The Vertical Distribution Patterns of Heterotrophic Bacteria in the Depths of the World Ocean and the Importance of their Regularity to Oceanography

1976 ◽  
Vol 61 (4) ◽  
pp. 417-438 ◽  
Author(s):  
A. E. Kriss
2018 ◽  
Vol 18 (6) ◽  
pp. 1976-1983
Author(s):  
Xiao-Bao Nie ◽  
Yun-Zi Tang ◽  
Chang-bo Jiang ◽  
Yuan-Nan Long ◽  
Pan-Pan He ◽  
...  

Abstract Aquatic worms propagated in granular activated carbon (GAC) filter has become a troublesome problem for drinking water supply. This study investigated the vertical distribution patterns of naidids in GAC filter beds and assessed the effect of an additional sand bed, located below the GAC bed, in preventing naidids from being present in effluent. The results indicated that the vertical distribution data of naidids in the GAC filter bed were well fitted by a Gaussian distribution, and the location of peak population density was mainly affected by downward flow. Backwashing experiments revealed that additional pressure air scouring shifted the distribution pattern of naidids in the GAC filter bed, resulting in a significant enhancement in naidid removal efficiency. Additionally, the addition of a sand bed exhibited pronounced interception and inactivation effects on naidids, suggesting that it may be a very promising technology for preventing naidids propagated in GAC filters from being present in the effluent.


2004 ◽  
Vol 61 (8) ◽  
pp. 1243-1252 ◽  
Author(s):  
A. Sabatés

Abstract The vertical distributions of the larvae of shelf and oceanic fish species that spawn during the winter-mixing period in the Mediterranean are described from 22 vertically stratified plankton tows. Diel differences in the vertical distribution patterns in relation to physical data and potential prey abundance throughout the water column were examined. Even in absence of stratification, the larvae of the various fish species showed different patterns of vertical distribution and diel changes. The larvae of shelf-dwelling species were found in the surface layers, mainly above 50-m depth, and with some exceptions, with very little diel variation in depth distribution. Therefore, the vertical distribution of the larvae of these species coincided with the maximum concentrations of their potential food, nauplii and copepodite stages of copepods. The larvae of mesopelagic fishes showed deeper distributions in the water column and most of these species were located closer to the surface during the day than at night. Given the homogeneity of the physical characteristics throughout the water column, except for light, this behaviour may be determined not only by the higher concentration of prey in the surface layers but also by adequate light levels for feeding.


Check List ◽  
2015 ◽  
Vol 11 (4) ◽  
pp. 1682 ◽  
Author(s):  
Atsunobu Murase

The community composition of rockpool fish on the southwestern coast of Yaku-shima Island, southern Japan, in the northwest Pacific was investigated by sampling of 22 rockpools and recording the range of vertical heights (a total of 76 sampling events from May 2009 to February 2010). A total of 72 species belonging to 19 families were collected from the study site. This species richness is the highest recorded of similar studies undertaken worldwide, reflecting the highest diversity of coastal fishes in the western Pacific. Increases in species richness due to transient and accidental visitors increased the total number of species in the lower vertical zones. Variations in the vertical distribution pattern of the resident and transient species suggests habitat partitioning and/or physical preferences for a particular habitat of each species. Color images of rockpool fish recorded at the site and a list of all the voucher specimens are provided.


ZooKeys ◽  
2020 ◽  
Vol 930 ◽  
pp. 199-219
Author(s):  
Mzia S. Kokhia ◽  
Sergei I. Golovatch

The diplopod fauna of Georgia, Transcaucasia, is very rich given the country’s relatively small territory; it presently comprises 103 species from 44 genera, 12 families, and 7 orders. Most of the Diplopoda known from Georgia (86 species, or 83%) demonstrate Caucasian distribution patterns, 36 and 46 species, as well as 8 and 9 genera being endemic or subendemic to the country, respectively. A single Holarctic family, Anthroleucosomatidae (order Chordeumatida), contains 44 Caucasian species and 20 genera, of which 27 species and 14 genera are endemic or subendemic to Georgia. Likewise, all species from the orders Polyzoniida, Siphonocryptida, Glomerida and Chordeumatida, as well as most species of Julida and Polydesmida are native, also endemic or subendemic to the Caucasus, but the genera and families they represent are widely distributed at least across the Euro-Mediterranean Realm. Most of the presumed troglobionts in the Caucasus appear to be confined to western Georgia’s karst caves (14 species, 5 genera). Within Georgia, the fauna of the western part (= Colchis) is particularly rich and diverse, while that of the central and eastern parts of the country grows increasingly depauperate inland following the gradual climatic aridisation from west (Black Sea coast) to east (Armenia and Azerbaijan). The vertical distribution of the Diplopoda in Georgia, as well as the Caucasus generally, shows the bulk of the fauna restricted to forested lowland to mountain biomes or their remnants. Only very few Chordeumatida and Julus species seem to occur solely in the subalpine to alpine environments and thus may provisionally be considered as high-montane elements. Ongoing and future research on the millipedes of the Caucasus, especially in cave and montane environments, will undoubtedly allow for many more novelties and details of the diversity and distribution of Georgia’s Diplopoda to be revealed or refined.


