead to potentially misleading conclusions if the underlying size structure is not analysed in detail.

scholarly journals The importance of offshore origination revealed through ophiuroid phylogenomics

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170160 ◽  
Author(s):  
Guadalupe Bribiesca-Contreras ◽  
Heroen Verbruggen ◽  
Andrew F. Hugall ◽  
Timothy D. O'Hara
Keyword(s):  
Deep Sea ◽  
Marine Invertebrates ◽  
Range Shift ◽  
Evolutionary Adaptation ◽  
Evolutionary Processes ◽  
Opposite Pattern ◽  
Bathymetric Range ◽  
Evolutionary Pattern ◽  
Transitional State ◽  
Over Time

Our knowledge of macro-evolutionary processes in the deep sea is poor, leading to much speculation about whether the deep sea is a source or sink of evolutionary adaptation. Here, we use a phylogenetic approach, on large molecular (688 species, 275 kbp) and distributional datasets (104 513 records) across an entire class of marine invertebrates (Ophiuroidea), to infer rates of bathymetric range shift over time between shallow and deep water biomes. Biome conservation is evident through the phylogeny, with the majority of species in most clades distributed within the same bathome. Despite this, bathymetric shifts have occurred. We inferred from ancestral reconstructions that eurybathic or intermediate distributions across both biomes were a transitional state and direct changes between shallow and deep sea did not occur. The macro-evolutionary pattern of bathome shift appeared to reflect micro-evolutionary processes of bathymetric speciation. Results suggest that most of the oldest clades have a deep-sea origin, but multiple colonization events indicate that the evolution of this group conforms neither to a simple onshore–offshore hypothesis, nor the opposite pattern. Both shallow and deep bathomes have played an important role in generating the current diversity of this major benthic class.

Sign in / Sign up

Export Citation Format

Share Document