2021 ◽  
Author(s):  
Manuel F. G. Weinkauf ◽  
Michael Siccha ◽  
Agnes K. M. Weiner

<p>Understanding the biology of reproduction is important for retracing key evolutionary processes (e.g. speciation and adaptation) in any group of organisms, yet gaining detailed insights often poses a major challenge. Planktonic Foraminifera are a group of globally distributed marine microbial eukaryotes that are important contributors to the global carbon cycle and, due to their fossil record, are widely used as model organisms to investigate the responses of plankton to past environmental changes. The extant biodiversity of planktonic Foraminifera shows restricted distribution patterns and local adaptations of some species, whereas others are cosmopolitan in the world ocean. Hypotheses on their diversification and population dynamics so far entirely rely on the assumption of a nearly exclusively sexual reproduction.</p><p>So far, reproduction in culture has not been successful under laboratory conditions, and thus details on their life cycle and its influence on the evolution of the group remain unknown. Only the production of flagellated gametes has been observed and is taken as an indication for sexual reproduction. Yet, sexual reproduction by spawning of gametes in the open ocean relies on sufficient gamete encounters to maintain viable populations. This represents a problem especially for unflagellated protists like planktonic Foraminifera, which lack the means of active propulsion and are characterized by low population densities in large areas of the world ocean.</p><p>To increase the sparse knowledge on the reproductive biology of planktonic Foraminifera, we applied a dynamic, individual-based modelling approach with parameters based on laboratory and field observations. We tested if random gamete encounters under commonly observed population densities are sufficient for maintaining viable populations or if alternative strategies, such as asexual reproduction or synchronization in depth and time, are indispensable to achieve reproduction success. Our results show that a strict synchronization of gamete release in time and/or space seems inevitable for a successful maintenance of populations. We further argue that planktonic Foraminifera optimized their individual reproductive success at the expense of community-wide gene flow, which may explain their high degree of diversity as well as hampered evolvability. Our modelling approach helps to illuminate the ecology and evolution of this important marine calcifier and to predict the existence of necessary reproduction strategies, which may be detectable in future field and laboratory experiments.</p>


Author(s):  
T.K. Pinto ◽  
M.C. Austen ◽  
C.E. Bemvenuti

Within a subtropical estuary in southern Brazil, an experiment was carried out to test the hypotheses that the deposit feeding macrofaunal polychaete Laeonereis acuta affects nematode community structure and the vertical distribution patterns of nematodes in sediments. Inclusion cages were deployed with two different densities of the polychaete and meiofaunal nematodes were sampled from six different vertical sediment layers: 0–1, 1–2, 2–4, 4–6, 6–8 and 8–10 cm depth. Although L. acuta did change the vertical distribution of both nematode and trophic groups in the sediment, allowing nematodes to inhabit deeper sediment layers, there were no apparent effects of different polychaete densities.


Author(s):  
M. K. James ◽  
J. A. Polton ◽  
A. R. Brereton ◽  
K. L. Howell ◽  
W. A. M. Nimmo-Smith ◽  
...  

Biophysical models are well-used tools for predicting the dispersal of marine larvae. Larval behavior has been shown to influence dispersal, but how to incorporate behavior effectively within dispersal models remains a challenge. Mechanisms of behavior are often derived from laboratory-based studies and therefore, may not reflect behavior in situ. Here, using state-of-the-art models, we explore the movements that larvae must undertake to achieve the vertical distribution patterns observed in nature. Results suggest that behaviors are not consistent with those described under the tidally synchronized vertical migration (TVM) hypothesis. Instead, we show (i) a need for swimming speed and direction to vary over the tidal cycle and (ii) that, in some instances, larval swimming cannot explain observed vertical patterns. We argue that current methods of behavioral parameterization are limited in their capacity to replicate in situ observations of vertical distribution, which may cause dispersal error to propagate over time, due to advective differences over depth and demonstrate an alternative to laboratory-based behavioral parameterization that encompasses the range of environmental cues that may be acting on planktic organisms.


Author(s):  
Yuichiro Nishibe ◽  
Yuuichi Hirota ◽  
Hiroshi Ueda

Community structure and vertical distribution of oncaeid copepods were investigated at an offshore site in Tosa Bay, southern Japan. Samples were collected with a 0.063 mm closing type net from eight discrete layers between the surface and 500 m depth in August and November 2005. A total of 45 species and three form variants belonging to the genera Triconia, Oncaea, Spinoncaea, Conaea and Epicalymma were identified. The greatest number of species was consistently found in the lower epipelagic zone, at 50–100 m. The vertical distribution patterns of oncaeid copepods were similar between August and November, with the highest abundances in the upper epipelagic zone above the thermocline. The oncaeid maxima corresponded with the depth where appendicularians occurred in high numbers. Dominant species in the water column (0–500 m) were O. venusta small form, O. media, O. scottodicarloi, O. waldemari, O. zernovi, O. tregoubovi, S. ivlevi, S. tenuis and T. conifera. The vertical succession of species composition was almost the same between August and November, although several species showed a downward shift of their depth-range to some extent in November. The oncaeid copepod community could be differentiated into three distinct groups according to the depth layers, each corresponding to different hydrographic conditions in the water column.


1987 ◽  
Vol 57 (1) ◽  
pp. 42-52 ◽  
Author(s):  
S. van der Spoel

The vertical distribution patterns of Paraphyllina ransoni Russell, 1956, Periphylla periphylla (Péron & Lesueur, 1809), Atolla parva Russell, 1958, A. vanhoeffeni Russell, 1957, and A. wyvillei Haeckel, 1880 are described. A comparison with other bathypelagic taxa shows that there are various upper limits to be drawn for the bathypelagic area. Four typically different vertical distribution patterns are described.


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